Hydrodynamics and Kinetics Study of Phenol Removal...

Ministry of Higher Education and Scientific Research University of Technology Chemical Engineering Department

Hydrodynamics and Kinetics Study of Phenol Removal

Treatment in wastewater in a Trickle Bed Reactor

A Thesis Submitted to the Department of Chemical Engineering

of the University of Technology in a Partial Fulfillment of the Requirements for the Degree of

Master in Chemical Engineering

BY

Luma Shihab Ahmed

B.Sc in Chemical Engineering 2008

2012

م ي ح لر ا نم ح الر لل ا م س ب

و ج ع ل ت ع ل م ون ش ي ئا ال أ مه ات ك م ب ط ون م ن و ا لل أخ ر ج ك م ت ش ك ر ون ل ع ل ك م و ا ال ف ئ د ة ا لسم ع و ا ال ب ص ار ل ك م

العظيم الل صدق

النحل 77/سورة

Linguistic Certification

This is to certify that I have read the thesis entitled " Hydrodynamics and Kinetics

Study of Phenol Removal Treatment in a Trickle Bed Reactor " and corrected

any grammatical mistakes I found. The thesis is therefore, qualified for debate.

Signature

Prof. Dr. Mumtaz Abdulahad Zablouk

Supervisor Certification

I certify that this thesis entitled" Hydrodynamics and Kinetics Study of Phenol

Removal Treatment in a Trickle Bed Reactor " presented by Luma Shihab

Ahmed was prepared under my supervision in the Department of Chemical

Engineering of the University of Technology in a partial fulfillment of the

requirements for the Degree of Master in Chemical Engineering.

(Supervisor) (Supervisor)

In view of the available recommendations, I forward this thesis for debate by the examination committee.

Head of Post Gradate Committee

Department of Chemical Engineering

Asst.Prof. Dr. Muhammad Fadil Abid Dr . Farah Talib Jasim

Asst.Prof. Dr.Muhammad Ibrahim Muhammad

To My lovely mother and father

My Sister and brothers

They granted me the needed strength to continue

Luma

Acknowledgments

First of all, I thank GOD for inspiring me and giving me the ability, patience and faith to do and

finish this modest work, words are inexpressive.

secondly to My mother, who has supported me and has been willing to make considerable sacrifices for

giving to me all possible advantages in my life.

I thank her for her affection and love. She always has been and will be my inspiration.

I wish to express my sincere thanks to Prof. Dr. Mumtaz Abdulahad Zablouk the Head of the

Chemical Engineering Department University of Technology and the members of the staff of the

Department for their assistance in providing the research facilities.

I wish to present my deepest affection, sincere gratitude and grateful appreciation with deep respect

to my supervisors Asst. prof .Dr. Muhammad Fadel Abd and Dr. Farah Talib Jasim for their very

helpful efforts, comments, guidance, information, emotional support, and for being generous in their

knowledge, advices, and experience to facilitate any impediments during the work.

Also, I would like to thank very much Mrs. Sama Muhammad for her help.

My deepest gratitude to My beloved friends for the help and support they provided to me whenever

needed.

Finally, heartily gratitude and grateful admiration to My family for their encouragement to

overcome all the difficulties.

Luma

I

Acknowledgments

First of all, I thank GOD for inspiring me and giving me the ability, patience

and faith to do and finish this modest work, words are inexpressive.

secondly to my mother, who has supported me and has been willing to make

considerable sacrifices for giving to me all possible advantages in my life.

I thank her for her affection and love. She always has been and will be my

inspiration.

I wish to express my sincere thanks to Prof. Dr. Mumtaz Abdulahad

Zablouk the Head of the Chemical Engineering Department University of

Technology and the members of the staff of the Department for their assistance

in providing the research facilities.

I wish to present my deepest affection, sincere gratitude and grateful

appreciation with deep respect to my supervisors Asst. prof .Dr. Muhammad

Fadel Abd and Dr. Farah Talib Jasim for their very helpful efforts, comments,

guidance, information, emotional support, and for being generous in their

knowledge, advices, and experience to facilitate any impediments during the

work.

Also, I would like to thank very much Mrs. Sama Muhammad for her help.

My deepest gratitude to my beloved friends for the help and support they

provided to me whenever needed.

Finally, heartily gratitude and grateful admiration to my family for their

encouragement to overcome all the difficulties.

Luma

II

Abstract

Experimental investigations have been carried out to study the performance of

trickle bed reactor. The effect of key parameters that play predominate role in

the performance of trickle bed reactor is studied. A laboratory unit was

constructed for this purpose where a versatile reactor setup required " high

pressure stainless steel reactor of 0.05m i.d × 1.25m height", in which the

hydrodynamic and kinetic experiments could be carried out under different

operating condition namely, superficial gas velocity(0.086-0.25 m/s) and liquid

velocity (0.0013-0.0085 m/s), reactor pressure(0.1-0.6 MP), bed temperature

(25-140oC)

and phenol concentration (900,1500, 2500 and 5000 mg/l). Air–

water system was used for hydrodynamic experiments pressure drop, dynamic

liquid holdup, and axial dispersion coefficients were estimated. It has been

demonstrated from the experimental results that the pressure drop tends to

increase with increasing superficial gas and liquid velocity and reactor pressure,

up to maximum (27.73Mpa at =0.25m/s, and 25ºC) while it

tends to decrease with increasing bed temperature. The results also show that

the dynamic liquid holdup increases with increasing liquid velocity up to

maximum (0.158 at =0.0085m/s, and 25ºC) and decreases with

increasing superficial gas velocity and bed temperature. For higher superficial

gas and liquid velocities the increasing in axial dispersion is observed up to

maximum (3.327* /s at =0.0085m/s, and 25ºC) while

it decreases when increasing bed temperature. Empirical correlations for

pressure drop, dynamic liquid holdup and axial dispersion were estimated for

air-water system as follows:-

III

- -

-

Catalytic wet oxidation of phenol was studied in the present work. The effect of

LHSV(4,7,13,20 and 24 ) h-1

, superficial gas velocity(0.086-0.25), reactor

pressure(0.1-0.6 MP), temperature (25-140oC) and initial phenol

concentration(900,1500, 2500 and 5000 mg/l) was studied for conventional

operation and saturation condition. Result show that phenol conversion

increased with increasing reaction temperature, reactor pressure, and superficial

gas velocity of oxygen, while decreased with increasing liquid hourly space

velocity (LHSV). The initial phenol concentration had little effect on the

conversion. The results exhibit that the highest phenol conversion (98%) was

obtained over Pt/γ-Al2O3 at the following conditions, LHSV=4h-1

,

temperature=140°C, oxygen partial pressure= 0.35MPa (equilibrium condition),

and phenol concentration= 900mg/l. According to the kinetic results, the

reaction behavior was first order with respect to phenol concentration,

(0.69,0.49) order with respect to oxygen for saturation and conventional

condition respectively and the activation energy equal to (24.616 and 29.299)

kJ/mol for saturation and conventional condition respectively. The rate

expression for CWO is :-

For saturation condition

69.010

2..

75.24616107234.2 Ophph XC

RTr

For conventional condition

49.09

2..

49.29299107.5 Ophph XC

RTr

IV

Contents

Acknowledgment……………………………………………………….…I

Abstract………………………………………………………….....…….II

Contents………………………………………………………………....IV

Notation……..………………………………………………………....VIII

Chapter One: Introduction.

1.1. Overview.......................................................................................................1

1.2. Three phase reactor.....................................................................................3

1.3. Trickle Bed Reactor Characteristics .........................................................5

1.4. Objective of the present work...............................................................8

Chapter Two: Literature Survey.

2.1. Introduction..............................................................................................

...9

2.2. Hydrodynamics Behavior in Trickle bed

reactor...................................9

2.2.1. Hydrodynamics parameters in TBRs......................................9

2.2.1.1. Flow

regime..........................................................................9

2.2.1.2. Press

ure drop and Liquid holdup...................................12

2.2.1.3. Axial

dispersion..................................................................16

V

2.2.2. Hydr

odynamic previous works....................................................17

2.3. Waste

water Treatment Technology..................................................21

2.4. Phen

ol oxidation in the catalytic reactor..........................................23

2.4.1. Wet

air oxidation and catalytic wet oxidation of phenol over noble

metal ....................................................................................23

2.4.2. Reacti

on mechanisms and pathways...........................................25

2.4.3. Reacti

on Kinetics for catalytic phenol oxidation......................30

2.4.4. Cataly

tic oxidation of phenol experiments previous works....32

Chapter Three: Experimental Methodology.

3.1. Introduction...................................................................................................

36

3.2. Experimental Work.......................................................................................39

3.2.1. Liquid and gas delivery and separation system...................................41

3.2.2. Tracer injection system..........................................................................41

3.2.3. Data Acquisition and system.................................................................42

3.3. Operating Conditions and Procedures .......................................................44

3.3.1 Hydrodynamic experiments....................................................................45

3.3.1.1. Pressure drop....................................................................................45

3.3.1.2. Liquid holdup and axial dispersion.................................................46

VI

3.3.2 Kinetic experiments...................................................................................46

3.4. Analytical procedures.....................................................................................47

3.4.1 UV spectrophotometer............................................................................47

3.4.2 High performance liquid chromatography (HPLC)............................47

Chapter Four: Results and Discussion.

4.1. Introduction..............................................................................................49

4.2. Signal analysis............................................................................................49

4.2.1. Pressure Drop........................................................................................49

4.2.2. Liquid holdup and Axial dispersion.....................................................51

4.3. Hydrodynamic..........................................................................................53

4.3.1. Effect of operating conditions on hydrodynamic parameter...........53

4.3.1.1. Pressure Drop..................................................................................53

4.3.1.2. Liquid Holdup.................................................................................57

4.3.1.3. Axial Dispersion .............................................................................57

4.3.2. Empirical Correlation.............................................................................61

4.4. Catalytic oxidation of phenol.................................................................64

4.4.1. Reactor Performance..............................................................................64

4.4.1.1. Reactant limitation..........................................................................64

4.4.1.2. Interface mass transfer(external diffusion).................................65

4.4.1.3. Intra Particle diffusion (internal diffusion).................................66

4.4.2. Estimation Reaction Kinetic Parameters............................................68

4.4.3. Effect of operating condition on the CWO of phenol.....................75

4.4.3.1. Effect of different variables on the CWO of phenol ...............75

4.4.3.2. Effect of Operating condition on the CWO of phenol at

saturation condition........................................................................83

Chapter Five: Conclusions and Recommendations.

VII

4.1. Conclusions...................................................................................................85

4.2. Recommendations for Further Work.......................................................87

References..........................................................................................................88

Appendix A:Calibration Curve.......................................................................A-1

Appendix B: Transport Parameters and Physico -chemical Properties..B-1

Appendix C: Experimental Results.............................................................C-1

Appendix D:Sample of calculation................................................................D-1

IV

VIII

Notation

Symbols

Description

Specific packing area

Units

/

CO2 Concentration of oxygen kmol / l

CPh Concentration of phenol kmol / l

ABD Molecular diffusivity m2/s

Effective diffusivity for phenol m2/s

Effective diffusivity for oxygen m2/s

Dispersion Coefficient m2/s

Reactor diameter m

hydraulic diameter m

G

g

Particle diameter

gas mass flow rate

gravity acceleration

m

m.

H

Henry constant

Frequency factor (case dependent units)

MPa

Liquid -solid mass transfer coefficient m/s

L

Gas-liquid mass transfer coefficient

liquid mass flow rate

m/s

n Order of reaction ( - )

Mwt Molecular weight kg/

P Total pressure (case dependent units)

∆P Pressure drop kPa

IX

Qg Volumetric gas flow rate

(case dependent units)

Ql Volumetric liquid flow rate


R Universal gas constant m3.atm/mol.K

robs Observed reaction rate kmol/ .h

T Temperature (case dependent units)

ug Superficial gas velocity


uL Superficial Liquid velocity


AV~

Molar volume m3/kmol

X conversion ( - )

xO2 Mole-fraction of oxygen ( - )

Z Reactor length

m

Greek Symbols:

Notation Description Units

Phenol order ( - )

, Dimensionless coefficient in external mass

transfer criteria

( - )

β Oxygen order ( - )

nc

Dynamic or darning liquid saturation

External liquid holdup

Total liquid holdup

( - )

( - )

( - )

Reactant limitation criteria ( - )

Bed voidage ( - )

G Gas Holdup ( - )

Lt Total liquid Holdup(Dynamic+Static) ( - )

X

p Particle voidage (porosity) ( - )

s Solid Holdup ( - )

Viscosity kg/m.s

Stoichiometric coefficients of oxygen ( - )

bed density kg/

Density of liquid kg/

Density of gas kg/

L Surface tension N/m

Space time

Catalyst pellet tortuosity ( - )

1 Dimensionless parameter (Table 2.1a) ( - )

2

Dimensionless parameter (Table 2.1a)

Two phase flow dissipation power rate

(Table 2.2)

( - )

kPa.

Dimensionless parameter (Table 2.1b) ( - )

Wave length ( nm )

Dimensionless group:

LaG Modified Galileo number 32

322

)1(

L

pL gd

Pe Peclet number Dax

ZU

eR Reynolds number

L

eLL du

eR Modified Reynolds number

1L

eLL du

eR~ Modified Reynolds number

LtL

eLL du

Sc Schmidt number

ABD

XI

hS Sherwood number AB

eLs

D

dK

LeW Weber number

L

LpL ud

2

GX

Lockhart-Martinelli

G

L

L

G

u

u

LX Lockhart-Martinelli GX

1

Subscripts:

in input

O2

out

Oxygen

output

ph Phenol

obs Observed

G Gas

L Liquid

f Fluid (liquid or gas phase)

p Particle

ᵒ Initial conditions

XII

XIII

Abbreviations :

γ-Al2O3

Gamma Alumina

CMC Carboxy methyl cellulose

COD Chemical oxygen demand

CTAB cetyl tri methyl ammonium bromide

CWAO Catalytic wet air oxidation

CWO Catalytic wet oxidation

DCP Di chloro phenol

EDTA Ethylene di amine tetra acetic acid

FBR Fixed bed reactor

L-H Langmuir-Hinshelwood

P-L Power law

PBR packed bed reactor

PBCR Packed bubble column reactor

PEG Poly ethylene glycol

SBCR

SBACR

Slurry bubble column reactor

Semi batch auto clave reactor

SR Slurry reactor

TBR Trickle bed reactor

TFBR Three phase fluidized bed reactor

AGR Three necked atmospheric glass reactor

TOC Total organic carbon

WAO Wet Air oxidation

LHSV Liquid hourly space velocity

ZVI Zero Valente iron particle

Chapter One Introduction

1

1.1. Overview

Industrial processes use significant amounts of water which require treatment

before discharging to surface water system (Tansel, 2008). While pollution

arising from non-point sources accounts for the majority of contaminants in

streams and lakes, it is much more difficult to control (Masende, 2004).

Aqueous wastes having an organic pollutant load in the range of few hundred to

few thousand ppms are too dilute to incinerate but yet too toxic. Phenol is one

of the most common organic water pollutants present in wastewater of various

industries such as refineries (6-500mg/l), coking operations (23-3900mg/l), coal

processing (9-6800mg/l), manufacture of petrochemical (28-1220mg/l), and

also in pharmaceutical, plastics, wood products, paint and pulp and paper

industries (0.1-1600 mg/l) (Gutierrez et al., 2010). Accordingly, high volumes

of wastewater containing these compounds are discharged to the environment

each year. The incapability of conventional methods to effectively remove

many organic pollutants has made it evident that new, compact and more

efficient systems are needed. At present, several treatment methods are

available: chemical, physical (adsorption, reverse osmosis), biological, wet air

oxidation (CWO), and incineration. In selecting a wastewater treatment process

among these methods, one should take into account the toxicities and

concentration of the pollutants in the waste stream (Guo and Al-Dahhan, 2005)

Advantages and disadvantages of physical, biological and chemical treatments

listed in Table (1.1).The wet-air or thermal liquid-phase oxidation (WAO)

process, in which the generation of active oxygen species, such as hydroxyl

radicals, takes place at high temperatures and pressures, is known to have a

great potential for the treatment of effluents containing a high content of organic

matter, or toxic contaminants for which direct biological purification is

unfeasible. In this process, molecular oxygen dissolved in the wastewater reacts

with the organic and inorganic pollutants. The oxidizing power of the process is


2

based on the high solubility of oxygen at these severe conditions and the high

temperature that increases the reaction rates and production of free radicals

(Roy et al., 2010). To reduce the cost, catalyst is added to lower the reaction

temperature and pressure, which is referred to as CWAO process. The catalyst

is usually made of transitional metal salt/metal oxide. By using CWAO, the

oxidation of phenol can be tremendously facilitated at milder conditions as low

temperature (Wu et al., 2003).

Table (1.1) Advantages and disadvantages of physical, biological and chemical

treatments (Belhateche, 1995 and Durai and Rajasimman, 2011).

Treatment Physical,

Physico -chemical

Biological Chemical

Types of

pollutants:

Typically industrial

wastewater.

Organics and some

inorganics , metals.

Industrial and domestic

wastewater.

Low concentration

organics, some

inorganics.

Typically industrial

wastewater.

Organics,

inorganics, metals.

Methods Filtration,

Adsorption,

Air flotation,

Extraction,

Flocculation,

Sedimentation

Anaerobic,

Aerobic,

Activated sludge

Thermal oxidation

(combustion),

Chemical oxidation,

Ion exchange,

Chemical

precipitation

Advantages:

Low capital costs,

Relatively safe,

Easy to operate

Volatile emissions,

Low maintenance,

Relatively safe,

Removal of dissolved

contaminants,

Easy to operate

Volatile emissions,

High degree of

treatment,

No secondary waste,

Removal of

dissolved

contaminants

Drawbacks:

High energy cost,

Difficult maintenance

Waste sludge disposal,

Susceptible to toxins

High capital and

operating costs,

Difficult to operate


3

1.2. Three phase reactor

Multiphase catalytic processes have been expanding into diverse areas of

applications and continue to make a significant impact on the development of

new synthetic routes and high-value added products (Chaudhari and Mills,

2004). Three-phase continuous catalytic processes involving gas, liquid and a

solid catalyst are widely used in industrial practice including the manufacturing

of commodity chemicals. The most common example includes liquid phase

catalytic hydrogenations, desulfurization, hydrocracking, oxidation (Lapkin

and Plucinski, 2010), and also employed in wastewater treatment (Dudukovic

etal., 2002). A fundamental division of three-phase reactors may be made by

whether the solid phase is present as a fixed bed or suspended in the liquid.

Reactors with the catalyst placed in a fixed bed mode can operate as (a) trickle

bed reactors, and (b) packed bubble column reactors as in Figure (1.1).The

second class with the catalyst dispersed in the liquid phase may exist in three

forms: (a) bubble columns,(b) mechanically stirred tanks, and (c) three-phase

fluidised beds (Biardi and Baldi, 1999; Lapkin and Plucinski, 2010).

Figure (1.1)Various types of three-phase packed bed reactors (a) trickle bed reactor, co-

current flow; (b) trickle bed reactor ,counter-current flow; (c) packed-bed reactor, co-

current up-flow (Lapkin and Plucinski , 2010)


4

In three-phase catalytic reactions, gas and liquid phase reactants are in contact

with a solid phase catalyst(GLS). Gas dissolves in the liquid phase, is

transported to the catalyst particle in the bulk of the liquid, and both gaseous

and liquid phase reactants diffuse into the porous structure of the catalyst where

they react at the active sites. Products diffuse out of the particle in the opposite

direction. Depending on the catalytic reaction rate transport through this liquid

film and diffusion in pores may be much slower (Kapteijn et al., 1999). Design

of multi-phase and catalytic reactors is more complex than that of homogeneous

reactors due to the following: the coexistence of more than one phase introduces

the mass transfer resistance represented disruption in three -phase reactor as

shown in Figure (1.2) (Hopper et al., 2001).

Figure(1.2) Gas-liquid-solid contact in three – phase reactors( Levenspiel, 1999)

The advantages and limitations of three-phase reactors as potential applications

used in CWO are listed in Table (1.2).


5

Table (1.2) Three phase Reactors Used in CWO (Lopes, 2009)

LIMITATIONS

ADVANTAGES

REACTOR TYPE

poor liquid-phase distribution

often only partial wetting of the

catalyst high intraparticle

resistance poor radial mixing

low mass transfer coefficient

temperature control can be

difficult

high conversion as both gas and

liquid flow regimes approach

plug flow low liquid hold-up

high catalyst loading low-

pressure drop

trickle bed reactor

catalyst separation

high axial mixing

low catalyst load

high liquid-to-solid ratio

high external mass transfer (G-

L, L-S) low intraparticle

resistance ease of catalyst

addition and regeneration ease

of thermal management

slurry phase and three-

phase fluidized bed

reactor

high axial backmixing

lower conversion compared to

trickle-bed reactors high-

pressure drop

flooding problem

high G-L mass transfer (better

G-L interaction)

high liquid holdup

well-wetted catalyst

channeling eliminated

good temperature control

bubble fixed-bed

reactor

The selection of a suitable reactor is one of the key criterion that affects the

industrial implementation of advanced wastewater treatment facilities. The most

frequently used in industry is the TBR as it allows a variety of flow regimes

making it more flexible. The large experience on the operation of TBRs in

industrial hydro-treatment processes makes them the first choice for the

performance of CWAO reactions (Eftaxias, 2002).

1.3. Trickle bed rector characteristics Trickle-bed reactors are the most widely used type of three-phase reactors. The

gas and liquid concurrently flow downward over a fixed bed of catalyst particles

(Kunda et al., 2001 and Lopes and Quinta-Ferreira, 2010).The liquid phase

flows over the catalyst as a thin film, while the gas phase flows continuously

between the catalysts (propp et al., 2000). They are employed in petroleum,

petrochemical and chemical industries, in waste treatment and in biochemical


6

and electrochemical processing as well as other application (Saroha and

Nandi, 2008).Trickle bed reactor are frequently used when large quantities of

gas and liquid without flooding (Lopes and Quinta-Ferreira, 2010). Most

commercial trickle-bed reactors operate adiabatically at high temperatures and

high pressures up to(30Mp) (Al-Dahhan et al., 1997 ) to improve the solubility

of the gaseous reactant and therefore to attain high conversion, slow down

catalyst deactivation and to handle large gas volume (Al-Dahhan et al., 1994);

trickle-bed reactors are packed following either the sock packing method in

which particles are randomly introduced inside the packed bed or the dense

packing method (by slowly pouring small amounts of particles and shaking

between the packing stages) (Bazmi et al., 2011). Various flow regimes exist in

TBRs depending on the superficial mass velocity, fluid properties and bed

characteristics (Al-Dahhan et al., 1994 and Urseanu et al., 2005) are ( trickle

flow, pulsing flow, mist flow and bubble flow) Figure (1.3) represents these

regimes (Urseanu et al., 2005).

Figure (1.3) Typical illustration of the location of flow regimes with respect to gas and

liquid flow rates (Urseanu et al ., 2005)


7

There are several advantages of TBRs listed below.

Table (1.3): Advantages of TBRs (Gianetto and Specchia, 1992; Sie and Krishna, 1998;

Medrose et al., 2009; Mary et al., 2009 and Tajerian, 2010 )

Advantages:

Liquid flow approaches plug flow behavior which leads to high conversions.

Low catalyst loss, important when costly catalysts are used.

Generally simple construction due to no moving parts.

Possibility of operating at higher pressure and temperature.

Larger reactor size.

Low liquid–solid volume ratio: less occurrences of homogeneous side reactions.

Lower investment and operating costs.

Possibility of varying the liquid rate according to catalyst wetting, heat and mass

transfer resistances.

Variety of flow regimes are allowed and is the most flexible with respect to varying

throughput demands.

Pressure drop through the bed is less which reduces pumping costs.

Easy operation with fixed adiabatic beds; for exothermic reaction systems gas or

liquid streams as quench and liquid and/or gas recycle limit temperature rises

Recommended for gas-limited reactions.

There are some drawbacks cause in TBRs such as flow mal distribution and

formation of hot spot for many reasons such as no enough amount of the liquid

to dray parts of the bed essentially no reaction in these regions occur and the

reactor is not fully utilized, if a sufficient amount of liquid is vaporized and

reaction still proceeds in these unwetted regions without any liquid phase

removing the reaction heat this leads to cause hot spot formation. These hot

spots cause the catalyst particles to sinter, damage the reactor casing and lead to

reactor run away (Boelhouwer, 2001). The most common criteria to ensure


8

uniform liquid distribution and hence eliminate wall flow along a catalytic bed

are based on minimum value of reactor-to-particle diameter ratio. The wide

variation in the values of ratio reported by different authors could be an

effect of particle orientation in the bed, i.e. the method of catalyst loading

affects liquid distribution. It has also been reported that the lower the surface

tension and density of liquid the lower the wall flow (Medros et al., 2009).

1.4. Object of the Present Work

The present work aims to study the performance of trickle bed reactor

experimentally as follows:-

Examining the effect of operating parameters (reactor pressure,

temperature, superficial gas and liquid velocity) on hydrodynamic

parameters (pressure drop, dynamic liquid holdup and axial dispersion)

Investigating the applicability of commercial 0.5% platinum /alumina

catalysts (from Baiji refinery) for catalytic oxidation of phenol in TBR

Investigating the kinetic parameters of the operating system (phenol and

oxygen) with effects of studied operating condition (LHSV, superficial

gas velocity, temperature, reactor pressure and initial phenol

concentration).

Chapter Two Literature survey

9

2.1. Introduction

In the last few decades the TBRs have been studied extensively by chemical

engineers due to their suitability for many operations in petroleum refining,

chemical and petro-chemical and bio-chemical processes. This chapter reviews

the characteristics of trickle bed reactor and the historical progress in steady

state operations for hydrodynamic and kinetic study.

2.2. Hydrodynamics behavior in TBRs

2.2.1.Hydrodynamic parameters in TBRs

2.2.1.1. Flow regime

Trickle bed reactors (TBRs) operate in a variety of flow regimes ranging from

gas continuous to liquid continuous pattern, depending on superficial mass

velocity, fluid properties and design parameter. Usually two broad regimes are

classified referred to as low interaction regime (LIR) (trickle flow regimes) and

high interaction regime (HIR) (pulse, spray and bubble or dispersed flow

regimes) (Aydin, 2008 and Al-Dahhan and Dudukovic, 1994 ).When gas and

liquid flow rates are small, liquid flows down in the form of a film over a solid

surface. This regime is called a film flow “see Figure 2.1(a)”in which both

phases are continuous (or semi continuous).


01

Figure (2.1) Physical picture of flow in trickle bed reactor (Prashant et al.,2005)

In this regime, depending on the liquid flow rate, the solid surface may be

completely or partially wetted. At low liquid flow rates, if the gas flow

increases, interaction of the gas phase with liquid film flowing over a solid

surface increases. Eventually, at certain gas velocity, gas starts entraining part

of the liquid. Thus, under such a condition, part of the liquid flows down in the

form of suspended droplets in the gas phase and part of the liquid flows down in

the form of film over a solid surface “as in Figure 2.1(b)”. This regime is called

trickle flow regime. More often than not, the film flow regime is also clubbed

with the trickle flow regime. If the gas flow rate increases further, a stage may

come when all the liquid flows down in the form of suspended droplets. This

regime is called a spray flow regime “see Figure 2.1(c)”. When the liquid flow

rate is increased at high gas velocity, two distinct gas and liquid rich bands

(pulses) flow downward through the packed bed. This regime is called a pulse


00

flow regime. If the liquid flow rate is increased further, a stage comes when gas

becomes a dispersed phase “see Figure 2.1(d)” and flows down in the form of

bubbles. This regime is called a bubbly flow regime (Al-Dahhan et al., 1997

and Prashant et al., 2005). In order to properly design trickle bed reactors

based on laboratory data, it is important to predict which flow regime the

reactor is operating for a given set of conditions. It is also important to find out

if pressure effects can be well accounted for in order to predict whether the

same flow regime will be preserved once scale up or scale-down is performed

(Al-Dahhan et al., 1997). The transition for a given system is shown in Figures

(2.2).

Figure (2.2) Region of trickle flow regime (Fukushima and Kusaka,1977a,b)


01

2.2.1.2. Pressure drop and Liquid holdup

Liquid holdup and pressure drop in the bed are the two key hydrodynamic

parameters whose knowledge is necessary while designing and scaling up of the

reactor (Bartelmus and Janecki, 2003).

- Pressure drop

Pressure drop represent the energy dissipated due to fluid flow through the

reactor bed it is important in determining the energy losses, the sizing of

compression equipment, liquid holdup, external contacting efficiency, gas-

liquid interfacial area and mass transfer coefficients, the energy dissipation in a

gas-liquid concurrent down flow packed bed reactor is due to the frictional

losses at the packing surface and the driving forces acting on the liquid flow.

The driving forces consist of pressure gradient and the gravitational force. The

pressure gradient depends on the velocity and on the density of the flowing

fluids (Al-Dahhan and Dudukovic,1994).

-liquid holdup

Liquid holdup plays an important role in trickle bed reactor hydrodynamic mass

and heat transfer; knowledge of liquid holdup is essential for avoiding hot spots

and prevent reactor run away. Liquid holdup which partially occupies the void

volume of the packed bed is a basic parameter for reactor design because it is

related to other important parameters (Al-Dahhan and Dudukovic, 1994). The

total holdup, is the total volume of liquid held in the reactor bed per unit bed

volume. An alternative definition, sometimes referred to as the liquid saturation,

is the total volume of liquid held in the reactor bed per unit void volume, For a

bed of porous particles the total holdup may be divided into the internal, or intra

particle holdup and the external, holdup. The latter can, in turn, be divided into

a dynamic, draining or non-capillary holdup and a static, residual or capillary

holdup. The dynamic holdup can be taken as that volume of liquid in the reactor

which is continually being renewed, whereas the static hold-up may be


01

considered to be that volume of liquid at the contact points between the particles

themselves and between the particles and the wall, which remains stagnant

(Ellman et al., 1990 and Aydin, 2008). There are different techniques used for

measuring liquid holdup in a laboratory trickle bed reactors at high and

atmospheric pressure such as tracer, weighing, electric conductivity,

electromagnetic radiation techniques (total liquid holdup) and drainage

technique (dynamic holdup) (Columbo et al., 1976; Ellman et al., 1990;

Larachi et al., 1991; Al-Dahhan et al., 1994 and Guo and Al-Dahhan,

2004a). Numerous attempts are being made to model the hydrodynamics of

TBRs "pressure drop and liquid holdup" at atmospheric and high pressure

operation in two different categories. The first category uses an empirical

approach based on dimensional analysis to produce explicit correlations for

pressure drop and liquid holdup (Ellman et al., 1988; 1990; Larachi et al.,

1991 and Wammes et al.,1991).The second category involves the development

of phenomenological models resulting from equation of motion and considers

determination of drag force of gas and liquid phases at various operating

regimes (Al-Dahhan et al., 1994, 1998 and Attou et al., 1999).


01

Table (2.1a) Correlations for prediction of two phase pressure drop in trickle bed

reactors.

Authors Packing Type

dp

cm

Dr

cm

εs Pressure

MPa

Temperature 0C

Ellman et al.,

1988

Spherical and

cylindrical alumna

0.11-

0.306

2.3-10 0.37-

0.48

0.1-10 20

High interaction regime

Low interaction regime

Wammes et al.,

1991

Cylindrical alumna 0.32*0.33 5.1 0.41 0.2-7.5 20

38.0

2 1

1155

2

1

G

pGG

GGG

p dU

U

d

Z

P

Larachi et al.,

1991

Glass bead 0.14-0.2 5 0.38 0.2-8.1 20

5.025.05.125.02

3.1713.3

1

2

/

GeeGeeg

Gp

XWRXWRU

dZP

LLLL

p

B

Bh

G

LG dd

L

GX

33.0

19

16;

Urseanu et al.,

2005

0.2% wt Pd/C 0.15 5.1 0.34 0.14-2 20

Al–Sudani,2007 0.5Pt/Al2O3 0.16 5 0.4 0.1-1 30-140

112147.03096.03235.12415.10.93394/

Laeeg

LLLLe

GWRRg

ZP

5.1

2

2001.0

L

L

e

e

R

R

1.02.165.1

25.0

1

17.31LL

LL

ee

ee

WR

WR

5.0

2

2.1

2285200

2

/

GG

G

Gh XXU

dZP

76.25.017.054.016

pwGL dfUZ

P

5.1

11227.53296.6

2

/

GG

G

Gh XXU

dZP


01

Table (2.1b) Correlations for predictions of liquid holdup in trickle bed reactors

Authors Packing Type dp

cm

Dr

cm

εs Pressure

MPa

Temperature 0C

Ellman et al.,

1990

Spherical and cylindrical

alumna(Glass, Ceramic,

porous)

0.11-0.306 2.3-10 0.37-0.48 0.1-10 20

163.0

13.016.0325.0

116.0log

hs

eeGnc

daWRX

LL

High interaction regime

1.0

14.024..0

142.0log

hs

eGnc

daRX

L

Low interaction regime

Wammes et al.,

1991

Glass bead 0.3 5.1 0.39 0.2-7.5 20

No gas flow

Gas-Liquid flow

if Re < 11 c=0.36 ;d=-0.39 , if Re > 15 c=0.55;d=0.42

Larachi et al.,

1991

Glass bead 0.14-0.2 5 0.38 0.2-8.1 20

Tsamatsoulis

et al., 1994

Silicate sand powder

and ceramic extrudates

0.0031-2.5 2.5 0.36-

0.49

10 20

b

Le aU Where ( a,b ) depend on boundary conditions

Saroha and

Khera,2006

Glass beads 0.4 10.2 0.39 0.1 25

egeLt RR 0026.000083.021.0

65.042.0

2

355.0

18.3

ps

LL

pL

L

pLL

nc

da

gZ

PgddU

d

L

pL

c

L

pLL

nc

gddU

2

3

3.16

2.015.0

15.0

22.1eLG

eL

RX

W

101t


01

2.2.1.3..Axial dispersion

Axial mixing represents the degree of flow mixing occurring during the

residence time in the reactor. It has also been called axial dispersion, back

mixing or longitudinal mixing. This deviation from ideal plug flow behavior has

been characterized with the development of the residence time distribution

(RTD) technique. (Levenspiel and Smith, 1957) were the first of two who

studied and described this phenomenon (Mary et al., 2009). Small catalyst beds

and low liquid flow rates are the main reasons of extended axial dispersion

effects on reactor performance. The use of fine catalyst particles prevents such

phenomena as radial or axial dispersion to influence reactor performance, and in

combination with high gas and liquid flow rates before every single experiments

operation in the high-interaction regime before each experiment, the absence of

liquid mal-distribution is ensured (Metaxas and Papayannakos, 2006). Some

correlations of prediction of axial dispersion in TBR are presented in Table

(2.2).

Table (2.2) Correlations for prediction of axial dispersion in trickle bed reactors.

Authors Packing Type dp

cm

Dr

cm

εs Pressure

MPa

Temperature 0C

Cassanello

etal.,1998

Glass bed 1.67 7 - - -

Singh et al.,

2004

Cylindrical

extradite

0.158 2.54 0.47 - 100-130

Saroha and

Khera,2006

Nonporous glass

bed

0.4 10.12 0.39 0.1 25


01

2.2.2.Hydrodynamic pervious works

Wammes et al., 1990,1991, found from their studies that holdup increases with

increasing liquid flow rate while decreases with increasing superficial gas flow

rate and densities of gas, and also found that pressure drop increases with

increasing gas and liquid velocities, and when compared with results from

nitrogen as the gas phase to those of helium showed that at equal gas densities

the hydrodynamic state are the same.

Larachi et al., 1991, studied the two phase pressure drop as a function of the

gas and liquid mass flow rate. The two phase pressure drop increases with both

mass flow rates and similar results were obtained when changing the value of

the total pressure also showed that the pressure drop is higher with coalescence

inhibiting (foaming) liquid than with coalescing liquids and illustrated the

pressure drop decreases with the particle diameter. Similar findings were

reported by Al-Dahhan and Dudukovic, 1994.

Iliuta et al., 1996, studied the effect of gas and liquid velocities on the liquid

holdup and pressure dope for Newtonian and non-Newtonian fluid. They found

that pressure drop increases with increasing gas and liquid flow rate for both

systems while pressure drop for non-Newtonian is more than for Newtonian

system, and also found that increasing liquid flow rate caused to increase the

liquid holdup while decreases with increase gas flow rate for both systems.

Pant et al., 2000, used radioisotope tracer technique for measuring liquid

holdup, using three different types of packing (i.e. non-porous glass beads,

porous catalysts of tablet and extradite shape). They observed that liquid holdup

increases with increasing liquid flow rate for all three types of packing and also

found that liquid holdup is independent of gas flow rate for all three types of

packing.


01

Chander et al., 2001, found from their work that increasing the liquid velocity

caused to increase the liquid holdup while decreases with increasing gas

velocity for both sizes of diluents particle and also found that axial dispersion

increases with increasing liquid velocity while the gas velocity had a negligible

effect on it.

Bartelmus and Janecki, 2003, determined the value of the liquid holdup,

through the packing for system foaming under the pulse flow regime as a

function of gas and liquid velocity and found that liquid holdup increases with

increasing liquid flow rate while decreases with increasing gas flow rate.

Similar finding were observed by Gupta and Bansal, 2010.

Guo and Al-Dahhan, 2004a, investigated the residence time distribution, liquid

holdup and pressure drop in TBR with porous particles operated under elevated

pressure and found that pressure drop increased with increasing gas and liquid

velocities but increasing liquid velocity caused to increase liquid holdup while

decreases with increasing gas velocity. Similar findings were reported by

Urseanu et al.,2005.

Aydin and Larachi, 2005; 2008, demonstrated experimentally two phase

pressure drop, liquid holdup and the liquid axial dispersion coefficient. These

parameters were determined for Newtonian and non -Newtonian systems. They

found that pressure drop and axial dispersion increased with increasing gas and

liquid velocities while decrease with increasing temperature and also found that

increasing liquid velocity caused increasing in liquid holdup while increasing in

temperature and gas velocity caused decreasing in liquid hold up .

Saroha and Nadi, 2008, performed experiments to study the effect of liquid

and gas velocity, liquid surface tension, liquid viscosity and particle diameter of

the packing in two phase pressure drop hysteresis. An understanding of the

hydrodynamics of trickle bed reactors (TBR) is essential for their design and

prediction of their performance was made by Saroha et al., 2008 on flow

variables, packing characteristics, physical properties of fluids and operation


09

modes influence the behavior of the TBR. The existence of multiple

hydrodynamic states or hysteresis (pressure drop, liquid holdup) due to the

different flow structures in the packed bed was studied. They developed the

parallel zone model for pressure drop hysteresis in the trickling flow was for

analysis of experimental data and flow structure.

Houwelingen et al., 2009, measured the residence time distribution (RTD) for

trickle flow in a bed of glass beads at different liquid flow rates and

hydrodynamic states to obtain axial dispersion and liquid holdup measurement

they found that an increase in superficial velocity caused to increasing in liquid

holdup and axial dispersion. Figure (2.3) shows the effect of superficial liquid

velocity on RTD.

Figure (2.3) Normalized RTD for the different superficial velocity of liquid

(Houwelingen et al., 2009)

Al-Naimi et al., 2011, studied the hydrodynamics in TBR in non-ambient

condition for pure organic liquid of low surface tension (air-water and air-

aceton). They demonstrated from the experimental result that the pressure drop

tends to increase with increasing superficial gas and liquid velocity and reactor

pressure, while it tends to decrease with increasing bed temperature. The results


11

also show that the dynamic liquid holdup increases with increasing liquid

velocity and decreases with increasing superficial gas velocity, reactor pressure

and bed temperature. The dynamic liquid holdup and pressure drop values are

obviously higher than those measured for air–water system at the same fluid

fluxes, reactor pressure and bed temperature due to the surface tension effects.

Table (2.3) Summary of hydrodynamic pervious works

System Operating condition Type of Catalyst and

Packing

Reactor Reference

(helium &nitrogen)-Water = 1.6 cm/s

Ug=36 cm/s.

Cleand nonporous

glasss pheres &porous

ceramic

TBR Wammes et al.,

1990,1991

Nitrogen-Water

1% ethanol-nirogen-water

P=(0.2-8.1)MPa Glass beads(spher) TBR Larachi et al.,

1991

(nitrogen& helium) -

(Water& hexane)

0.31 ≤ P ≤ 5 MPa

1 ≤ ≤ 11.7cm/s

239≤ ≤ 1482cm/s

T298 K

0.5% Pd/alumina TBR Al-Dahhan and

Dudukovic,

1994

Air-(water& CMC)

P=1atm & T=25 C Glass spheres FBR Iliuta et al.,1996

Air -water Ql=

Qg =

(non-porous glass

beads, porous

catalysts of

tablet and extrudates)

TBR pant et al., 2000

Air- water LHSV= (0.75- 3) Cylindrical pellets of

alpha alumina

TBR Chander et al.,

2001

(argon,nitrogen&helium)_

(methanol,ethanol&isopropa

nol)

_ glass spheres PBR Bartelmus and

Janecki, 2003

Air - water 25 ºC

0.8-2.2MPa

Ql= (2 - 9.2)ml/ min

Al–Fe

PBR Guo and Al-

Dahhan, 2004a

hydrogen- Cumene 0.14-2 MPa

=0.04-0.2 m/s

=0.0014 -0.016 m/s

(2wt %Pd/C) TBR Urseanu et al.,

2005

Air-(water &CMC)

P up to 0.7MPa

25-75C

Glass beads TBR Aydin and

Larachi, 2005

Air - (CTAB&CMC)

25-90C Glass beads TBR Aydin and

Larachi, 2008

Air- (water,CMC&SDS)

25ºC

1atm

Spherical glass beds TBR Saroha and

Nadi, 2008

Air - water 25ºC

1atm

Glass spheres PBR Houwelingen et

al., 2009

PEG-Water _ Spherical class beads TBR Gupta and

Bansal, 2010

Air-(water & acetone) 30-140 C

0.1-1MPa

Pt/ TBR Al-naimi et al.,

2011


10

2.3. Wastewater Treatment Technology

There is no doubt that water pollution, especially by a large number of different

organic chemical species, is a continuing and even growing problem that arises

from human activities. No unique solution seems possible for destroying all

these types due to the heterogeneous composition of real wastes as well as the

diversity of the pollutants chemical properties. Some wastes treatment methods

merely transfer the toxic component from one phase to another. While this may

serve to concentrate the waste in a more readily disposable form, it does not

alter the chemistry of the pollutant. Other processes use chemical reactions to

transform the waste into less toxic by product or harmless end products such as

carbon dioxide and water (Mauri, 2007). Wastewater can be divided into four

broad categories, according to its origin, namely domestic, industrial, public

service and system loss/leakage. Among these, industrial wastewaters occupy a

42.4% of the total volume and domestic 36.4%. In particular, increasing

quantities of wastewater with a high organic load result from numerous

industrial and domestic applications (Roy et al., 2010). The numerous available

processes for treating waste water streams contaminated with phenol can be

divided into three types of processes :biological, physical, and chemical. A

combination of biological , physical and (or) chemical processes may also be

used (Benali and Guy, 2007). It is clear that the selection of the correct process

or the combination of treatments is a difficult task that should be generally

made depending on the treated wastewater characteristics (concentration and

grade of refractoriness of contaminants, the flow rate) and the destination of the

effluent (grade of mineralization required). Also considering the main factors,

both technical (treatment efficiency, plant simplicity, flexibility) and

economical (investment and operating costs, including regent and energy

consumption) (Mauri, 2007). Many waste water streams contain toxic organic

pollutants in so high concentrations (more than 200mg/l) that direct biological


11

treatment is technically infeasible, because of their poor biodegradability (Singh

et al., 2004). The physical processes present two drawbacks: they are selective

in the treatment of waste water, and they require storage and disposal of the

eliminate contaminants. The chemical processes use conventional oxidation

agents such as molecular oxygen, chlorine, chlorine dioxide, potassium

permanganate, hydrogen peroxide, ozone, ultraviolet radiations, sulphate ions,

and others (Belhateche, 1995 and Benali and Guy, 2007). In general, the

numerous unit operations and processes to remove wastewater contaminants

may be grouped together to provide various levels of treatment. Various

chemical oxidation techniques have emerged in the last decades, in particular

for the treatment of industrial wastewaters. The use of conventional wastewater

treatment processes, especially in the case of moderate to higher organic loads,

has become increasingly challenged with the identification of more and more

organic and non-biodegradable contaminants. On the other hand, the emerging

wastewater treatments methods are increasingly gaining popularity since they

have shown the potential of converting harmful organic pollutants into

innocuous compounds such as carbon dioxide and water (Oliviero et al., 2003).

A simple classification of the emerging chemical technologies is given in Table

(2.4).


11

Table (2.4) Emerging chemical wastewater treatment technology

(Oliviero et al., 2003)

2.4. Phenol oxidation in the catalytic reactor

The majority of studies for CWAO mainly focus on the removal of toxic

reactant. However, a sufficient knowledge for reaction mechanisms and kinetics

for CWAO is essential to optimize the reaction conditions.

2.4.1.Wet air oxidation and Catalytic wet oxidation of

phenol over noble metal

Wet air oxidation (WAO) is a method of oxidizing dissolvable or suspended

organic compounds as well as reducible inorganic compounds with oxygen or

Description Process(Technique) Conditions

Thermal

oxidation

process

Wet air oxidation (WAO)

200-350 0C

70-230 bar

Air or O2

Catalytic wet air oxidation

(CWAO)

<200 0C

<50 bar

Air or O2 (and catalyst)

Supercritical water oxidation

(SCWO)

> 375 0C

> 221 bar

Air , O2 or H2O2 (and

catalyst)

Wet peroxide

oxidation

process

Wet peroxide oxidation

(WPO)

>100 0C

> 1 bar

H2O2

Fenton (WPO) 25 0C

1 bar

H2O2 +Fe+2

AOPs Advanced oxidation

process

(AOPs)

OH. radical as intermediate

(electrodes ,UV light,

ultrasound pulses or O3

Combined

Treatment

Combined Treatment O3 +UV

Biological +APOs

Adsorption on activated

carbon +CWAO


11

air under the circumstances of high temperature and high pressure in liquid

phase. The application of traditional WAO is limited because of the high

operation temperature, high operation pressure and long operation time.

Catalytic wet air oxidation (CWAO) was a new technology developed on the

basis of WAO in the 1970s. It is a process that can speed the reaction, lower the

reaction temperature and pressure with catalyst. It is an available method used

in disposing high-concentration effluents, as well as poisonous, detrimental and

hardly degradable wastewater (Zhu et al., 2002 and Yang et al., 2010). CWAO

processes can be divided into two groups, the first one includes the use of

homogeneous catalysts (mainly Cu or Fe salts) that supposes still using high

temperature and pressures and the following two important problems: catalysis

recollection is needed and the risk of leaching to the environment appears. The

second one includes the use of heterogeneous catalysts, that avoid the need of a

separation step of the catalyst (except in slurry operation) and the pollution of

the water stream (Gutierrez et al., 2010). Among the harmful organic

compounds, phenolic substances have deserved more attention because of their

toxicity and frequency of industrial wastewaters. They give off unpleasant odor

and taste even at very low concentrations (Lin et al., 2003 and Lee et al.,

2010). Moreover, phenol is considered to be an intermediate in the oxidation

pathway of higher molecular weight aromatic compounds and thus is mainly

taken as a model compound for advanced wastewater treatments(Santos et al.,

2002). Noble metals such as Ru, Rh, Rd, and Pt generally show higher catalytic

activity and also higher resistance to metal leaching than base metal oxide

catalysts. They are usually supported on , , , , and carbon

materials with less than 5% of metal loading. Noble metals have demonstrated

high efficiency in the treatment of different pollutants present in wastewater

treatment such as phenols (Matatov and Sheintuch, 1998 and Oliviero et al.,

2001). Among the noble metals used for the CWAO of phenol, Pt is one of the

most active catalysts. The CWAO of phenol with the Pt catalyst on different


11

supports, namely graphite, , , and AC was investigated by Masende

et al., 2005. Pintar et al., 2008 reported that the Ru/ catalysts enabled

complete removal of phenol without the formation of carbonaceous deposits at

temperatures above 210◦C and 50 bar of oxygen partial pressure. Qin et al.,

2001 found out that catalytic activity decreases in a reverse order Pt > Pd > Ru.

Moreover, promoters have also been used with noble metal catalysts. Table

(2.5) lists some authors who studied CWO by using noble metal.

Table (2.5) Summary of studies on CWAO of organic compounds over noble

metal catalysts.

2.4.2. Reaction mechanisms and pathways

The definite mechanisms and reaction pathways for CWAO have not been

established even for a pure compound because the oxidation of organic

compounds goes through very complicated routes and leads to the formation of

various intermediates (Mantzavinos et al., 1996). Generally, the final

intermediates are short-chain organic acids such as acetic acid, formic acid,

oxalic acid, etc., regardless of initial organic compounds (Eftaxias et al., 2001

and Santos et al., 2002). The wet oxidation of an organic compound involves

Catalyst System Operating

condition

Reactor Max

Conversion

Author

Ru/ Ce Maleic acid - 160C

2MPa

SR _ Olivro et al., 2001

(Pt , pd , Ru) /

(Ac, Ce , )

P-clorophenol- 180C

2bar

SR <98% Qin et al., 2001

Ru/Zr , AC&

graphite

Phenol- 140C

2MPa

SR _ Castillejos-Lopez

et al., 2009

Pt/ &

Pt/Ce

Phenol- 423K

1.4MPa

Batch >95% Lee et al., 2010


11

two main stages: (i) a physical stage, which involves the oxygen transfer from

the gas phase to the liquid phase, and (ii) a chemical stage, involving the

reaction between the transferred oxygen (or an active oxygenated species

formed during degradation) and the organic compound. Essentially, the physical

stage of WO involves the oxygen transfer from gas to the liquid phase, for

which the only significant resistance to transfer is located at the gas/liquid

interface (film model), with the following three limiting cases (Trunfio, 2008)

(i) oxygen reaction within the film because of a rapid chemical reaction (oxygen

transfer rate is enhanced);

(ii) rapid oxygen reaction within the bulk liquid, where its concentration is close

to zero (the overall rate is equal to the rate at which oxygen is transferred);

(iii) oxygen concentration within the bulk liquid is equal to the interface (or

equilibrium) concentration (the overall rate is the chemical step rate, and it is

usually low).

Figure (2.4) shows reaction steps for the catalytic multi-phase reactor.

Figure (2.4) Reaction steps of catalytic multiphase reactions (Trunfio, 2008)


11

Most studies have reported that the chemical reaction of WAO chiefly proceeds

via free radical reactions. Several free radical reactions consisting of initiation,

propagation, and termination of free radical have been proposed to take place

during the WAO of various organic compounds (Robert et al., 2002 and Garg

et al., 2010). Phenol and its derivatives have been the subject of many studies in

CWO as a model reaction. Studies on the mechanisms for oxidation of phenol

require some knowledge of the short-lived intermediates as well as the final

reaction products (Eftaxias, 2002), that can take place in the homogeneous

phase or on the catalyst surface.

RH − OH + cat -------- R • H = O + •H – cat………………………….2.1

R • H = O + O2 ------------RHO − OO • ………….………………….2.2

RHO − OO • +RH − OH ------- ROH − OOH + R • H = O …………..2.3

In this mechanism RH − OH corresponds to phenol, R • H = O corresponds to

the phenoxy radical and RHO − OO• corresponds to the peroxy radical. (Wu et

al., 2003). Wu et al., 2003 found that, during phenol oxidation, the oxidation

involves an induction period, in which the generation of radicals is poor,

followed by a higher steady-state activity period with a fast free-radical reaction

regime. These mechanisms occur for noble metal catalysts, Figure (2.5) shows

the general pattern ruling the oxidation reaction of phenol. Generally, the

reaction intermediates reported on phenol oxidation catalyzed by supported

metal oxides, like copper, zinc, manganese and other metal catalysts, are similar

to those of non-catalyzed phenol oxidation. The reaction products that have

been reported from the oxidation of phenol by oxygen and ozone can be

attributed to three classes: primary intermediates (hydroquinone, catechol, P-

benzoquinone, o benzoquinone), secondary intermediates ( maleic acid, formic

acid, pyruvic acid, oxalic acid, oligomers of primary intermediates), and end

products (formic acid, acetic acid, carbon dioxide and water). Figure (2.6) gives


11

the summary of a variety of partial oxidation and polymerization products

observed during wet oxidation. The oxidation of phenol has in most cases

involved oxidation, decarboxylation, dehydration and rearrangement of the

molecules or some combination of these steps while platinum catalysts have the

potential to change the reaction pathways of organic compounds to the desired

end products CO2

and H2O. There is still limited information on the oxidation

routes as well as the catalytic mechanisms (Eftaxias, 2002).

Figure (2.5) General pattern ruling the free- radical oxidation of phenol

(Benali and Guy, 2007)


19

Figure (2.6) Possible reaction pathways for phenol oxidation in liquid phase adapted

(Devlin and Harris,1984)


11

2.4.3 Reaction kinetics for catalytic phenol oxidation

It is desired that the kinetic models correspond reasonably with reaction

mechanism and experimental data. Reaction parameters including reaction

temperature, oxygen partial pressure, reactant concentration, the solid-to-liquid

volumetric ratio, usually called catalyst concentration, etc. influence the

reaction rate. Studies on the kinetics of CWAO have been extensively

performed by using model compounds over a wide range of temperatures and

pressures. Fixed -bed reactors is mainly used to carry out the CWAO runs. For

the heterogeneous catalytic oxidation of aqueous organic pollutants, the

apparent kinetic models are generally expressed in terms of either the simple

power law or more complex equation based on adsorption–desorption

mechanism, i.e. Langmuir-Hinshelwood-Hougen-Watson (LHHW) model. Both

kinetic models have provided reasonable simulations of the observed results for

the CWAO of reactants (Fortuny et al., 1999; Eftaxias et al., 2001and

Eftaxias et al., 2005). Guo and Al-Dahhan, 2003 suggested the kinetic

equations for heterogeneous contribution, based on the reaction mechanism

where the adsorption and desorption steps are assumed to be instantaneous

compared to the surface reaction. The simplest form of surface reaction rate

could be correlated with the power law kinetic model. Guo and Al-Dahhan,

2003 evaluated a group of kinetic models considering both power law and

LHHW approaches to describe the kinetics for the CWAO of phenol over Al-Fe

pillared clay in a basket stirred-tank reactor. The results showed that the

apparent catalytic kinetics of phenol disappearance complied with a LHHW rate

law derived from a dual site adsorption mechanism with a rate-determining

surface reaction between adsorbed phenol and adsorbed oxygen atoms. Fortuny

et al., 1999 carried out the CWAO of phenol under 120–160◦C and 0.6–1.2MPa

of using a commercial copper oxide catalyst (Harshaw Cu 0803 T1/8,

Engelhard) in a trickle-bed reactor. They described the phenol degradation


10

using a simple power law expression in which reaction order for phenol and

oxygen were 1 and 0.5, respectively. In their successive work, the same

experimental data was described using a LHHW expression accounting for the

adsorption effects together with simple power law expression. The model

predictions significantly improved when LHHW expressions were incorporated

for all intermediate compounds, except for phenol that did not adsorb on the

catalyst. Eftaxias et al., 2005 reported that simple power law model accurately

predicted the entire experimental data for the CWAO of phenol using AC in a

trickle-bed reactor, while more complex LHHW model did not significantly

improve the data fitting. Table (2.6) represent kinetic parameters for CWO and

CWAO of organic compounds .

Table (2.6) Kinetic parameters for CWAO of phenolic compound

Compound Catalyst Ea (KJ/mol) Reference

phenol Cuo. Zno. Al2O3 84 1 0.5 Pinter and

Levec, 1992

phenol Cuo/- Al2O3 85 1 0.5 Fourtuny et al.,

1995

phenol CARULITE

150 129.704(7.3) 1.094(0.09) 0.29(0.19) Zhang and

Savage, 1998

phenol Cuo/- Al2O3 85 1 0.5 Fourtuny et al.,

1999

phenol AC 73 1 - Stuber et al.,

2001

phenol AC 69.3 1 1.015(0.02) Eftaxias et al.,

2005

phenol Cu/AC 35.4 - - Wu et al., 2005

phenol MnO2/CeO2 38.4/53.4 - - Luna et al.,

2009

Phenol Pt/ Al2O3 33.8657 1 0.87 Safa'a, 2010


11

2.4.4.Catalytic Oxidation of phenol experiments pervious

works

Fortuny et al., 1995, studied the catalytic oxidation of phenol in an aqueous

solution in a continuous trickle bed reactor and found that when pressure is

doubled the conversion is only multiplied by 1.7, while an increment of only

40C produces three times more conversion of phenol.

Harmankayaya and Gunduz, 1998, studied the oxidation of aqueous phenol at

atmospheric pressure. They investigated the effect of operating parameters

such as temperature, oxygen and initial phenol concentration on phenol

conversion over the active catalyst (Cuo and Zno) chosen and they developed a

rate equation for the reaction .

Miro et al., 1999, obtained efficient and durable catalysts and determined that

the optimal process conditions are the key to successfully implementing the

waste water treatment from phenolic compound .Therefore they focused their

studies on the influence of the PH on the performance of prepared catalyst

(copper-based catalyst supported over either silica or -alumina). Their results

show that increasing the inlet PH, decrease the rate of deactivation for both

catalyst .

Stuber et al., 2001, performed CWAO of aqueous solution using active carbon

as a catalyst in slurry and trickle bed reactor and found that the mineralization

was much lower in the slurry reactor. Also found the kinetic parameter's.

Iliuta and Larachi, 2001, developed a model that discusses the interaction

between reaction kinetics, transport phenomena and hydrodynamics. The

simulation results indicate that when wet oxidation is liquid-reactant limited,

packed bubble columns outer perform, trickle beds regardless of the pressure

level, whereas three-phase fluidizing beds exhibit a critical particle size

maximizing the pollutant conversion. At equal effluent residence times, slurry

bubble column are found less efficient than three - phase fluidizing bed reactors.


11

Eftaxias et al., 2003, developed a non -isothermal trickle bed transport-reaction

model their model was tested for the catalytic wet air oxidation of phenol over

Cu/- . The model parameters indicate that interaparticle diffusion and for

complete wetting, gas-to-liquid mass transfer strongly influence the reactor

performance. Non-isothermal simulations show that water evaporation must be

taken into account in scale up and adiabatic catalytic wet oxidation reactor

design. Neglecting evaporation can lead to erroneous calculation of the exit

stream temperature and phenol conversion, especially at high conversions. The

adiabatic temperature rise is shown to strongly depend on the superficial

velocity of the gas stream .

Wu et al., 2003, studied the CWAO phenol in a batch stir reactor found that

phenol conversion increases with the increase of the temperature of the reaction

when using copper nitrate as a homogenous catalytic oxidation .

Cybulski and Trawezynski, 2004, elaborated a kinetic analysis of phenol

conversion in catalytic wet air oxidation based upon lumped reaction network

according to which oxidation of phenol proceeds substantially via two routes :

(1) directly to carbon dioxide, and (2) through intermediates which are difficult

to oxidize over the catalysts studied. Modified power law kinetic equations

describe satisfactorily CWAO of phenol removal over the catalysts of this work.

Massa et al., 2004, found that the distribution of intermediate products, and

consequently the selectivity depends on the mass of catalyst/ volume of liquid

ratio. A reactor with low liquid to catalyst ratio such as trickle bed reactor

would be more suitable to favor the selectivity towards complete oxidation.

Singh et al., 2004, studied the influence of temperature and pressure and

found that phenol conversion reaction was strongly affected by the temperature

and pressure; however, pressure had less effect.

Guo and Al-Dahhan 2004b, 2005, studied experimentally and theoretically the

effects of reaction parameters on local flow distribution and on the performance


11

of the catalytic wet oxidation process, by accounting for the phase change. they

studied the effect of temperature, pressure, LHSV, gas superficial velocity and

effect of feed concentration and found that removal of phenol increase with

increasing the temperature, pressure and gas superficial velocity while

temperature have more pronounced effect than pressure and decrease the

removal of phenol with increasing of LHSV and feed concentration.

Eftaxias et al., 2006, found from their study that the increase of both

temperature and pressure increased the phenol conversion and found that

pressure is seen to have a strong positive effect. While Luna et al., 2009, found

that the catalytic oxidation of phenol attain high conversion even at a low

temperature and pressure as compared to the removal oxidation of phenol.

Rubalcaba et al., 2007, investigated the catalytic wet air oxidation (with AC

as a catalyst) and hydrogen peroxide promoted catalytic wet air oxidation in an

intensified process, to give an effluent that could be later biologically treated.

Principal advantages of using these promising processes is to decrease the

conventional wet air oxidation and wet peroxide oxidation process costs,

keeping high conversion of pollutant in industrial waste water, and also the use

of a low cost catalyst, non-modified activated carbon, which avoids leaching

problems associated to heterogeneous processes using metal-based catalysts.

Sanchez et al., 2007b, found from their study that the higher the initial

concentration of phenol the lower the conversion while increasing temperature

leads to an increase in the phenol conversion.

Pinter et al., 2008, They found that the employed (Ru/ ) catalysts for

catalytic wet oxidation of phenol enable complete removal of phenol at

temperature above 483 K; at these conditions, no carbonaceous deposits were

accumulated on the catalyst surface.

Garg et al., 2010, studied the oxidative phenol in a three necked atmospheric

glass reactor (AGR) and concluded that the operating condition should be


11

optimized by adjusting reaction temperature and pressure, since both these

factors have positive effects on oxygen solubility.

Safa'a, 2010, studied CWO of phenol in TBR over three types of catalyst (Pt/

Al2O3 and Fe/Ac) and found that the highest phenol conversion was achieved

over the ( Pt/γ-Al2O3) and also found that phenol conversion increases with

increasing gas flow rate, temperate of reaction and oxygen partial pressure

while decrease with increasing of LHSV.

Table (2.7) Summary of Catalytic oxidation pervious work

Systems Reaction

Conditions

Type of

Catalyst

Reactor Removal

(%)

Reference

Phenol - (O2&Air) 120,140&160C

0.6-1.2Mpa Cuo/- TBR 95%X

85%COD

Fortuny et al., 1995

Phenol- 1atm Cuo & Zno Four- neck _ Harmankaya and

Gnduz.,1999

Phenol- Air 140C

4.7MPa(total)

Cu/(silica or -

)

TBR _ Miro et al .,1998

Phenol - Air 100-160C

0.71-0.82MPa

AC TBR&

SR

99%X Stuber etal., 2001

Phenol- 180C

3MPa

Mixture Of Cuo,

Zno &CoO

TBR,PBCR,

TFBR&SB

_ Iluta and Larachi., 2001

Phenol- 433 K

0.6 MPa Cu/- TBR _ Eftaxias etal.,2003

Phenol -

313-333K

1.2-2.3Mp

Aqueous copper

nitrate

BSR _ Wu et al., 2003

Phenol - Air 393&473K

5&8MPa(total)

Pt & Ru FBR _ Cybulski and

Trawezynski,2004

Phenol - 140C

2bar

Cuo+Zno

Cuo+Nio

Cuo+

SBAR _ Massa etal., 2004

Phenol- 373-403K

1-15atm CuO/ TBR _ Singh et al., 2004

Phenol -Air 150-170C

1.5-3.2MPa

Fe-Al PBR >90%X Guo&Al_Dahhan.,

2004b,2005

Phenol - Air 120-160C

1-2bar

AC TBR 99%X

85%COD Eftaxias et al., 2006

(o-cresol, p- nitrophenol

) &Phenol)- (Air, 140C

2bar

AC TBR _ Rubalcaba etal., 2007

Phenol - Air 20-50C

1atm

ZVI,EDTA SR 85%X Sanchez et al., 2007b

Formic acid ,acetic acid and

phenol-

328-523K

10.2-49.7bar Ru /Ti TBR 95%X

85%TOC Pintar et al., 2008

(Phenol ,DCP&-D) - 80-200C

2.04-4.76MPa

MnO2/Ce SR _ Luna et al., 2009

Phenol - Air

100-140C

0.4-0.8 MPa

(CuSO4.5H2O)

&(CuO- ZnO/Ce

O2,Cu/13X and

LaCoO3)

AGR 90%X

83%COD Garg et al., 2010


11

Phenol- 120-160C

8-12bar Pt/ &Fe/AC TBR 97.4% X Safa'a, 2010

Chapter Three Experimental Methodology

63

3.1.Introduction

This chapter describes in details the experimental set-up of hydrodynamic and

CWAO, materials and analytical methods were used for characterizing the

effluents of the CWAO process as well as the techniques employed for

evaluation of hydrodynamic and kinetic parameters. These characterization

techniques were selected and adapted to deal with the complex matrix found in

the outlet samples from phenol oxidation on one hand, and on the other hand to

shed some light on the catalytic performance of 0.5pt/-Al2O3. Additional

experimental investigation in the form of; hydrodynamic experiments were

performed under steady state. A schematic illustration of the experimental

facility set up is shown in Figure (3.1).


63

Figure (3.1a) Photographic view of the experimental facility


63

Figure (3.1b) Schematic diagram for the experimental setup


63

3.2.Experimental Work

The main unit of the process is the trickle bed reactor. It was made up of

stainless steel tube able to withstand temperature up to (140)C and pressures up

to 4MP(40bar) with 0.05m inside diameter and 5mm wall thickness packed with

(800gm &0.6m height) of catalyst particles. Table (3.1) represents some

characteristics of catalyst, pre and post packing, trickle bed reactor and material

used through the experiment. The trickle bed reactor was packed with different

packing layers of inert particles besides the catalyst layer. A first 0.2m from the

top a layer (pre-packing) of 2mm×2mm glass cylinder was set just before the

catalyst bed in order to ensure uniform radial liquid distribution over the reactor

cross-section, then 0.5%Pt/Al2O3 catalyst particles bed with a height of

0.6m.The last layer (post-packing) again contains 2mm×2mm glass cylinder

particles with a height of 0.45m,which supports the catalyst packing to complete

a total bed height of (1.25m).The reactor to particle diameter ratio of 31.25 was

sufficient to prevent wall effect (Al-Dahhan et al., 1997). The packing was

maintained by means of a stainless steel screen placed at the column bottom

and had a mesh openings large enough to prevent art factual bed flooding but

narrow enough to impede particle crossings. This configuration is used in

kinetic and hydrodynamic experiments. To measure the two phase pressure drop

through the reactor bed, pressure taps were drilled in the reactor head and in the

bottom of the reactor and a differential pressure transducer was mounted. The

output signal of the transducer was fed to an A/D converter and stored in PC,

with sampling frequency of (250)HZ .The reactor was externally heated with

electrical tape heater (Heraeus-Wittmann Gmbh Heidelberg, type MS6) which

was connected to a temperature controller (Yang Ming CX TA 3000) that

maintained the bed temperature within ±3oC of the set point temperature by

means of on-off regulator control which manipulated the heat supply of the


04

external tap heater. Three thermocouples (Type T) were situated within the bed

at different axial positions are located in the reactor axially.

Table (3.1) Catalyst, reactor and material characteristics

Parameters Characteristics

Reactor Characteristics

Reactor diameter (I.d/o.d) (0.05/0.0003) m

Total length 1.25 m

Type of inert bed (Glass Cylinder ) 3*3 mm

packing depth 0. 6m

Bed porosity 0.38-0.4

Catalyst Characteristics

Active metal 0.5%Pt

Catalyst support -

Particle shape Sphere

Particle diameter (cm) 0.16

Surface area( /gm) 250

Pellet density(gm/ ) 0.56

Phenol Characteristics

Color White

PH (4.5-6)

Molecular weight (gm/gmol) 94.11

Chemical structure Purity(%) 99.5

Freezing point(ºC) (40-41)

Dye Characteristics

Type of dye Reactive red

Commercial name Forosyn red

Chemical structure

Molecular weight(gm/gmol) 991.82

Wave length((nm)) 485


04

3.2.1. Liquid and Gas Delivery and Separation System

After the synthetic solution was heated with an immersed electric heater in the

storage tank (100 liter capacity ) up to a max of 60ᵒC it was pumped by means

of a metering pump (Dose pump, BALDOR FRUM DUTY, USA) to a high

pressure small stainless steel tank (Damper, 0.04 id *0.35m length ) to damp the

pulsation due to pumping. The gas was delivered from a high pressure cylinder

equipped with a pressure regulator to adjust the operating pressure. A flow

meter coupled with needle valve enabled the gas flow rate to be set and

measured. The liquid and gas streams were mixed and preheated in the pre

heater before entering the reactor at the top through a distributor containing

29holes (=0.5mm) . Discharged fluids (gas and liquid) from the reactor flow

through the gas-liquid separator. In the top flange of the separator, stainless

steel mesh demister was placed to trap the liquid mist from the effluent gas

stream. Pressure indicator and safety valve was mounted to prevent pressure

build up in the gas and liquid delivery and exit streams. One way valve was

located in gas and liquid line to assure the flow in one direction.

3.2.2. Tracer injection system

An aqueous solution (Forosyn red) supplied from (14 Ramadan factory of

textile industries – ministry of industry) was used as tracer and injected of the

column by means in to a specially designed injection loop. A 1.5 L-carbon steel

vessel was connected to the top of TBR via an on - off solenoid valve which

was energized with time. The system consisted of three valves: two of them

being used for injecting the tracer, and pumping air while other is being used for

feeding the injection line from a tracer tank to the reactor by means of pumping

air through a pulse - type feeding response.


04

3.2.3. Data Acquisition and system

An electronic circuit was built to measure the temperature and pressure drop

along the catalyst bed. A schematic diagram of this circuit is shown in Figure

(3.3) .The circuit makes the computer communicate with the real world through

the parallel port which is expanded to three main ports: A, B, and C. Port A was

used as the control port (signals were transferred from the computer to the

outside world). Port B and C were used to transfer data from outside world to

the computer. Each signal (temperature and pressure drop) owes its meaningful

information to appropriate software written and executed in Microsoft Visual

Basic, which works under Microsoft excel spreadsheet application.

For temperature measurements, the output transducer signals from the

thermocouples (Type T) were incorporated to the terminal block of a

multiplexer data acquisition board unit which feeds the electrical signals to

an analog-digital (A/D) converter then proceed to a data acquisition board of

a personal computer (P4:Open type).

The output signals of high pressure differential pressure transducer (for

pressure drop measurements) (Rosemount, model E1151 G P5523, 55T)

were also connected similarly to a data acquisition multiplexer.


06

Figure (3.4) The Data Acquisition System.

The pressure transducer, thermocouple, gas rotameter and pump were calibrated

as shown in (Appendix A).The experimental accuracy was within ±4%.


00

3.3. Operating Conditions and Procedures

This work deals with the effect of hydrodynamic parameter on trickle bed

reactor and studied the oxidation of phenol by catalytic wet oxidation process.

Experiments were carried out for a range of temperature, pressure and

superficial gas and liquid velocities which consisted the trickle flow regime as

shown in Figure (3.5). Some temperature, and pressure were selected to be at

the saturation states of gas-liquid phase. Table (3.2) shows the range of

operating conditions.

Figure (3.5) Region of trickle flow regime covered experimentally in this study (flow

map based on Fukushima and Kusaka 1977a,b).


04

Table (3.2) Rang of operating conditions in hydrodynamic and kinetic study

3.3.1.Hydrodynamic experiments

Hydrodynamic experiments were aimed to study the effect of operating

conditions (reactor pressure, bed temperature, superficial gas and liquid

velocity) on the hydrodynamic parameter (i.e. , Pressure drop, liquid holdup and

axial dispersion).

3.3.1.1.Pressure drop

Before starting, the reactor is operated in high interaction regime at high liquid

flow rate for at least 1hr after the bed is heated up to10◦C above the desired

temperature when operating in non-ambient temperature, followed by reducing

the liquid flow rate to the desired level. This helps to achieve perfect bed pre-

wetting and prevents hysterics effects (Al- Dahhan and Dudukovic,

1994).This procedure was repeated for each experiment. The data for pressure

A-Hydrodynamic experiments

system (water - air)

Temperature(C) (25-85)

Pressure(MPa) (0.1-0.6)

Superficial liquid velocity(m/s) (0.0013-0.1)

Superficial gas velocity(m/s) (0.08-0.25)

B-Kinetics experiments

system (phenol - oxygen)

Temperature (C) (85-140)

Pressure(MPa) (0.1-0.6)

Superficial liquid velocity(m/s) (0.0013-0.0085)

Superficial gas velocity(m/s) (0.08-0.13)

Initial phenol concentration(mg/l) (900-5000)


03

drop measurements collected for a period of at least 10min with sampling

frequency of 250Hz.

3.3.1.2 Liquid holdup and axial dispersion

The dynamic liquid holdup and axial dispersion were determined by using

tracer technique method. Before starting the experiment, the bed was fully

wetted by passing water at slightly higher rate. Then the flow rate of air and

water were adjusted to the desired values. It took approximately 30min to attain

steady state. The attainment of steady state was determined by measuring the

flow rates of gas and liquid at the outlet. It was observed that the flow rates did

not change after 30 min of operation. The pulse of tracer was then injected

through the pneumatic injection system connected with an on–off solenoid

valve opened within controlled time open in (5min) and then closed. The

samples were drawn from the bottom of reactor in each run to evaluate the

change of tracer concentration with time for each (4sec). UV is used to detect

the concentration of tracer by assistance calibration curve show in appendix A.

An RTD curve is constructed and a statistical method (i.e., slope method) is

used to estimated axial dispersion coefficient.

3.3.2 Kinetic experiments

phenol supplied from (Thomas Baker (Chimicals) PVT. Limited 4/86,

Bharat Mahala, Marine-400002,India), using 0.5pt/- as a catalyst

supplied from (Norther Refineries Company–Baiji). The reactor setup was

operated to enable comparative tests of reactor performance. In a typical series

of oxidation experiments, the phenol solution and compressed oxygen is mixed,

preheated and then fed at the highest liquid flow rate to the reactor to saturate

the catalyst under toxic conditions. When the bed saturation is achieved (after 1

h), the flow rate slowly decreases to a desired value. The sample withdrawn in

each run was analyzed by HPLC.


03

3.4. Analytical procedures

3.4.1.UV spectrophotometer To measure dye concentration, JASCO ultraviolet/visible (UV-VIS/530)

spectrophotometer was used. The dye that have occurred calibration curve of

UV spectrophotometer was checked to correct deviations in peak height

dye calibration curve was made by collecting samples of stocks solution in the

range of (0.5-1991mg/l) and measuring the absorbency against each

concentration then plotting concentration values against absorbency see

calibration curve figure (A-9) in (Appendix A). Prior to measuring, each

reaction solution was diluted by taking 0.1 ml of sample solution and then

making up to 3 ml with tap water to obtain a solution with dye concentration

in the above range and then measuring the absorbency for each sample. The

same procedure was done in CWAO samples.

3.4.2 High performance liquid chromatography(HPLC) Liquid phase samples were analyzed by means of an HPLC

DIONEX(UV(JYNKOTEK)/VIS160S), which contains a C18 reverse phase

column (Philips, 5μm 25 x 0.4 cm). A mixture of 65% / 35% vol. of methanol to

water (slightly acidified) was used as a mobile phase. For all compounds, the

flow rate of the mobile phase was 1 ml/min. Detection of the compounds was

performed using UV absorbance at a wavelength of 254 nm. Detection of low

molecular weight carboxylic acids was performed with the UV absorbance

method at a wavelength of 210 nm. In the end, sample measurement of

wavelength was switched to 254 nm to detect phenol correctly, to obtain the

concentration profiles of phenol and intermediates. To properly separate phenol

from the partial oxidation products, single compounds were quantitatively

identified by injecting pure samples of the expected partial oxidation products.

However not all of these compounds could be identified in the reaction sample


03

solution. In Table (3.6) the approximate retention times of all the pure

compounds injected are given. An example of such a standard solution,

including the most important intermediate compounds is given in (Appendix A)

Figures (A.5–A.8).

Table (3.6) HPLC retention times of phenol and possible partial oxidation products

(Analytical Laboratory – Chemical engineering- university of Tikrit).

Compound

(pure)

Retention

time(min.)

Formic acid 1.761

Maleic acid 2.988

Acetic acid 3.051

Phenol 4.425

Chapter Four Results and Discussion

94

4.1.Introduction

The present chapter includes four sections. The first concerns with the effect of

operating variables studied on the hydrodynamic parameters (pressure drop,

liquid holdup and axial dispersion) and the second section deals with the

developing of empirical correlations which relate the objective function with the

operating variables. The third section deals with kinetic parameter estimation.

The final section deals with the effect of (temperature, LHSV, superficial gas

velocity, pressure and initial phenol concentration) for catalytic phenol

oxidation.

4.2 .Signal analysis

4.2.1. Pressure drop

In the present work, the pressure drop through the bed was measured by using

pressure transducers, recording the pressure fluctuations (signals) analysis.

Figure (4.1) shows sample of pressure drop oscillation versus time, increasing

proportionally with reactor pressure, superficial gas and liquid velocity while

decreasing with temperature. To determine the pressure drop over a period of

time, for various signals from recorded sets of data, the average value is

calculated.


05


05

Figure (4.1) Pressure drop signals operation at different operating conditions

4.2.2. Liquid holdup and Axial dispersion

The tracer technique, described in details in chapter 3, was used to measure the

liquid holdup and axial dispersion. Figure (4.2) depicts a comparison between

experimental RTD curves for different sets of temperatures, superficial gas and

liquid velocities. By analyzing the curve in Figure (4.2), some notes can be

concluded, 1st as the flow rate increased, the mean residence time of the RTD

curve decreased. 2nd

, as the liquid velocity increased scanning the selecting

range of operating conditions, the RTD curve increasingly deviate from

symmetry which means a more back mixing occurred in the liquid phase. 3th

, as

the temperature increasing caused an increase in mean residence time which

leads to low back mixing. The measured data were transferred into dynamic

liquid and axial dispersion through a some calculation is done see sample of

calculation in Appendix D.

0

20

40

60

80

100

120

0 50 100 150 200 250 300 350

Dye c

on

ctr

ati

on

(mg

/l)

Time(sec)

Ul=0.0013m/s,Ug=0.086m/s,T=50C

Ul=0.0025m/s,Ug=0.086m/s,T=50C

Ul=0.007m/s,Ug=0.086m/s,T=50C

a


05

Figure (4.2) Curves a,b,c (Dye concentration vs. time)

0

20

40

60

80

100

120

140

160

0 50 100 150 200 250

Dye c

on

ctr

ati

on

(mg

/l)

Time(sec)

UG=0.0086m/s,ul=0.007m/s,50C

UG=0.129m/s,ul=0.007m/s,50C

0

20

40

60

80

100

120

140

160

0 50 100 150 200 250 300

Dye c

on

ctr

ati

on

(mg

/l)

Time(sec)

ug=0.086m/s,ul=0.007m/s,25C

ug=0.086m/s,ul=0.007m/s,50C

ug=0.086m/s,ul=0.007m/s,85C

b

C


05

4.3. Hydrodynamic

The experimental runs were carried out in a trickle bed reactor. The effects of

pressure drop, liquid and axial dispersion were studied. Each experiment was

repeated twice to reduce the experimental errors. The results of experimental

runs are shown in appendix C.

4.3.1.Effect of operating conditions on hydrodynamic parameter 4.3.1.1.Pressure drop

Figure (4.3) depicts the effect of superficial gas and liquid velocities on pressure

drop at a given reactor pressure and temperature. As expected, the figure shows

a proportional relationship between pressure drop and superficial gas and liquid

velocities. The increasing pressure drop may be attributed to the increased shear

stresses exerted by the drag forces between the phases ,it can be seen from

Figure (4.3) that the pressure drop is (1.4947kPa/m) at [ug=0.086m/s, ul=

0.0013m/s] while (11.49kPa/m) at [ug =0.086,ul = 0.01m/s] and (14.3 kPa /m)

at [ug=0.129m/s, ul= 0.01m/s]. These results are in agreement with Wammes et

al.,1990, 1991; Larachi et al., 1991; Al-Dahhan and Dodukovic, 1994 and

Iliuta et al., 1996.


09

Figure (4.3) Pressure drop as a function of superficial gas and liquid velocities at

[ 0.1MPa , 250C]

Figure (4.4) shows the effect of operating pressure on the pressure gradient

along the trickle bed reactor. As indicated before; the pressure gradient depends,

besides the bed characteristics, on the velocities of both phases and on

physicochemical properties of the flowing fluids. Regarding the fluids

physicochemical properties, mainly gas density is influenced by pressure. Thus

for a given gas and liquid velocities, a higher gas density produces a higher

interfacial drag force equivalent to a higher pressure gradient. This trend is

shown in Figure (4.4). As shown in this figure pressure drop is (1.159Kpa/m) at

[0.1Mpa,ug= 0.086m/s] while (1.397 kPa /m) at [0.6Mpa,ug =0.086m/s]. The

pressure drop is more sensitive to velocity changes than to pressure changes for

example as shown in Figure(4.4), the pressure drop at superficial gas velocity

of 0.173m/s and 0.1 MPa reactor pressure has a higher value than at 0.086m/s

superficial gas velocity and 0.6 MPa. This result is attributed to the fact that in

the first case, elevated pressure results in higher gas density, which

consequently produces a higher drag force at the gas-liquid interphase and

lower inertia force of the gas-phase. In the second case, at high superficial gas

velocity, the pressure drop increases in comparison to the gravitational force

which is more affected than the drag force at high pressure and low gas


00

velocity. These results are in agreement with the finding of Guo and Al-

Dahhan, 2004a; Urseanu et al., 2005 and Al-naimi et al., 2011.

Figure (4.4) Pressure drop as a function of pressure and superficial gas velocity [50ºC]

Figure (4.5) illustrates the effect of operating temperature on the pressure

gradient along the reactor for various superficial gas and liquid velocities and

pressure. It can be seen that the pressure drop is (2.955 kPa /m) at

[25ºC,ug=0.173m/s] while (1.612 kPa /m) at [85C,ug=0.129m/s]. Also the

pressure drop decreased with increasing temperature. As indicated before, under

the present conditions, pressure drop mainly depends on viscosity, density,

surface tension and velocity of the fluids. As the liquid viscosity decreases with

respect to temperature, the gas viscosity follows an opposite trend, the net of

shear stress at the gas-liquid and liquid-solid interfaces is not obvious, since the

effect of temperature on gas viscosity is less pronounced in comparison to that

on liquid viscosity, increased temperatures are likely to weaken the frictional

forces at the gas-liquid and liquid-solid interfaces. An additional contributing

factor in favor of influence is that the pressure drop decreases with elevated


05

temperatures due to the decrease in gas phase inertia with temperature (via gas

density). These results illustrate how pressure drop behaves as a function of

shear stress and inertial forces. Also at high superficial gas and liquid velocities,

the effect of temperature on pressure drop is more significant. These results are

in agreement with findings of Aydin and Larachi, 2005, 2008 and Al-naimi et

al., 2011.

Figure (4.5) Effect of temperature on pressure drop[0.6MPa]

Figure (4.5) shows the comparison between the present work with data of

Urseanu et al., 2005.


05

Figure (4.6) Effect of temperature, Pressure, superficial liquid and gas velocity on

pressure drop in comparison with literature

4.3.1.2.Liquid holdup

Liquid holdup results from the balance between the driving forces and the

resistances. Figure (4.7) shows a proportional trend between superficial liquid

velocity and liquid holdup at a given superficial gas velocity. While superficial

gas velocity has an adverse effect on the liquid holdup, it can be seen from

figure that the liquid holdup is 0.0657 at [ug=0.086m/s,ul=0.0013m/s] while

0.053588 at [ug=0.25m/s,ul=0.0013m/s] and 0.2199 at [ug=0.086m/s,

ul=0.01m/s]. The increase in liquid holdup with liquid throughput is due to film

thickening on the catalyst particle. The reduction in liquid holdup with gas flow

is attributed to the drag force at the gas-liquid interface, which is a driving force

for the liquid flow (cocurrent flow). This drag force depends on gas velocity and

density. Hence the drag force increases with gas velocity and density, shorter

liquid mean residence time arise occasioning a reduction in liquid holdup. These

results are in agreement with findings of Chander et al., 2001;Guo and Al-

Dahhan, 2004a and Aydin, 2008.


05

Figure(4.7) Effect of superficial gas and liquid velocity on liquid holdup at [25C]

Figure (4.8) shows the effect of operating temperature on liquid holdup. It

shows an adverse impact of operating temperature on liquid holdup, the liquid

holdup decreases with increasing temperature at constant superficial liquid and

gas velocities. As clear from this figure liquid holdup is 0.10549 at

[25ºC,ul=0.0025m/s] while 0.0953&0.0714 at [50ºC&85ºC,ul=0.0025m/s]

respectively. This can be explained by a decrease in liquid viscosity as

temperature increases, so the shear stress at the gas liquid and liquid - solid

interfaces decreases resulting in lower liquid holdup. Liquid surface tension

which is a resisting factor to gas flow, decreases with temperature thereby

reducing the number of events corresponding to film collapse around and

between particles. These results are in agreement with findings of Aydin and

Larachi, 2008 and Al-naimi et al., 2011.


04

Figure (4.8) Effect of temperature on liquid holdup

Figure (4.9) shows the comparison between the present work with data of Al-

naimi et al., 2011.

Figure (4.9) Effect of temperature, superficial liquid and gas velocity on liquid holdup

in comparison with literature


55

4.3.1.3. Axial dispersion

Figure (4.10) illustrates the effect of superficial gas and liquid velocity on the

liquid axial dispersion coefficient. The figure shows a positive trend between

the gas and liquid velocity and the dispersion coefficient and this can be

attributed to the effect of back mixing in the liquid phase. It can be seen from

the figure that dispersion coefficient is (4.5319* ) at [ug=0.086m/s,

ul=0.0013m/s], at [ug=0.129m/s,ul=0.0013m/s] and

(1.890279* ) at [ ug=0.086m/s, ul=0.01m/s]. These results are in agreement

with findings of Aydin, 2008 and Houwelingen et al., 2009.

Figure (4.10) Effect of gas and liquid velocity on axial dispersion at[ 25C]

The variation of liquid axial dispersion with operating temperature is shown in

Figure (4.11).As clear from this figure dispersion coefficient is (7.16282* )

at [25ºC,ul=0.0025m/s] and (6.83355* &6.39754* ) at [50&85ºC,

0.0025m/s] respectively. This may be described by lowering in back mixing due

to a decrease in liquid holdup with temperature. These results are in agreement

with findings of Aydin and Larachi, 2005.


55

Figure (4.11) Effect of temperature on axial dispersion coefficient

Figure (4.12) shows the comparison between the present work with data of

Aydin and Larachi, 2005.

Figure (4.12) Effect of temperature, superficial liquid and gas velocity on Axial

dispersion coefficient in comparison with literature

4.3.2.Empirical Correlation


55

The pressure drop, dynamic liquid holdup and axial dispersion coefficients are

correlated in this work where operating parameters (superficial gas and liquid

velocities) are taken into account, the relevant system properties (viscosity,

density and surface tension) varied in the experiments due to variation in reactor

pressure and temperature, as follows:-

TU

Ug

LL,

1,, …4.1a

TPUUP gL

1,,, ...4.1b

...4.1C

Therefore the following correlations are proposed:-

...4.2a

…4.2b

…4.2c

Based on non-linear regression analysis by, Least square method of statistica

software version 8 was used to estimate the coefficients ai and exponent's bi , ci ,

di, e for the above correlations. The results are shown in Table (4.1). A

comparison between the experimental results and the predicted values is shown

in Figure (4.13).

Table (4.1) Constants and exponent coefficients of the empirical correlation


55

(i: integer number from 0 to 2)

Pressure Drop

0 5 10 15 20 25 30 35 40 45

Predicted Values

0

5

10

15

20

25

30

35

40

45

50

Ob

serv

ed V

alu

es

Coefficients

Pressure drop 0.51 0.88 0.18 0.47

Correlation coefficient = 98.47%

Variance = 96.97%

Liquid holdup 0.5377 -0.3053 -0.51 -


Variance = 98.46%

Axial dispersion 0.0000134 0.7 0.53 -0.32 -


Variance = 99.7%

a


59

Liquid holdup

0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26

Predicted Values

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.22

0.24

Ob

serv

ed V

alu

es

Axial Dispersion

0.00000050.0000010

0.00000150.0000020

0.00000250.0000030

0.00000350.0000040

Predicted Values

0.0000005

0.0000010

0.0000015

0.0000020

0.0000025

0.0000030

0.0000035

0.0000040

Ob

serv

ed V

alu

es

Figure (4.13) Observed and predicted values of empirical correlation estimated of

Pressure drop(a), Holdup(b) and Axial dispersion(c).

4.4.Catalytic Oxidation of phenol

.1. Reactor performance4.4

In the present work such effects were greatly reduced by the correct choice of

particle and reactor geometry ( =1.25m, =0.05m and = 0.0016m). The

relevant criteria of and take values of 781.25 and 31.25,

respectively, which match the critical value of 20 established for safe operation

(Mederos et al., 2009).The calculated axial dispersion coefficient has a very

b

C


50

small value in the order of ( ) , which ensures the absence of

axial dispersion in present study, these which confirm a good assumption of

plug flow.

4.4.1.1.Reactant limitation

The performance of the TBRs depend upon the type of reactant limitation used.

A criterion was developed by (Beaudry et al., 1987). Equation (4.3) was used

to diagnose the operation mode (reactant limiting):-

...4.3

to determine the limiting reactant of the reaction. If γ >>1, the reaction will be

limited by the gas reactant; if γ <<1, it will be limited by the liquid. Based on

the employed operating conditions, the resulting ratio of the diffusion

fluxes (γ) of the two reactants are listed in Table (4.2a,b).

Table (4.2a)Values of γ

140ºC 120ºC 100ºC 85ºC

(kmol/ ) 0.6MPa 0.6MPa 0.3MPa 0.6MPa 0.3MPa 0.6MPa 0.3MPa 0.1MPa

0.09 0.09 0.18 0.09 0.18 0.09 0.18 0.54 0.009432

0.15 0.15 0.30 0.15 0.31 0.15 0.30 0.91 0.015933

0.24 0.25 0.51 0.25 0.51 0.25 0.51 1.52 0.026555

0.49 0.51 1.02 0.51 1.02 0.51 1.01 3.04 0.05311


55

Table (4.2b)Values of γ at saturation conditions

140ºC 120ºC 100ºC

(kmol/ )

0.15 0.28 0.54 0.009432

0.25 0.47 0.92 0.015933

0.42 0.78 1.53 0.026555

0.84 1.57 3.06 0.05311

It can be noticed from Table (4.2a,b) under various phenol concentration,

temperature and oxygen pressure the reaction varied from gas to the liquid

limiting reactant.

4.4.4.4 . Interface mass transfer (external diffusion)

The influence of external solid - liquid mass transfer resistance must be

ascertained before a true kinetic model could be developed. To this purpose, the

αgl and αls criteria is used, defined in Equations (4.4) and (4.5) were now

calculated in the following way (Eftaxias, 2002):-

The solid–liquid and gas–liquid mass transfer coefficient values were

obtained for various operating condition by using Wu et al., 2009 correlation

see (Appendix B).

Table (4.3a) Values of and at 0.129m/s gas velocity and 0.0045m/s liquid velocity

based on initial phenol concentration (900mg/l)

TEMP(C) P (MPa)

....4.4

....4.5


55

Kmol/kg .h ( ) ( )

6.6934* 0.002566 0.000106

26.817 0.699556 85 0.1

9* 0.003776

0.000177 33.36537 0.795363 100 0.3

9.92 0.004912 0.0002267 53.39442 1.077897 140 0.6

Table (4.3b) Values of and at 0.129m/s gas velocity and 0.0045m/s liquid velocity

based on initial phenol concentration (900mg/l) at saturation condition

(Kmol/kg.h)

( )

( )

Temp (ºc ) P (MPa)

0.000137 0.006344

0.000348 42.97978 0.931319 120

0.000115

0.005704 0.000362 53.39442 1.077897 140

The above demonstrates that the mass transfer limitation in the present study

can be neglected and the rate may be either surface reaction controlled or intra

particle diffusion controlled see Table (C-(17 a,b-18)).

4.4.4.3 Intra particle diffusion (internal diffusion)

The existence of internal diffusion limitations the wisze-prater criterion

modified for n-order reactions is used (Fogler, 1997):-

where Lp is the ratio of catalyst volume to the catalyst surface. For n-order

reactions, if Φ << 2/(n+1) it can be considered that internal diffusion limitations

can be neglected. It can be seen from Table (4.4a,b) the Φ values are law, thus

internal mass transfer resistances should have only a slight influence. Again,

...4.6


55

due to the higher reaction rates at saturation condition the criteria exhibit higher

values see Table (C-(19-20)).

Table (4.4a) Values of at 0.129m/s gas velocity and 0.0085m/s superficial liquid

velocity

140ºC 120ºC 100ºC 85ºC

(kmol/ ) 0.6MPa 0.6MPa 0.3MPa 0.6MPa 0.3MPa 0.6MPa 0.3MPa 0.1MPa

0.674842 0.714792 0.686221 0.80533 0.580717 0.529621 0.509251 0.448141 0.009432

0.665951 0.421692 0.674878 0.468408 0.566365 0.512001 0.491631 0.430521 0.015933

0.65706 0.252097 0.663535 0.275992 0.552013 0.494381 0.474011 0.412901 0.026555

0.648169 0.125566 0.695925 0.135444 0.537661 0.476761 0.456391 0.395281 0.05311

Table (4.4b) Values of at 0.129m/s gas velocity and 0.0085m/s superficial liquid

velocity at saturation conditions

140ºC 120ºC 100ºC

(kmol/ )

0.889077 1.079228 1.038654 0.009432

0.869689 1.072015 1.034008 0.015933

0.889077 1.064803 1.029363 0.026555

0.878365 1.057591 1.024717 0.05311

In conclusion, the comparison of our experimental reaction rates with mass

transfer rates calculated from literature correlations clearly suggests that phenol

oxidation was kinetically controlled in the present study.

4.4.4. Estimation reaction kinetic parameters

For studying the reaction kinetics of phenol in a trickle bed reactor, a set of

experiments were carried out with the flowing operating condition [(0.1-

0.6MPa), (85-140C), (ug=0.086-0.169m /s) and initial phenol concentration of


54

(900-5000 ppm)].The first step is to consider only the phenol degradation

reaction described by equation

C6H6O + 7O2 → 6CO2 + 3H2O …4.7

In agreement with observations in the literature Fortuny et al., 1995; 1999;

Eftaxias, 2002; Eftaxias et al., 2005; 2006, a simple power law was convenient

to describe the phenol oxidation. Thus, the following rate equation for phenol

destruction was used:

…4.8 phobph CKr .

,the oxygen partial pressure was incorporated in (According to (Forment., 1990

. obK to the expression of

2

.. O

ob

ob PRT

kK

phph rR

phob

phCK

d

dC.

Equation 4.12 can be linearised in the following way:

phobph LogCKLogrLog

i.e. -rph = ko . EXP [-Eob / RT]. phC .

2OP

Because the reaction actually takes place in the liquid phase. Thus, the solubility

of oxygen characterizes the oxygen contribution to the kinetic expression rather

…4.9

...4.12

…4.10

…4.11

…4.13


55

than the oxygen partial pressure. Furthermore, the oxygen solubility is not only

a function of pressure but also of temperature. Therefore, the oxygen mole

fraction in the liquid phase was considered to be more represented. This mole

fraction was calculated using Henry law (Wu et al., 2003). The conversion of

phenol is independent of the inlet concentration within the rang investigated as

can be seen in Table (C-(4-14)) in (Appendix C), and there for the order of

reaction with respect to phenol is first order .This finding in agreement with

findings of Pintar and Levec, 1992; Stuber et al., 2001; Eftaxias, 2002;

Eftaxias et al., 2005; Quintanilla et al., 2007 and Safa’a, 2010. Also an ideal

plug flow was considered in the reactor, because of the high reactor diameter to

particle diameter ratio 31.25 and the very law magnitude of back mixing as can

be obtained in the present study see Table(C.3) in (Appendix C). can be

calculated from experimental data by the flowing way (Stuber et al., 2001).

...4.14

where ( ) is the apparent kinetic rate constant, τ ( )

is the liquid space-time and is the measured phenol conversion. Plotting

ln( ) vs τ as shown in Figure(4.14a and b) since the slope represents the

.


55

Figure (4.14a) Ln (1 − ℎ) vs. space time at [0.6MPa].

Figure (4.14b) Ln (1 − ℎ) vs. space time at equilibrium condition

The values of should be independent of inlet phenol concentrations, ie the

same should result for all conversion obtained (at different inlet phenol

concentrations). This means that is not correlated to the inlet phenol

concentration (Eftaxias et al., 2005) as shown in Figure (4.15a,b). The phenol

conversion data are therefore in line with the postulated first order of reaction

with respect to the inlet phenol concentration. This result may also suggest that


55

the phenol concentration at the catalyst surface is directly proportional to its

bulk liquid concentration.

Figure (4.15a) at different initial phenol concentration at

[ 85-140◦C, 0.6MPa of O2].

Figure (4.15b) at different initial phenol concentration at

equilibrium condition [85-140◦C].

To calculate the other unknown kinetic parameters k , obE and , equation 4.9

can be linearised in the following way:


55

RT

EPkK ob

oob 2Olnlnln ….4.15

OR

RT

EXkK ob

Ooob 2lnlnln (Where HXP OO .

22 ) ... .4.16

Based on non-linear regression analysis by, Least square method of statistica

software version "8" was used and utilizing different values of obK available at

different temperatures and pressures to evaluate these parameters. The results

are shown in table (4.5). A comparison between the experimental results and

the predicted values is shown in Figure (4.16).

Table (4.5) kinetic parameters of empirical correlation

Coefficients obK β (KJ/mol)

Conventional

condition

0.49 29.29949


Variance = 97%

Equilibrium

condition

0.69 24.61675


Variance = 99 %


59

Figure (4.16) Observed and predicted values of empirical correlation estimated of

obK at equilibrium and other operating condition

(0.69 and 0.49) oxygen order were found at equilibrium pressure and other

operating condition respectively which close to the values 0.5 obtained by

Fortuny et al ., 1995, 1999 and 0.74 obtained by Quintanilla et al., 2007. The

observed activation energy for phenol destruction was found to be (24.61675

and 29.29949) kJ/mol at equilibrium pressure and other operating condition

respectively which is much lower than the values reported by other studied

(35.4 KJ/mol by Wu et al., 2005; 38.4 KJ/mol by Luna et al., 2009 and 33.9

KJ/mol by Safa'a, 2010). These data and results are shown in Table (4.6).

Considerably, it is well known that the big gas/liquid ratio employed by this

type of reactor permits better contact between the gas and liquid phases, thus

improving the mass transfer between phases and emphasis that the mass transfer

limitation can indeed be neglected. The frequency factor was found to be (27

and 5.7) *109

(Liter/ .h) at equilibrium pressure and other operating

condition respectively, which is much lower than the values 1011

obtained by

Fortuny et al., 1999; 1011.36

obtained by Eftaxias.,2002 and 1014.36

obtained by

Eftaxias et al., 2006.

Values of Ln(Kob)

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Predicted Values

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Ob

serv

ed V

alu

es

Values of Ln(Kob)

(Equlibrium condtion)

1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6

Predicted Values

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

Ob

serv

ed V

alu

es


50

Table (4.6) Kinetic parameters estimation in comparison with data in the current

scientific literature

Quintanilla

et al., 2007

Eftaxias et

al., 2006

Wu et

al., 2005

Fortuny et

al .,

1995,1999

Present work Parameter

Equilibrium

condition

Conventional

condition

- 1014.36

- - 2.723*1010

5.723*109

K (L / . h)

5 1 - 1 1 β

0.74 - - 0.5 0.69 0.49 α

- - 35.4 - 24.616 29.299 (KJ/mol)

When those results are compared with those of this study, it can be seen that the

kinetic parameters are slightly different or closed to the values given in the

literature. The difference in the results may arise from the reaction conditions

and the type of catalyst used. Finally, The rate expression for equilibrium and

other operating conditions respectively is as follows:-

...4.17a

49.09

2..

49.29299107.5 Ophph XC

RTr

69.010

2..

75.24616107234.2 Ophph XC

RTr

…4.17b


55

4.4.3.Effect of operating condition on the CWO of phenol

The experimental runs were carried out in a trickle bed reactor using Pt base

catalyst. The effects of LHSV, gas flow rate, temperature, oxygen partial

pressure, initial phenol concentrations on phenol removal were studied. The

results of experimental runs are shown in appendix C.

4.4.3.1. Effect of different variables on the CWO of phenol

The effect of LHSV on phenol removal rate is presented in Figure (4.17). As

can be seen, increasing LHSV has an adverse impact on phenol conversion,

Figure (4.17) depicts the effect of liquid flow rate on phenol conversion .As

clear from the figure phenol conversions of 63.27% was achieved at

LHSV=4 , while at LHSV equal to 20 and 24 phenol conversion were

55% and 51.66% respectively. Actually increasing liquid flow rate reduces the

residence time of the reactant thus reducing the time of reaction of phenol with

oxygen (gas reactant). Moreover, higher liquid flow rates give greater liquid

holdup which evidently decrease the contact of liquid and gas reactants at the

catalyst active site, by increasing film thickness. The finding of Singh et al.,

2004 and Guo and AL-Dahhan, 2004b,2005 confirm our results .


55

Figure(4.17) Effect of LHSV and gas velocity on conversion of phenol at

[ initial phenol concentration 900PPm and 0.3 MPa]

Figure (4.17) also demonstrates the variation of conversion with superficial gas

velocity, the phenol conversion was enhanced by increasing the gas velocity. It

can be seen from the figure that the high phenol conversion of 67.47% was

achieved at 0.129m/s gas velocity while at the same LHSV achieved 63.27% at

0.086m/s gas flow rate. At low gas velocities, gravity (or buoyancy) force plays

an important role. The catalyst particles are not fully wetted at the liquid flow

rates used, which facilitates the access of the gas reactant to the pores of the

catalyst from the externally dry parts. In addition, the pressure gradient (P/Z)

increases significantly and so does the shear stress on the gas–liquid interface

(Al-Dahhan and Dudukovic, 1995). Therefore, liquid film thickness at a

constant liquid flow rate decreases, which leads to a better spreading of the

liquid film over the external packing area and across the reactor diameter.

Accordingly, the catalyst wetting efficiency and gas–liquid interfacial area

improved considerably, which is supported by the finding of Larachi et al.,

1992. Since the trickle-bed pellets get progressively entirely wetted by

increasing the gas superficial velocity. Figures (4.18) illustrates the effect of

LHSV and gas velocity on intermediate compounds, where acetic acid, formic


55

acid and maleic acid concentrations increase with increasing LHSV. This is due

to reduction in the time required to achieve complete oxidation. These results

are in agreement with Singh et al., 2004 and Eftaxias et al., 2005; 2006. In

addition, increasing gas flow rate provides sufficient quantity of oxygen for

competitive reactions of intermediate over catalyst active sites forming

increasing intermediate compounds .These results are in agreement with Miro

et al., 1999 and Eftaxias et al., 2001.

Figure (4.18) Intermediate concentration at different LHSV and gas velocities

[85ºC,0.3MPa,900PPm]

Figure (4.19) shows that high conversion at high temperature is achieved. As

clear from this figure phenol conversion of 88.59% was achieved at 140C

while at temperature 120,100 and 85C, phenol conversion were75.6%, 65%

and 43.86% respectively. The general behavior is, higher conversion is achieved

at higher temperature due to the fact that at higher temperature, kinetic constant

(rate constant) is favorably affected resulting in increasing in phenol

conversion, according to Arrhenius equation:


54

4.18

RT

EAK aexp

In addition at high temperatures in aqueous solutions; the form in which oxygen

participates in chemical reactions is complex. The necessary elevated

temperatures can accelerate the formation of oxygen radicals, O∙, which in turn

can react with water and oxygen to form peroxide, H2O2, and ozone, O3, so that

these four species O∙, O2, O3, and H2O2 are all capable of participating in the

phenol oxidation. In addition, at higher temperature the mass transfer coefficient

and kinetic constants are favorably affected resulting an increase in phenol

conversion. The result is in agreement with Lee et al., 2010.

Figure(4.19) Effect of temperature on conversion of phenol at different gas and liquid

velocities [0.6MPa, initial phenol concentration=900ppm]

Figure (4.20) illustrates the analysis of the liquid effluent, at low temperatures

showing the carboxylic acid (acetic acid, formic acid and maleic acid) that were

detected in high amount. These results are in agreement with Fortuny et al.,

1999 and Sanchez et al., 2007a.


55

Figure (4.20) Intermediate concentration at different temperature

[0.6Mpa,Ug=0.086m/s,900PPm]

Compared to temperature, reactor pressure has less influence on the phenol

conversion. It can be seen from Figure (4.21), that increasing reactor pressure

from 0.3MPa to 0.6MPa resulted in an increase in phenol conversion from 39%

to 43.86%, at 85ºC while increasing temperature from 100 to 120°C causes an

increase in phenol conversion from 65% to 75.6%. In general elevated levels of

pressure improve the solubility of oxygen. This in turn increases the mass

transfer driving force for gas to the inactively wetted catalyst surface, and

facilitates the rate of mass transport to the wetted catalyst surface. The elevated

pressure causes a decrease in liquid holdup. These results are in agreement with

the work of Fortuny et al., 1995; Singh et al., 2004; Suwanprasop, 2005 and

Eftaxias et al., 2005; 2006.


55

Figure (4.21) Effect of pressure on conversion of phenol at different temperature

[Ug=0.169m/s, initial phenol concentration=900ppm]

Figure (4.22) illustrates the intermediate compounds (i.e. acetic acid ,formic

acid and maleic acid) which achieved the highest concentration at reactor

pressure of 0.6MPa. This is due to the same reason mentioned previously. These

results are in agreement with the work of Fortuny et al., 1995; Singh et al.,

2004; Suwanprasop, 2005 and Eftaxias et al., 2005, 2006.

Figure (4.22) Intermediate concentration at different pressure

[58ºC,900PPm,Ug=0.169m/s]


55

Figure (4.24) shows the effect of initial concentration of phenol to be reduction

during catalytic wet oxidation run over 0.5Pt/ catalyst at ug= 0.169m/s

and pressure 0.3MPa. The conversion variation from high to the lowest value

when initial phenol concentration increased is marginal as illustrated in Figure

(4.24). It is clear that phenol conversion decreases from 88.59% to 88% only,

when initial phenol concentration increases from 900 to 5000 mg/l. At high

phenol concentration provides a high reaction rate, yet strong oxidation

limitation is present as shown in Figure (4.23). At higher phenol feed

concentration can be explained by limited amount of the catalyst needed to fully

convert phenol. This suggests that when the reaction is carried out with proper

oxygen and phenol loads, platinum catalyst deactivation can be avoided. This

was in agreement with findings of Masende, 2004.

Figure (4.23)Effect of initial phenol concentration on rate of reaction[140ºC]


55

Figure (4.24)Effect of initial phenol concentration on conversion of phenol at

[140ºC,Ug=0.169m/s, 0.6MPa]

Figure (4.25) profile of intermediate compounds, these figures show that when

using phenol feed concentrations 900 and 1500 mg/liter acetic acid, formic acid

and maleic acid are detected in low amounts, but these were detected in high

amounts when using inlet phenol concentration of 5000 mg/l. These results are

agree with Masende, 2004; Singh et al., 2004 and Eftaxias et al., 2005.

Figure (4.25)Intermediate concentration at different initial phenol concentration at

[100C, 0.3MPa and 0.169m/s]


59

4.4.3.2. Effect of different variables on the CWO of phenol

at saturation condition

As shown from Figure (4.26) the conversion of phenol at equilibrium pressure

is 92.61% while 75.6% at other operating conditions.

Figure (4.26) Effect of saturation condition on conversion of phenol at

[initial phenol concentration of 900PPm]

One probable explanation of this phenomenon is that, each pore of catalyst

which filled with liquid reactant could be considered as a micro equilibrium

stage between liquid reactant and O2 which enhance the mass transfer of O2 into

the liquid and more degradation of phenol occurred simutansly. In TBR the

catalyst pellet assumed to be internally filled up with liquid, is exposed partially

to the gas phase. The liquid within the pores of the pellet has more chance to

transfer to the gas phase from the dry pellet surface, which creates the capillary

driving force for the liquid diffusing from wet pellet surface in to pellet pores.

Thus, more reactant from liquid phase gets inside the catalyst pellet and reaches

the catalyst’s active site. When the reaction is limited by the liquid phase

reactant, such limitation is alleviated by better availability of the liquid reactants

at longer residence time. On the other hand the dry pellet surface facilitates the


50

gas reactant diffusing in to catalyst pores. The contact between O2 and liquid –

phase phenol over the catalyst’s active site is there for enhanced, which results

in higher phenol conversion. Figure (4.27) shows the effect of superficial gas

and liquid velocity and temperature at saturation condition.

Figu

re (4.27) Effect of gas flow rate on conversion of phenol at

[initial phenol concentration of 900PPm]

Phenol feed concentration is another critical reaction parameter. Phenol

conversion is plotted in Figure (4.28) as a function of inlet phenol

concentration, In the selected concentration range, it is shown that phenol

conversion decrease with increasing phenol concentration.

Figure (4.28) Conversion of phenol at different initial phenol concentration at

60

62

64

66

68

70

72

74

76

78

0 5 10 15 20 25 30

Con

ve

rsio

n o

f p

he

nol(

%)

LHSV( ^(− ))

900PPm

1500PPm

2500PPm

5000PPm


55

[initial phenol concentration of 900PPm,Ug=0.169m/s,111C]

Chapter Five Conclusions and Recommendations

58

5.1 Conclusions

From the present work, the following conclusions can be drawn:-

Hydrodynamics

The effect of the operating variables (i.e., gas and liquid superficial velocities,

operating pressure and temperature) on the hydrodynamic parameters(i.e.,

pressure drop, liquid holdup and axial dispersion) were studied with the

flowing observations:

1. Both gas and liquid superficial velocities have positive impact on

pressure drop and axial dispersion. When increasing gas and liquid

velocity from (0.0013-0.01m/s and 0.086-0.25m/s) respectively caused to

increasing of pressure drop and axial dispersion from (1.499-20.45Mpa)

and ((0.563-3.3277)* /s) respectively.

2. Operating temperature has negative impact on pressure drop, liquid

holdup and axial dispersion. Increasing temperature from (25-85ºC)

which caused to decrease of pressure drop (1.494-0.81Mpa),liquid holdup

(0.0657-0.05) and axial dispersion ((0.563-0.4)* /s)

3. Increasing of reactor pressure caused to increase in two phase pressure

drop. When increasing of reactor pressure from (0.1-0.6Mpa) caused to

increasing pressure drop (1.494-2.026Mpa).

4. Liquid holdup was decreased by increasing gas superficial velocity while

it increased with increasing liquid superficial velocity.

Kinetics

Studies on the CWO of phenol illustrate the potential of CWO as a treatment

technology for industrial wastewater. The catalytic wet oxidation in aqueous

solution involves a heterogeneous free radical mechanism. Radicals are


58

probably initiated on the catalyst surface and play a role in the oxidation route.

The following conclusions could be drawn out from the present investigation:

1.The highest phenol conversion (98 %) was achieved under equilibrium

condition (LHSV=4h-1, temperature=140°C,superficial gas velocity =0.169m/s,

and initial phenol concentration=900mg/l).

2. It was found that phenol conversion increases with increasing gas flow rate

3.Increasing reactor temperature from (100) to(140) enhanced phenol

conversion from(59.66%) to (83.88%).

4. It was found that conversion of phenol is independent of inlet phenol

concentration. When phenol concentration in solution was decreased from 5000

ppm to 900 ppm, an increase of (88% to 88.59) only is obtained for phenol

conversion.

5.It was found that phenol conversion decreases with increasing the liquid flow

rate.

6.It was found that phenol conversion at equilibrium condition is more than at

normal condition at the same superficial gas and liquid velocity, reactor

pressure and temperature.

7. It was found that the oxidation reaction of phenol is first order with respect to

phenol concentration and 0.69 and 0.49 order with respect to oxygen solubility

at saturation and other operating condition respectively, observed activation

energy equal to 24.6161and 29.299 kJ/mol at equilibrium pressure and other

operating condition respectively , and pre-exponential factor equal to (2.723 *

109

and 5.723* 10

10 )

L/ .h at equilibrium pressure and other operating

condition respectively.


58

5.2 Recommendation for further works

1.The data stated in this thesis is limited in terms of flow condition. More

results will help in a better understanding of flow dynamics of other flow

regimes (e.g., pulse flow regime).

2.Wetting efficiency measurement methods can be investigated since the

wetting efficiency distributions gives an extra dimension for flow modeling.

3.Using various sizes of packing and column diameters to determine the effect

they have on pressure drop, liquid holdup an axial dispersion for use in scale-up

calculation.

4.Using advanced analysis tool such as computational fluid dynamics (CFD) to

simulate the behavior of the system.

5.Developing a more detailed study of the axial profiles of (composition,

pressure, and temperature) along the reactor which would be helpful for design

improvement of the reactor and avoiding hot spots during operations of highly

exothermic.

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Appendix A Calibration Curve

1A-

Thermocouples Calibration

y = 0.9683x + 1.8676R² = 0.9999

0

50

100

150

200

250

0 50 100 150 200 250

Th

erm

om

ete

r R

ea

din

g o

C

Thermometer Reading oC

Control thermocouple

Column thermocouple

Figure (A.1) Calibration curve for thermocouple

Rotameter Calibration

y = 0.0083x + 0.0043R² = 0.999

0

0.05

0.1

0.15

0.2

0.25

0.3

0 5 10 15 20 25 30 35

Su

per

fici

al

Vel

oci

ty(m

/s)

Rotameter Reading

Figure (A.2) Calibration curve for rotameter


2A-

Pump Calibration

y = 0.0008x2 + 0.0003x + 0.002R² = 0.9881

0

0.005

0.01

0.015

0.02

0.025

0.03

0 1 2 3 4 5 6

Sup

erfi

cial

Vel

oci

ty(m

/s)

Pump Range

Figure (A.3) Calibration curve for pump range.

Pressure Transducer Calibration

Pressure transmitter was specially designed for differential pressure

measurement. When attached to a supply voltage of 12-24 VDC, the instrument

provides a 4 to 20 mA output. A properly calibrated transmitter’s output may be

calculated using the following formula or figure (A.4):

44.124267.31

spanrtransmitte

rangeendlowpressureknownoutputmA

The calibration steps include:

1. Connect the differential ends of the transmitter into a well known

pressure near the low end of the range and allow the readings to stabilize.

2. Adjust the ZERO pot to cause the ammeter to read 4 mA.

3. Connect the differential ends of the transmitter into a well known

pressure near the upper end of the range and allow the readings to

stabilize.

4. Adjust the SPAN pot to cause the ammeter to read 20 mA.


3A-

5. Repeat steps 2 through 5 until no further adjustments are necessary.

when this process is completed, any pressure within the selected range can be

known directly from the mA output of the transmitter. The transmitter output

should be near or equal to the calculated output given by the above equation.

y = 31.267x - 124.44R² = 0.9999

0

100

200

300

400

500

600

0 5 10 15 20 25

Pre

ssu

re (

mb

ar)

Current(mA)

Figure (A.4) Calibration curve for Transducer

HPLC Calibration

Figure (A.5): HPLC calibration curve for Phenol


4A-

.

Figure. (A.6): HPLC calibration curve for Formic acid

Figure. (A.7): HPLC calibration curve for Maleic acid .


5A-

Figure. (A.8): HPLC calibration curve for Acetic acid

UV Calibration

y = 0.0049x R² = 1

0

1

2

3

4

5

6

7

8

9

10

0 500 1000 1500 2000

Ab

sorb

ance

Phenol Concentration(g/l)

Figure. (A.9) RTD Calibration curve of UV spectrophotometer for the Dye


6A-

y = 12.237x R² = 0.9995

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035

Ab

sorb

ance

Phenol Concentration(g/l)

Figure(A.10) Calibration curve of UV spectrophotometer for the phenol

Appendix B Physico-Chemical Properties

1B-

I- Correlation of Transport Parameters

Diffusivity

Diffusion in Liquid Phase ,(Willke and Chang correlation 1955):-

6.0

5.0

,8

, ~10*4.7AB

Bwt

LABV

TMD

B-1

were A =Ph , B=

Effective Diffusivity :-

B-2

pAB

ei

DD

Mass Transfer Coefficients (Wu et al., 2009)

B-3a

B-3b

Henry Law constant(Wu et al., 2003)

B-4

Kinetic Parameters.

phenol conversion (XPh ) (Sanchez et al,.2007a)

B-5

Rate of reaction(Zhang and Savage.,1998)


2B-

B-6

II- physical Properties.

Density

o Gases

RT

PM wtG B-7

o Liquid ( Perry et al 1997; Reid, 1977)

Water 018.1662

2

TT

DCTBTA

C

L B-8

A=57

B=33.37*10-3

C=-0.4*10-4

D=-0.8381*103

TableB.,3 . Densities of water

T(C) (kg/m3)

25 995.958

85 968.376

100 958.92

120 944.6935

140 928.55


3B-

Surface Tension (Reid, 1977)

3101 B

rL TA B-9

Water A=129.7, B=1.02

Viscosity

o Liquid (Reid, 1977 )

3

3210exp

T

D

T

C

T

BAL B-10

A B*10-3 C*10-6 D*10-9

Water -2.9868 -0.389 1.0377 0

TableB.,4. Viscosity of Liquid

o Gases(Reid, 1977;Perry et al,1997 )

At atmospheric pressure "Low Pressure"

3

5.1

101

DT

CTG B-11

C=5.465*10-6 , D=50.28*10-4

T(c) l(Kg/m.s)*10^3

25 0.8999

85 0.3357

100 0.2824

120 0.2315357

140 0.195466


4B-

For High Pressure (Reid et al, 1977)

58.0*3*2**

)1(

61.096.055.01 TatmG

G

B-12

oGb *

ob =64.5 cm3/mole for air

o

kTT

*

, k

o =78.6

Appendix C Tables of Results

1C-

A-Hydrodynamic Results

Table:( C.1) Experimental results for Pressure Drop

Superficial

Gas

Velocity

m/s

Superficial

Liquid

Velocity m/s

At 25 oC Bed

temperature

At 50oC Bed

temperature

At 85oC Bed

temperature

0.1

MPa

0.3

MPa

0.6

MPa

0.1

MPa

0.3

MPa

0.6

MPa

0.1

Mpa

0.3

MPa

0.6

MPa

0.086 0.0013 1.494 1.801 2.026 1.159 1.397 1.57 0.81 0.83 1.105

0.129 0.0013 1.859 2.241 2.522 1.443 1.739 1.95 1.01 1.04 1.376

0.173 0.0013 2.179 2.626 2.955 1.691 2.038 2.29 1.18 1.22 1.612

0.25 0.0013 2.658 3.204 3.605 2.063 2.486 2.79 1.45 1.49 1.968

0.086 0.0025 2.873 3.463 3.896 2.229 2.687 3.02 1.56 1.60 2.125

0.129 0.0025 3.576 4.311 4.850 2.775 3.345 3.76 1.95 2.00 2.646

0.173 0.0025 4.191 5.051 5.683 3.252 3.920 4.41 2.28 2.34 3.101

0.25 0.0025 5.11 6.162 6.933 3.967 4.782 5.38 2.79 2.86 3.785

0.086 0.0045 5.172 6.234 7.014 4.013 4.837 5.44 2.82 2.89 3.825

0.129 0.0045 6.438 7.760 8.730 4.996 6.022 6.77 3.51 3.60 4.763

0.173 0.0045 7.543 9.093 10.23 5.854 7.056 7.93 4.11 4.22 5.583

0.25 0.0045 9.203 11.09 12.48 7.141 8.608 9.68 5.02 5.16 6.813

0.086 0.007 8.045 9.697 10.91 6.243 7.525 8.46 4.38 4.49 5.950

0.129 0.007 10.01 12.07 13.58 7.771 9.367 10.5 5.46 5.60 7.410

0.173 0.007 11.73 14.14 15.91 9.106 10.97 12.3 6.40 6.57 8.685

0.25 0.007 14.31 17.25 19.41 11.10 13.39 15.0 7.81 8.03 10.59

0.086 0.008 9.195 11.08 12.46 7.135 8.6 9.67 5.01 5.14 6.800

0.129 0.008 11.44 13.79 15.52 8.881 10.70 12 6.24 6.40 8.468

0.173 0.008 13.41 16.16 18.18 10.40 12.54 14.1 7.31 7.51 9.925

0.25 0.008 16.36 19.72 22.18 12.69 15.3 17.2 8.93 9.17 12.11

0.086 0.009 10.34 12.46 14.02 8.027 9.675 10.8 5.64 5.78 7.650

0.129 0.009 12.87 15.52 17.46 9.992 12.04 13.5 7.02 7.21 9.527

0.173 0.009 15.08 18.18 20.46 11.70 14.11 15.8 8.23 8.45 11.16

0.25 0.009 18.40 22.18 24.96 14.28 17.21 19.3 10.0 10.3 13.62

0.086 0.01 11.49 13.85 15.58 8.919 10.75 12.0 6.26 6.42 8.500

0.129 0.01 14.30 17.24 19.40 11.10 13.38 15 7.80 8.01 10.58

0.173 0.01 16.76 20.20 22.73 13.00 15.68 17.6 9.14 9.39 12.40

0.25 0.01 20.45 24.65 27.73 15.87 19.12 21.5 11.1 11.4 15.14


2C-

Table:( C.2) Experimental results for Liquid Holdup

Liquid holdup(-) Superficial

Gas Velocity m/s

Superficial Liquid

Velocity m/s

At 25 o

C Bed temperature

At 50 o

C Bed temperature

At 85 o

C Bed temperature

0.086 0.0013 0.065718961 0.059397 0.050442

0.129 0.0013 0.065787 0.059419 0.044484

0.173 0.0013 0.060066 0.054252 0.040615

0.25 0.0013 0.053588 0.0484 0.036235

0.086 0.0025 0.105499 0.095287 0.071429

0.129 0.0025 0.093038 0.084032 0.062992

0.173 0.0025 0.084947 0.076725 0.057514

0.25 0.0025 0.075785 0.068449 0.051311

0.086 0.0045 0.14406 0.130115 0.097652

0.129 0.0045 0.127044 0.114747 0.086118

0.173 0.0045 0.115996 0.104768 0.078629

0.25 0.0045 0.103485 0.093468 0.070148

0.086 0.007 0.182072 0.164448 0.123528

0.129 0.007 0.160567 0.145024 0.108937

0.173 0.007 0.146603 0.132412 0.099464

0.25 0.007 0.130791 0.11813 0.088736

0.086 0.008 0.195425 0.176508 0.132622

0.129 0.008 0.172342 0.155659 0.116958

0.173 0.008 0.157355 0.142123 0.106787

0.25 0.008 0.140382 0.126793 0.095269

0.086 0.009 0.208013 0.187877 0.141198

0.129 0.009 0.183443 0.165686 0.124521

0.173 0.009 0.167491 0.151278 0.113692

0.25 0.009 0.149425 0.134961 0.101429

0.086 0.01 0.219959 0.198667 0.149339

0.129 0.01 0.193978 0.175201 0.1317

0.173 0.01 0.177109 0.159965 0.120247

0.25 0.01 0.158006 0.142712 0.107277


3C-

Table:( C.3) Experimental results for Axial Dispersion

(Axial Dispersion( /s))*

Superficial

Gas Velocity

m/s

Superficial

Liquid

Velocity m/s

At 25 o

C Bed

temperature

At 50 o

C Bed

temperature

At 85 o

C Bed

temperature

0.086 0.0013 0.563902 0.432363 0.404777

0.129 0.0013 0.565843 0.536015 0.501815

0.173 0.0013 0.656397 0.626223 0.586267

0.25 0.0013 0.79783 0.761154 0.712589

0.086 0.0025 0.716282 0.683355 0.639754

0.129 0.0025 0.887999 0.847178 0.793124

0.173 0.0025 1.037443 0.989752 0.926602

0.25 0.0025 1.260979 1.203012 1.126256

0.086 0.0045 1.080873 1.031186 0.965392

0.129 0.0045 1.339995 1.278395 1.196829

0.173 0.0045 1.565507 1.493541 1.398247

0.25 0.0045 1.902824 1.815352 1.699526

0.086 0.007 1.472633 1.404937 1.315296

0.129 0.007 1.825673 1.741747 1.630617

0.173 0.007 2.132921 2.034871 1.905039

0.25 0.007 2.592499 2.473322 2.315515

0.086 0.008 1.616921 1.542592 1.444169

0.129 0.008 2.004552 1.912403 1.790385

0.173 0.008 2.341905 2.234248 2.091694

0.25 0.008 2.846512 2.715658 2.542389

0.086 0.009 1.755883 1.675166 1.568284

0.129 0.009 2.176828 2.076759 1.944255

0.173 0.009 2.543173 2.426264 2.27146

0.25 0.009 3.091147 2.949048 2.760888

0.086 0.01 1.890279 1.803383 1.688321

0.129 0.01 2.343443 2.235715 2.093068

0.173 0.01 2.737828 2.611971 2.445317

0.25 0.01 3.327744 3.174769 2.972207


4C-

B-Kinetic results

Table:( C.4) Experimental results for Phenol conversions and Intermediate

Intermediate conc.(ppm) TEMP=85C,0.1MPa

Formic acid Acetic acid Maleic acid Conversion

(%)

Superficial

gas Velocity

m/s

Superficial

liquid

Velocity m/s

At 900PPm

1.01 1.85 - 25 0.086 0.0013

1.25 2.21 - 23 0.086 0.0025

1.32 2.33 - 21 0.086 0.0045

1.35 2.36 - 18.9 0.086 0.007

1.39 2.42 - 17 0.086 0.0085

1.02 1.95 - 30.89 0.169 0.0013

1.26 2.31 - 28 0.169 0.0025

1.33 2.43 - 27.4 0.169 0.0045

1.36 2.46 - 26.4 0.169 0.007

1.4 2.52 - 22 0.169 0.0085

At 1500PPm

1.03 2.05 - 24.236 0.086 0.0013

1.27 2.41 - 22.246 0.086 0.0025

1.34 2.53 - 20.17 0.086 0.0045

1.37 2.56 - 18.07 0.086 0.007

1.41 2.62 - 16.17 0.086 0.0085

1.04 2.15 - 30.1 0.169 0.0013

1.28 2.51 - 27.135 0.169 0.0025

1.35 2.63 - 26.535 0.169 0.0045

1.38 2.66 - 25.535 0.169 0.007

1.42 2.72 - 21.135 0.169 0.0085

At 2500PPm

1.05 2.25 - 23.472 0.086 0.0013

1.29 2.61 - 21.492 0.086 0.0025

1.36 2.73 - 19.34 0.086 0.0045

1.39 2.76 - 17.24 0.086 0.007

1.43 2.82 - 15.34 0.086 0.0085

1.06 2.35 - 29.31 0.169 0.0013

1.3 2.71 - 26.27 0.169 0.0025

1.37 2.83 - 25.67 0.169 0.0045

1.4 2.86 - 24.67 0.169 0.007

1.44 2.92 - 20.27 0.169 0.0085

At 5000PPm

1.07 2.45 - 22.708 0.086 0.0013

1.31 2.81 - 20.738 0.086 0.0025

1.38 2.93 - 18.51 0.086 0.0045

1.41 2.96 - 16.41 0.086 0.007

1.45 3.02 - 14.51 0.086 0.0085

1.08 2.55 - 28.52 0.169 0.0013

1.32 2.91 - 25.405 0.169 0.0025

1.39 3.03 - 24.805 0.169 0.0045

1.42 3.06 - 23.805 0.169 0.007

1.46 3.12 - 19.405 0.169 0.0085


5C-

Table:( C.5)Experimental results for Phenol conversions and Intermediate


Formic acid Acetic acid Maleic acid

Conversion

(%)

Superficial

gas Velocity

m/s

Superficial liquid

Velocity m/s

At 900PPm

1.09 2.05 - 33.5 0.086 0.0013

1.33 2.41 - 26.3

0.086

0.0025

1.4 2.53 - 24 0.086

0.0045

1.43 2.56 - 22.95 0.086 0.007

1.47 2.62 - 20 0.086 0.0085

1.1 2.15 - 39 0.169 0.0013

1.34 2.51 - 34 0.169 0.0025

1.41 2.63 - 30.45 0.169 0.0045

1.44 2.66 - 28 0.169 0.007

1.48 2.72 - 24 0.169

0.0085

At 1500PPm

1.11 2.25 - 32.736 0.086 0.0013

1.35 2.61 - 25.546 0.086 0.0025

1.42 2.73 - 23.17 0.086 0.0045

1.45 2.76 - 22.12 0.086 0.007

1.49 2.82 - 19.17 0.086 0.0085

1.12 2.35 - 38.21 0.169 0.0013

1.36 2.71 - 33.135 0.169 0.0025

1.43 2.83 - 29.585 0.169 0.0045

1.46 2.86 - 27.135 0.169 0.007

1.5 2.92 - 23.135 0.169 0.0085

At 2500PPm

1.13 2.45 - 31.972 0.086 0.0013

1.37 2.81 - 24.792 0.086 0.0025

1.44 2.93 - 22.34 0.086 0.0045

1.47 2.96 - 21.29 0.086 0.007

1.51 3.02 - 18.34 0.086 0.0085

1.14 2.55 - 37.42 0.169 0.0013

1.38 2.91 - 32.27 0.169 0.0025

1.45 3.03 - 28.72 0.169 0.0045

1.48 3.06 - 26.27 0.169 0.007

1.52 3.12 - 22.27 0.169 0.0085

At 5000PPm

1.15 2.65 - 31.208 0.086 0.0013

1.39 3.01 - 24.038 0.086 0.0025

1.46 3.13 - 21.51 0.086 0.0045

1.49 3.16 - 20.46 0.086 0.007

1.53 3.22 - 17.51 0.086 0.0085

1.16 2.75 - 36.63 0.169 0.0013

1.4 3.11 - 31.405 0.169 0.0025

1.47 3.23 - 27.855 0.169 0.0045

1.5 3.26 - 25.405 0.169 0.007

1.54 3.32 - 21.405 0.169 0.0085


6C-




Conversion

(%)

Superficial

gas Velocity

m/s

Superficial liquid

Velocity m/s

At 900PPm

2.39 2.55 0.12 38.91 0.086 0.0013

2.63 2.91 0.127 35 0.086 0.0025

2.7 3.03 0.133 28 0.086 0.0045

2.73 3.06 0.18 24 0.086 0.007

2.77 3.12 0.243 21 0.086 0.0085

2.4 2.65 0.19 43.86 0.169 0.0013

2.64 3.01 0.197 40.7 0.169 0.0025

2.71 3.13 0.203 34.4 0.169 0.0045

2.74 3.16 0.25 31.5 0.169 0.007

2.78 3.22 0.313 26 0.169 0.0085

At 1500PPm

2.41 2.75 0.26 38.146 0.086 0.0013

2.65 3.11 0.267 34.246 0.086 0.0025

2.72 3.23 0.273 27.17 0.086 0.0045

2.75 3.26 0.32 23.17 0.086 0.007

2.79 3.32 0.383 20.17 0.086 0.0085

2.42 2.85 0.33 43.07 0.169 0.0013

2.66 3.21 0.337 39.835 0.169 0.0025

2.73 3.33 0.343 33.535 0.169 0.0045

2.76 3.36 0.39 30.635 0.169 0.007

2.8 3.42 0.453 25.135 0.169 0.0085

At 2500PPm

2.43 2.95 0.4 37.382 0.086 0.0013

2.67 3.31 0.407 33.492 0.086 0.0025

2.74 3.43 0.413 26.34 0.086 0.0045

2.77 3.46 0.46 22.34 0.086 0.007

2.81 3.52 0.523 19.34 0.086 0.0085

2.44 3.05 0.47 42.28 0.169 0.0013

2.68 3.41 0.477 38.97 0.169 0.0025

2.75 3.53 0.483 32.67 0.169 0.0045

2.78 3.56 0.53 29.77 0.169 0.007

2.82 3.62 0.593 24.27 0.169 0.0085

At 5000PPm

2.45 3.15 0.54 36.618 0.086 0.0013

2.69 3.51 0.547 32.738 0.086 0.0025

2.76 3.63 0.553 25.51 0.086 0.0045

2.79 3.66 0.6 21.51 0.086 0.007

2.83 3.72 0.663 18.51 0.086 0.0085

2.46 3.25 0.61 41.49 0.169 0.0013

2.7 3.61 0.617 38.105 0.169 0.0025

2.77 3.73 0.623 31.805 0.169 0.0045

2.8 3.76 0.67 28.905 0.169 0.007

2.84 3.82 0.733 23.405 0.169 0.0085


7C-




Conversion

(%)

Superficial

gas Velocity

m/s

Superficial liquid

Velocity m/s

At 900PPm

0.49 1.65 0.09 50.38 0.086 0.0013

0.73 2.01 0.097 48 0.086 0.0025

0.8 2.13 0.103 39 0.086 0.0045

0.83 2.16 0.15 36 0.086 0.007

0.87 2.22 0.213 30 0.086 0.0085

0.5 1.75 0.14 55.18 0.169 0.0013

0.74 2.11 0.147 52.6 0.169 0.0025

0.81 2.23 0.153 45.4 0.169 0.0045

0.84 2.26 0.2 43.5 0.169 0.007

0.88 2.32 0.263 35 0.169

0.0085

At 1500PPm

0.51 1.85 0.19 49.616 0.086 0.0013

0.75 2.21 0.197 47.246 0.086 0.0025

0.82 2.33 0.203 38.17 0.086 0.0045

0.85 2.36 0.25 35.17 0.086 0.007

0.89 2.42 0.313 29.17 0.086 0.0085

0.52 1.95 0.24 54.39 0.169 0.0013

0.76 2.31 0.247 51.735 0.169 0.0025

0.83 2.43 0.253 44.535 0.169 0.0045

0.86 2.46 0.3 42.635 0.169 0.007

0.9 2.52 0.363 34.135 0.169 0.0085

At 2500PPm

0.53 2.05 0.29 48.852 0.086 0.0013

0.77 2.41 0.297 46.492 0.086 0.0025

0.84 2.53 0.303 37.34 0.086 0.0045

0.87 2.56 0.35 34.34 0.086 0.007

0.91 2.62 0.413 28.34 0.086 0.0085

0.54 2.15 0.34 53.6 0.169 0.0013

0.78 2.51 0.347 50.87 0.169 0.0025

0.85 2.63 0.353 43.67 0.169 0.0045

0.88 2.66 0.4 41.77 0.169 0.007

0.92 2.72 0.463 33.27 0.169 0.0085

At 5000PPm

0.55 2.25 0.39 48.088 0.086 0.0013

0.79 2.61 0.397 45.738 0.086 0.0025

0.86 2.73 0.403 36.51 0.086 0.0045

0.89 2.76 0.45 33.51 0.086 0.007

0.93 2.82 0.513 27.51 0.086 0.0085

0.56 2.35 0.44 52.81 0.169 0.0013

0.8 2.71 0.447 50.005 0.169 0.0025

0.87 2.83 0.453 42.805 0.169 0.0045

0.9 2.86 0.5 40.905 0.169 0.007

0.94 2.92 0.563 32.405 0.169 0.0085


8C-




Conversion

(%)

Superficial

gas Velocity

m/s

Superficial liquid

Velocity m/s

At 900PPm

2.09 2.5 0.1 59.66 0.086 0.0013

2.33 2.86 0.107 56

0.086

0.0025

2.4 2.98 0.113 53 0.086 0.0045

2.43 3.01 0.16 48 0.086 0.007

2.47 3.07 0.223 42 0.086 0.0085

2.1 2.6 0.17 65 0.169 0.0013

2.34 2.96 0.177 62 0.169 0.0025

2.41 3.08 0.183 56.4 0.169 0.0045

2.44 3.11 0.23 51.7 0.169 0.007

2.48 3.17 0.293 47 0.169

0.0085

At 1500PPm

2.11 2.7 0.24 59.11 0.086 0.0013

2.35 3.06 0.247 55.24 0.086 0.0025

2.42 3.18 0.253 52.17 0.086 0.0045

2.45 3.21 0.3 47.17 0.086 0.007

2.49 3.27 0.363 41.17 0.086 0.0085

2.12 2.8 0.31 63.06 0.169 0.0013

2.36 3.16 0.317 62 0.169 0.0025

2.43 3.28 0.323 58.57 0.169 0.0045

2.46 3.31 0.37 54.67 0.169 0.007

2.5 3.37 0.433 46.17 0.169 0.0085

At 2500PPm

2.13 2.9 0.38 58.56 0.086 0.0013

2.37 3.26 0.387 54.48 0.086 0.0025

2.44 3.38 0.393 51.34 0.086 0.0045

2.47 3.41 0.44 46.34 0.086 0.007

2.51 3.47 0.503 40.34 0.086 0.0085

2.14 3 0.45 62.51 0.169 0.0013

2.38 3.36 0.457 60.18 0.169 0.0025

2.45 3.48 0.463 57.74 0.169 0.0045

2.48 3.51 0.51 53.84 0.169 0.007

2.52 3.57 0.573 45.34 0.169 0.0085

At 5000PPm

2.15 3.1 0.52 58.01 0.086 0.0013

2.39 3.46 0.527 53.72 0.086 0.0025

2.46 3.58 0.533 50.51 0.086 0.0045

2.49 3.61 0.58 45.51 0.086 0.007

2.53 3.67 0.643 39.51 0.086 0.0085

2.16 3.2 0.59 61.96 0.169 0.0013

2.4 3.56 0.597 59.42 0.169 0.0025

2.47 3.68 0.603 56.91 0.169 0.0045

2.5 3.71 0.65 53.01 0.169 0.007

2.54 3.77 0.713 44.51 0.169 0.0085


9C-




Conversion

(%)

Superficial

gas Velocity

m/s

Superficial liquid

Velocity m/s

At 900PPm

0.17 1.1 0.084 63.27 0.086 0.0013

0.41

1.46 0.091 60.88

0.086

0.0025

0.48 1.58 0.097 55 0.086 0.0045

0.51 1.61 0.144 53 0.086 0.007

0.55 1.67 0.207 49.66 0.086 0.0085

0.18 1.2 0.134 67.47 0.169 0.0013

0.42 1.56 0.141 63.58 0.169 0.0025

0.49 1.68 0.147 61.4 0.169 0.0045

0.52 1.71 0.194 54.33 0.169 0.007

0.56 1.77 0.257 52.33

0.169 0.0085

At 1500PPm

0.19 1.3 0.184 62.506 0.086 0.0013

0.43 1.66 0.191 60.126 0.086 0.0025

0.5 1.78 0.197 54.17 0.086 0.0045

0.53 1.81 0.244 52.17 0.086 0.007

0.57 1.87 0.307 48.83 0.086 0.0085

0.2 1.4 0.234 66.68 0.169 0.0013

0.44 1.76 0.241 62.715 0.169 0.0025

0.51 1.88 0.247 60.535 0.169 0.0045

0.54 1.91 0.294 56 0.169 0.007

0.58 1.97 0.357 51.465 0.169 0.0085

At 2500PPm

0.21 1.5 0.284 61.742 0.086 0.0013

0.45 1.86 0.291 59.372 0.086 0.0025

0.52 1.98 0.297 53.34 0.086 0.0045

0.55 2.01 0.344 51.34 0.086 0.007

0.59 2.07 0.407 48 0.086 0.0085

0.22 1.6 0.334 65.89 0.169 0.0013

0.46 1.96 0.341 61.85 0.169 0.0025

0.53 2.08 0.347 59.67 0.169 0.0045

0.56 2.11 0.394 54.94 0.169 0.007

0.6 2.17 0.457 50.6 0.169 0.0085

At 5000PPm

0.23 1.7 0.384 60.978 0.086 0.0013

0.47 2.06 0.391 58.618 0.086 0.0025

0.54 2.18 0.397 52.51 0.086 0.0045

0.57 2.21 0.444 50.51 0.086 0.007

0.61 2.27 0.507 47.17 0.086 0.0085

0.24 1.8 0.434 65.1 0.169 0.0013

0.48 2.16 0.441 60.985 0.169 0.0025

0.55 2.28 0.447 58.805 0.169 0.0045

0.58 2.31 0.494 55.07 0.169 0.007

0.62 2.37 0.557 53.07 0.169 0.0085


11C-




Conversion

(%)

Superficial

gas Velocity

m/s

Superficial liquid

Velocity m/s

At 900PPm

0.38 1.5 0.099 67.27 0.086 0.0013

0.62 1.86 0.106 64

0.086

0.0025

0.69 1.98 0.112 57 0.086 0.0045

0.72 2.01 0.159 55 0.086 0.007

0.76 2.07 0.222 51.66 0.086 0.0085

0.39 1.6 0.149 75.6 0.169 0.0013

0.63 1.96 0.156 66.33 0.169 0.0025

0.7 2.08 0.162 61.93 0.169 0.0045

0.73 2.11 0.209 57.33 0.169 0.007

0.77 2.17 0.272 55.33

0.169 0.0085

At 1500PPm

0.4 1.7 0.199 66.506 0.086 0.0013

0.64 2.06 0.206 63.246 0.086 0.0025

0.71 2.18 0.212 56.17 0.086 0.0045

0.74 2.21 0.259 54.17 0.086 0.007

0.78 2.27 0.322 50.83 0.086 0.0085

0.41 1.8 0.249 75.4 0.169 0.0013

0.65 2.16 0.256 66.13 0.169 0.0025

0.72 2.28 0.262 61.73 0.169 0.0045

0.75 2.31 0.309 57.13 0.169 0.007

0.79 2.37 0.372 55.13 0.169 0.0085

At 2500PPm

0.42 1.9 0.299 65.742 0.086 0.0013

0.66 2.26 0.306 62.492 0.086 0.0025

0.73 2.38 0.312 55.34 0.086 0.0045

0.76 2.41 0.359 53.34 0.086 0.007

0.8 2.47 0.422 50 0.086 0.0085

0.43 2 0.349 75.2 0.169 0.0013

0.67 2.36 0.356 65.93 0.169 0.0025

0.74 2.48 0.362 61.53 0.169 0.0045

0.77 2.51 0.409 56.93 0.169 0.007

0.81 2.57 0.472 54.93 0.169 0.0085

At 5000PPm

0.44 2.1 0.399 64.978 0.086 0.0013

0.68 2.46 0.406 61.738 0.086 0.0025

0.75 2.58 0.412 54.51 0.086 0.0045

0.78 2.61 0.459 52.51 0.086 0.007

0.82 2.67 0.522 49.17 0.086 0.0085

0.45 2.2 0.449 75 0.169 0.0013

0.69 2.56 0.456 65.73 0.169 0.0025

0.76 2.68 0.462 61.33 0.169 0.0045

0.79 2.71 0.509 56.73 0.169 0.007

0.83 2.77 0.572 54.73 0.169 0.0085


11C-




Conversion

(%)

Superficial

gas Velocity

m/s

Superficial liquid

Velocity m/s

At 900PPm

0.23 1.28 0.039 83.88 0.086 0.0013

0.47

1.64 0.046 75.7

0.086

0.0025

0.54 1.76 0.052 69 0.086 0.0045

0.57 1.79 0.099 62 0.086 0.007

0.61 1.85 0.162 55 0.086 0.0085

0.24 1.38 0.089 88.59 0.169 0.0013

0.48 1.74 0.096 79.8 0.169 0.0025

0.55 1.86 0.102 77.5 0.169 0.0045

0.58 1.89 0.149 75.1 0.169 0.007

0.62 1.95 0.212 63

0.169 0.0085

At 1500PPm

0.25 1.48 0.139 86.77 0.086 0.0013

0.49 1.84 0.146 77.83 0.086 0.0025

0.56 1.96 0.152 71.17 0.086 0.0045

0.59 1.99 0.199 64.17 0.086 0.007

0.63 2.05 0.262 57.17 0.086 0.0085

0.26 1.58 0.189 88.37 0.169 0.0013

0.5 1.94 0.196 79.03 0.169 0.0025

0.57 2.06 0.202 76.67 0.169 0.0045

0.6 2.09 0.249 74.27 0.169 0.007

0.64 2.15 0.312 62.17 0.169 0.0085

At 2500PPm

0.27 1.68 0.239 86.57 0.086 0.0013

0.51 2.04 0.246 77.33 0.086 0.0025

0.58 2.16 0.252 70.34 0.086 0.0045

0.61 2.19 0.299 63.34 0.086 0.007

0.65 2.25 0.362 56.34 0.086 0.0085

0.28 1.78 0.289 88.17 0.169 0.0013

0.52 2.14 0.296 78.53 0.169 0.0025

0.59 2.26 0.302 75.84 0.169 0.0045

0.62 2.29 0.349 73.44 0.169 0.007

0.66 2.35 0.412 61.34 0.169 0.0085

At 5000PPm

0.29 1.88 0.339 86.4 0.086 0.0013

0.53 2.24 0.346 76.46 0.086 0.0025

0.6 2.36 0.352 69.51 0.086 0.0045

0.63 2.39 0.399 62.51 0.086 0.007

0.67 2.45 0.462 55.51 0.086 0.0085

0.3 1.98 0.389 88 0.169 0.0013

0.54 2.34 0.396 77.66 0.169 0.0025

0.61 2.46 0.402 75.01 0.169 0.0045

0.64 2.49 0.449 72.61 0.169 0.007

0.68 2.55 0.512 60.51

0.169 0.0085


12C-


Intermediate conc.(ppm)

TEMP=100C,equilibrium pressure


(%)

Superficial

gas Velocity

m/s

Superficial

liquid

Velocity m/s

At 900PPm

2.77 3.07 0.43 74.3 0.086 0.0013

3.01 3.43 0.437 73.3

0.086

0.0025

3.08 3.55 0.443 70 0.086 0.0045

3.11 3.58 0.49 66 0.086 0.007

3.15 3.64 0.553 60 0.086 0.0085

2.78 3.17 0.5 76.07 0.169 0.0013

3.02 3.53 0.507 75.9 0.169 0.0025

3.09 3.65 0.513 72.6 0.169 0.0045

3.12 3.68 0.56 68.6 0.169 0.007

3.16 3.74 0.623 62.6

0.169 0.0085

2.79 3.27 0.57 74.12 0.086 0.0013

3.03 3.63 0.577 73.02 0.086 0.0025

3.1 3.75 0.583 69.72 0.086 0.0045

3.13 3.78 0.63 65.72 0.086 0.007

3.17 3.84 0.693 59.72 0.086 0.0085

2.8 3.37 0.64 75.89 0.169 0.0013

3.04 3.73 0.647 75.62 0.169 0.0025

3.11 3.85 0.653 72.32 0.169 0.0045

3.14 3.88 0.7 68.32 0.169 0.007

3.18 3.94 0.763 62.32 0.169 0.0085

2.81 3.47 0.71 73.94 0.086 0.0013

3.05 3.83 0.717 72.74 0.086 0.0025

3.12 3.95 0.723 69.44 0.086 0.0045

3.15 3.98 0.77 65.44 0.086 0.007

3.19 4.04 0.833 59.44 0.086 0.0085

2.82 3.57 0.78 75.71 0.169 0.0013

3.06 3.93 0.787 75.34 0.169 0.0025

3.13 4.05 0.793 72.04 0.169 0.0045

3.16 4.08 0.84 68.04 0.169 0.007

3.2 4.14 0.903 62.04 0.169 0.0085

2.83 3.67 0.85 73.76 0.086 0.0013

3.07 4.03 0.857 72.46 0.086 0.0025

3.14 4.15 0.863 69.16 0.086 0.0045

3.17 4.18 0.91 65.16 0.086 0.007

3.21 4.24 0.973 59.16 0.086 0.0085

2.84 3.77 0.92 75.53 0.169 0.0013

3.08 4.13 0.927 75.06 0.169 0.0025

3.15 4.25 0.933 71.76 0.169 0.0045

3.18 4.28 0.98 67.76 0.169 0.007

3.22 4.34 1.043 61.76 0.169 0.0085


13C-





(%)

Superficial

gas Velocity

m/s

Superficial

liquid

Velocity m/s

At 900PPm

1.06 2.06 0.419 89.54 0.086 0.0013

1.3 2.42 0.426 87.8

0.086

0.0025

1.37 2.54 0.432 80 0.086 0.0045

1.4 2.57 0.479 76.8 0.086 0.007

1.44 2.63 0.542 71.7 0.086 0.0085

1.07 2.16 0.469 93.15 0.169 0.0013

1.31 2.52 0.476 91.79 0.169 0.0025

1.38 2.64 0.482 87 0.169 0.0045

1.41 2.67 0.529 85 0.169 0.007

1.45 2.73 0.592 81

0.169 0.0085

At 1500PPm

1.08 2.26 0.519 89.35 0.086 0.0013

1.32 2.62 0.526 87.15 0.086 0.0025

1.39 2.74 0.532 79.45 0.086 0.0045

1.42 2.77 0.579 76.25 0.086 0.007

1.46 2.83 0.642 71.15 0.086 0.0085

1.09 2.36 0.569 92.96 0.169 0.0013

1.33 2.72 0.576 91.14 0.169 0.0025

1.4 2.84 0.582 86.45 0.169 0.0045

1.43 2.87 0.629 84.45 0.169 0.007

1.47 2.93 0.692 80.45 0.169 0.0085

At 2500PPm

1.1 2.46 0.619 89.16 0.086 0.0013

1.34 2.82 0.626 86.5 0.086 0.0025

1.41 2.94 0.632 78.9 0.086 0.0045

1.44 2.97 0.679 75.7 0.086 0.007

1.48 3.03 0.742 70.6 0.086 0.0085

1.11 2.56 0.669 92.77 0.169 0.0013

1.35 2.92 0.676 90.49 0.169 0.0025

1.42 3.04 0.682 85.9 0.169 0.0045

1.45 3.07 0.729 83.9 0.169 0.007

1.49 3.13 0.792 79.9 0.169 0.0085

At 5000PPm

1.12 2.66 0.719 88.97 0.086 0.0013

1.36 3.02 0.726 85.85 0.086 0.0025

1.43 3.14 0.732 78.35 0.086 0.0045

1.46 3.17 0.779 75.15 0.086 0.007

1.5 3.23 0.842 70.05 0.086 0.0085

1.13 2.76 0.769 92.58 0.169 0.0013

1.37 3.12 0.776 89.84 0.169 0.0025

1.44 3.24 0.782 85.35 0.169 0.0045

1.47 3.27 0.829 83.35 0.169 0.007

1.51 3.33 0.892 79.35 0.169 0.0085


14C-





(%)

Superficial

gas Velocity

m/s

Superficial

liquid

Velocity m/s

At 900PPm

0.91 1.86 0.359 97.99 0.086 0.0013

1.15

2.22 0.366 94.4

0.086

0.0025

1.22 2.34 0.372 87 0.086 0.0045

1.25 2.37 0.419 83 0.086 0.007

1.29 2.43 0.482 81 0.086 0.0085

0.92 1.96 0.409 98.009 0.169 0.0013

1.16 2.32 0.416 94.8 0.169 0.0025

1.23 2.44 0.422 87.3 0.169 0.0045

1.26 2.47 0.469 83.3 0.169 0.007

1.3 2.53 0.532 81.3

0.169 0.0085

At 1500PPm

0.93 2.06 0.459 97.98 0.086 0.0013

1.17 2.42 0.466 94.29 0.086 0.0025

1.24 2.54 0.472 86.89 0.086 0.0045

1.27 2.57 0.519 82.89 0.086 0.007

1.31 2.63 0.582 80.89 0.086 0.0085

0.94 2.16 0.509 97.999 0.169 0.0013

1.18 2.52 0.516 94.69 0.169 0.0025

1.25 2.64 0.522 87.19 0.169 0.0045

1.28 2.67 0.569 83.19 0.169 0.007

1.32 2.73 0.632 81.19 0.169 0.0085

At 2500PPm

0.95 2.26 0.559 97.97 0.086 0.0013

1.19 2.62 0.566 94.18 0.086 0.0025

1.26 2.74 0.572 86.78 0.086 0.0045

1.29 2.77 0.619 82.78 0.086 0.007

1.33 2.83 0.682 80.78 0.086 0.0085

0.96 2.36 0.609 97.989 0.169 0.0013

1.2 2.72 0.616 94.58 0.169 0.0025

1.27 2.84 0.622 87.08 0.169 0.0045

1.3 2.87 0.669 83.08 0.169 0.007

1.34 2.93 0.732 81.08 0.169 0.0085

At 5000PPm

0.97 2.46 0.659 97.96 0.086 0.0013

1.21 2.82 0.666 94.07 0.086 0.0025

1.28 2.94 0.672 86.67 0.086 0.0045

1.31 2.97 0.719 82.67 0.086 0.007

1.35 3.03 0.782 80.67 0.086 0.0085

0.98 2.56 0.709 97.979 0.169 0.0013

1.22 2.92 0.716 94.47 0.169 0.0025

1.29 3.04 0.722 86.97 0.169 0.0045

1.32 3.07 0.769 82.97 0.169 0.007

1.36 3.13 0.832 80.97 0.169 0.0085


15C-

Table:( C.15) Experimental results for Rate of reaction(

(conventional condition)

At 140oC Bed

temperature

At 120 oC Bed

temperature

At 100 oC Bed

temperature

At 85 oC Bed

temperature

Superfici

-al gas

Velocity

m/s

Superficial

liquid

Velocity

m/s

0.6MPa 0.6MPa 0.3MPa 0.6MPa 0.3MPa 0.6MPa 0.3MPa 0.1MPa

At 900PPm

9.742314754 7.56563 7.22297 6.929262 5.66607 4.3334 3.73087 2.78423 0.086 0.0013

16.90802311 13.8419 13.3655 12.50791 10.3814 7.4959 5.63266 4.92590 0.086 0.0025

27.7413824 22.1908 21.7348 21.30859 15.1832 10.794 9.25234 8.09579 0.086 0.0045

38.77494966 33.3075 32.5799 30.01931 21.8013 14.392 13.7626 11.3339 0.086 0.007

41.76794583 37.9887 37.0682 31.89552 22.0608 15.292 14.5636 12.3791 0.086 0.0085

10.28936176 8.50248 7.70245 7.549480 6.20591 4.8846 4.34339 3.44019 0.169 0.0013

17.8237813 14.3458 13.9582 13.84805 11.3763 8.7167 6.61785 5.99675 0.169 0.0025

31.15879907 24.1101 24.2639 22.67556 17.6748 13.262 11.7196 10.5631 0.169 0.0045

46.96772129 34.7185 33.3974 32.33330 26.3432 18.889 18.2603 15.8316 0.169 0.007

47.8432834 40.6875 39.0612 35.69260 25.7376 18.932 18.2046 16.0201 0.169 0.0085

At 1500PPm

17.02100957 7.47971 12.0518 6.865381 9.42448 7.1750 6.15747 4.55866 0.086 0.0013

29.35999434 13.6788 22.2938 12.33816 17.2581 12.387 9.24045 8.04678 0.086 0.0025

48.32679096 21.8677 36.1546 20.97489 25.0976 17.690 15.0861 13.1328 0.086 0.0045

67.78031397 32.8049 54.1635 29.50023 35.9719 23.467 22.4036 18.3016 0.086 0.007

73.32644049 37.3784 61.5593 31.26520 36.2284 24.806 23.5763 19.8867 0.086 0.0085

17.33486938 8.47999 12.8565 7.324157 10.3313 8.1012 7.18710 5.66165 0.169 0.0013

29.81267317 14.3026 23.2538 13.84805 18.8979 14.409 10.8642 9.81522 0.169 0.0025

52.06147341 24.0323 40.4028 23.54801 29.2828 21.834 19.2304 17.2771 0.169 0.0045

78.44855724 34.5973 58.1398 34.19074 43.6071 31.027 29.9643 25.8624 0.169 0.007

79.73945784 40.5404 64.8812 35.06229 42.3948 30.912 29.6825 25.9929 0.169 0.0085

At 2500PPm

28.30296183 7.39378 19.8408 6.801501 15.4656 11.718 10.0229 7.35827 0.086 0.0013

48.6189636 13.5157 36.6905 12.16841 28.3045 20.191 14.9461 12.9567 0.086 0.0025

79.60532237 21.5446 59.3345 20.64119 40.9198 28.583 24.2428 20.9873 0.086 0.0045

111.5060279 32.3022 88.8363 28.98114 58.5384 37.710 35.9382 29.1017 0.086 0.007

120.436466 36.7680 100.854 30.63488 58.6626 39.642 37.5925 31.4432 0.086 0.0085

28.82606151 8.45749 21.1737 7.260277 16.9687 13.254 11.7308 9.18843 0.169 0.0013

49.37342831 14.2593 38.2218 13.44154 30.9698 23.493 17.5855 15.8372 0.169 0.0025

85.82979313 23.9544 66.3758 23.21431 47.8567 35.452 31.1120 27.8565 0.169 0.0045

129.2864334 34.4763 95.0656 33.67166 71.2041 50.252 48.4803 41.6438 0.169 0.007

131.1248283 40.3933 106.317 34.43197 68.8674 49.747 47.6978 41.5485 0.169 0.0085

At 5000PPm

56.50540429 7.30786 39.1980 6.737621 30.4532 22.963 19.5705 14.2402 0.086 0.0013

96.16205957 13.3527 72.4627 11.99866 55.7015 39.480 28.9887 25.0090 0.086 0.0025

157.3616157 21.2214 116.844 20.30749 80.0356 55.376 46.6931 40.1808 0.086 0.0045

220.1311799 31.7996 174.833 28.46206 114.268 72.633 69.0874 55.4117 0.086 0.007

237.3690896 36.1577 198.259 30.00457 113.910 75.896 71.7960 59.4951 0.086 0.0085

57.55180067 8.43500 41.8477 7.196397 33.4435 26.018 22.9707 17.8849 0.169 0.0013

97.67127317 14.2161 75.3888 13.27179 60.8980 45.953 34.1345 30.6372 0.169 0.0025

169.8129016 23.8765 130.851 22.88060 93.8353 69.041 60.3581 53.8458 0.169 0.0045

255.6986878 34.3552 190.617 33.15258 139.485 97.603 94.0581 80.3825 0.169 0.007

258.7498399 40.2463 223.057 33.80165 134.179 95.967 91.8669 79.5660 0.169 0.0085


16C-

Table:( C.16) Experimental results for Rate of reaction (

(saturation condition)

At 140oC Bed

temperature

At 120 oC Bed

temperature

At 100 oC Bed

temperature

Superficial gas

Velocity

m/s

Superficial liquid

Velocity

m/s At 900 PPm

11.26615 10.04618 8.356278 0.086 0.0013

21.21879 18.66081 15.85336 0.086 0.0025

35.38031 32.79983 27.25194 0.086 0.0045

51.9084 47.33309 39.96905 0.086 0.007

61.51279 54.49013 44.12168 0.086 0.0085

11.38229 10.57246 8.555344 0.169 0.0013

21.44214 19.7585 16.41569 0.169 0.0025

36.18441 34.77178 28.26415 0.169 0.0045

53.15921 52.37375 41.54359 0.169 0.007

63.03163 61.43202 46.03362 0.169 0.0085

At 1500PPm

19.02579 16.92489 14.07899 0.086 0.0013

35.79558 31.27581 26.67295 0.086 0.0025

59.68023 55.02958 45.84254 0.086 0.0045

87.55353 79.37132 67.2186 0.086 0.007

103.7498 91.33671 74.17073 0.086 0.0085

19.02952 17.79254 14.4152 0.169 0.0013

35.94647 33.16682 27.62269 0.169 0.0025

59.88394 58.96074 47.55211 0.169 0.0045

87.87041 87.88466 69.87788 0.169 0.007

104.1346 103.0611 77.39986 0.169 0.0085

At 2500PPm

31.70638 28.13745 23.408 0.086 0.0013

59.59014 51.72467 44.28446 0.086 0.0025

99.34255 91.10416 76.0974 0.086 0.0045

145.7289 131.3338 111.5537 0.086 0.007

172.6812 151.0722 123.0383 0.086 0.0085

31.71259 29.58353 23.96835 0.169 0.0013

59.84163 54.93815 45.86735 0.169 0.0025

99.68207 97.54485 78.94666 0.169 0.0045

149.6371 145.5227 115.9858 0.169 0.007

177.4268 170.6129 128.4202 0.169 0.0085

At 5000PPm

63.41816 56.14408 46.71082 0.086 0.0013

119.0644 102.6653 88.2446 0.086 0.0025

198.4735 181.0188 151.6096 0.086 0.0045

291.1253 260.8134 222.1946 0.086 0.007

344.957 299.8896 244.9635 0.086 0.0085

63.43059 59.03678 47.83173 0.169 0.0013

119.5674 109.2171 91.41098 0.169 0.0025

199.1527 193.6801 157.3093 0.169 0.0045

295.809 289.1965 231.0605 0.169 0.007

350.6443 338.9783 255.7293 0.169 0.0085


17C-

Table:( C.17a) Experimental results for absence external mass transfer resistance


Value of

(mg/l)

Superfici

-al gas

Velocity

m/s

Superfici

-al liquid

Velocity

m/s

At 85 oC Bed

temperature

At 100oC Bed

temperature

At 120oC Bed

temperature

At 140oC

Bed

temperat

u-re

0.1

MPa

0.3

MPa

0.6

MPa

0.3

MPa

0.6

MPa

0.3

MPa

0.6

MPa

0.6

MPa

900 0.086 0.0013 0.0017 0.002 0.0027 0.003 0.0028 0.003486 0.00365 0.004062

900 0.086 0.0025 0.0018 0.0021 0.0028 0.0035 0.003 0.0038 0.00400 0.004224

900 0.086 0.0045 0.001967 0.0022 0.0026 0.0032 0.003 0.0039 0.004049 0.004373

900 0.086 0.007 0.001948 0.0023 0.0024 0.0033 0.003348 0.004205 0.004299 0.004324

900 0.086 0.0085 0.001827 0.00215 0.002257 0.002864 0.003055 0.004109 0.004211 0.004001

900 0.169 0.0013 0.00221 0.002791 0.003138 0.003507 0.003148 0.003717 0.004103 0.004291

900 0.169 0.0025 0.002308 0.002548 0.003356 0.003852 0.00346 0.004036 0.004148 0.004453

900 0.169 0.0045 0.002566 0.002847 0.003221 0.003776 0.003575 0.004427 0.004399 0.004912

900 0.169 0.007 0.002721 0.003138 0.003246 0.003982 0.003606 0.004311 0.004481 0.005238

900 0.169 0.0085 0.002365 0.002687 0.002794 0.003341 0.003419 0.00433 0.004511 0.004583

1500 0.086 0.0013 0.001734 0.002342 0.00273 0.003153 0.001695 0.003444 0.002137 0.004202

1500 0.086 0.0025 0.001834 0.002106 0.002823 0.00346 0.001825 0.003817 0.002342 0.004343

1500 0.086 0.0045 0.001889 0.00217 0.002544 0.003175 0.001958 0.003906 0.002362 0.004511

1500 0.086 0.007 0.001862 0.00228 0.002388 0.003219 0.001948 0.004139 0.002507 0.004476

1500 0.086 0.0085 0.001738 0.00206 0.002168 0.002785 0.001 0.0040 0.00245 0.004159

1500 0.169 0.0013 0.002154 0.002734 0.003082 0.003457 0.001808 0.003673 0.002423 0.00428

1500 0.169 0.0025 0.002237 0.002476 0.003284 0.003788 0.002048 0.003981 0.002449 0.00441

1500 0.169 0.0045 0.002485 0.002766 0.00314 0.003704 0.002198 0.004365 0.002596 0.00486

1500 0.169 0.007 0.002631 0.003049 0.003157 0.003902 0.002258 0.004443 0.002644 0.00518

1500 0.169 0.0085 0.002272 0.002594 0.002702 0.003259 0.001989 0.004259 0.002661 0.004523

2500 0.086 0.0013 0.00168 0.002288 0.002675 0.003105 0.001008 0.003401 0.001268 0.004193

2500 0.086 0.0025 0.001772 0.002044 0.002761 0.003404 0.00108 0.003769 0.001388 0.004315

2500 0.086 0.0045 0.001811 0.002092 0.002467 0.003106 0.001156 0.003846 0.001396 0.004458

2500 0.086 0.007 0.001777 0.002194 0.002302 0.003143 0.001148 0.004073 0.001481 0.004418

2500 0.086 0.0085 0.001649 0.001971 0.002079 0.002705 0.001043 0.003972 0.001448 0.004099

2500 0.169 0.0013 0.002097 0.002678 0.003025 0.003407 0.001076 0.00363 0.00145 0.00427

2500 0.169 0.0025 0.002166 0.002405 0.003213 0.003725 0.001193 0.003926 0.001465 0.004382

2500 0.169 0.0045 0.002404 0.002685 0.003059 0.003632 0.0013 0.004302 0.001553 0.004807

2500 0.169 0.007 0.002542 0.00296 0.003068 0.003823 0.001334 0.004359 0.001581 0.005122

2500 0.169 0.0085 0.002179 0.002501 0.002609 0.003176 0.001172 0.004187 0.001591 0.004462

5000 0.086 0.0013 0.001625 0.002233 0.00262 0.003056 0.000499 0.003359 0.000626 0.004184

5000 0.086 0.0025 0.00171 0.001982 0.002699 0.003349 0.000532 0.003721 0.000686 0.004267

5000 0.086 0.0045 0.001733 0.002014 0.002389 0.003037 0.000569 0.003786 0.000688 0.004406

5000 0.086 0.007 0.001691 0.002108 0.002217 0.003067 0.000564 0.004008 0.000729 0.00436

5000 0.086 0.0085 0.00156 0.001882 0.001989 0.002626 0.00051 0.003903 0.000712 0.004038

5000 0.169 0.0013 0.002041 0.002621 0.002969 0.003356 0.000533 0.003586 0.000723 0.004262

5000 0.169 0.0025 0.002095 0.002334 0.003142 0.003662 0.000589 0.003871 0.00073 0.004334

5000 0.169 0.0045 0.002323 0.002604 0.002978 0.00356 0.000641 0.00424 0.000774 0.004754

5000 0.169 0.007 0.002453 0.002871 0.002979 0.003744 0.000657 0.004369 0.000787 0.005065

5000 0.169 0.0085 0.002086 0.002408 0.002516 0.003093 0.000575 0.004392 0.000792 0.004402


18C-

Table:( C.17b) Experimental results for absence external mass transfer resistance


Value of

(mg/l)

Superfic

-ial gas

Velocity

m/s

Superficial

liquid

Velocity

m/s

At 85 oC Bed

temperature

At 100oC Bed

temperature

At 120oC Bed

temperature

At 140oC

Bed

Tempera

ture

0.1

MPa

0.3

MPa

0.6

MPa

0.3

MPa

0.6

MPa

0.3

MPa

0.6

MPa

0.6

MPa

900 0.086 0.0013 4.76409E-05 6.38388E-05 7.41E-05 7.79E-05 5.95492E-05 7.71E-05 8.08E-05 8.37E-05

900 0.086 0.0025 4.99532E-05 5.71204E-05 7.6E-05 8.46E-05 6.37055E-05 8.46E-05 8.76E-05 8.61E-05

900 0.086 0.0045 5.13002E-05 5.86288E-05 6.84E-05 7.73E-05 6.78154E-05 8.59E-05 8.77E-05 8.83E-05

900 0.086 0.007 5.04352E-05 6.12427E-05 6.4E-05 7.8E-05 6.70913E-05 9.05E-05 9.25E-05 8.67E-05

900 0.086 0.0085 4.71612E-05 5.54838E-05 5.83E-05 6.76E-05 6.10293E-05 8.81E-05 9.03E-05 7.99E-05

900 0.169 0.0013 5.88651E-05 7.43198E-05 8.36E-05 8.53E-05 6.48793E-05 8.22E-05 9.08E-05 8.84E-05

900 0.169 0.0025 6.08126E-05 6.71111E-05 8.84E-05 9.27E-05 7.0531E-05 8.83E-05 9.08E-05 9.08E-05

900 0.169 0.0045 6.69345E-05 7.42631E-05 8.4E-05 9E-05 7.21659E-05 9.59E-05 9.53E-05 9.92E-05

900 0.169 0.007 7.04491E-05 8.12567E-05 8.41E-05 9.42E-05 7.22629E-05 9.27E-05 9.64E-05 0.000105

900 0.169 0.0085 6.10321E-05 6.93547E-05 7.21E-05 7.88E-05 6.82947E-05 9.29E-05 9.67E-05 9.15E-05

1500 0.086 0.0013 4.6185E-05 6.23829E-05 7.27E-05 7.67E-05 3.49335E-05 7.62E-05 4.73E-05 8.66E-05

1500 0.086 0.0025 4.83156E-05 5.54828E-05 7.44E-05 8.33E-05 3.72075E-05 8.35E-05 5.12E-05 8.85E-05

1500 0.086 0.0045 4.92726E-05 5.66012E-05 6.64E-05 7.57E-05 3.95241E-05 8.46E-05 5.12E-05 9.11E-05

1500 0.086 0.007 4.82203E-05 5.90278E-05 6.18E-05 7.62E-05 3.90372E-05 8.9E-05 5.39E-05 8.97E-05

1500 0.086 0.0085 4.48586E-05 5.31812E-05 5.6E-05 6.57E-05 3.54208E-05 8.66E-05 5.26E-05 8.31E-05

1500 0.169 0.0013 5.73596E-05 7.28143E-05 8.21E-05 8.41E-05 3.72679E-05 8.13E-05 5.36E-05 8.82E-05

1500 0.169 0.0025 5.89339E-05 6.52324E-05 8.65E-05 9.12E-05 4.17608E-05 8.71E-05 5.36E-05 8.99E-05

1500 0.169 0.0045 6.48214E-05 7.215E-05 8.19E-05 8.83E-05 4.43727E-05 9.46E-05 5.63E-05 9.81E-05

1500 0.169 0.007 6.81409E-05 7.89484E-05 8.18E-05 9.23E-05 4.52441E-05 9.56E-05 5.69E-05 0.000104

1500 0.169 0.0085 5.86325E-05 6.6955E-05 6.97E-05 7.69E-05 3.97225E-05 9.13E-05 5.71E-05 9.03E-05

2500 0.086 0.0013 4.47291E-05 6.0927E-05 7.12E-05 7.56E-05 2.07651E-05 7.53E-05 2.8E-05 8.64E-05

2500 0.086 0.0025 4.6678E-05 5.38452E-05 7.27E-05 8.2E-05 2.20173E-05 8.25E-05 3.04E-05 8.8E-05

2500 0.086 0.0045 4.7245E-05 5.45736E-05 6.43E-05 7.4E-05 2.33371E-05 8.33E-05 3.03E-05 9E-05

2500 0.086 0.007 4.60054E-05 5.6813E-05 5.96E-05 7.44E-05 2.30102E-05 8.76E-05 3.19E-05 8.85E-05

2500 0.086 0.0085 4.2556E-05 5.08786E-05 5.37E-05 6.38E-05 2.0824E-05 8.52E-05 3.1E-05 8.19E-05

2500 0.169 0.0013 5.58542E-05 7.13089E-05 8.06E-05 8.29E-05 2.21657E-05 8.03E-05 3.21E-05 8.8E-05

2500 0.169 0.0025 5.70553E-05 6.33537E-05 8.46E-05 8.97E-05 2.43209E-05 8.59E-05 3.21E-05 8.93E-05

2500 0.169 0.0045 6.27084E-05 7.0037E-05 7.98E-05 8.66E-05 2.62463E-05 9.32E-05 3.36E-05 9.7E-05

2500 0.169 0.007 6.58326E-05 7.66401E-05 7.94E-05 9.05E-05 2.67343E-05 9.38E-05 3.4E-05 0.000103

2500 0.169 0.0085 5.62328E-05 6.45554E-05 6.73E-05 7.49E-05 2.34051E-05 8.98E-05 3.41E-05 8.91E-05

5000 0.086 0.0013 4.32732E-05 5.94711E-05 6.98E-05 7.44E-05 1.02831E-05 7.43E-05 1.39E-05 8.62E-05

5000 0.086 0.0025 4.50404E-05 5.22076E-05 7.11E-05 8.06E-05 1.08531E-05 8.14E-05 1.5E-05 8.7E-05

5000 0.086 0.0045 4.52174E-05 5.2546E-05 6.23E-05 7.24E-05 1.14778E-05 8.2E-05 1.49E-05 8.89E-05

5000 0.086 0.007 4.37905E-05 5.45981E-05 5.74E-05 7.26E-05 1.12969E-05 8.62E-05 1.57E-05 8.74E-05

5000 0.086 0.0085 4.02535E-05 4.8576E-05 5.14E-05 6.19E-05 1.01959E-05 8.37E-05 1.53E-05 8.07E-05

5000 0.169 0.0013 5.43487E-05 6.98034E-05 7.91E-05 8.17E-05 1.09833E-05 7.93E-05 1.6E-05 8.78E-05

5000 0.169 0.0025 5.51766E-05 6.1475E-05 8.28E-05 8.82E-05 1.20046E-05 8.47E-05 1.6E-05 8.83E-05

5000 0.169 0.0045 6.05953E-05 6.79239E-05 7.77E-05 8.49E-05 1.29321E-05 9.19E-05 1.68E-05 9.6E-05

5000 0.169 0.007 6.35243E-05 7.43318E-05 7.71E-05 8.86E-05 1.31586E-05 9.4E-05 1.69E-05 0.000101

5000 0.169 0.0085 5.38331E-05 6.21557E-05 6.49E-05 7.3E-05 1.14861E-05 9.42E-05 1.7E-05 8.79E-05


19C-

Table:( C.18) Experimental results for absence external mass transfer resistance

(saturation condition)

(mg/l)

Superficial

gas Velocity

m/s

Superficia

-l liquid

Velocity

m/s

At 100oC Bed

temperature

At 120oC Bed

temperature

At 140oC Bed

Temperature

900 0.086 0.0013 0.004722079 0.000115 0.004848 0.000107 0.004698 9.68E-05

900 0.086 0.0025 0.005367572 0.000129 0.005396 0.000118 0.005301 0.000108

900 0.086 0.0045 0.005822246 0.000139 0.005984 0.00013 0.005578 0.000113

900 0.086 0.007 0.00604097 0.000143 0.006109 0.000131 0.005789 0.000116

900 0.086 0.0085 0.005727742 0.000135 0.006041 0.00013 0.005892 0.000118

900 0.169 0.0013 0.00483457 0.000118 0.005102 0.000113 0.004746 9.78E-05

900 0.169 0.0025 0.005557963 0.000134 0.005713 0.000125 0.005357 0.000109

900 0.169 0.0045 0.006038501 0.000144 0.006344 0.000137 0.005704 0.000115

900 0.169 0.007 0.006278947 0.000149 0.00676 0.000145 0.005929 0.000119

900 0.169 0.0085 0.005975945 0.000141 0.00681 0.000146 0.006038 0.000121

1500 0.086 0.0013 0.004710639 0.000115 0.004836 0.000107 0.004697 9.68E-05

1500 0.086 0.0025 0.005347068 0.000129 0.005354 0.000117 0.005295 0.000108

1500 0.086 0.0045 0.005798957 0.000138 0.005945 0.000129 0.005571 0.000112

1500 0.086 0.007 0.006015341 0.000142 0.006066 0.00013 0.005782 0.000116

1500 0.086 0.0085 0.005701013 0.000134 0.005995 0.000129 0.005884 0.000118

1500 0.169 0.0013 0.00482313 0.000117 0.005084 0.000112 0.004698 9.68E-05

1500 0.169 0.0025 0.00553746 0.000133 0.005678 0.000124 0.005317 0.000108

1500 0.169 0.0045 0.006015212 0.000143 0.006369 0.000138 0.00559 0.000113

1500 0.169 0.007 0.006253319 0.000148 0.006716 0.000144 0.005802 0.000116

1500 0.169 0.0085 0.005949215 0.00014 0.006765 0.000145 0.005906 0.000118

2500 0.086 0.0013 0.0046992 0.000114 0.004824 0.000107 0.004697 9.68E-05

2500 0.086 0.0025 0.005326565 0.000128 0.005313 0.000116 0.005289 0.000108

2500 0.086 0.0045 0.005775668 0.000138 0.005905 0.000128 0.005564 0.000112

2500 0.086 0.007 0.005989713 0.000142 0.006022 0.00013 0.005774 0.000116

2500 0.086 0.0085 0.005674283 0.000134 0.00595 0.000128 0.005876 0.000117

2500 0.169 0.0013 0.004811691 0.000117 0.005072 0.000112 0.004698 9.68E-05

2500 0.169 0.0025 0.005516956 0.000133 0.005643 0.000123 0.005311 0.000108

2500 0.169 0.0045 0.005991923 0.000143 0.006322 0.000137 0.005583 0.000113

2500 0.169 0.007 0.00622769 0.000147 0.006673 0.000144 0.005929 0.000119

2500 0.169 0.0085 0.005922486 0.00014 0.006719 0.000144 0.006038 0.000121

5000 0.086 0.0013 0.00468776 0.000114 0.004812 0.000106 0.004696 9.68E-05

5000 0.086 0.0025 0.005306061 0.000128 0.005272 0.000115 0.005283 0.000108

5000 0.086 0.0045 0.005752379 0.000137 0.005865 0.000127 0.005557 0.000112

5000 0.086 0.007 0.005964084 0.000141 0.005978 0.000129 0.005766 0.000116

5000 0.086 0.0085 0.005647554 0.000133 0.005904 0.000127 0.005868 0.000117

5000 0.169 0.0013 0.004800251 0.000117 0.00506 0.000112 0.004697 9.68E-05

5000 0.169 0.0025 0.005496452 0.000132 0.005608 0.000123 0.005305 0.000108

5000 0.169 0.0045 0.005968634 0.000142 0.006276 0.000136 0.005576 0.000113

5000 0.169 0.007 0.006202062 0.000147 0.006629 0.000143 0.005859 0.000117

5000 0.169 0.0085 0.005895756 0.000139 0.006674 0.000143 0.005965 0.000119


21C-

Table:( C.19) Experimental results for absence intra particle mass transfer

resistance at conventional condition (Weisz-Prater criterion)

(mg/l)

Superfic

-ial gas

Velocity

m/s

Superfic

-ial

liquid

Velocity

m/s

At 85 o

C Bed

temperature

At 100oC Bed

temperature

At 120oC Bed

temperature

At 140oC

Bed

temper-

ature

0.1

MPa

0.3

MPa

0.6

MPa

0.3

MPa

0.6

MPa

0.3

MPa

0.6

MPa

0.6

MPa 900 0.086 0.0013 0.0778852 0.104366 0.1212 0.1278 0.156345 0.1268 0.1329 0.1374178

900 0.086 0.0025 0.1377959 0.157567 0.2096 0.2342 0.282215 0.2348 0.2431 0.2384919

900 0.086 0.0045 0.2264695 0.258822 0.3019 0.3425 0.480785 0.3818 0.3898 0.3912991

900 0.086 0.007 0.3170537 0.384994 0.4026 0.4919 0.677324 0.5723 0.5851 0.5469304

900 0.086 0.0085 0.3462907 0.407401 0.4277 0.4977 0.719657 0.6512 0.6673 0.5891474

900 0.169 0.0013 0.0962350 0.121501 0.1366 0.1400 0.170339 0.1353 0.1493 0.1451340

900 0.169 0.0025 0.1677515 0.185126 0.2438 0.2566 0.312453 0.2452 0.2520 0.2514089

900 0.169 0.0045 0.2954888 0.327842 0.3709 0.3987 0.511628 0.4262 0.4235 0.4395027

900 0.169 0.007 0.4428687 0.510809 0.5284 0.5943 0.729535 0.5867 0.6099 0.6624915

900 0.169 0.0085 0.4481410 0.509251 0.5296 0.5807 0.80533 0.6862 0.7147 0.6748415

1500 0.086 0.0013 0.0755050 0.101986 0.1188 0.1259 0.091717 0.1253 0.0778 0.1421523

1500 0.086 0.0025 0.1332786 0.153049 0.2051 0.2305 0.164829 0.2318 0.1422 0.2452024

1500 0.086 0.0045 0.2175186 0.249871 0.2930 0.3352 0.28021 0.3760 0.2274 0.4036052

1500 0.086 0.007 0.3031302 0.37107 0.3886 0.4805 0.394103 0.5633 0.3412 0.5660730

1500 0.086 0.0085 0.3293836 0.390494 0.4108 0.4839 0.417681 0.6403 0.3888 0.6123919

1500 0.169 0.0013 0.0937738 0.11904 0.1341 0.1380 0.097846 0.1337 0.0882 0.1447736

1500 0.169 0.0025 0.1625692 0.179944 0.2386 0.2524 0.185 0.2418 0.1487 0.2489830

1500 0.169 0.0045 0.2861605 0.318513 0.3616 0.3911 0.314585 0.4202 0.2499 0.4347957

1500 0.169 0.007 0.4283581 0.496298 0.5139 0.5825 0.456765 0.6047 0.3598 0.6551697

1500 0.169 0.0085 0.4305209 0.491631 0.5120 0.5663 0.468408 0.6748 0.4216 0.6659508

2500 0.086 0.0013 0.0731249 0.099606 0.1164 0.1239 0.054518 0.1238 0.0461 0.1418247

2500 0.086 0.0025 0.1287613 0.148532 0.2006 0.2268 0.097537 0.2289 0.0843 0.2436272

2500 0.086 0.0045 0.2085677 0.240921 0.2840 0.3279 0.165451 0.3703 0.1344 0.3988983

2500 0.086 0.007 0.2892067 0.357147 0.3747 0.4692 0.232301 0.5544 0.2016 0.5587512

2500 0.086 0.0085 0.3124765 0.373587 0.3939 0.4702 0.245556 0.6294 0.2294 0.6035011

2500 0.169 0.0013 0.0913126 0.116579 0.1317 0.1360 0.058195 0.1321 0.0527 0.1444459

2500 0.169 0.0025 0.1573869 0.174761 0.2334 0.2482 0.107742 0.2385 0.0889 0.2474078

2500 0.169 0.0045 0.2768321 0.309185 0.3523 0.3836 0.186076 0.4142 0.1495 0.4300888

2500 0.169 0.007 0.4138474 0.481788 0.4994 0.5707 0.269898 0.5933 0.2151 0.6478479

2500 0.169 0.0085 0.4129008 0.474011 0.4943 0.5520 0.275992 0.6635 0.2520 0.6570600

5000 0.086 0.0013 0.0707447 0.097226 0.1140 0.1220 0.026998 0.1222 0.0228 0.1415462

5000 0.086 0.0025 0.1242439 0.144015 0.1961 0.2231 0.048079 0.2260 0.0416 0.2408863

5000 0.086 0.0045 0.1996167 0.23197 0.2751 0.3207 0.081373 0.3645 0.0662 0.3941914

5000 0.086 0.007 0.2752832 0.343223 0.3608 0.4578 0.114049 0.5454 0.0992 0.5514293

5000 0.086 0.0085 0.2955693 0.35668 0.3770 0.4564 0.120229 0.6185 0.1128 0.5946104

5000 0.169 0.0013 0.0888515 0.114118 0.1292 0.1340 0.028836 0.1305 0.0263 0.1441674

5000 0.169 0.0025 0.1522045 0.169579 0.2282 0.2440 0.053181 0.2352 0.0443 0.2446668

5000 0.169 0.0045 0.2675037 0.299857 0.3429 0.3760 0.091683 0.4082 0.0744 0.4253819

5000 0.169 0.007 0.3993368 0.467277 0.4848 0.5589 0.132844 0.5947 0.1071 0.6405261

5000 0.169 0.0085 0.3952807 0.456391 0.4767 0.5376 0.135444 0.6959 0.1255 0.6481692


21C-

Table:( C.20) Experimental results for absence intra particle mass transfer

resistance at saturation condition (Weisz-Prater criterion)

(mg/l)

Superfic-

ial gas

Velocity

m/s

Superficial

liquid

Velocity

m/s

At 100oC Bed

temperature

At 120oC Bed

temperature

At 140oC Bed

temperature

900 0.086 0.0013 0.188542 0.17649 0.158912

900 0.086 0.0025 0.357698 0.32783 0.299296

900 0.086 0.0045 0.614884 0.576222 0.499048

900 0.086 0.007 0.90182 0.83154 0.732181

900 0.086 0.0085 0.995515 0.957274 0.867653

900 0.169 0.0013 0.193034 0.185735 0.16055

900 0.169 0.0025 0.370386 0.347114 0.302447

900 0.169 0.0045 0.637723 0.610865 0.51039

900 0.169 0.007 0.937346 0.920094 0.749824

900 0.169 0.0085 1.038654 1.079228 0.889077

1500 0.086 0.0013 0.188085 0.176048 0.158895

1500 0.086 0.0025 0.356332 0.325323 0.29895

1500 0.086 0.0045 0.612424 0.572404 0.498424

1500 0.086 0.007 0.897994 0.8256 0.731211

1500 0.086 0.0085 0.990869 0.950061 0.866475

1500 0.169 0.0013 0.192577 0.185073 0.158927

1500 0.169 0.0025 0.36902 0.344993 0.30021

1500 0.169 0.0045 0.635263 0.613295 0.500126

1500 0.169 0.007 0.93352 0.914154 0.733857

1500 0.169 0.0085 1.034008 1.072015 0.869689

2500 0.086 0.0013 0.187629 0.175607 0.158879

2500 0.086 0.0025 0.354966 0.322816 0.298603

2500 0.086 0.0045 0.609965 0.568585 0.497801

2500 0.086 0.007 0.894168 0.819661 0.73024

2500 0.086 0.0085 0.986224 0.942849 0.865297

2500 0.169 0.0013 0.19212 0.184632 0.15891

2500 0.169 0.0025 0.367654 0.342872 0.299863

2500 0.169 0.0045 0.632804 0.608782 0.499502

2500 0.169 0.007 0.929694 0.908214 0.749824

2500 0.169 0.0085 1.029363 1.064803 0.889077

5000 0.086 0.0013 0.187172 0.175166 0.158863

5000 0.086 0.0025 0.353599 0.320309 0.298257

5000 0.086 0.0045 0.607505 0.564767 0.497177

5000 0.086 0.007 0.890342 0.813721 0.72927

5000 0.086 0.0085 0.981578 0.935637 0.864119

5000 0.169 0.0013 0.191663 0.184191 0.158894

5000 0.169 0.0025 0.366287 0.34075 0.299517

5000 0.169 0.0045 0.630344 0.60427 0.498878

5000 0.169 0.007 0.925868 0.902275 0.741003

5000 0.169 0.0085 1.024717 1.057591 0.878365

Appendix D Sample of Calculations

1D-

Liquid holdup and axial dispersion :

The liquid holdup and dispersion coefficient were calculated using the RTD

method ,and by the use of the tracer RTD data from experiments. The following

sample of calculation analyzes the RTD data of experiment

Superficial liquid velocity = 0.0013 m.sec-1

Superficial gas velocity = 0.086 m.sec-1

and temperature 25C

Liquid holdup

where are mean residence time (s) ,volumetric flow rate of

liquid( /s) and reactor volume( ) respectively.


2D-

Table (D.1): values of & for each tracer concentration

Concentration

(Kg/m-3)

Time (sec)

0 0 0 0 0

114.6816 28.6704 7.1676 1.7919 4

535.1808 66.8976 8.3622 2.09055 8

1261.498 105.1248 8.7604 2.1901 12

2242.662 140.1664 8.7604 2.1901 16

3822.72 191.136 9.5568 2.3892 20

5642.335 235.0973 9.79572 2.44893 24

21353.71 762.6326 27.23688 6.80922 28

32620.54 1019.392 31.856 7.964 32

70185.14 1949.587 54.1552 13.5388 36

100155.3 2503.882 62.59704 15.64926 40

135064.3 3069.644 69.76464 17.44116 44

220188.7 4587.264 95.568 23.892 48

301485.2 5797.792 111.496 27.874 52

382668.5 6833.367 122.0244 30.5061 56

430056 7167.6 119.46 29.865 60

326205.4 5096.96 79.64 19.91 64

353525.1 5198.899 76.4544 19.1136 68

334824.4 4650.339 64.58804 16.14701 72

276000.4 3631.584 47.784 11.946 76

260454.7 3255.683 40.69604 10.17401 80

280969.9 3344.88 39.82 9.955 84

266490 3028.295 34.41244 8.603111 88

248058.8 2696.292 29.30752 7.32688 92

220188.7 2293.632 23.892 5.973 96

236371.5 2363.715 23.63715 5.909288 100

228525.8 2197.363 21.12849 5.282123 104

141474.7 1309.951 12.12917 3.032293 108

140959.5 1258.567 11.2372 2.809301 112

142045.3 1224.529 10.55628 2.639071 116

145301.6 1210.847 10.09039 2.522597 120

152210.9 1227.507 9.899252 2.474813 124

160623.6 1254.872 9.803684 2.450921 128

169293 1282.523 9.71608 2.42902 132

162032.4 1191.414 8.7604 2.1901 136

156094.4 1114.96 7.964 1.991 140

0 0 0 0 144


3D-

Then liquid holdup equal to 0.065718961

Axial dispersion ( )

where


4D-

Then

I

الخالصة

حيث تم دراسه Trickle bed Reactor. تضمن البحث دراسة عملية لكفاءة أداء عمود الطبقه الوشله

نصب ةتضمنت الدراس .ةالوشل ةتاثير المتغيرات الرئيسيه التي تلعب دور اساسي في اداء عمود الطبق

اذ تم اجراء ( م2.1.) يوقطر داخل( م52.1)ذات طول المقاوم للصدأ الفوالذمصنوع من جهاز مختبري

ةسرع,( دقيقه/م0.086-0.25 )الغاز ةسرع{ ةتحت ظروف مختلف ةوالحركي ةالتجارب الهيدروداينميكي

المفاعل ةدرجه حرار ,(ميكا باسكال 0.1-0.6) ضغط المفاعل ,(دقيقه/م -500.0085..2.) السائل

(º140-25م), سا 4 -24)للمحلول ةالفراغي ةالسرع-5

نظام 2}(لتر/مغم ...1 -..0) لفينولوتركيز ا(

دراسه االنحدار بلضغط تظمنت الدراسه ةهواء قد تم استخدامه في حاله التجارب الهيدروديناميكي-ماء

(Pressure drop) ونسبه السائل (Liquid holdup) والتفرق المحوري (Axial dispersion) وقد

هبوط بالضغط بزياده سرعه الغاز والسائل وكذلك بزياده تم اال ستنتاج من خالل النتائج العمليه يزداد ال

بزياده سرعه داد السائل يز نسبه تبين النتائج بأنه 2 ، بينما يقل بزيادة درجة حرارة المفاعل الضغط

ل بزياده سرعه الغاز والسائ التفرق المحوري يزداد ، بزياده سرعه الغاز ودرجه الحرارهالسائل وتقل

نسبة السائل و , تم إيجاد معادالت تجريبية لكل من االنحدار في الضغط2 درجة الحرارة بزياده يقل بينما

- :التفرق المحوري

السرعه الفراغيه {2في حاله الظروف االعتياديه وعند ضغط التوازن دراسة أكسدة الفينولوقد تم

سا 4 -24)للمحلول -5

,(ميكا باسكال 0.1-0.6) ضغط المفاعل ,(دقيقه/م0.086-0.25 )سرعه الغاز ,(

لية أكسدةالسلوك العام لعم2 }رلت/مغم ...1 -..0) وتركيز الفينول ,(مº140-25) درجه حراره المفاعل

سرعه و المفاعل ضغط التفاعل و يشير الى ان تحول الفينول يزداد بزيادة درجة حرارة الفينول

نسبه النتائج أظهرت ان اعلى2(LHSV)، بينما ينخفض بزيادة السرعة الفراغية للمحلول االوكسجين

سا LHSV 4)التاليه ظروفالتحت عليه تم الحصول %98)) للفينول لتحو-5

.54=حرارة درجة,

اما نتائج 2(لتر/غمم ..0=والتركيز األبتدائي للفينول ميكاباسكال 201.=الضغط الجزئي لألوكسجين ,°م

0.49,0.69),) بينما االولى بالنسبة لتركيز الفينولدراسة حركية التفاعل ، أثبتت أن التفاعل من المرتبة

وطاقة 2على التوالي روف التشغيليه االخرىوعند الض ضغط التوازن عند بالنسبة لذوبانية األوكسجين

II

ضغط التوازن وعند الضروف التشغيليه عند مول/كيلوجول (24.616 , 29.299 ) التنشيط الظاهرية

التفاعل تكون عند ضغط التوازن وعند الضروف وبذلك فأن معادلة سرعة2 على التوالياالخرى

:تكون كلتالي التشغيليه االخرى على التوالي

69.010

2..

75.24616107234.2 Ophph XC

RTr

49.09

2..

49.29299107.5 Ophph XC

RTr

علميالبحث الوزارة التعليم العالي و

جامعة التكنلوجيهال

هقسم الهندسة الكيمياوي

المحركة القوى علم دراسة

الفينول إزالة و معالجة في وهيدروناميكا

الطبقة الوشلة مفاعل أستخدامب

كاحد متطلبات نيل هالتكنلوجي ةفي الجامع هالكيمياوي ةالى قسم الهندس ةمقدم ةأطروح

هالكيمياوي هفي الهندسالماجستير ةشهاد

اعداد

لمى شهاب احمد

2008بكلوريوس هندسه كيمياويه

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