PROPYLEN OXIDE CO-PRODUCTION WITH t-BUTYL ALCOHOL BY THE TEXACO HYDROPEROXIDATION

PROCESS

Designer: Sultan Alharbi

Supervised by:Prof.M.Fahim

ENG: Yousif Ismail

Outline :

1 -Heat exchanger ( heater , cooler )

2 -Distillation column

3 -Reactor

4 -Pump design

5 -Compressor

Heat Exchanger Design

For E-104:

- To increase the temperature

For E-103:

- To decrease the temperature

Objectives:

Assumptions: - Use shell and tube heat exchanger.

- Assume the refrigent inter in tube side in cooler and steam in heater

The value of the overall heat transfer coefficient was assumed to be:

- For (E-103) = 300 w/m^2C. - For (E-104) = 900 w/m^2C. - For E-103 refrigent inlet temperature (t1) = -10 Crefrigent outlet temperature (t2) = 35 C -For E-104

Steam inlet temperature (t1) = 200 C

Steam outlet temperature (t2) = 70 C

Main design procedures: Main design procedure:Calculate the duty or heat load.

Where,m: mass flow rate, kg/hrCp: specific heat, kJ/kg°C

∆T: temperature difference, °CCollect physical properties.

coldphotp TmCTmCQ

• -Calculate Log mean Temperature

Where,

Tm = Ft Tlm.

∆Tlm : log mean temperature difference.

T1 : inlet shell side fluid temperature.

T2 : outlet shell side temperature fluid temperature.

t1 : inlet tube side fluid temperature .

t2 : outlet tube side fluid temperature.

-Assume U : overall heat transfer coefficient, W/m2oC

-Calculate heat transfer area required. mo TU

QA

12

21

1221

lntTtTtTtT

Tlm

- Calculate area of one tube, m2.

Where

-Outer diameter (do), (mm)

-Length of tube (L), (mm)

- Calculate number of tubes = provisional area / area of one tube

LdA o

- Calculate bundle diameter.

Where

- Outside diameter (mm).

- Number of tubes.

- K1 & n1 are constant.

1

1

10 )( nt

b K

NdD

- Calculate shell diameter.

Ds = Db + Bundle diametrical clearance

- Find tube side heat transfer coefficient hi, W/m2°C

- Find shell side heat transfer coefficient ho, W/m2°C

• Calculate U overall heat transfer coefficient using:

Where :

- Uo : overall coefficient based on outside area of the tube ,w/m^2.C - ho : outside fluid film coefficient, w/m^2.C, from Table (12.2) - hi : inside fluid film coefficient ,w/m^2, from Table (12.2) - hod : outside dirt coefficient (fouling factor) ,w/m^2.C - hid : inside dirt coefficient (fouling factor),w/m^2.C - kw : thermal conductivity of the wall material w/m.Cs for cupronickel - di : tube inside diameter m - do : tube outside diameter m

SdSw

i

oo

i

o

idio hhk

d

dd

d

d

hhU

11

2

ln111

-Calculate tube and shell side pressure drop.

- Calculate Shell thickness.

Where

- t: shell thickness (in).

- P: internal pressure (psig).

- ri: internal radius of shell (in).

- EJ: efficiency of joints.

- S: working stress (psi).

- Cc: allowance for corrosion (in).

cJ

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t

6.0

Pr

Results Equipment NameHerter

ObjectiveTo increase temperature of isobutene stream

Equipment NumberE-104

DesignerSultan Al-Harbi

TypeShell And Tube

LocationBefore recycle

Material of ConstructionCarbon Steel

InsulationGlass wool

Cost ($)44000

Operating Condition

Shell Side

Inlet temperature (oC)3.1Outlet temperature (oC)134

Tube Side

Inlet temperature (oC)200Outlet temperature (oC)70

Number of Tube Rows2Number of Tubes241

Tube bundle Diameter (m)

0.472Shell Diameter (m)0.5307

Q total (KW)7912LMTD (oC)53.157

U (Btu/hr. oF . ft2)900.1Heat Exchanger Area

(m2)68.96

Equipment NameCooler

ObjectiveTo decrease temperature of Isobutane stream

Equipment NumberE- 103

DesignerSultan Al-Harbi

TypeShell And Tube

LocationBefore separator V-102

Material of ConstructionCarbon Steel

InsulationGlass wool

Cost ($)90000

Operating Condition

Shell Side

Inlet temperature (oC)116.8Outlet temperature (oC)1.39

Tube Side

Inlet temperature (oC)-10Outlet temperature (oC)35

Number of Tube Rows2Number of Tubes1020

Tube bundle Diameter (m)

0.7113301

Shell Diameter (m)0.77533

Q total (KW)7540LMTD (oC)30.36941

1

U (Btu/hr. oF . ft2)299.864Heat Exchanger Area (m2)391.125

Distillation ColumnT-(102) design

Objective :To separate TBHP from t-ButanolTo separate TBHP from t-Butanol

Assumptions

1 .Tray column.2 .Sieve plate.

3 .Material of the distillation is carbon steel.4 .Plate spacing= 0.6 m

5 .Efficiency = 50%6 .Flooding % = 85%

7 .Weir height = 50 mm8 .Hole diameter = 5 mm9 .Plate thickness =5 mm

1 (Actual number of stages = (hysys number stages/η)

2 (FLV= ( Lw / Vw)*( ρv / ρL)^.5

Where-: Lw: liquid flow rate

ρL: liquid densityVw: vapor flow rate,ρv :vapor densityFLv: liquid-vapor flow factor

3 (Find K1 (Top) & K1 (Bottom) from fig .

K1correction = (σ/0.02)^.2*K1 Where: -

σ: Surface tension

Main design procedures:

4( Uf (bottom)= K1 ((ρL- ρv)/ ρv) 0.5 Uf (Top) = K2 ((ρL- ρv)/ ρv) 0.5

Where:

Uf : flooding vapor velocity K1: constant obtained from figure

5 (uv = uf * x

Where-: Uv : maximum velocity

X : percentage of flooding at max flow

6 (Max flow-rate = (Lw*Mwt / ρL*3600)

Where -: Max.: Maximum Volumetric Flow rate .

Lw: liquid flow rate ρL: liquid density

M.wt: molecular weight

7 (Anet = Mmax/uv

Where-: Anet: Net area required

8 (Ad = An/(1-y*10^-2) Where: Ad: down comer area

9 (D =(Ad*4/(3.14))^.5

Where-: D: column diameter

10 (H= (Tray spacing * actual NO. stage ) + D

Where-: H: Column height

11 (MVL =(Lbottom*Mwt)/(3600* ρL)

Where-: MVL: maximum volumetric liquid rate

12 (Ac = (3.14/4)*D^2

Ad = 0.12Ac An = Ac-Ad

Aa = Ac-2Ad Ah take %10 Aa as first trial = %10*Aa

Where- :

Ac: column area

Aa: active area Ah: hole area

Ad= Downcomer area

13( max Lw = Lw*Mwt/3600

min Lw @ % turn down = %*max Lw

max how =750 (max Lw/ρL*wierlength)^(2/3)

min how =750 (min Lw/ ρL*wierlength)^(2/3)

actual minimum vapor = vapor rate min/Ah

Where-: max Lw: maximum liquid rate.

min Lw : minimum liquid rate.

14 (The actual min vapor velocity = vapor rate min/An

15 (uh = Vw max/Ah

hr = 12.5E+03/ ρL

Where-:

uh: maximum vapor velocity through holes

max.Vw: maximum volumetric flow rate

hd: dry plate drop

hr: Residual head

Aap= wier length*hap hdc= 166*(max liquid flowrate/ ρL*Aap)^2 hb= Minimum rate (hw + how) + ht + hdc

Where:- Aap: Area under arpon hdc: head losses in the down comer

17)tr =

Where :

tr : residence time , should be > 3 s

flowmassliquid

ρhA Lbδ

18) Percent flooding =

f

v

u

u

Where :- uv: vapor velocity, uf: flooding vapor velocity

19 (Number of holes Area of one hole = (π/4)*(hole diameter^2)

Total number of holes = Ah / area of one hole Holes on one plate = total Number of holes/number of stages

20 (Area of condenser& reboiler = Q/(U*∆T)

21 (Thickness = [(ri P)/(Ej S-0.6P)]+Cc

Where -: ri = Inside radius of the shell

P =Maximum allowable internal pressure

S = Maximum allowable working stress

EJ = Efficiency of joints Cc = Allowance for corrosion

Equipment NameDistillation column

ObjectiveTo separate TBHP from t-Butanol

Equipment NumberC-101

DesignerSultan Al-Harbi

TypePlate column

LocationAfter reactor 101

Material of ConstructionCarbon steel

InsulationGlass wool

Cost ($)515350

Column Flow Rates

Feed (kgmole/hr)897Recycle (kgmole/hr)-

Distillate (kgmole/hr)1059Bottoms (kgmole/hr)1378

Dimensions

Diameter (m)2.6039Height (m)41.6039

Number of Trays65Reflux Ratio1

Tray Spacing0.6Type of traySieve

single pass

Number of Holes20608Number of Caps/Holes-

Cost

Vessel164200Trays68250

Condenser Unit75400Reboiler207500

Reactor Design

Objectives:

- R-101: To produce TBHP from Isobutane

and oxygen.

)CH3 (3 CH + O2 → (CH3)3COOH

-The limiting reactant is (CH3) 3 CH in the R-101 reactor.

-The conversion equal to 0.24 in the R-101 reactor

Assumptions:

Main design procedures:

1.Find Volume:

V=(Fao-Fa)/-ra = (Fao-Fa)/kCao(1-X)

Where Fao : inlet mass flow Fa : outlt mass flow

K : kinetic rate Cao : density*Fao/total mass

flow rate X : conversion

2. Find diameter of reactor

Volume = PI * (D/2)^2 * H = PI * D^3

Where H = 4D

D = (V/PI)^1/3

3. Calculate the height of reactor:

Height of reactor (H) = 4 * Diameter

Total height of reactor = 0.5 + 0.5 + H+ 2 (D/2)

4. Calculate the thickness

Where,

t is thickness in inch

P is internal pressure in psig,

ri is the radius of the reactor, in,

S is the stress value of carbon steel (S=13700 psia),

Ej is the joint efficiency (Ej=0.85 for spot examined

welding),

Cc is the corrosion allowance (Cc=1/8 in)

6. Calculate cost from www.matche.com

cJ

i CPSE

t

6.0

Pr

Equipment NameReactor

ObjectiveProducing TBHP

Equipment NumberR-101

DesignerSultan Al-Harbi

TypeCSTR Reactor

LocationBefore distillation column C-101

Material of ConstructionCarbon steel

InsulationGlass Fiber

Operating Condition

Operating Temperature (oC)

134Volume of Reactor (m3)248

Operating Pressure (kpa)2114Reactor Height (m)18

Feed Flow Rate (Kgmole/h)

2535Reactor Diameter (m)4.5

Conversion (%)24Reactor Thickness (m)0.07

Cost ($)302900

Compressor Design

Objectives:

-To increase gases pressure.

Main design procedures: • 1.Calculate the compression factor (n) using the

following equation:

•

Where,

P1,2 : is the pressure of inlet and outlet respectively (psia)

T1,2 : is the temperature of the inlet and outlet respectively (R)

11 1

2 2

n

nP T

P T

2. Calculate the work done in Btu/lbmol by:

1 2( )

1

nR T TW

n

Where ,

R is the ratio of the specific heat capacities (Cp/Cv)

3. Calculate the horse power, Hp using the following equation:Hp=W*M

Where, M is the molar flow rate in lbmol/s

4 .Calculate the efficiency of the compressor using the following equation :

1

1

nnEp

KK

1.986p

p

MwCK

MwC

Where ,

Mw :is the molecular weight of the gas in the stream

CP :is the specific heat capacity (Btu/lb◦ F )

5. Calculate the cost of the compressor from www. Matche . com

Equipment NameCompressor

Equipment NumberK-100

ObjectiveTo compress feed sour gas

DesignerSultan Al-Harbi

TypeCentrifugal Compressor

Material of ConstructionCarbon steel

Cost ($)184000

Operating Condition

Feed flow rate (kg/hr) 52150

Inlet pressure (psia)14.7

outlet pressure (psia)306

Inlet temperature (Cº)25

Outlet temperature (Cº)134

Power ( hp)590.4

Efficiency (%) 75

Pump Design

Assumptions:Centrifugal pump.

Design procedures:

1.Calculate the flow rate

m= ρ *Q

2.Calculate the work shift

Ws = -ha * g

3.Assume efficiency ζ.

4.Calculate the Brake horse power

-) =Ws * m) / (ζ * 1000(

5.Calculate the diameter, d.

Where,∆P is the pressure difference between the inlet and outlet streams in kpa

Q: flow rate kg/sρ: the density of the fluid kg/m3μ: viscosity cpD: pipe diameter mm

84.4116.084.11013.4 dQEP

66 . .Calculate the cost of the compressor fromCalculate the cost of the compressor from www. Matche . com

Equipment NamePump

ObjectiveTo increase pressure of Isobutane stream

Equipment NumberP-101

DesignerSultan Al-Harbi

TypeCentrifugal pump

LocationBefore R-101

Material of ConstructionCast Iron

Insulation-

Cost ($)6600

Operating Condition

Inlet Temperature (oC)44Outlet Temperature (oC)45

Inlet Pressure (psia)689.48Outlet Pressure (psia)2117

Efficiency (%)62Power (KW)2697.75

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