Internship Report of Nimir Chemicals

8/11/2019 Internship Report of Nimir Chemicals

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NIMIR VISION STATEMENT

NIMIR Chemicals Pakistan Limited will fulfill the stakeholder

expectations of our "Customers," "Shareholders," "Employees,"

"Business Partners," "Local Communities and the

Environment.".

NIMIR MISSION STATEMENT

Create Social Value while fulfilling the stakeholder

expectations.

Statement of Ethics

We believe in a stimulating and challenging team oriented work

environment that encourages, develops and rewards

excellence. We are committed to diligently serving our

community and stakeholders while maintaining high standardsof moral and ethical values.


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Table of contents

1.Health ,safety and environment department

2.Quality control department

3.Ware house

4.Electrical department

5.Mechanical department

6.Instruments department

7.Utility plants

Demine water

Boiler

Turbine

Compressor Nitrogen generation

8.Process and production department

PHTHALIC ANHYDRIDE

MALEIC ANHYDRIDE

DI-OCTYL PHTHALATE


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2. Quality control laboratory

Purpose

This laboratory is used for all the chemical reaction occuring in industry and check all the quality

of the raw material, product and water using in the industry. This lab contain different types of

apparatus for different test such as water analysis, acid value, total fatty acid, free acid,

moisture content etc .the plant contain different intermediate point where the sample is

collected and then it is send to Q.C lab where the chemist check out the complete analysis of

the sample and then make report by performing different test .then the report is send to plantoperator where dosing is done according to the requirement. The apparatus use in the lab is

following.

1. Gas chromatography

2. Hydrogen generator

3. Refractor meter

4. Sensodirect

5. Weighting scale

6. Titration

7. Viscometer

8. Water bath

9. Gas analyzer

10.Magnetic stirrer hot plate

Apparatus and their function

1 .Gas chromatography

It is basically a separation technique .this is used to check out the quality of the product

and raw material .it contain two phases one phase is stationary and and other is mobile phase.

Gas chromatography is a common type ofchromatography used inanalytical

chemistry forseparating and analyzing compounds that can be

vaporized withoutdecomposition.Typical uses of GC include testing the purity of a particular
http://en.wikipedia.org/wiki/Chromatographyhttp://en.wikipedia.org/wiki/Analytical_chemistryhttp://en.wikipedia.org/wiki/Analytical_chemistryhttp://en.wikipedia.org/wiki/Separation_processhttp://en.wikipedia.org/wiki/Vaporizedhttp://en.wikipedia.org/wiki/Chemical_decompositionhttp://en.wikipedia.org/wiki/Chemical_decompositionhttp://en.wikipedia.org/wiki/Vaporizedhttp://en.wikipedia.org/wiki/Separation_processhttp://en.wikipedia.org/wiki/Analytical_chemistryhttp://en.wikipedia.org/wiki/Analytical_chemistryhttp://en.wikipedia.org/wiki/Chromatography


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substance, or separating the different components of a mixture (the relative amounts of such

components can also be determined). In some situations, GC may help in identifying a

compound. In gas chromatography, the mobile phase (or "moving phase") is a carriergas,

usually aninert gas such ashelium or anun-reactive gas such as nitrogen. The stationary

phase is a microscopic layer ofliquid orpolymer on an inertsolid support, inside a pieceofglass ormetal tubing called a column. The gaseous compounds being analyzed interact with

the walls of the column, which is coated with different stationary phases. This causes each compound

toelute at a different time, known as the retention time of the compound. The comparison of retention

times is what gives GC its analytical usefulness.

2.Hydrogen generator

This apparatus is used for the generation of hydrogen that is used in the lab .

3.Refractro meterThis apparatus is used for the calculation of refractive index of different chemical used in

industry.

4.Viscometer

This is used for the calculation of viscosity of the chemicals.

5.Senso direct

This is used for the calculation of PH value and conductivity of different chemicals

6.Titration

Titration is used for different test which include hardness of water, ca ions, ma ions, total acid

value, free acid etc.

7.Specrophotometer

This apparatus is also used for different types of test. A spectrophotometer is a device or more

specifically a photometer that is used to measure intensity of light as a function of the

wavelength of light. A spectrophotometer is the combination of two devices, a spectrometer

and a photometer. Spectrometer is used for producing light of any selected wavelength or color

while a photometer is used for measuring the intensity of light. When an aqueous sample of

compound is placed in the light path of the spectrophotometer, the sample may absorb all the
http://en.wikipedia.org/wiki/Gashttp://en.wikipedia.org/wiki/Inerthttp://en.wikipedia.org/wiki/Heliumhttp://en.wikipedia.org/wiki/Reactivity_(chemistry)http://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Polymerhttp://en.wikipedia.org/wiki/Solidhttp://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Elutionhttp://en.wikipedia.org/wiki/Elutionhttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Solidhttp://en.wikipedia.org/wiki/Polymerhttp://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Reactivity_(chemistry)http://en.wikipedia.org/wiki/Heliumhttp://en.wikipedia.org/wiki/Inerthttp://en.wikipedia.org/wiki/Gas


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Result:

Its color will be blue.

Procedure

Lets find the A.V of DOP sample.

Take the sample of DOP at any instant like reactor, stripper and Run down. Take methanol

Commercial in flask. Indicator is Bromoethyle Blue two drops. Titrate it against KOH.

Result

If its color would change like Yellow then its mean that it has some Acid value.

If no change in color occurs then its mean that it has no Acid value.


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CHEMICAL REACTION OCCURING IN INDUSTRY

[O]

1. Orhtho-xylene --------------------> phthalic anhydride + maleic anhydride + citraconic

anhydride

V2O5+Sb2O3

+ benzoic acid + phthalide + ortho-tolyaldehyde

DOP preparation

catalyst

phthalic anhydride + 2 alkyl alcohol ------------------> DI-octyl phthalate +water

Test analysis for 2-EH

Sr.no Test limits

1 Acid value (mg of KOH/g) 0.05

2 Moisture content % 0.13 Purity by GC % wt Min 99.7

4 Appearance clear

5 Specific gravity 20 degree C 0.832-0.833

6 Colour Max 5(APHA)

Test for DOP

Sr .no Tests Limits

1 Acid value 0.022 Moisture content 0.05

3 Purity by GC Min 99.7

4 Appearance Clear

5 Colour Max 30

6 Specific gravity 0.986+0.02


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Test for PA

Sr.no Tests Limits

1 Solidification point 130.9 C

2 Colour (APHA) 203 Heat hazard at 250 C(APHA) 40


5 Benzoic acid % 0.05

6 Sheild life /expiry 0.6 month

Test for MA

Sr.no Tests Limits1 Solidification point 52.4 C

2 Maleic acid(%)


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WATER ANALYSIS

Tests Demin water Boiler feed

water

Boiler blow

down

Cooling water

Limits Limits Limits LimitsPH 6---7 9---9.5 10---10.5 6.5---7

Cond US


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3.Ware house

Purpose

Ware house is also known as the back bone of the industry .it contain all the records of the

stock available in industry such as raw material, packing of material, finishing goods

.equipments etc. moreover warehouse are profit-oriented enterprises so their goal is to

provide the highest service standard at the lowest possible cost and by the highest utilization

of their resources .main objective of ware house is to facilitate all department related to

receipt and issue of material at the right time ,in the right quantity and quality. for the issue of

any material the indent is made for it the main purpose of the indent is to describe the whole

process of receiving ,weighting ,unloading ,storage different raw material received in bulk

quantity in order to ensure effectiveness of material and to avoid any kind of losses ,miss-

happening /accidents during unloading. The ware house department does the following works.

1. Daily stock report.

2. drum inspection

3. Daily drum scale

4. reduce daily wagers over time

5. color coding

Indent procedure

Indent is the document prepared to raise the demand of any item and then owned information

to the procurement dept for subsequent purchase of the indent items. The main purpose of

rising a complete information to the procurement dept .which must be sufficient for purchasing

the required item..indent must be prepared in such a manner that procurement dont have to

reach for the indent department for clarification in general to get them clarified regarding what

actually is the item indented .similarly indent also provide a tool to the warehouse .


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4.Electrical Department

Purpose:

This department control all the parameters or instruments electrically. This department usesfour sources of electricity. 1

st is from WAPDA producing about 1200kv at a cost of 10 Rs. per

unit. The 2nd

source is gas turbine which is the cheapest source of electricity producing 1064kv

at a cost of 4 Rs. per unit. The 3rd source is diesel turbine producing about 800 kv at a cost of

26 Rs. per unit. The 4th

source is steam turbine producing 1150kv.


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5.Mechanical department

Purpose

Tool is the basic of mechanical dept. This dept deal with all the mechanical part of the plant and

solved out all the problem happened mechanically .

Mechanical department deals with the

a) Maintenance, replacement and repair of all Mechanical Engineering equipment and systems.

b) Operation and monitoring of the dynamic positioning system.

c) Plan and construct the installation of mechanical systems.

d) Plan and discuss Risk Assessment Procedures

e) Mechanical equipment inspection and repair.

f) Maintain documentation in compliance with regulatory requirements.

g) Conduct tests to ensure compatibility and safety of components.

h) Coordination of maintenance schedule for mechanical systems and components.

1. 1.stationary part

2. 2.rotary part

1. Stationary part

This include all the stationary part .which is as follows

grinder,dry scale,level ,valve,torque spanner,pipe ranch ,fabrication ,insulation gas ket

,flanges,gland packing,distillation column ,reactor ,column pipening etc

Welding

welding is used for joining metal .it is of three types

electric stick

gas tug

pvc rod

Grinder

This is used for grinding different instrument. This is of two types

disc


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cutting

Spanner

Spanner is used for opening and closing of nut, bolts, etc it is of three types

open

ring

combination

Valve

Valve is used to control pressure, level, flow rate, volume it is of several types which is as

follows.

1.Gate valve

General Characteristics

Straight flow

Directionless valve

Minimum pressure drop

Valve's bore

pipe opening

Not recommended for throttling

Occupy less space as compare to Globe

Low cost

Frequent opening/closing not recommended

A metallic gate/disc is used to stop the flow

2,Globe valve

Causing Turbulence & highP

Plug prone to wear/erosion


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Recommended for throttling

Used for unidirectional flow

Valves bore < pipe opening

3,Plug valve


Used for quick opening and closing

Not recommended for throttling

Used for more than one inlet/outlet lines

Provides straight through flow

Used for low pressure services

Turn plug at 90o for opening/closing

No gland packing used

Tapered plug is used to avoid sticking

4. Butterfly valve


Reliable & long service life

Lines cannot be cleaned by pig

Suitable for low pressure service, 10-20 bar


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Leakage 0.5% of rated CV.

Easy to operate, both manually & by remote control.

Circular shaped disc used for quick opening/closing

5 Check valve

GENERAL CHARACTERISTICS

LowP

Quick opening

Low maintenance costs

To control the direction of flow

Used for both high/low pressure

Most reliable and long service life

Used for both horizontal & vertical flow

6.Non-return valve

7.Flaper valve

8.Angle valve

Fabrication

It is used for different line arrangement it include elbow and t-shape. Elbow is of different angle.

Gas-kit

It is used to prevent leakage .it is of different types. Such as graphite, asbestos, sparo-gram, rubber etc


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Flanges

It is used for joint for two pipes

Neck weld, orifice is its types.

Heat exchanger

A heat exchanger is a piece of equipment built for efficientheat transfer from one medium to

another. The media may be separated by a solid wall, so that they never mix, or they may be in

direct contact exchangers.

Types

shell and tube

plate

After a period of use the fouling factors arise in the exchangers that is the rusting and a layer of

foreign items get settled at the bottom decreasing the flow rate. The fouling can arise due to

the following factors.

1.Sedimentation

2.Corrosion

3.Algae growing

4.Salt deposit

5.Coking

6.Chemical reaction

The techniques which are used during operation fouling encountered in heat exchangers are as

under:

1. Mechanical cleaning

2. Chemical cleaning

2. Rotary part

This include all the rotary parts

Compressor, pumps, turbine etc
http://en.wikipedia.org/wiki/Heat_transferhttp://en.wikipedia.org/wiki/Heat_transfer


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Compressor

It is used for making air compressed which is used in plant for different purpose

PumpsIt is used for transferring the liquid from low elevation to high elevation.it is of two types. Pumpis a machine that imparts energy to the liquid.Move liquids from lower pressure areas to areas ofhigher pressure.1. Centrifugal 2.positive displacement

Turbine

This is used for generating electricity from steam and gas


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6. Instrument department

Instrument is an caught device which we can use in process, monitor this action .give the result

on Distribution control system.(DCS) . It is used to control the following parameter.

1. Temperature

2. Pressure

3. Flow rate

4. Level

1. Temperature

Temperature is the measure of hotness or coldness of the body .in nimir for temperature calculation

.thermo couple is used.

Thermo couple

A thermocouple consists of two conductors of different materials (usually metal alloys) that

produce avoltage in the vicinity of the point where the two conductors are in contact. The

voltage produced is dependent on, but not necessarily proportional to, the difference of

temperature of the junction to other parts of those conductors. Thermocouples are a widely

used type oftemperature sensor for measurement and controland can also be used to convert

a temperaturegradient into electricity.

The thermo couple used in nimir is k type American standard. Yellow wire is +ve charge is made

of nickel-chromium and red wire ve charge is nickel aluminium.it have two junction hot and

cold .hot sense the heat and convert it into micro voltage and sent to transmitter which gives

result on the DCS.

2. Pressure

Many techniques have been developed for the measurement ofpressure andvacuum.

Instruments used to measure pressure are called pressure gauges or vacuum gauges.

A manometer could also refer to apressuremeasuring instrument,usually limited to measuringpressures near to atmospheric. The term manometer is often used to refer specifically to liquid

column hydrostatic instruments.

A vacuum gauge is used to measure thepressure in avacuumwhich is further divided into

two subcategories, high and low vacuum .The applicable pressure range of many of the

techniques used to measure vacuums have an overlap. Hence, by combining several different
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types of gauge, it is possible to measure system pressure continuously from 10 mbar down to

1011

mbar.

3. Flow rate

Flow rate is measured by rotameter. A rotameter is a device that measures theflow

rate ofliquid orgas in a closed tube.

It belongs to a class of meters calledvariable area meters,which measure flow rate by allowing

the cross-sectional area the fluid travels through to vary, causing some measurable effect
http://en.wikipedia.org/wiki/Bar_(unit)http://en.wikipedia.org/wiki/Flow_ratehttp://en.wikipedia.org/wiki/Flow_ratehttp://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Gashttp://en.wikipedia.org/wiki/Variable_area_meterhttp://en.wikipedia.org/wiki/Variable_area_meterhttp://en.wikipedia.org/wiki/Gashttp://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Flow_ratehttp://en.wikipedia.org/wiki/Flow_ratehttp://en.wikipedia.org/wiki/Bar_(unit)


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7. UTILITY PLANTS

a) Demin water

b) Boiler

c) Turbine

d) Compressor

e) Nitrogen generation

f) Cooling tower

a)DEMIN WATER

Purpose

It is mostly used for steam generation which is used as a heating medium in plant . It is also used as a cooling medium.

As water is an excellent solvent for many chemicals. So another important utility of

water is as a solvent for preparation of various solutions.

Making of demin water

Cation bed

Raw water from the storage tank is first sent into the cation ion vessel from the top resin RH isadded in it.the +ions in raw water release and the following reaction take place .

2HR+cacl2 CaR2 +2hcl

2HR +CaSo4 CaR2 +h2so4

2HR +Ca(HCO3)2 CaR2 +2H2Co3

De gaser vessel

This vessel is used to remove the dissolve oxygen from water .force draft fan is placed at the

bottom.

Anion bed

In this bes vessel the raw water donate ve ion and the resin ROH is added in it the following

reaction takes place


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Raw

wate Cation bed DegaserAnion

bed

Mixed

bedDemir

water

BoilerBoiler is used to produce steam .

Law on which it works

It works on the basis of 2nd

law of thermodynamics which states that thermal energy is

converted in to mechanical energy, and Charles law ,boyles law and gas law.

Purpose

1. heating medium

2. turbine

Steam types


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Steam produced is of two types saturated and super saturated .the steam which is below its

critical temperature is called wet steam it contains traces of moisture and steam above critical

temperature is dry steam it doesntcontain any moisture .the boiler is mainly of two type .

Boiler types

1. fire-tube boiler

2. water tube boiler

Fire tube boiler contains hot gases inside the tube and water inside the shell side .where as

water heat boiler contains water inside the tube and hot gases out side the tube

Description

Boiler used in nimir chemicals is fired tube boiler it is made by German company SILLER AND

JAMART TECHNISCHE DIENSTE .it is package type 3- pass boiler .with the heating capacity of 8

ton /hr (eigth ton of steam generate from water per hour ) and produce the steam at a

pressure of 28 bar at temperature 340 degree centigrade .the basic purpose to produce steam

is for heating medium and run the turbine and the level is maintain above 60 if it is less then

chances of explosion take place .it is the 1st

class of boiler with heating surface area 22006

sqr/fts.the length of tube is about 20 fts and dia of tube 3 inches .the boiler get trip due to

following reasons

Triping reasons

1 low air pressure

2 low oil pressure

3 low Gas pressure

4. high steam pressure

Burner

1. Natural gas

2. Diesel


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Working of boiler

Demin water is used in the boiler . fuel is mixed with air and it is burnt in burner the hot gases

pass through the first stage where it heat the water .then it is pass through tubes of 2 pass and

further heat the water and produces saturated steam and then this steam is sent to pre heaterand convert into super heated steam .this steam is then sent in to plant and then it is used

where it required.

C) turbine

A steamturbine is a device that extractsthermal energy from pressurizedsteam and uses it to

domechanical work on a rotating output shaft.

D) compressor

It is a device which is used to compress the gas and increase it pressure.

Principle

It operate on Boyleslaw which state that volume is inversely proportional to the pressure.

V inversely proportional to pressure

Description

The compressor used in nimir chemical is made by MANNESMANN DEMAG Company Germany. It is

positive displacement compressor .two stages double acting compressor with 4 suction valve and 4

discharge valve .in the first stage air is compressed due to this temperature is increased and for this

purpose an inter cooler is attached with it to reduce the increase in temperature .In the second stage

the air is further compressed and then passing through cooler .it is then store in the main tank .the air is

then pass through drier to remove moisture .the compressed air produced is used for 2 different

purposes .

Plant air

Instrument air

Triping of compressor

Interruption fan

Oil pressure

Over heating motor
http://en.wikipedia.org/wiki/Turbinehttp://en.wikipedia.org/wiki/Thermal_energyhttp://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Work_(physics)http://en.wikipedia.org/wiki/Work_(physics)http://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Thermal_energyhttp://en.wikipedia.org/wiki/Turbine


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Over heating water

Over heating air

e) Nitrogen

Two sources for the nitrogen is used in nimir

1, nitrogen from air

2, liquid nitrogen

F) Cooling tower

The basic function of cooling tower is cool down the hot water from the plant where it necessary. It is

basically a cooling medium.

Types of cooling tower

Natural

Mechanical

Mechanical is further divided into two categories

Induced draft

Forced draft

They are further divided on the basis of their flow

Co-current

Counter

Cross

Description

The cooling tower used in nimir chemical is forced draft. And the flow is cross which mean that water is

introduced from the top and air from fans is introduced from the side.Differnt chemicals is used in it for

different purposes.

Sulphuric acid

It is added to maintain the PH round about 6.5

Zinc chromate


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It is added to make thin film layer on pipe to prevent corrosion.

Sodium hypochlorite

It is added to kill the biological germs.


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8. Process and Production department

A.Phthalic anhydride (PA)

B.Maleic anhydride (MA)

C.Di-octyl phthalate (DOP)

A)Phthalic anhydride (PA)

This colourless solid is an important industrial chemical, especially for the large scale production

ofplasticizers for plastics.

Appearance

White Flakes

Chemical Name of PA 1, 2 benzene di-carboxylic acid

Molecular formula C8H4O3

Molecular Weight: 148

Melting Point 131.9C

Boiling point 284.5C

Flash Point: 152C

Auto ignition Temperature: 570C

Appearance It is clear and colorless solid.

Raw Materials for PA:

1) Ortho-Xylene

2) Air
http://en.wikipedia.org/wiki/Plasticizerhttp://en.wikipedia.org/wiki/Plasticizer


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Specifications

Sr.no Tests Limits

1 Solidification point 130.9 C

2 Colour (APHA) 20

3 Heat hazard at 250 C(APHA) 40


5 Benzoic acid % 0.05

6 Sheild life /expiry 0.6 month

Chemical reaction

V205

C8H10 + 3O2 C8H4O3 + 3H2O

Process description

The reaction takes place in the fixed bed tabular reactor. The reactor is equipped with 5028

tubes. The tubes are filled with four layers of catalyst. But vanadium pentaoxide (V2O5) and

titanium dioxide (TiO2) are the main catalyst. In the oxidation of orth-oxylene in the presence

of a catalyst, the main reaction is the formation of phthalic anhydride and water by-products

are maleic anhydride, benzoic acid, Citra conic acid and aldhyde it is highly exothermic reaction.

The heat of reaction is removed by circulating molten salt, mixture of sodium nitrate and

potassium nitrate through the shell side of the reactor from bottom to top. A steam generator

is attached with the reactor for cooling the salt. Also an electrical heater for heating up the

reactor during startup.

Reaction gas cooling

The reaction mixture leaving the reactor at approximately 370C is allowed to pass through two

stage gas cooler, having three bundles of tubes, in first stage 30 bar steam is produced by

recovering heat of gases coming from reactor and in next stage water for boiler feed water is

preheated.

Switch condensers


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To recover phthalic anhydride (PA) from the product gases, the gas mixture is further cool

down in the switch condensers to a temperature at which the PA is completely condensed as

solid where asby-product gases remain in the gaseous form. Switch condensers are operated

by an automatic cycle timer so that the three condensers are on loading one is on melting at a

time. Switch condensers consist of finned tubes around which the reaction gas flows. The PA isseparated and deposits on the finned tubes of the condensers which are on cooling (loading) in

the form of crystals. While PA is melted from condenser and transfer to crude PA storage

vessel.

Pretreatment:-

Now Crude PA is subjected to pretreatment, this treatment is carried out at atmospheric

pressure and temperature is kept about 275C- 285C for dehydration as well as conversion of

certain by-products into compounds which can be separate easily in the upcoming distillation.

The pretreatment takes place in three vessels with an average retention time of 18 hours. Each

vessel is provided with agitator and the vapors of water, low boilers and PA formed , passes

through the condenser , vapors of PA condenses while water, low boilers and traces of PA is

sent to switch condensers for PA recovery.

Distillation Columns:-

a) Fore running column

b) Pure PA distillation column

The fore running column is equipped with 14 fixed valve trays and sieves separates the low

boiling components from PA. The low boilers mainly benzoic acid (BA), traces of water etc. are

collected in the residue vessel. The PA is leaving the column above a certain level by means of a

funnel and enters the pure PA distillation column.

Pure PA distillation column is equipped with 25 trays. Distillation is carried out under vacuum

pure PA is received in pure PA tank from where it is delivered to flaking or to liquid storage

tank. Purity of PA is ensured with 99.9% with color index hazen max. 20. The bottom product

from the pure PA column is further processed batch wise to recover PA in a residue

concentration system under vacuum. After residue concentration the residue is drained in the

residue vessel.


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Uses of PA

Phthalic anhydride is widely used in industry for the production of certaindyes. A

well-known application of this reactivity is the preparation of

theanthroquinone dyequinizarin by reaction with para-chlorophenol followed byhydrolysis of the chloride

The primary use of phthalic anhydride (PA) is as a chemical intermediate in the

production of plastics from vinyl chloride. Phthalate esters, which function as

plasticizers, are derived from phthalic anhydride. Phthalic anhydride has another

major use in the production of polyester resins and other minor uses in the

production of alkyd resins used in paints and lacquers, certain dyes (anthraquinone,

phthalein, rhodamine, phthalocyanine, fluorescein, and xanthene dyes), insect

repellents, and urethane polyester polyols. It has also been used as a rubber scorch

inhibitor and retarder. Alkyd Resins (Glyptal), to modify physical properties of Synthetic Resins.

Phthalic anhydride is used to make halogenated anhydrides used as fire Retardants;

pigments; dyes; perfumes; pharmaceuticals; tanning and curing Agents; solvents;

insect repellents.
http://en.wikipedia.org/wiki/Dyeshttp://en.wikipedia.org/wiki/Anthroquinonehttp://en.wikipedia.org/wiki/Quinizarine_Green_SShttp://en.wikipedia.org/wiki/Quinizarine_Green_SShttp://en.wikipedia.org/wiki/Anthroquinonehttp://en.wikipedia.org/wiki/Dyes


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B)maleic anhydride (MA)

Appearance

Moltan colorless liquid or white solids .penetrating odor.sinks and mixer slowly with water.

Physical properties

Chemical name 2-5 furandione


Molecular weight 98.06

Boiling point 202 degree C

Melting point 52.4 degree C

Thermal decomposition >=2oo degree C

Flash point 101.7 degree c

Auto ignition temperature 475 degree c

Hazard identification

Health hazards

Liquid or solid will burn skin and eyes .skin contact cause irritation and redness.harmfull if

swallowed .inhalation causes coughing. Sneezing and throat irritation, vapour cause severe eye

irritation ,photophobia and double vision may occur.

Specifications

Sr.no Tests Limits

1 Solidification point 52.4 C2 Maleic acid(%)


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PROCESS DESCRIPTION

The wash water of the off-gas scrubber in the adjacent PA-Plant contains maleic acid, Citra

conic acid, benzoic acid, phthalide, orthotolaldehyde and traces of phthalic acid. The maleic

anhydride from solution of different organic compounds as mentioned before is recovered in

the maleic anhydride recovery plant in a two-stage distillation system.

1) Dehydration

For the recovery of maleic anhydride (MA) dissolved in the wash water of the off-gas scrubber

the free and chemical bonded water have first to be separated from the organic compounds,

such as maleic acid, phthalic acid and others. This is done in an azeotropic distillation using

orthoxylene (OX) as entertainer.

The column is equipped with 19 sieve trays. The solution from scrubber first passed through

crystallizer for the recovery of pthalic anhydride and then passing it through filter to remove

(PA) crystals in the form of cake and remaining solution is fed to the 15th

tray of dehydration

column. The necessary heat for dehydration is supplied in reboiler by SM steam.

The overhead vapors (ortho-xylene and water) are condensed in condenser and cooled in

cooler using cooling water. The mixture is separated in separator from where the orthoxylene

(OX) is fed as reflux to the column.

2) MA-Distillation

MA-distillation consists of packed column. The bottom product of the dehydration column,

consisting of maleic anhydride, ortho-xylene, Citra conic anhydride, phthalic anhydride etc, is

collected in the intermediate tank. This tank is equipped with an agitator to prevent settling of

solids. The mixture of compounds from intermediate tank is fed to the pure MA-distillationcolumn and separated batch-wise.

There are 5 stages in this column which are mentioned below:

1) Ortho-Xylene recovery (1st

Stage)


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2) Ortho-Xylene recovery (2nd

Stage) low boiling fraction with residual Orthoxylene

3) Pretreatment

4) Pure MA Recovery

5) Residue concentration

After residue concentration the residue is drained in the residue vessel.

Uses of Maleic Anhydride:

It is used in the formation of Unsaturated polyester resins and alkyd resins ,used

in general construction, bathroom fixtures, corrosion resistant tank, pipes and

ducts, electrical components, synthetic marble, paints and coatings,fibre glassreinforced plastic.

Used in the manufacturing of fumaric and malic acid, they are used in paper

sizing resins and beverage acidulants and in pharmaceuticals.

Used in the manufacturing of lubricating oil additives which are used in gasoline

and diesel engine crankcase oils as dispersants and corrosion inhibitors, prolong

oil change intervals and improve the efficiency of automotive engines.

The addition of maleic anhydride to drying oils decreases the required drying

time and improves the coating quality of lacquers.

It is used in making vinyl copolymers that are used in paper treatment, emulsifier,stabilizing agents, adhesives, detergents, cosmetics etc.

Its use in agricultural chemicals like herbicides, pesticides, plant growth regulator

and soil sterilizer.


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C) Di-Octyl phthalate (D.O.P)

DOP is produced by esterification process, it is highly compatible with PVC and has an excellent

plasticizing effect and has average characteristics of various plasticizers. In PVC processing the

consumption of DOP is the highest among all plasticizers.

Appearance

Clear

Colorless oily liquid

Water like appearance

Faint odor

Physical properties

Chemical name 1,2 benzene di carboxylic acid (2-ethyl hexyl )ester


Molecular weight 390

Melting point - 50.0 degree C

Boiling point 230. Degree c

Specific gravity 0.986

Stability stable under ordinary condition

Flash point 199 degree c

Auto ignition temperature 390 degree c

Toxicity Oral rat LD50: 30 gm/kg

Hazard identification

Main hazards

Possible risk of impaired fertlilty .possible risk of harm to the unborn child.


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Health hazards

Eyes : liquid or mist may cause slight transient irritation

Skin : prolong or repeated contact with skin may cause slight irrition

Inhalation :exposure to vapors at higher concentrations may cause irritation of nose .throat

,and respiratory tract.

Raw material for DOP

Pthalic anhydride

2 ethyle hexanol

Chemical reaction

C8H4O3 + 2C8H18O C24H38O4 + H2O

(Pthalic anhydride) (2-ethyl hexanol) (DOP)

(Water)

Spacification of DOP

Sr .no Tests Limits

1 Acid value 0.02

2 Moisture content 0.053 Purity by GC Min 99.7

4 Appearance Clear

5 Colour Max 30

6 Specific gravity 0.986+0.02

Process description

Major sections

1. Mono-ester

2. Reactor

3. Stripper

4. Crude

5. Filtration unit


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1.Mono-ester

In mono-ester 2-ethyl hexanol is charged from main storage tank T-431, to heat alcohol up to

90C for approximately 1 hour and then sent to reactor for reaction with phthalic anhydride

(PA).

2) Reactor

In reactor charge phthalic anhydride from main storage tank to react with alcohol to form

mono-ester in the presence of tetra isopropyl titanate Ti (OC3H7)4 as catalyst at 220C

temperature. Reaction needs 6 hours for completion to get the required Acid value (A.V) 0.2 mg

KOH/g of sample. After this, product is shifted to Stripper.

3.Stripper

This is used to remove unreacted alcohol and by product water. For this there are nine steps to

get the required steps in DOP like low acid value ( 0.02 g KOH ), low moisture content (0.05 %)

,color 15-20 APHA( American physical health association) and no smell of alcohol.it contain 9

steps

a)Vacuum Stripping

Create a vacuum in stripper up to 0.15mbar pressure for 45minutes to remove alcohol and

water. In this procedure 85% of alcohol will be removed.

b)Steam Stripping

Now inject steam at 3.5 bar having temperature 200C with flow rate 600kg/hr for 80minutes

to remove remaining alcohol and water. It will increase the temperature of crude DOP in

stripper to 175-180C.Now break vacuum with nitrogen.

c) Cooling

After steam stripping now start cooling to cool the crude DOP up to 105C by the help of shelland tube condenser and air cooler.

d) Dosing


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Now add (10kg NaOH + 400 liter water) solution by creating vacuum up to 0.9mbar to make

salt of phthalic anhydride which had not reacted with alcohol to form DOP After this break

vacuum.

e) Agitation

Start agitation for 30min to homogenize the material and for complete reaction of phthalic acid

with caustic soda.

f) Settling

Stop agitator for 30 min to settle down, water, alcohol etc.

g) Draining

Remove water by opening drain line valve.

h) Heating

Now start heating under vacuum of 0.15mbar to rise the temperature of the material up to

155C, this process will take about 45min.Now stop heating and start steam stripping for 30 min

to remove moisture content (M.C) and traces of recycle alcohol.

i) Sample

Now sample of crude DOP is sent to laboratory for testing if the results will be according to our

requirement e.g. acid value(A.V) should be 0.02g KOH , moisture content(M.C) 0.05%, color

15APHA.Now product is ready for filtration.

4) Filtration Process

a) Filling with precoat susp

First of all fill the filtrate vessel with crude DOP and add resin (in the powder form) which iscalled as precoating susp.

b) Precoating

Now start filtration of the material in filtrate vessel by shifting it into filtration unit for

precoating of Socks on candles.


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c) Bleeding

In this step we shift the filtered DOP from filtration unit to filtrate vessel for precoating of

candles in next batch.

d) Filtration

In this step filtration of crude DOP is done.

e) Emptying

In this process empty the filtration unit by shifting the DOP back to crude vessel When socks

will block due to cake formation and more DOP can not be filtered.

f) Drying

Dry the filtration unit by injecting air at 6.5 bar pressure for 18 min.

g) Depressurizing

Depressurize the system by stopping the injection of air and open a vent.

h) Removal of cake

Inject air in socks at 7bar pressure and depressurized then pressurized the system again, repeatthis step 3-4 times , cake will left the socks free, now remove the remaining cake manually.

i) Depressurize

In this step UV 3420 will open for vent to depressurize the system again.

Uses of DOP

It is used in Versatile Plasticizer, Used in Plasticizing Poly Vinyl Chloride (PVC)

Binder in Paints, Pigmented and Unpigmented Lacquers and for Grinding Pigments.

DOP is used as a dielectric fluid in electric capacitors.

DOP is used as the solvent in erasable ink, as an inert ingredient in pesticides, as vacuum

pump oil.


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DOP is used as a Plasticizer in PVC resins for fabricating flexible vinyl product like:

tablecloth, shower, curtain, raincoat, shoes, swimming pools liners, polymeric coating,

cable coating, component of paper & paperboard, deforming agents, surface lubricants

Block diagram of DOP

Fumes

Of 2EH

r

2-EH

P-14

Kiquid 2-EH

P-20

P-21

P-27

F-311

Mono-

ester

Rea

ctor

D-

321

stripperCrude

vessel

F-341D-

331

Ejector

dr

u

m

Slope

vesse

condenserCondenser

condenser

Separator

Heat

Exchanger

Filter

Sepa

rator

Recylce

alchol

Recylce

alcholStor

agetank

Storag

e tank

Li

qu

id

2-

EH

hT IN

Ht

out

PA

Dosing of

NAOH

Recyle alcohol

Liq DOP

Crude DOP

H20


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Internship Report of Nimir Chemicals

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