resin production

7/22/2019 Resin Production

1/22

Under the guidance of:-

Er. Abhishek Sharma

Presented by:-

Jayant Kushwaha

Pawan kr. Ful faki r

Final year, chemical Engg.

Dr. B. R. Ambedkar ni t , Jalandhar (Punjab)

Understanding & Study of the Resin

Production Process

Vocational Industrial Training Project Presentation

1


2/22

ABOUT SRF

SRF is a multi business entity engaged in the manufacture of

Chemical based industrial intermediates. Today its business

portfolio covers Technical Textiles, Chemicals, Packaging

films and Engineering Plastics. SRF Limited is a USD 760MIndustrial group. From its inception in 1974, SRF today

operates from eight plant locations in India and abroad.

Packaging Film Business (PFB) involves the production of

Bi-axially Oriented Poly Ethylene Terephthalat (BOPET) orPolyester Film.

2


3/22

INTRODUCTION TO RESIN PLANT

In Resin Plant, PET Resins (Chips of PET Polymer) are made from

which the packaging films are made.

In Resin Plant, Batch Polymerization (BP) & Continuous

Polymerization (CP) both are running simultaneously.

At full capacity CP runs at 150 tons/day and BP runs at 20

tons/day.

Polyester or Poly Ethylene Terephthalat (short PES or PET), is

produced in two chemical steps.

The raw material, 1 mol of Pure Terephthalic Acid (PTA) reacts

with 2 mol of Mono Ethylene Glycol (MEG or simply EG) at

raised temperature (240C 260C) to form Bis (2-Hydroxyethyl)

Terephthalat (BHET) also named Di-glycol Terephthalat (DGT).

3


4/22

INTRODUCTION (cont inued)

This first step of reaction is called esterification and can be

carried out at different pressures.

In this plant MEG or EG (monomer) is fed at lower

molecular ratio than 2. Due to which the product obtained,the monomer is a mixture of monomer, pre-polymer & non-

reacted PTA and EG.

In the second step the monomer is poly-condensed by the

use of a catalyst (Sb2O3) & heat stabilizer at Vacuum and

temperature between 270C - 285C.

4


5/22

RAW MATERIAL FOR RESIN PLANT

Pure Terephthalic Acid (PTA)

PTA is a white crystalline free

flowing powder.

It is delivered in tank trucks,container or 1 ton flexible big bags

which are kept at discharge station.

These big bags are lifted to the top

of the PTA feeding tank by an

elevator.

These bags are then emptied

directly into the PTA feeding tank.

5


6/22

RAW MATERIAL FOR RESIN PLANT

Mono-Ethylene Glycol (MEG

or EG)

MEG is a clear liquid, mixable with

water. It is delivered in tank trucks or

railway tank wagons.

After laboratory check, the MEG is

pumped into the storage tank. From there the MEG is

automatically pumped to the

consumers in the poly-building.

6


7/22

OTHER CHEMICALS USED IN RESIN PLANT

Di-Ethylene Glycol (DEG)

Catalyst:- Antimony Tri-Oxide (Sb2O3)

Poly-Phosphoric Acid

Colour Additive RED (RG)Colour Additive BLUE (RH)

Silica

Magnesium AcetateHeat Transfer Fluids (HTF):-

Therminol 66

Therminol VP-1

7


8/22

Chemistry of Polyesters (PET)

Polyesters are highly polymeric substances, the individualunits of macromolecules are connected by the ester groups.

O

| |CO

Esterification Reaction:

n HOOC COOH +(n+1) HOCH2CH2OH

n HOCH2CH2OOC OOC-CH2CH2OH +2n H2O

Condensation Reaction:

HOCH2CH2OOC -[-COOCH2CH2OOC -]-(n)COOCH2OH +

HOCH2CH2OOC OOC-CH2OH HOCH2CH2OH +

HOCH2CH2OOC -[-COOCH2CH2OOC -]-(n+1)COOCH2OH

8


9/22

PROCESS DESCRIPTION9

Polyester or Poly Ethylene Terephthalat (short PES or PET), is

produced in two chemical steps. The raw material, 1 mol of

Pure Terephthalic Acid (PTA) reacts with 2 mol of Mono

Ethylene Glycol (MEG or simply EG) at raised temperature

(240C - 260C) to form Di-glycol Terephthalat (DGT).

The production plant consists of the following main process

steps:-

1) Paste Making2) Esterification with Pre-polymerization

3) Polycondensation

4) Chips Production


10/22

PASTE MAKING10

o The paste making system for both CP & BP are locatedbelow the PTA feeding tank. This tank has double cone andserves both paste mixing system for CP & BP.

o All raw material PTA, MEG, DEG are mixed to form a paste

which is feed to the esterification.o The paste is white slurry. Its viscosity is depending on mole

ratio, form and size distribution of PTA crystal.

o Mixing of all raw material including colorful additives is

done in the paste mixer at atmospheric pressure, but withnitrogen purge.

o The mole ratio of EG/PTA, is determined according to thesource and type of PTA and other operating factors.


11/22

CATALYST PREPARATION SYSTEM11

EG moistured Antimony Trioxide is used as poly-

condensation catalyst.

The catalyst is dissolved in virgin Ethylene Glycol at a

temperature of 130 to 140C. The conc. of catalyst in the solution should be 1 to max

1.5%. The catalyst is poured into the dissolving vessel.

The catalyst solution is dosed into the paste mixer

according to the PTA feed. Normal feed is 270ppm Sb onpolymer.


12/22

ESTERIFICATION12

Esterification and pre-polymerization takes place in UPR

(Universal Polymerization Reactor). UPR have 3 zones:

1. The ester 1 zone

2. The ester 2 zone3. The prepoly zone

In the esterification zones the raw materials are reacting

and forming the monomer DGT. The esterificationreaction is carried out in two reaction zones, one at the

top of the other and at a product temperature of approx.

255C to 262C and overpressure.


13/22

ESTERIFICATION (cont inued)13

The first reaction zone is equipped with an inbuilt heatexchanger and an agitator that works as a circulation

pump. That agitator circulates the product through the

heat exchanger coils and mix the new PTA/EG slurry

with the reacted monomer.

The second reaction zone serves for further reaction. In

both zones reaction water and EG are Evaporated.

In the first zone, which is operated at approx 2 to 2.5 barsoverpressure, the large amount of heat, which is

required to heat the raw materials and to evaporate

water and EG is transferred to the product.


14/22

ESTERIFICATION (cont inued)14

The monomer of first esterification zone is feed to the secondzone by pressure difference. The second zone is operated at

a lower pressure, preferably at 0.4 to 0.7 bar overpressure.

The product operating temperature is about 260C to 262C.

The product transfer from 2ndester zone to the Prepoly zone,

which is the lower part of the UPR reactor is achieved by the

difference in operating pressure. The ester 2 operates at 0.4

to 0.7 bar & the Prepoly zone at a vacuum of 25 to 40 mbar.

In this plant a monomer connection from ester 2 to the batch

plant is foreseen. By a mass flow meter and control valve a

certain quantity of monomer can be continuously taken out

and fed to the esterification reactor of the batch plant.


15/22

PROCESS COLUMN & STRIPPING COLUMN

15

o The Process vapor of esterification is led to a Process

Column to separate water from EG.

o The column top is operated at atmospheric pressure and has

a re-boiler at its lower end.

o At the top of the column, the low boilers like water &

aldehydes are bleed off. Whereas the high boilers, EG &

some water leave the column at the bottom.

o The condensed reaction water is led to a stripping column inorder to reduce the BOD & COD values. The water is

flowing from top to bottom whereas air is passed in counter

current.


16/22

POLYCONDENSATION16

In Polycondensation, the remaining excess EG is evaporated, whichresults in the formation of long molecular chains of polymer withthe required properties of the Polyester.

The reaction takes place in two steps at raised temperatures, 270Cto 285C and vacuum between 40 and 0.5 mbar.

The first step of Polycondensation is made in the Prepoly reactorthat is installed in the lower part of the UPR reactor. This part ofthe reactor is a combination of flasher and pre-polymerizer inwhich up to 95% of the excess EG is evaporated.

From the outlet of Prepoly the polymer flows to a polymer gear

pump that transports the pre-polymer to the Finisher. Aviscometer is installed in the polymer line that measurescontinuously the viscosity of the polymer that is fed to theFinisher. In the Finisher the pre-polymer is brought to its finalviscosity and properties.


17/22

FINISHER17

o The FINISHER is a horizontal jacketed heated vessel with a

horizontal, ex-centric shaft less cage agitator with disks.

o The speed of the shaft can be varied between from 0.5 to 5

rpm. A standard speed is 2 to 3 rpm.

o In the product inlet zone, where the viscosity is relatively

low, the pre-polymer is moved upwards by cups mounted to

the disk rings.

o While rotating to the top, the cups are emptied and thepolymer flows down, forming films & strings.

o The internals of the reactor are designed to work as a

cascade to avoid remixing of the polymer.


18/22

CHIPS PRODUCTION18

Behind the polymer filter, the polymer flows to the two die(casting) heads of the underwater (Reiter Supply).

The polymer is pressed through the holes of the die plate,

forming wires of approx. 2mm to 3mm diameter. Below

the spinnerets the polymer wires are cooled down on the

special stainless steel cooling board, they solidify and are

led to the cutter.

In the cutter the wires are cut to length. Solidification andcutting is done under water to cool the polymer and to

avoid sticking.


19/22

CHIPS PRODUCTION (continued)19

The mixture of cooling water and chips, coming from thecutter is pre-separated in special screen. A part of the

water flows back to the water tank of the cutting system.

The chips and remaining water is passing a pre-dryer,

centrifuge in the centrifuge the remaining water is

separated from the chips and also flows to the water tank.

The chips are falling on a screen that separates uncut or

long parts.


20/22

STABILIZER PREPARATION SYSTEM20

Poly Phosphoric acid is used as heat stabilizer.

The stabilizer is a viscous liquid that is dissolved in virgin

EG at a temperature of 30 to 40C.

The conc. of stabilizer in the solution should be 1 to 1.5%.Normally the concentration of active stabilizer in the paste

is around 82 to 84%.

The stabilizer solution is dosed into the monomer after

esterification.

Normal feed is 10 to 15ppm phosphorous on polymer.


21/22

SILICA PREPARATION SYSTEM21

Silica slurry is prepared using silica and virgin glycol.

The final conc. (ppm) of silica slurry to be prepared is first

decided, then measured quantity of virgin EG is taken in

preparation vessel.

Measured quantity of silica powder is then added to

preparation vessel over a period of 2-3 hrs.

The slurry is then passed through a pearl mill which crushes

the agglomerates. Then this slurry is transferred to an adjustment vessel where

the conc. is measured & glycol is added to adjust the

concentration.


22/22

22

resin production

Documents