INTERNSHIP REPORT PREPARED BY: ZEESHAN AHMED (CH-038) SHARJEEL ZAHEER(CH-055)

DEPARTMENT: CHEMICAL ENGINEERING (THIRD YEAR)

24-05-2012 TO 23-06-2012

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INDEX

S.NO. CONTENTS PAGE NO.

1 INTRODUCTION TO NOVATEX 3

2 GROUP PRODUCTS 4

3 MONOMERS AND POLYMERS 5

4 PPLYMERISATION 6

5 INTRODUCTION TO PET 7

6 HSE (HEALTH AND SAFETY ENVIRONMENT ) 8

7 POLY CONDENSATION II 10

8 BATCH PREPARATION 13

9 FILTER CLEANING AREA 19

10 FURNACE 21

11 SSP (SOLID STATE POLYMERIZATION) 23

12 NITROGEN PURIFICATION SYSTEM 26

13 UTILITY 29

14 LABORATORY 37

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INTRODUCTIONGatron (Industries) Ltd. and Novatex Limited belong to a group of companies, G&T – Gani & Tayub. The group is in business since 1948. These five decades of operational excellence, experience and expertise have all formed a combined strength to empower the group as a leading name in fashion garments (BONANZA), Synthetic Textiles, Polyester Filament Yarn, Polyester Chips and PET Resin in Pakistan. The group employs more than 6,000 people in the country.

Novatex Limited {along with Gatron (Industries) Limited} is the only PET Resin Bottle Grade manufacturer in Pakistan, with the brand name of "Gatronova."

Novatex produces PET Resin for Domestic & Export sales.

Gatron produces PET Resin for in-house use in the manufacturing of PET Preforms.

The Group is in Polymer production since 1988 and in PET Resin production since 1998.

The total PET resin production capacity is 235,000 mt/annum, out of which more than 70% of the quantity is available for export.

Certified to meet FDA & EEC standards. Suitable for all applications of PET, including

sheet. Widely approved by major CSD and Mineral water

brands in the World. Used by customers in more than 45 countries

with major quantities going to Western Europe. Fast Reheat resin is also available.

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With the advantage of regular in-house testing on both injection molding and blow molding machines, Gatronova has the advantage of utilizing this complete loop to continuously optimize it's quality.

Capacity to produce over 1.5 billion preforms per year. The PET Resin (raw material) for these preforms is produced in-house by Gatron and Novatex and therefore gives standardized & consistent preforms.

Sizes range from 13 gms to 55 gms, with neck sizes 28 mm PCO / BPF & 30/25, for 330ml to 2250 ml Water / CSD bottles.

Produced on Husky HyPET & G-Line Machines mainly installed after 2004.

Nearly half of the perform production is exported. Preforms are tested not only in the laboratory but also

by actual blowing into bottles on regular basis. So, quality of preforms is also monitored in actual use.

GROUP PRODUCTSPET Resin Bottle Grade

PET Preforms for Bottles

PET Bottles

Polyester Chips Textile Grade

Polyester Filament Yarn

Warp Knit & Raschel Fabrics

Curtains

Ready-Made Garments

Scarves

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Bed Linen

Home Textiles

Circular & Flat Knit Fabrics

Woven Fabrics on Shuttle-Less Looms

MONOMERS AND POLYMERMonomers are the building blocks of more complex molecules, called polymers. Polymers consist of repeating molecular units which usually are joined by covalent bonds.

Monomers

Monomers are small molecules which may be joined together in a repeating fashion to form more complex molecules called polymers.

Polymers

A polymer may be a natural or synthetic macromolecule comprised of repeating units of a smaller molecule (monomers). While many people use the term 'polymer' and 'plastic' interchangeably, polymers are a much larger class of molecules which includes plastics, plus many other materials, such as as cellulose, amber, and natural rubber.

Examples of Polymers

Examples of polymers include plastics such as polyethylene, silicones such as silly putty, biopolymers such as cellulose and DNA, natural polymers such as rubber and shellac, and many other important macromolecules.

POLYMERIZATIONPolymerization The process by which monomers are transformed into polymers is called polymerization.

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Polymers are macro-sized molecules of relatively high molecular mass, which find extensive use in our daily life.

Polymers are large but single chain-like molecules in which the repeating unit derived from small molecules called monomers are covalently linked. Structurally, they are characterized by many repeating molecular units which form linear chains or a cross-linked network.

Common examples of materials made from polymers are plastic dishes, cups, non-stick pans, automobile tyres, plastic bags, rain coats, television and computer cabinets, flooring materials and materials for biomedical and surgical operations.

ADDITION POLYMERIZATIONDefinition: A chemical reaction in which simple molecules (monomers) are added to each other to form long-chain molecules (polymers) without by-products. The molecules of the monomer join together to form a polymeric product in which the molecular formula of the repeating unit is identical with that of the monomer. The molecular weight of the polymer so formed is thus the total of the molecular weights of all of the combined monomer units.

CONDENSATION POLYMERISATIONCondensation polymerisation is when two molecules of the same substance (monomer) react together to form polymer chain (like polythene) and eliminate a smaller (usually water) molecule.

For example, Nylon-6 is prepared by using condensation polymerisation of ε-Caprolactum

An Introduction to PET(Polyethylene terephthalate)

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PET (also abbreviated PETE) is short for polyethylene terephthalate, the chemical name for polyester.

PET is a clear, strong, and lightweight plastic that is widely used for packaging foods and beverages, especially convenience-sized soft drinks, juices and water. Virtually all single-serving and 2-liter bottles of carbonated soft drinks and water sold in the U.S. are made from PET.

It is also popular for packaging salad dressings, peanut butter, cooking oils, mouthwash, shampoo, liquid hand soap, window cleaner, even tennis balls. Special grades of PET are used for carry-home food containers and prepared food trays that can be warmed in the oven or microwave.

The basic building blocks of PET are ethylene glycol and terephthalic acid, which are combined to form a polymer chain. The resulting spaghetti-like strands of PET are extruded, quickly cooled, and cut into small pellets. The resin pellets are then heated to a molten liquid that can be easily extruded or molded into items of practically any shape.

PET was first synthesized in North America in the mid-1940s by Dupont chemists searching for new synthetic fibers. Dupont later branded its PET fiber as “Dacron.” Today, more than half of the world’s synthetic fiber is made from PET, which is called “polyester” when used for fiber or fabric applications. When used for containers and other purposes, it is called PET or PET resin.

In the late 1950s, researchers found a way to stretch a thin extruded sheet of PET in two directions to create PET film, which is now used extensively for video, photo and packaging films. In the early 1970s, the technology was developed for blow-stretch molding PET into bottles. The PET bottle was patented in 1973.

HSE (HEALTH AND SAFETY ENVIRONMENT)

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SAFETY CONCEPTS:HEALTH AND SAFETY:HAZARD:RISK:CONTROL MEASURE:ACCIDENTS:INCIDENTS:NEAR MISS: UNSAFE ACT:UNSAFE CONDITIONS:LOCKOUT/TAGOUT:

TRIANGLE OF FIRE:

There are three things need for fire.1. Heat2. Air3. Fuel

PRINCIPLES OF FIRE:

STARVATION: When we remove fuel from the fire then this is known as “starvation”.

SMOOTHERING: When we remove air from the fire then this is known as “smothering ”.

COOLING: When we remove heat from the fire then this is known as “cooling”.

CLASS OF FIRE:

There are four classes of fire.

A class fire:

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Fire of the wood.Water is use to remove this fire.

B class fire:

Fire of the liquids, liquids like oil, paints etc.Foams is use to remove this fire.

C class fire:

Energized electrical appliances.

CO2 is use to remove this fire.

D class fire:

Fire of the metals.Dry chemicals is use to remove this fire.

Water is not use for metal fire because metals have very high temperature about 1000 °C and water boils at 100 °C so when water boils hydrogen and oxygen produce and oxygen increases the fire.

PASS TECHNIQUE :

Pass technique is use to remove the fire.P: pull the pinA: aim the nozzleS: squeeze the levelS: sweep side by side

In fire extinguisher if needle on the red it means it can not use but if the needle is on yellow or green then it can be use.

CO2 extinguisher has a big discharge nozzle and has not any meter.

16 is the telephone number for fire brigade.

Q: what should you do in case of fire?

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1. Raise the fire alarm and shout fire, fire , fire2. Telephone (16) for fire brigade.3. Fire extinguisher/ fire hydrant

POLY CONDENSTION IIRAW MATERIALS SPECIFICATIONS:

PTA (PURE TYEREPHTHALIC ACID)

M.WT:166.13Appearance: white powderWater content: ≤0.3wt%Mean particle size: 115-135 micro metersMelting point: 300 C

MEG (MONO ETHYLENE GLYCOL):

M.wt:62.07 g/molAppearance: colorless transparent liquidDEG: ≤0.05wt%Density (20C): 115.1-115.6 kg/m3Melting point: -13 CBoiling point: 197.6 C

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ADDITIVES :

BLUE TONOR:

Its chemical name is classified. However it is a form of dispersed dye. Its function is to keep PET B value below 1.if the value gets more than 1, chips appear to be yellow.

RED TONOR(COBALT ACETATE):

m.wt:249.08 g/molAppearance: dark purple red solidMelting point: 100CSpecific gravity: 1.705

DEG

M. wt: 106.12Appearance: colorless liquidMelting point: -8CBoiling point: 245.8C

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H3PO4 (PHOSPHORIC ACID):

Appearance: colorless viscous liquidBoiling point: 158CSpecific gravity: 1.685 @ 25CMelting point: 21C

IPA (ISO PHTHALIC ACID):

M.wt:166.1Appearance: white powderWater content: : ≤0.2wt%Melting point: 345 C-348 C

CATALYST:

CAT (NORM): ANTIMONY TRI ACETATEAppearance: white crystal powderSpecific gravity: 1.22Solubility @ 20C: soluble in EG to clear solution

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BATCH PREPARATIOIN

CAT (NOR) BATCH RECIPIE:

Conc.: 1.8%Total EG taken: 6615 kgTotal amount of catalyst (antimony tri acetate):135 kgTemperature: 60CSample collection time: after 1 hour of batch completionLab result: 7200 ppm to 7800ppm

CAT(Co) RED TONER BATCH RECIPIE:

Conc.:0.600%Total EG taken: 2940kgTotal amount of catalyst (antimony tri acetate):60kgTotal amount of cobalt acetate: 20kg

Temperature: 60CSample collection time: after 1 hour of batch completionLab result: 7100ppm to 7600 ppm

H3PO4 (PHOSPHORIC ACID) BATCH RECIPIE:

Conc.:0.85%Total EG taken: 4126kgTotal amount of H3PO4 : 42.75kgSample collection time: after 4 hours of batch completionLab result: 0.80% to 0.95%

BLUE TONER BATCH RECIPIE:

Conc.:0.0084%Total EG taken: 3200kgTotal amount of blue toner: 300 gSample collection time: after 4 hours of batch completionLab result: 22% to 30%

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PROCESS:-

PASTE PREPALATION VESSEL:-(11 TA-01) The key point of paste preparation process is to ensure definite ratio of EG/PTA & IPA in 11-TA01 so that it is required to feed PTA,EG,IPA and the catalyst, and the additives solution in accordance with the set ratio.

PTA and IPA is tipped into the paste preparation vessel in which IPA is 20kg and PTA is 840kg at the ratio of 0.023, where agitation is done to form a fine paste. Different additives are also tipped into this except H3PO4,it is fed into the esterification 2 reactor (13R01). Nitrogen gas is also passed through this vessel so as PTA can’t stick with each other to form lumps. Two pumps use to transfer the paste into 13R01.two sets of paste pumps 11-P01 ½ are installed. the capacity of each pump should meet the requirement of the whole load of the line. during normal operations two sets of pumps are in operation but if there is something wrong with one of them another pump shall take over the whole load.

ESTERIFICATION 1:-(12-RO1)

The paste which is formed is pumped to the first reactor. It is basically the continuous stirred tank reactor having a temperature of 260˚C.In this reactor, the two heating material is used to give an appropriate temperature to the paste or a material present in it. One is the sandotherm present in liquid form in the coils and the other is the dowtherm present in vapors from in the jacket. Agitation is done in all the reactors to convert in monomers.

ESTERIFICATION 2:-(13-R01) The purpose of this reactor is same as the first reactor that is to increase the intrinsic viscosity by agitation. The temperature of this reactor

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267˚c.it is also the continuous stirred tank reactor.the conversion is 96.5%.

COLUMN:-(13C01) After passing through two reactor’s the vapors of EG as well as water is then fed into the column in which the temp of bottom is at about 180˚c, so water vapors go up in the column with very small amount of EG .by showering of EG liquid, the vapors of EG condensed and go down and water vapors is condensed by off gas sprinkling tower so as to remove contents of aldehyde.

TOP VAPOR FRACTION TO CONDENSER

It is controlled that EG content in water at top of column is less then 0.5 wt % and water content in EG in bottom of column is less then 1.5%,

PRE POLY- CONDENSATION 1: (14-R01) The product is fed into the chamber of 14R01 from 13R01 due to pressure difference. This is basically the plug flow type reactor at a temperature of 277.5 degree centigrade. 14R01 is in vacuum

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FEED

REFLUX

VAPORS

condition. The purpose of vacuum is to decrease B.P of a mixture so as to separate vapors of water and E.G immediately and easily. E.G produce in poly condensation reaction and water produce in esterifIcation reaction are evaporated at a very high speed so product is mixed completely and it is not necessary to install an agitator in the reactor. The HTM is used for heating inner coils as well as jacket. The intrinsic viscosity of 14R01 at the outlet is 0.13.

SCRAPPER CONDENSOR: (14-E01)

Mixed vapor of E.G and water is fed into the scrapper condenser from 14R01 and contact with spray E.G in opposite direction. The most of E.G and a part of water in vapor will be condensed. The vapors of E.G and water that coming from 14R01 having some amount of oligomers vapors which is then converted into solid after being contact with spray E.G and then blocked the line that's why we use scrapper condenser that scraps these solid oligomers.

PRE POLY-CONDENSATION 2: (15-R01)

Material flows from 14-R01 into 15-R01 under pressure difference. 15R01 is horizontal reactor with disc rings. Material between two discs is mixed completely by the rotating disc. This is disc ring reactor having the temperature of 282.4 degree centigrade. 15R01 is equivalent to a series of completely mixed reactor in function so that reaction in the reactor is increased. The intrinsic viscosity at the outlet is ranging from 0.25 to 0.30. The revolution of a disc is controlled by an inverter.

SCRAPPER CONDENSOR: (15-E01)

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HTMHTM

The vapors of E.G and water from 15-R01 is condensed by contact with spray E.G in adverse current. This is same as 14-E01.

FILTER: (16-F01)

The material is then fed into the filter where the dust and impurities separated out to ensure the purity of the material. The size of 16F01 is 100 micron and has 70 candles.

DISC RING REACTOR: (17-R01)

Final poly condensation reactor 17R01 is a horizontal reactor with disc rotor and driven by a double shaft. HTM vapors is present in the jacket to melt the polymer that stick with wall as the material is so viscous as well as to maintain the temperature of the reactor at 283.5 degree centigrade. The purpose of using disc ring reactor is to mix the material as we know that the mixture is highly viscous that agitator can't do this operation.

SCRAPPER CONDENSOR: (17-E01)

The vapors of E.G and water is fed into 17E01 where it is condensed but some amount of E.G vapors remain uncondensed and it is low velocity vapors therefore a super sonic velocity vapors of E.G that coming from glycol evaporator take these slow vapors to the jet through venturi to maintain the pressure.

E.G VAPOUR JET: (17-J01)

17-J01 is a unit with 4 stage of E.G vapor jet and three condenser. Off gas from 17E01 is sucked by the first jet where it is condensed by showering of spray E.G with jacketed heating to prevent the formation of oligomers. It is then fed into second and at last third jet where the remaining vapors are condensed. 17T02 is used to collect the condensed E.G from the three jets. 17TO3 is used to collect all spent E.G including E.G condensate by 13C01, 14E01 and 15E01. The remaining

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uncondensed is then sucked by the vacuum where it is further condensed and remaining E.G is then vent to the atmosphere but it is less in amount.

FILTER: (18-F01)

The material from 17R01 is enter into 18F01 where the further impurities is taken out. 18F01 is the filter with the size of 40 micron and having 74 candles. The material from 17R01 is highly viscous and due to its smaller micron size as compared to 16F01, 18F01 filter is blocked easily and then sent to the filter cleaning area.

CUTTER:

The material from 18F01 is then divided into 2 sections. One goes to three cutters and other goes to another three cutters by passing through dia head having 78 laces, 39 in front and 39 at the back. Dihead has 19 sensors that alarm at any dangerous and unhealthy conditions, in this situation cutter goes at the waste. It uses three types of water:

1) CONVEYING WATER: It is used in the cutter to prevent from high temperature.

2) OVER FLOW WATER: It is used to convey the laces or spaghetti.

3) SPRAY WATER: It is used to maintain the temperature during conveying.

The cutter consists of 2 parts to ensure efficient cutting:

1) UPPER FEED ROLLER2) LOWER FEED ROLLER

DRYER:

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After cutting, the chips are fed into the dryer where the water content is removed from them by an air sucked with the help of blower.

VIBRO:

Over size and under size chips is separated in this section and then sent to the SSP plant by the help of conveying air.

EVAPORATOR:

The evaporators (12V01, 14V01, 15V01 and 17V01) are used to heat up the condensate of HTM vapors by using HTM liquid. HTM vapors are responsible for jacketed heating.

FILTER CLEANING AREA

The two filters “16F01” and “18F01” after being used in the process are going to filter cleaning area and pass through some steps to clean the filter.

1. Hydrolysis2. first wash3. okaite4. second wash5. demin6. ultrasonic treatment

HYDROLYSIS: (28T01)

The first step is the hydrolysis. it is done in a large tank vessel has temperature of 330 C . In this step, steam is used to melt up the thick layer of polymer that stick with filter for 18 to 20 hours and thus all polymer particles drain out and then we send it to different toys and plastics companies and industries.

FIRST WASH: (28MO4)

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After hydrolysis, we wash the filter by using a high pressure gun called “curchur”.

OKAITE:(28T03)

The third step is the treatment of filter with okaite solution. In this solution, the concentration of NaOH is 12 %.the purpose of NaOH is that it is so impressive in shining as well as to prevent the corrosion. it is also done in a tank vessel has a temperature of 115 C for eight hours. okaite is basically a Singaporean product.

SECOND WASH : (28M04)

Again, we wash the filter by the same high pressure gun.

DEMIN: (28T04)

After being washed the filter, filter is treated with dimineralize water (demin).the large tank vessel serves for this purpose at 100 C for eight hours. In this vessel coiling is used to heat up the water present in the vessel and through this coil, steam is passed so at 100 C, water boils therefore heating is done there by water.

ULTRASONIC TREATMENT:(28M06)

The last step of filter cleaning is the treatment of filter with ultrasonic or laser rays. the duration of this is four hours and we can run 07 candles at a time.after completing the treatment, a black particles present at the bottom of water in which candles is treated.

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FURNACE

The two heating material used in the whole process is the sandotherm (di phenyl ether) and dowtherm (di phenyl oxide) .they both come from the furnace with sufficient amount of heat. Three things are necessary for fire or burning.FuelAirHeat

BLOWER

The blower sucks the atmospheric air and sent it to the economizer.

ECONOMIZER

In economizer, heat exchange is done the hot air from furnace heat up the air which is coming from blower and then vent to the atmosphere through stack and upcoming hot air is entered into furnace.

ELECTRICAL IGNITER

Electrical igniter is made up of silicon carbide or nitride and as electricity passes through the igniter, it will become red hot and ignite the pilot gas.

FLAME SENSOR

The purpose of this is to sense the flame either it is on or off, the fuel gas is entered into the furnace so if flame is not properly switched on then pressure will increase and cause a damage that’s why we have to sense the flame.

Why do we use fuel gas instead of furnace oil?

We use fuel gas in the furnace because it is cheaper than oil and we have to maintained the pressure of gas up to 600 mbar but if the gas is not coming at that pressure, we use furnace oil that’s why we have given a line of furnace oil normally we don’t use it so we have to circulate it

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continuously through pumps and give some amount of heat through steam because it is highly viscous and vegetate in the lines.

ATOMIZATION

When we use the furnace oil, we entered it in the furnace with some amount of steam so as to atomized it (break it into small particles like atom) as it is so good for efficient burning. for this purpose we installed here a steam generator.

INSULATION

The insulation is made up of glass wool having glass particles. foam can be used but normally it is used for chillers.

PDRC

It is used to maintain the pressure of gas.

PROCESS

There are three furnaces installed in series in which two furnaces serve at a time and one is on stand by.

There are six coils inside the furnace in which HTM is present to get heat. The temperatures of these six coils are approximately to 325C, 325C, 326C, 326C, 327C, and 327C.

The hot air coming from the economizer at a flow rate of 800-1200 m/h entered into the furnace and contacts it with fuel gas and then electrically heating, a flame created up to the height of 6 ft, and there are two flames inside the furnace.

The supply of HTM is at 327C and a flow rate of 480-515 m/h and the temperature difference between return and supply is approx 32C.

Nitrogen gas is used when we need to prevent from any harm or burning or fire or a side reaction during any job or activity.

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Aldehyde can be used for fire in furnaces but we do not use it because it the lines as it is acidic that is why we vent it into the atmosphere at standard height.

SSP (SOLID STATE POLYMERISATION):

The amorphous chips coming from poly 2 is then feed into the three storage silos having capacity of 300m,300m,80m and then it is conveyed by air to the surge silo from the two silos 2PK2A and 2PK2B ,one is running at a time and one is on stand by.

SURGE SILO (4BE-100)

Automatic control system switch the feeding of chips , high level condition switches off and low level condition switches on. The chips level indicator indicates the level of the chips. in surge silo, there is a gravimetric feeder which is continuously purged by the stream of nitrogen ,the pressure of nitrogen gas is slightly lighter from the loop pressure to allow the chips to flow.The surge silo is sized and shaped in such a way that the PET solids remains inside the silo while the transport air will be vented to the atmosphere outside the plant.

SHANK UNIT

Electric motor moves the paddle. The system measuring the torque of wheel versus chips, measure the throughput (coriolis principle) ,then compare it by set value and then adjust the speed of upper rotary valve.

ROTARY VALVE The rotary valve with variable speed controlled by the inverter used for feeding and the other rotary valve 4G-100 with fixed rotary valve for nitrogen isolation purpose.

PRE-CRYSTALLIZER

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It is continuously fed through the rotary valve. in pre-crystallizer the following operations are performed.Heating the chipsPre crystallization of chips of PET to about 35 % by weight with agitation to prevent sticking I glass transition phase.Dedusting of polymer

In pre crystallization there are two chambers, the temperature of first is 156 C and temperature of second is 150 C .the pressure of first is 155 mbar and the other is at 125 mbar. In pre-crystallizer the hot nitrogen gas first fluidized the chips and then heat up to about 200 C in order to obtain certain degree of crystallization. The fluidized nitrogen is processed to twin cyclone.

NITROGEN LOOP

TWIN CYCLONE (4F-100 A/B)

The fluidized nitrogen is hen processed to twin cyclone .the major amount of dust is removed through the twin cyclone and some amount of chips that come here with nitrogen gas and then it collected in the dust collection.

NITROGEN FILTER (4F-101)

The nitrogen gas is then processed in the nitrogen filter in order to remove the further amount of dust if present.

HEATER (4E-100)

It is basically an oil to gas heat exchanger. After passing the nitrogen filter the gas is blower to the heater. After the heater, nitrogen gas is again recycling to the pre-crystallizer. The purpose of nitrogen gas used in pre-crystallizer is to fluidize the chips and to prevent it from sticking at glass transition state.

CRYSTALLIZATION

The PET is then fed to crystallizer 1 (4E-300) and then crystallizer 2 (4E-301) .the crystallization process is completed in the crystallizer and chips

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temperature is increased up to the required conditions. the machines are kept at crystallization temperature by recirculation of HTM in the paddle type screw conveyors, two paddles running at about 10 rpm, as well as in the jacket. wet nitrogen removes the fines as well as acetaldehyde released during heating by counter current .the nitrogen is then fed to cyclone 4F-401 for dust separation .the degree of crystallization at the outlet is about 45% by weight. The chips coming in the crystals having an amount of following groups.Carboxylic end groupsVinyl ester end groupsHydroxyl end groupsWet nitrogen having amount of water react with these groups to form acetaldehyde.

SSP REACTOR

The hot chips from the second crystallizer 4E-301 are fed through the rotary valve 4G-401 to the reactor. The reactor is jacketed vessel where circulation of HTM is provided to maintain the temperature. The HTM is pumped by 4G-705 a/b to the reactor. The hot nitrogen is flowed counter currently to collect the side products and its temperature is controlled by the heater 4E-402.the reactor is equipped with nine temperature indicators. Nitrogen coming from reactor is mixed with nitrogen from second crystallizer is then processed to cyclone 4F-401 and then sent to pre-crystallization loop.

COOLING

The incoming chips are at about 210C but at the outlet of fluidized bed (4E-500) its temperature is reduced to 173 C.

FLUIDIZED BED COOLER

In the cooler deduster 4E-500 the fluidization of the bed, the heat exchange and the dedusting operations are performed.The first phenomenon is directly related to the nitrogen velocity through the bed.The second one is related to the mass flow rate of nitrogen and relevant temperature and pressure. The second one is related again to the mass flow rate of nitrogen but also not the bed depth.

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STATIC COOLER

The second cooling step is take place in the static cooler 4E-501 .it is a shell and tube heat exchanger tubes side chips and nitrogen, shell side cooling water. In this device the PET chips are cooled down to 50 C before being discharged through the rotary valve 4G-502.The heat exchanging efficiency is strictly related to the chips residence time inside the 4E-501 just in order to keep the right residence time the LIC-510 controls the level of chips, acting to the inverter controlled rotary valve 4G-502.

NITROGEN PURIFICATION SECTION

The stream resulting from the mixing of following users is exhaust nitrogen and is feed through the blowers 4G403/4 to the purification section.

PRECRYSTALLIZERCRYSTALLIZER 1CRYSTALLIZER 2FLUIDIZED BED COOLERREACTOR

The inert gas coming from these users having an amount of water, acetaldehyde, ethylene glycol and vinyl end groups. The dirty nitrogen will fed to purification plant by 4G-403 and 4G-404 blowers.It is divided into two sections.

OXIDATION UNIT

The impurities are then oxidized in a catalytic bed reactor (4R-200) using instrument air in the presence of Pt/Pd catalytic bed and the product is CO2

and water.

NITROGEN FILTERS (4F200 A/B)

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It is then fed into the filters to remove solid particles.

GAS TO GAS ECONOMIZER (4E-200)The nitrogen gas at about 208 C is then fed to economizer for the partial recovery of reaction temperature heat. The nitrogen gas at its outlet is about 288 C.

MIXING WITH AIRThe nitrogen gas is then mixed with a control flow of air in order to supply the right quantity of combustion oxygen necessary to perform the combustion catalytic reaction.

ELECTRICAL HEATER (4E-201)It is used to lift the nitrogen gas temperature to the required reaction temperature of about 320 C.At the outlet of the reactor, amount of residual oxygen is measured by analyzer and then through the controller, amount of reaction air will control.After reactor nitrogen gas is fed to the 4E-200 economizer for the reaction heat recovery.Then this gas is free of hydrocarbon, just a few ppm with some moisture, in order to verify the contents the hydrocarbon there is a flame ionization detector is installed then this gas is sent to drying unit.

DRYING SECTION

HEAT EXCHANGER (4E-202)The nitrogen gas that comes from 4E-200 heat recovery economizer at a temperature of 250 C. will flow through the heat exchanger where it is cooled down with cooling water to about 35 C.

DRYERS (4D-200)The gas is fed through the number of automatic selection valves to the one of the two dryers that is active.In a dryer, a moisture adsorbent molecular sieve made up of aluminum silicate that remove all the moisture present in the inert gas.

DRYER REGENERATION SYSTEM

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As was explained in the previous section that after some time, the dryer is saturated with water.The dryer generation system is made up of following two steps.The heating of dryer saturated bed in order to remove the moisture.The cooling down of dryer regenerated bed.

The heating of dryer saturated bed is the first phase and takes about 8 hours during which all moisture in the dryer will be removed.The gas regeneration loop uses nitrogen as a regenerative gas at temperature of about 250 C.

In period of 4 hours the dryer will cool down to the temperature of about 40C.at this stage dryer is regenerated and ready for the exchange with the saturated one.

HTM CIRCUIT:The HTM uses are:

PRECRYSTALLIZER NITROGEN REACTORCRYSTALLIZER 1CRYSTALLIZER 2REACTORThe oil circuit is connected to the HTM expansion vessel purged with nitrogen.The HTM oil that is delivered from HTM circuit to crystallizer 1 and 2 is divided into three streams.The crystallizer jacketCrystallizer first shaftCrystallizer second shaftThe three streams are then collected to the outlet of crystallizer. the oil return header is connected to suction side of HTM pumps and also connected to HTM expansion vessel.

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"UTILITIES" USERS:

1) POLY I2) POLY II3) S.S.P I4) S.S.P II5) MOULDING

MAIN PLANTS:

1) NITROGEN GENERATION PLANT2) DEMIN WATER PLANT3) COMPRESSOR4) CHILLER5) FRESH WATER/RAW WATER/MOBILE WATER6) DRYERS

1) NITROGEN GENERATION PLANT:

NITROGEN GENERATORS

PSA VSA MEMBRANE PLANT

PURE N2 TECHNICAL N2

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(100%free of O2) (99.5% to 99.99% free of O2)

PRESSURE SWING ADSORPTION:

a) Air Filtrationb) Air Supply (Pressurization)c) Adsorptiond) Re-Generationf) Exhaust/swing

AIR SUPPLY

Air is pressurized at 9 bars into the first adsorber and the other is at stand by. In adsorber carbon molecular sieves is used having a small opening. Oxygen molecule is smaller than nitrogen molecule that's why these sieves adsorb oxygen and nitrogen passed through it. After some time, CMS is saturated with oxygen and needs to be re-generated. During re-generation air is pressurized into the other adsorber. In re-generation, valve is opened and all the oxygen is moved from 9 bars to 1 bar and creates a noise that's why muffler (silencer) is installed to minimize the sound. In this way all the oxygen is exhaust (swing) into the atmosphere.

2) DEMIN WATER:

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ADSORBER 1 ADSORBER2

MUFFLER

a) Filtrationb) Cation Exchangec) Anion Exchanged) Re-Generation

a) FILTRATION: The raw water or a fresh water is first filtered by passing through two filters "SAND FILTER" where dust or a gravel particles is separated out and then this water is passed through "CARBON FILTER" in which activated carbon is used to dechloronize the water.

b) CATION EXCHANGE: The Cations of water like Ca,Mg is separated by passing it through cation exchanger in which cation resins is used to take out these cations to form cation free water. We use two cation exchanger; one is at service and other is at stand by.

c) ANION EXCHANGE: The water is then passed through anion exchanger in which anion of wter like CO3,HCO3 is adsorbed by anion resins. The two anion exchanger is used; one is at service and other is at stand by. Now the water is free of ions and recall it "DEMIN WATER" or "DEIONIZE WATER".

d) RE-GENERATION: After some time, the two exchangers are saturated with the ions. So they need to re-generate for re-use.

i) CATION EXCHANGER RE-GENERATION: The Cation exchanger is treated with hydrochloric acid(HCl) to re-generate, the H-positive ions of HCl replace the ions of Mg and Ca adsorb by the exchanger and Mg,Ca react with the ions of Cl to become MgCl2 and CaCl2 and then passed out. This H-positive ions add up in the water when we will reuse it.

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ii) ANION EXCHANGER RE-GENERATION: The Anion Exchanger is treated with NaOH to re-generate, the OH-negative ions of NaOH replace the ions of CO3 and HCO3 and then they react with Na to form Na2CO3 and NaHCO3. These OH-negative ions add up to water when we will reuse it.

ANION EXCHANGER

RAW WATER

CATION EXCHANGER DEMIN WATER

3) COMPRESSOR:

AIR COMPRESSORS

5 HIGH PRESSURE 3 LOW PRESSURE (8-10 bar) (3-3.5 bar)

Instrument air conveying air

Types:

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CARBON FILTER

SAND FILTER

Dynamic (rotary)Displacement

a) screwb) b)scrollc) reciprocating

COMPRESSOR:a) Air Filterb) Low pressure Elementc) Inter coolerd) High pressure Elementf) After cooler

a) AIR FILTER: The air is entered at 1 bar pressure into the filter where the dust particles are separated.

b) LOW PRESSURE ELEMENT: After the filtration, the air is compressed in the low pressure element by passing it b/w the two different size screws, the pressure at the outlet of LP element is 3.0 - 3.5 bar. Cooling water is circulating in the LP element to maintain the temperature. Small size screw rotates faster than large size screw. The different rotations of the screw done by the help of a shaft in gear box driven by a motor.

c) INTER COOLER: After the L.P element the air is cooled by circulating cooling water in a coil. After the L.P element, the temperature of air is high because of increase in pressure.

d) HIGH PRESSURE ELEMENT: After the inter cooler, the air is passed through high pressure element, This is same as L.P element and they both are of a type of screw compressor. At the outlet, the pressure is about 7.5 - 10 bar.

f) AFTER COOLER: Now this pressurized air is at last passed through another cooler where it is further cooled by cooling water. The compressor

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with two elements and two coolers are "DOUBLE STAGE COMPRESSOR" and the compressor with single element and a cooler are "SINGLE STAGE COMPRESSOR". After cooler the air is dried to remove moisture and then this air is distributed where it is use.

4) CHILLER:

1) VAPOUR COMPRESSION2) VAPOUR ABSORPTION

1) VAPOUR COMPRESSION: First the refrigerant gases R-22, R-134A and R-404 is compressed to attain the pressure, then this gas enters into the condensor where it is converted into small droplets of liquid by using cooling water. The boiling point of refrigerant gases is about -40 degree centigrade. So below -40 degree centigrade it is in liquid form and after condensor the small droplets of liquid are gathered in a expansion valve. After passing the expansion valve the refrigerant liquid is entered into the evaporator where it cools the chilled water and discharge it at 7

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degree centigrade return to the process. In this way the refrigerant gases vapourize and enters into the compressor and the cycle goes on. The temperature of cooling water is equal to the wet bulb temperature and inlet of chilled water is at 12 degree centigrade.

CHILLED WATER IN

C.W IN

CHILLED WATER OUT

C.W OUT

2) VAPOUR ABSORPTION: The solution of lithium bromide(LiBr) and water is entered into the generator where the water is vaporized at 100 degree centigrade by flue gas entering at 380 degree centigrade. Lithium bromide is separated out from water and enters into the absorber while water vapors fed into the condenser where it is condensed by cooling coil. Vapor absorption cycle is basically under the vacuum and that's why water is condensed at very low temperature, then this condensed water is entered into the evaporator where it cools the chilled water and discharges it at 7 degree centigrade. In this way water is vaporized and absorbed by LiBr in an absorber and again enters into the generator and cycle goes on. The boiling point of LiBr is about 690 degree centigrade. FLUE GAS

H2O VAPORS CW OUT CW IN LiBr & H2O

H2O LIQUID

H2O VAPORS

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GENERATOR CONDENSOR

EVAPORATORABSORBER

EXPANSION VALVE

VAPORSCOMPRESSOR

CHILLED CHILLED WATER IN WATER OUT

5) DRYER:

1) DESICANT DRYER2) INSTRUMENT AIR DRYER3) REFRIGERANT DRYER

DESICANT DRYERS: The compressed air is entered into the desiccant dryer. A long shaft rotating in the dryer driven by a motor. Silica Jel is in contact with the rotating shaft that adsorbs the moisture from the air. Instrument air dryer is none but the two desiccant dryers connected in series.

MOISTURE FREE AIR

COMPRESSEDAIR

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QUALITY LAB1) DETERMINATION OF ALDEHYDES IN LIQUID SAMPLES: PRINCIPLE: The carbonyl group(=C=O) of many aliphatic and aromatic aldehydes and that of aliphatic and hydro aromatic ketones with sodium bisulphite by forming addition compounds so called alpha-oxysulphonic acid. After this reaction, the excess sodium hydrogen bisulphite is first oxidized by titration with iodine solution to form sulphate, then sulphite link to carbonyl group is visually titrated with 0.1N iodine standard solution unsing starch solution as the indicator. Upon oxidation some addition compounds is formed which is then decomposed by adding sodium hydrogen carbonate.

ACCURACY: + 5 % relative/ - 5 % relative

TIME REQUIRED: About 2 hrs

2) DETERMINATION OF THE IV OF PET: PRINCIPLE:i) The polymer is dissolved in the mixture of phenol and 1,2 dichloro benzene or 1,1,2,2-tetrachloroethane where upon the time of flow is determined in an ubbelohde viscosimeter.

ii) The relative viscosity is obtained from the quotient of time of flow of polymer solution to that of pure solvent. iii) The relative viscosity is linked with intrinsic viscosity by "BILLMEYER'S EQUATION"

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iv) The intrinsic viscosity is defined as the limiting value of the ratio of natural logarithm of relative solution viscosity to the concentration of polymer in the solution.

ACCURACY: +1 % relative/ -1 % relative

TIME REQUIRED: 45 min

REQUIRED AMOUNT: Amorphous: 0.580 - 0.620 S.S.P : A-74 => 0.720 - 0.760 A-80 => 0.780 - 0.820

A-84 => 0.820 - 0.860

3) DETERMINATION OF CARBONYL END GROUPS IN PET: PRINCIPLE: The PET sample is dissolved at boiling temperature and the reflux in the mixture of O-Cresol and chloroform. After cooling to room temperature, the carbonyl end groups are determined photo metrically using bromophenol blue as an indicator.

REACTION: R-COOH + KOH ---------------> R-COOK + H20

TIME REQUIRED: 45 min

ACCURACY: +1 mmole/kg / -1 mmole/kg

REQUIRED AMOUNT: 35 - 50 mmole/kg

4) DETERMINATION OF M.P OF POLYESTER: PRINCIPLE: The polymer specimen is observed b/w crossed polarizers

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while heated at a constant heating rate. The differentiate scaling curve is plotted ranging from 30 - 300 degree centigrade. By this method, we can also determine the glass transition state and out of melt(cool).

TIME REQUIRED: 1 hr after the temperature calibration has been calibrated.

ACCURACY: + 1 degree centigrade absolute/ -1 degree centigrade absolute

REQUIRED AMOUNT: BGC: 245 - 250 degree centigrade FGC: 250 - 255 degree centigrade

5) DETERMINATION OF THE COLOUR NUMBER OF PET: PRINCIPLE:i) The tristimulun color difference meter determine the color of the sample in three photocells which are considered by red, green, blue filter respectively.

ii) The crystallized and grinded sample contain in a measuring cup is exposed to standard illumination C (daylight)/standard observer 2 degrees at an angle of 45 degree.

iii) The reflected beams are measured at an angle of 0 degree.

iv) The color is measured as X.Y and Z values, from these values yellowish ness index (YI) or the color number l, a, b (hunter) can be calculated.

ACCURACY: +0.3 units/ -0.3 units. TIME REQUIRED: Approx 2 hrs

6) DETERMINATION OF ACETALDEHYDE IN PET:

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PRINCIPLE:i) First the PET is cooled in liquid nitrogen at -197 degree centigrade then it is grinded to 500 micron particle size. The purpose of cooling is to prevent it from being vaporized as it is so volatile during grinding.

ii) It is then sealed in a small tube and gives the temperature of 150 degree centigrade in head space and it becomes in gaseous form.

iii) Then injector injects the gas and fed into the gas chromatographer and then we can determine the contents of acetaldehyde.

TIME REQUIRED: About 90 min

REQUIRED AMOUNT: Less than 1 ppm(0.73 is standard)

7) DETERMINATION OF MOISTURE CONTENTS IN PET: PRINCIPLE:I) The PET specimen is contained in a pointer in the heater at 205 degree centigrade and nitrogen is then passed through the specimen and sucks the moisture from it.

ii) Then this moisture containing nitrogen gas is fed into detector(MECCO moisture analyzer) that detects moisture contents.

REQUIRED AMOUNT: S.S.P: Less than 100 ppm Amorphous: 600 - 700 ppm

TIME REQUIRED: About 70 min

8) DETERMINATION OF YELLOW CHIPS IN PET: PRINCIPLE: A back of chips is holed on the screen and the ultravoilet rays is passed through it by which we can determine yellow chips

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easily.

9) DETERMINATION OF ASH CONTENT IN POLYESTER: PRINCIPLE: A sample is taken in porcelain crucibles and then gradually increase the heating lod up to the heating stage 6 until all the carbonacues matter is ashed. Transfer the crucibles to the muffle furnace and ignite at 700 degree centigrade for 30 min. Transfer the crucibles from the furnace to the desiccators and allow cooling and determining the weight.

ACCURACY: +2 % / -2 %

TIME REQUIRED: About 6 -7 hrs

TEST FOR POLY II:

1) PTA/IPA :( ONCE PER DAY)

a) WATER CONTENT: Less than 0.2 % wtb) PARTICLE SIZE : < 40 micrometer(0 - 20 % wt) 150 - 250 micrometer(0 - 15 % wt) > 250 micrometer(0 - 3 % wt)c) ACID NUMBER : 671 - 677 mg KOH per gramd) COLOUR NUMBER : b => 0 - 2.5

2) PASTE:(ONCE PER DAY)

a) PTA CONTENT : 69 - 71 %b) DENSITY : 1.331 - 1.431g/cm3c) MOLE RATIO : 1.08 - 1.18

3) EST 1:(ONCE PER DAY)

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a) ACID NUMBER : 47 - 53 mg KOH per gm(every 8 hours)b) COLOUR NUMBER : L => 94 - 98 a => -1 to 1 b => 0 - 1.5 YI => -0.2 to 2c) SAP NUMBER : 550 - 570 mg KOH per gmd) IV : 0.08 - 0.1 dl/gme) DEG : 1.05 - 1.3 %f) IPA : 1.85 - 2.2 %g) A.A : 40 - 85 ppm

4) PP II:

a) IV : 0.24 - 0.3 dl/gmb) CEG : 85 - 110 mole/kgc) COLOUR NUMBER : L => 42 - 96 a => -1 to -0.25 b => -0.75 to +0.75 YI => -2 to +2d) DEG : 1.1 - 1.5 %e) IPA : 1.85 - 2.15 %f) A.A : 4.5 - 10.5 ppm

5) CATALYST:

a) Sb CONTENT PER BATCH: 6500 - 8000 ppm

6) R.T:

a) Sb CONTENT PER BATCH: 6500 - 8000 ppm

7) H3PO4:

a) H3PO4 CONC. : 0.85 %

8) B.T:

a) B.T CONC. : 0.0084 %

9) COLUMN:

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a) ALDEHYDE: 0 - 500 ppmb) E.G : 95 - 100 %c) H2O : 1 - 3 %

S.S.P:-

1) PRE CRYSTALLIZER:(ONCE PER WEEK)

a) IV : b) CARBONYL END GROUP : c) MOISTURE :d) COLOUR NUMBER : e) CHIPS SIZE :f) DEG :g) IPA :h) A.A :i) Sb CONTENT :j) M.P : (once per month) The readings of above are same as amorphous.

2) FIRST CRYSTALLIZER:(ONCE PER WEEK)

a) IV : b) CARBONYL END GROUP : c) MOISTURE :d) COLOUR NUMBER : e) CHIPS SIZE :f) DEG :g) IPA :h) A.A :i) Sb CONTENT :j) M.P :

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(Once per month) The readings of above are same as amorphous.

3) SECOND CRYSTALLIZER :( ONCE PER WEEK)

a) IV : b) CARBONYL END GROUP: c) MOISTURE :d) COLOUR NUMBER : e) CHIPS SIZE :f) DEG :g) IPA :h) A.A :i) Sb CONTENT :j) M.P : (Once per month) The readings of above are same as amorphous.

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