training report concord textile corporation vietnam nhon trach 2 industry park, nhon trach district, dong nai province

Then the paste is discharged by the pump 2202A/B to go into the esterification stage 1 reactor 1201.. The suspension is fed in the esterification stage 2 reactor 1202 by pump 2204A/B.. t

CONCORD TEXTILE CORPORATION VIETNAM Nhon Trach 2 industry park, Nhon Trach District, Dong Nai Province

TRAINING REPORT

Name: Nguyen Huynh Thoa

Code: 12117

Position: Poly staff

Day of submit: 21-12-2015

1 Theory basis

2 Process technology of POLY plant description

2.1Preparing catalyst and PTA

2.2Preparing TiO2

2.3Esterification stage 1 and 2

2.3.1 Esterification stage 1

2.3.2 Esterification stage 2

2.4 Rectification column 1401

2.5 Prepolycondensation stage 1 and 2

2.5.1 Prepolycondensation stage 1

2.5.2 Prepolycondensation stage 2

2.6 Vapour noncondensation of prepolycondensation

2.7 Final polycondensation

2.8 Vapour noncondensation of final polycondensation

2.9 EG evaporator jet ejector 2218

1 Theory basis

Polyethylene terephthalate (PETP) is made by reacting pure terephthalate acid PTA and ethylene glycol EG to form diglycol terephthalate DGT which is the monomer of PETP The reaction to form PETP is result both of esterification and polycondensation reaction

This reaction process include 5 reaction stage:

 Two esterification reaction

 Two prepolycondensation reaction

 One final polycondensation reaction

Physical parameters of raw materials will participate into the process production as: Ethylene glycol (EG)

Boiling heat (at 101.3 kPa) 197.60 0C

Melting temperature (at 101.3kPa) -13 0C

Density (at 200C) 1.1135 g/cm3

Heat of vaporization (at 101.3

kpa)

52.24 kJ/mol

Ignition temperature 410 0C

Viscosity (at 200C) 19.83 Ns/m

Pure terephthalic acid (PTA)

Molecular formula C6H4(COOH)2

Melting temperature (at 101.3kPa) 402 0C

Density (at 200C) 1.14318 g/cm3

Evaporation (at 200C, 101.3kPa) 5.74

Antimon acetate

Melting temperature (at 101.3kPa) 128.5 0C

Density ( at 200C) 1.22 g/cm3

Titanium dioxide

Boiling heat (at 101.3 kPa) 2972 0C

Melting temperature (at 101.3kPa) 1843 0C

Density ( at 200C) 4.23 g/cm3

Esterification

2HO-CH2-CH2-OH + HOOC- -COOH HO-CH2-CH2-OOC- -COO-CH2-CH2

-OH + 2*H2O

Polycondensation

n*(HO-CH2-CH2-OOC- -COO-CH2-CH2-OH) H-(O-CH2-CH2-OOC- -CO)n

-O-CH2-CH2-OH + (n-1)* HO-CH2-CH2-OH

Balance of chemical equation:

PTA + 2EG = DET + 2H2O DET = PETP + EG

PTA + EG = PETP + 2H2O Molecular weight: 166 62 X 2*18

X = 166 + 62 – 2*18 = 192 Raw materials wanted to create 1kg Chip: PTA + EG = PETP + 2H2O

Molecular weight: 166 62 192 36

166192 19262 192192 19236 Amount raw material (kg): 0.846 0.32 1 0.187

Since, the capacity of the polycondensation plant calculated to create how much chip tons per day Theoretically, there would be 2 mol EG required 1 mol PTA but the process reaction is actually requires a mol ratio 1.7 – 1.8 only

2 Process technology of POLY plant description

2.1 Preparing catalyst and PTA

2203A/B 2202A/B

1201 The process line starts with continouns preparation of mix paste of pure EG and PTA powder

The pure EG go through the filter 1302A/B then enter the catalyst preparation vessel

1102 together the catalyst is poured into by handmade through a feed funnel A amount of

EG have calculated with the pre-set of FQI01-02 A certain amount of EG prepare batch with the right amount of catalyst in a concentration of 2% weight

The catalyst use for this process is antimon acetate – Sb(CH3COO)3, which is used as

a polycondensation reaction catalyst Level in the vessel 1102 give signal to the inventer LSL01-04 control the agitator 2302

On the other side, the vessel 1102 is equipped with the coils system as a HTM heated jacket The vessel 1102 is supplied the heat by pump 2230 and adjust temperature about 60 – 650C by the inventer TSH01-05 control valve TV01-05

After the paste of EG and catalyst which homogenised in the vessel 1102 and conveyed down the filter 1303 to the storage vessel 1103

After the mass of PTA powder transferred the stored silo 1701, the nitrogen is charged in 1701 combinate with PTA powder generated a fluidize phenomenon to avoid obstruction in here PTA powder is discharged down continously by gravimetric of PTA powder into the paste preparation tank 1101

Nitrogen as carrier of the PTA is fed back to the conveying area by passing the filter

1301 at the top 1701

Catalyst 1302

1701 1102

1114

1303

The quantity of PTA powder is continously calculated and rechecked by the pre-set value A quantity of PTA is fed into the tank 1101 by the inventer LRC02-09 will interlock WQRC02-07 to control valve WV02-07

At the same, the inventer WRC02-07 will interlock for both FQRC01-13 and FQRC01-15

The inventer FQRC01-13 will control the speed of pump 2203A/B to discharge the mix of EG and catalyst of the storge vessel 1103 feed into the tank 1101

The inventer FQRC01-15 will control the valve FV01-15 to adjust a amount of EG feed into the tank 1101 In the case star up, the flow of pure EG feed into vessel 1101 will

be provided by the filter 1302A/B and when the plant is normal stable operation, the flow

of EG will be provided by the amount of EG generate in the process reaction collected and contained in the vessel 1114

This process controller how to ensure the feed of mol ratio must exactly

The mix of PTA, EG and catalyst will be stirred by the agitator to become a homogeneous paste of PTA, EG and catalyst Then the paste is discharged by the pump 2202A/B to go into the esterification stage 1 reactor 1201 The inventer FRC02-15 will control SIK02-11 and SIK02-12 to adjust the speed of pump 2202A/B have how much amount the paste must provide to the reactor 1201 In the case one pump fail, the remaining pump must run automatically full capasity of plant

2.2 Preparing TiO 2

The Ti2O fed into the preparation vessel 1118A from the TiO2 feed hopper 1702 where EG has already resided before At here, the mix of TiO2 and EG are stirred by agitator to form a suspension The concentration is about 50% weight in EG Amount of TiO2 prepare batch with a certain quantity

The suspension discharge through the filter and pumped to the pearl mill 2702 by pump 2710A then enter 1118B The pearl mill is operating at certain rate given by its feed pump and disperse the suspension with a certain particle size distribution

After the suspension passed the pearl mill for the first time and ressided in 1118B The suspension will continously pass the pearl mill again then enter the dilution vessel

1104 where a certain amount of EG has already waited before At here, the suspension will

be agitated and diluted with a concentration about 10.5% weight in EG

1308 1304

2402

1105A 1104

1118B

1501 1602

1401 1702

1202

The

suspension continued pump 2701B convey to the centrifuge 2402 make the suspension become more homogeneous and charge into the intermediate vessel 1105 In the case centrifuge have the problem, the suspension go into 1105 that it do not go through centrifuge 2402 After passing the centrifuge, the concentration of TiO2 particles became less about 10% weight in EG

After centrifugation, the residue of TiO2 bigger particles will be cleaned by supply of

a small flow EG and discharged back into the preparation vessel 1118A

The suspension resides in the intermediate vessel 1105 in a certain time and passed throught the filter system 1304/1308 transferred into the suspension feed vessel 1106 by air pressure The agitator of vessel 1106 is stirred continuously with a low speed

One of both dosing pump 2204A/B are normal in operation and will change if meet problem The suspension is fed in the esterification stage 2 reactor 1202 by pump 2204A/B the inventer FRC02-15 will interlock SFRC03-17 and SFRC03-18 to control the speed of pump 2204A/B how to provide enough a mol ratio and amount TiO2 feed into the reactor 1202 already calculate before

2.3Esterification stage 1 and 2

1110

2702

2204A/B

1202 1201

TiO2

1101

DEG

2208A/B 2207A/B

Beside the esterification reaction of two reactor

1201 and 1202, the polycondensation reaction is occur at the same time with a low molecular product In all control parameter influence to the esterification reaction, only two temperature and residennce time profiles influence direction and decied effective of both the esterification reaction but the most important is temperature If it is raised, the esterification will increase and conversely

2.3.1 Esterification stage 1

After prepare the paste of EG, PTA and catalyst in the tank 1101 The paste is conveyed into the esterification stage 1 reactor 1201 depend on the speed of pump 2202A/

B discharge from the tank 1101

At the same, the amount EG circulation from the rectification column 1401 also enter the reactor 1201 The inventer FRC02-15 interlock FQRC04-01 control valve FV04-01 adjust how much amount EG circulation from 1401 required reflux rate back 1201 to maintain the feed mol ratio

LIRC04-06 will measure level in 1201 then give signal command to FRC02-15 control the speed of pump 2202A/B will provide a certain amount of the paste from 1101 Moreover, LIRC04-06 will also control the agitator 2703 in the condition safety

The temperature in 1201 is provided by the HTM circulation pump 2206A/B with form the coils system put at the bottom reactor 1201 TRC04-03 will measure the temperature in 1201 then give signal command to TRC04-07 control valve TV04-07 adjust the amount heating oil of the feed HTM into the HTM circulation pump 2206A/B The flow of HTM to 1201 is liquid HTM

1203

1114

The temperature of jacket 1201 and 1202 is provided by the HTM evaporator 1601 and TRC04-44 measure the temperature outlet of 1601 control valve TV04-44 adjust amount heating oil of the feed HTM into 1601 The flow of HTM to the jacket of 1201 is vapour HTM

The temperature of vapour pipe outlet 1201 is provided by the HTM evaporator 1611 and TRC11-11 measure the temperature outlet of 1611 control valve TV11-11 adjust amount heating oil of the feed HTM into 1611 The flow of HTM to the vapour pipe of

1201 is vapour HTM

PRC04-10 control valve PV04-10 to adjust the pressure in 1201 The reactor 1201 is protected by rupture discs in order to against overpressure and blowed into the chamber

At this mechanism, the esterification reaction stage 1 achieved high effection about 86%, required temperature about 2530C, pressure about 0.5 bar, level about 36%, residence time about 4.5 hours

The esterification reactor 1201 happen the esterification consists of two main components is EG and PTA form Diethylglycol terephthalate – DGT and Water Besides, the reaction also generated some secondary reaction to creacte agent unexpected

After performed the esterification, the evaporating EG and water are fed into the rectification column 1401 and the liquid product is discharged by pump 2208A/B feed into the esterification stage 2 reactor 1202 If on pipe go from pump 2208A/B to 1202 is protected against overpressure, the other pipe refluxed back to 1201 The pipe of flow product from 1201 to 1202 is also jacketed heated by pump 2205A/B which provide heated liquid

2.3.2 Esterification stage 2

After completed the esterification stage 1 reaction, the product fed into the reactor

1202 to continue the esterification stage 2 LRC04-24 measure level in 1202 to control valve LV04-24 and also control the agitator in the condition safety

At the same, the suspesion TiO2 – EG and Diethylene glycol – DEG are also fed into

1202 The purpose of TiO2 is make the color for PETP, DEG is make PETP keep the stable color of PETP and adjust the melting temperature of PETP The amount EG in the suspension TiO2 –EG and DEG are fed into 1202 to maintain the real mol ratio

FQRC04-20 control valve FV04-20 to adjust amount DEG feed into 1202 The flow feed of suspension TiO2 – EG is adjusted by SFRC03-17 and SFRC03-18 control the speed

of pump 2204A/B

The temperature in 1202 is provided by the HTM circulation pump 2209A/B with form the coils system put at the bottom reactor 1202 TRC04-22 will measure the temperature in 1202 to control valve TV04-22 The flow of HTM to 1201 is liquid HTM

The jacket 1202 is provided by the HTM evaporator 1601 with vapour HTM.

At this mechanism, the esterification reaction is optimised complete more than about 96%, require temperature limited about 258oC, pressure about 108 mbar, level about 41%, residence time about 1.5 hour

The vapour leave at the top reactor 1202 to go into 1401 When low pressure, a amount vapour of reactor 1202 is not go into 1401, the nitrogen is pressed into 1202 to push up amount vapour move to 1401 The vapour pipe outlet 1202 is heated by the HTM evaporator 1611 The flow of HTM to the vapour pipe of 1202 is vapour HTM

The flow from 1202 to 1203 is transferred by the difference of pressure and height between the two reactor The jacket of this pipe is heated, too

2.4 Rectification column 1401

The vapours left the esterification reactors and a amount EG of vessel 1110 are fed into the bottom of the process column 1401 The column 1401 is used to separate between low and high boiling components, the main component is glycol and water 1401 have 16 trays, on each tray have many bubble cap type Damage pressure on each tray about 5 mbar

The temparature in the column 1401 is heated at the bottom of column with a coil system Pump 2205A/B provide heat with liquid HTM TRC05-30 receive temperature at outlet of pump 2205A/B then control TV05-30 adjust flow feed HTM

The vapours leave overheads of the process column 1401 are passed through the condenser 1602 where is cooled by cooling water, the excess vapour will move to the chiller 1501 system The liquid of 1602 flow down the reflux vessel 1108 with the help of gravimetric flow Continuously, the liquid is fed back to 1401 as reflux to maintain temperature of 1401 TRC05-26 receive temperature of 1401 and interlock FRC05-14 control LV05-14 to adjust reflux flow fed back to 1401.The remaining water of 1108 is discharged the overhead of vessel into the waste water system

The bottom product is discharged through the filter system by pump 2207A/B feed into 1201 to maintain a mol ratio The level of 1401 maintain a certain level When the level of 1401 is high, the inventer LRC05-12 control valve LV05-12 to feed into the vessel

1114 to against overlevel in 1401

Besides, the reflux product pipe return 1401 to increase the matabolism It also protect the pump 2207A/B against overpressure when flow product discharge from 1401 to 1201 ensure a mol ratio

The pressure in column is protected against the overpressure to avoid break disc, which will have a vent to blow down the chamber

2.5 Prepolycondensation stage 1 and 2

1603B 1603A

1204 1203

1604

1109B 1109A

1110

2218

After the esterification reaction complete, the prepolycondensation

prepolycondensation stage, the catalyst will participated in the process reaction The chains of polyethylene terephthalate are formed by split-off of

EG The product is formed in two prepolycondensation stage with low viscosity

2.5.1 Prepolycondensation stage 1

The inlet product of precondensation stage 1 reactor 1203 is fed from 1202 and level

in the reactor is maintained by LRC06-05 control valve LV06-05 to adjust the flow feed into

The teparature in 1203 is controlled by TRC06-06 control valve TV06-06 on heated pipe outlet The HTM circulation pump 2209A/B provide heat for the reactor with the coil system put at the bottom of reactor, heated by liquid HTM

1205 1202

2214

1401

1114