CONCORD TEXTILE CORPORATION VIETNAM Nhon Trach 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 Content Page Theory basis Process technology of POLY plant description 2.1 Preparing catalyst and PTA 2.2 Preparing TiO2 2.3 Esterification stage and 2.3.1 Esterification stage 2.3.2 Esterification stage 2.4 Rectification column 1401 2.5 Prepolycondensation stage and 2.5.1 Prepolycondensation stage 2.5.2 Prepolycondensation stage 2.6 Vapour noncondensation of prepolycondensation 2.7 Final polycondensation 2.8 Vapour noncondensation of final polycondensation 2.9 EG evaporator jet ejector 2218 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 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) Molecular formula OHCH2CH2OH Mass molecular 62 g/mol 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 52.24 kJ/mol kpa) Heat of combustion 19.07 MJ/kg Ignition temperature 410 0C Viscosity (at 200C) 19.83 Ns/m Pure terephthalic acid (PTA) Molecular formula C6H4(COOH)2 Mass molecular 166 g/mol Melting temperature (at 101.3kPa) 402 0C Density (at 200C) 1.14318 g/cm3 Evaporation (at 200C, 101.3kPa) 5.74 Antimon acetate Molecular formula Sb(CH3COO)3 Mass molecular 298 g/mol Melting temperature (at 101.3kPa) 128.5 0C Density ( at 200C) 1.22 g/cm3 Titanium dioxide Molecular formula TiO2 Mass molecular 80 g/mol 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 + HOOCOH + 2*H2O -COOH HO-CH2-CH2-OOC- -COO-CH2-CH2- Polycondensation n*(HO-CH2-CH2-OOC- -COO-CH2-CH2-OH) CH2-CH2-OH + (n-1)* HO-CH2-CH2-OH H-(O-CH2-CH2-OOC- -CO)n-O- 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: + 2H2O Molecular weight: 166 62 Amount raw material (kg): 0.846 0.32 PTA + EG = PETP 192 36 0.187 Since, the capacity of the polycondensation plant calculated to create how much chip tons per day Theoretically, there would be mol EG required mol PTA but the process reaction is actually requires a mol ratio 1.7 – 1.8 only Process technology of POLY plant description 2.1 Preparing catalyst and PTA Catalyst 1302 1102 1114 1303 1701 1103 2203A/B 1101 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(CH 3COO)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 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 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 1118A 1118B 2.2 1104 1105A 1105B 1116 Preparing TiO2 The Ti2O fed into the preparation vessel 1118A from the TiO feed hopper 1702 where EG has already resided before At here, the mix of TiO 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 1304 1702 2402 1308 2702 2701A 1401 1202 1501 1602 2204A/B 2701B 1108 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 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 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 TiO feed into the reactor 1202 already calculate before 2.3 Esterification stage and 1110 TiO2 1101 1203 DEG 2208A/B 2207A/B 1114 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 1202 temperature If it is reaction 1201 but the most important is raised, the esterification will increase and conversely 2.3.1 Esterification stage After prepare the paste of EG, PTA and catalyst in the tank 1101 The paste is conveyed into the esterification stage 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 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 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 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 After completed the esterification stage reaction, the product fed into the reactor 1202 to continue the esterification stage 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 TiO – 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 into the bottom of the process column 1401 The column 1401 is 2211 separate between low and high boiling components, the main is glycol and water 1401 have 16 trays, on each tray have many type Damage pressure on each tray about mbar 1110 are fed used to component bubble cap 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 and 2218 1202 1205 2214 1603A 1603B 2210A/B/C 1401 2211A/B 1114 After the esterification reaction complete, the 1204 1203 prepolycondensation reaction take place under a certain vacumn pressure and high temperature At this prepolycondensation stage, the catalyst will participated in the process The chains of polyethylene 1604 reaction terephthalate are formed by split-off of EG The product is 1109A in two 1109B formed 1110 prepolycondensation stage with low viscosity 2.5.1 Prepolycondensation stage The inlet product of precondensation stage 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 The jacket of 1203 is provided by the HTM evaporator 1605 and TRC06-17 control valve TV06-17 to adjust temperature of jacket 1203, heated by vapour HTM The vapour product go outlet on top reactor into the scraper condenser 1603A and heated with jacket by the HTM evaporator 1611, heated by vapour HTM On the vapour pipe outlet have instal PRC06-03A/B to control valve PV06-03A/B to adjust the vacumn pump 2211A/B create vacumn pressure for 1203 The liquid product is transfered to the prepolycondensation stage reactor 1204 by different vacumn pressure between the two reactor The jacket of discharge pipe is also heated by the HTM circulation pump 2209A/B The reactor 1203 is not have the agitator 2.5.2 Prepolycondensation stage The product is continuously removed to the prepolycondensation reactor 1204 with purpose in order to increase the converts of prepolycondensation reaction The level of reactor is maintained by the inventer LRC06-13 control valve LV06-13 will open how much allow more or less product feed into 1204 The temperature of reactor is provided by the pump 2213A/B after go through the HTM heat exchanger 1613 and is maintained by the inventer TRC06-30 control valve TV06-30 The product is agitated by the discs installed on a through shaft of reactor, in order to generate a large surface and combinate with vacumn pressure, it allows a amount EG form in the process reaction The speed agitator has a great influence to the process reaction but it is not use to control, because only have a small change of the speed agitator will change the prepolymer product, too The shaft of agitator is operated by around change motors with connected gearbox and inventer speed SIK06-18 It is lubricated by oil circulation system and sealed by sealing system with silicon oil The vapours formed in the process reaction are removed into the scraper condenser 1603B by suction of vacumn The vacumn is formed by the EG vapour jet ejector 2218 and is maintained by PRC06-11 control PV06-11 The liquid product is discharged by pump 2214A/B to fed into the final polycondensation 1205 2.6 Vapour noncondensation of prepolycondensation The vapours of reactor 1203 are sucked into the scraper condenser 1603A together the flow EG condensate circulation is adjusted by FAL07-08 in order to condense vapour EG In the scraper condenser 1603A have a agitator form horizontal tye with low speed agitator The rotating bars of the agitator keep the oligomer floated together the EG condensation move down 1109A The vessel 1109A have a building weir The EG condensate go over the building weir and filted by a pair of mesh sieve instal on the weir Continue pulled through the filter 1309A/B by the pump 2210A/B and 1606 cooled by the cooler 1604A/B system then enter 1603A to ensure the flow reflux of EG circulation The level of 1109A is in order to open valve allow a level of 1109A still high, a 1109A 1607 maintained by LIC07-01 control valve LV07-01 amount EG go to the vessel 1110 In the case amount EG will enter the small pipe instal in The vapour noncondensation of 1603A is sucked off by the vacumn pump 2211A/B Then go to the vessel 1115A/B and move down the cooler 1615A/B A part go back pump 2211A/B to sealing and remain part go down the vessel 1110 A amount EG in the vessel 1110 contain rather more water, so it will transfer to 1401 in order to separate again The inventer LRC07-23 control valve LV07-23 to open valve allow the flow EG remove to the collecting vessel 1114 to maintain the level of 1110 The vapours of reactor 1204 are sucked into the scraper condenser 1603B together the flow EG condensate circulation is adjusted by FAL07-18 The constructing principle of 1603B and 1109B operate similar 1603A and 1109A Only have two different thing as: The first, the vapour of 1603B is pulled to the EG vapour jet ejector 2218 The remain, the inventer LIC07-11 control valve LV07-11 allow a mount EG move to the vessel 1115 after cooled by the cooler 1604B/C system to maitain level in the vessel 1109B 2.7 Final polycondensation After the prepolycondensation complete, the prepolymer product is discharged by pump 2214A/B and transferred to the disc ring reactor 1205 The final polycondensation will take place The gear pump 2214A/B is driven by around change motors with reduction gear and inventer speed control 2218 Cutting 1305 2215 1205 1204 2214 Spinning 2217 The level of 1205 is maintained by 1111 inventer LIC09-07 The inventer LIC09-07 give signal command to SFYIK08-01 which interlock SFRC08-01 Then SFRC08-01 will control SIK08-13 and SIK08-14 to adjust the speed of pump 2214A/B The prepolymer product is pumped continuously through the filter 1305A/B The inventer PRC08-04 control valve PV08-04 to adjust pressure of flow product passed the filter 1305A/B The purpose of reactor 1205 is to increase the expected viscosity of polymer product The viscosity of product is decided by two pressure and speed of agitator parameters The product is agitated by the disc rings, in order to generate a large surface and combinate with deep pressure vacumn to splip off a amount vapour EG generate in the polycondensation reaction The disc rings, which are arranged on each of these chambers and are installed on a through shaft The shaft is driven by an around change motor with connected reduction gear and inventer speed control SIK09-02 It is lubricated by oil circulation system and sealed by sealing system with silicon oil The temperature of reactor 1205 is provided by the pump 2219A/B after go through the HTM heat exchanger 1608 and is maintained by the inventer TRC09-40 control valve TV09-40, heated by liquid HTM The vapours of reactor 1205 are removed into the scraper condenser 1606 by suction of vacumn The vacumn is formed in by the EG vapour jet ejector 2218 and is maintained by PRC09-08 control PV09-08 The HTM evaporator 1611 provide heating for the vapour pipe After the product reached viscosity as expect, the product is discharged by pump 2215A/B with heated by the HTM pump 2219A/B The gear pump 2215A/B is driven by around change motors with reduction gear and inventer speed control SIK12-02 and SIK12-03 The polymer down 2.8 1610 polymer pumped throught the POY plant to textile and excess transfer to the cutter chip system to form the chips production then go the chip vessel 1703A/B Vapour noncondensation of final polycondensation The vapours of reactor 1205 are sucked into the scraper condenser 1606 together the flow EG condensate circulation go down in order to condensate the vapour, which adjust by preset inventer FAL10-11 The scraper condenser 1603A have a agitator form horizontal tye with low speed agitator The rotating bars of the agitator keep the oligomer floated together the EG condensation move down 1111 The vessel 1111 have a building weir The EG condensate go over the building weir and filted by a pair of mesh sieve instal on the weir Continue pulled through the filter 1311A/B by the pump 2217A/B and cooled by the cooler 1607A/B system then enter 1606 to ensure the flow reflux of EG circulation The level of 1111 is maintained by LRC10-14 control valve LV10-14 in order to open valve allow a amount EG go to the vessel 1114 In the case level of 1111 still high, a amount EG will enter the small pipe instal in 1114 The vapour noncondensation of 1606 is pulled through the EG vapour jet ejector 2218 by the vacumn pump 2221A/B 2.9 EG evaporator jet ejector 2218 The vapour leave the scraper 1606 is pulled into the ejector 2218 by the flow vapour EG of 1610 provide into spray nozzle of the ejector 2218 with high pressure The deep vacumn pressure is formed in here by the suction of pump 2221A/B combinate with the flow evaporate EG of 1610 The vapour of scraper 1603B is also pulled to 2218 by vacumn Each stage of three stage EG ejector 2218 also have the jet ejector 1603B 1606 2221 2218 1609 1101 1112 2227A/B 1114 2225A/B Each stage of three stage EG ejector 2218 is distributed by three flow EG condensate circulation entered at the top of ejector 2218 to condensate vapours and adjusted by preset of three flowmeter The condenser remove down the vessel 1112 Continue pulled through the filter by the pump 2227A/B convey the EG condensation to the individual spray nozzle condenser while only the flow to the first stage is passed the cooler 1609 in order to receive the required temperature profile enter the ejector 2218 to separate the low boilers After ensure the flow reflux of EG circulation Level of 1112 is maintained by LIC1124 control valve LV11-24 to adjust a amount EG move to pump 2221A/B The part noncondensation is sucked through the vacumn pump 2221A/B The vacumn is maintained in the ejector 2218 by the inventer PRC11-17A/B control valve PV1117A/B Then go to the vessel 1117A/B and move down the cooler 1616A/B A part go back pump 2211A/B to sealing and remain part go down the collecting vessel 1114 The amount EG is provided to the evaporator 1610 to be discharged from the vessel 1112 The amount of glycol leave the evaporator is compensated by the flow liquid glycol branched off from the flow EG circulation loop of ejector 2218 system Level of evaporator 1606 is maintained by LRC11-55 control valve LV11-55 to adjust a amount EG feed into evaporator The heat of 1610 is provided by pump 2223 with a removable heating coil The inventer TRC11-70 control valve TV11-70 to adjust temperature in the evaporator, heated by liquid HTM The collecting vessel 1114 have function collect the split off of EG of the process The amount EG contain water is almost less, so it is transferred back to the tank 1101 by pump 2225A/B as raw material