Discage Reactor spray vacuum final Polyester reactor Polymer PET

Uhde Inventa-Fischer UIF lesson: Polyester – Process ® Part 4: DISCAGE & VACUUM SYSTEM January 2011 Martin Hittorff Uhde Inventa-Fischer's PET Technology Contents … what is PET Raw materials UIF's PET processes … Additives 2R - PET Technology Paste mixing ® Tower Reactor (2R) ESPREE ® Finisher DISCAGE (Polycondensation) Vacuum system Melt filtration & distribution Chip production storage & transp PET direct applications ® ® , DFC) (MTP , MTR Melt Conditioning (MC) PET Recycling (PETryc) Plant heating Uhde Inventa-Fischer's PET Technology ® DISCAGE Reactor (Polycondensation) Uhde Inventa-Fischer's PET Technology NEW PROCESSES DEFINITION PTA, IPA EG Ester Ester Prepoly Finisher Storage SSP PET resin iV=0.72-0.82 Precursor i V = 0.62… 0.65 PTA, IPA EG ® ESPREE ®- DISCAGE MV PET resin AA Cond iV=0.65-0.85 Option FTR PET resin iV=0.62 0.68 BOPET Line PTA, EG ® ESPREE ®- LV DISCAGE BOPET Line BOPET Film iV=0.62-0.65 PET resin AA Cond PTA, IPA EG iV=0.65-0.85 Calendering Line ® ESPREE ®- DISCAGE MV Calendering Line PET Sheet iV=0.65-0.85 MTR® - Technology Main Process Parameters PET 50 – 80° C atm Temperature Pressure 120 Hold-up 1.3 – 1.5 Mole ratio 30 – 40 rpm 252 – 265 ° C 1.1 – 1.8 barg 60 – 80 88 – 92 % 265 – 275 ° C 500 – 1000 mbar 50 – 60 98 % 4,9 Stirrer Temperature Pressure Hold-up conversion Temperature Pressure Hold-up Conversion DP 272 – 278 ° C Temperature 60 / 10 mbar Pressure 25 / 30 Hold-up 20 – 40 275 – 285 ° C DP Temperature 0.6 – mbar Pressure 70 – 90 Hold-up 90 – 108 0.6 – 3.0 rpm DP Cage agitator Uhde Inventa-Fischer's PET Technology PFD; POLYCONDESATION Uhde Inventa-Fischer's PET Technology DESIGN REVIEW POLYCONDESATION Uhde Inventa-Fischer's PET Technology DESIGN REVIEW POLYCONDESATION Uhde Inventa-Fischer's PET Technology ® LV Reactor DISCAGE Requirements • High vacuum to force degasing • High surface renewal rate to force degasing • No dead spots & "Plug Flow" • Viscosity up to 250 Pa s • Residence time 90 – 120 / (kg/h) • Surface renewal ~ m • Product on discs ~ 45 – 50 % Uhde Inventa-Fischer's PET Technology ® LV Reactor DISCAGE Design • Cage type agitator • Design of the discs changes with increasing viscosity, bucketwheel discs – > spoke discs -> pipe-ring discs rombus type • Overflow weir in low viscosity section • Product temperature 282° C 286° C • Pressure < 1.0 mbar Uhde Inventa-Fischer's PET Technology Operating Principle of Steam Jet Vacuum Pumps The compression ratio of a single stage steam jet vacuum pump is limited In order to reach higher vacuum levels, steam jet vacuum pumps are arranged in series Multi-stage steam jet vacuum pumps are available for suction pressures down to 0.01 mbar If possible, inter-stage condensers are used to condensate the motive steam of the preceding stage This reduces the load in the following pump stage Naturally, the utilisation of inter-stage condensers is limited to higher inter- stage pressure, as the condensation pressure, which can be reached is governed by the temperature of the available cooling water Uhde Inventa-Fischer's PET Technology Operating Principle of Steam Jet Vacuum Pumps Example: WCL inlet temperature is 25° C Temp rise from process is 10° C WCL outlet (condensing) temp = 35° C 35° C corresponds to a condensing pressure of 56 mbar A lower condensing pressure of, for example, 42.5 mbar corresponding to 30° C would require duplication of the cooling water consumption To compress process gases from a pressure of 0.3 mbar to an inter-stage condenser pressure of 56 mbar (i.e a compression ratio of 56 : 0.3 = 186.67) two jet stages are just sufficient, each handling a compression ratio of √186.67 = 14 The maximum compression ratio for a steam jet vacuum pump depends on the suction pressure and the pressure of the available motive steam Uhde Inventa-Fischer's PET Technology Operating Principle of Steam Jet Vacuum Pumps Example: WCL inlet temperature is 33° C Temp rise from process is 9° C WCL outlet (condensing) temp = 42° C 42° C corresponds to a condensing pressure of 82 mbar A lower condensing pressure of, for example, 64.5 mbar corresponding to 37.5° C would require duplication of the cooling water consumption At a suction pressure below mbar, the corresponding saturated steam temperature drops below 0° C Ice can then formed inside the suction chamber affecting the operation To avoid this, all ejectors are heated with steam (except vent group ejectors) Uhde Inventa-Fischer's PET Technology Vacuum Unit Pre Poly 21 * * 11 22 WCL * * WCL WCL 41 FI * Process Steam 11 Heated ejector for PP 21 Heated ejector 22 41 DISCAGE DISCAGE * 42 * PE 43 Unheated Vent Group Ejector to Process 42 43 Unheated Vent Group Vent Ejector Unheated Vent Group Ejector Vacuum seal pot Uhde Inventa-Fischer's PET Technology Vacuum System Stage Ejector DISCAGE Uhde Inventa-Fischer's PET Technology Vacuum System Stage Ejector DISCAGE in Manufacturing Heating Jacket Uhde Inventa-Fischer's PET Technology Condenser 24E53 What's wrong here? Uhde Inventa-Fischer's PET Technology Wrong Material of head of ejector of the vent group Uhde Inventa-Fischer's PET Technology Suction Characteristic Ejector DISCAGE discontinous, unsteady Uhde Inventa-Fischer's PET Technology Suction Characteristic Ejector DISCAGE More steady Uhde Inventa-Fischer's PET Technology stripper Uhde Inventa-Fischer's PET Technology Stripper Requirements • Collect all process vents • Strip-out process water with air from process vents - condensables goes to waste water - non-condensables goes to HTM heater for off-gas incineration • Stripped water as reflux to process column Uhde Inventa-Fischer's PET Technology Stripper Design • Stripper column filled with RASCHING SUPER ring • Off-gas heater to avoid condensation => corrosion • Material of construction of shell and internals SS • Off-gas venting during start of HTM heater, reason => AA accumulation Uhde Inventa-Fischer's PET Technology Stripper 24D53 Hot Well Vacuum Uhde Inventa-Fischer's PET Technology Stripper 24B61 24T61 Diam 1100 7'000 Nm /h ... Inventa-Fischer's PET Technology ® MV Reactor Marriage DISCAGE 400 mt/d Uhde Inventa-Fischer's PET Technology ® Reactor 500 mt/d DISCAGE ® LV DISCAGE PV-Tex (500 mt/d) DIAMETER SHELL ® MV DISCAGE Tango... Option FTR PET resin iV=0.62 0.68 BOPET Line PTA, EG ® ESPREE ®- LV DISCAGE BOPET Line BOPET Film iV=0.62-0.65 PET resin AA Cond PTA, IPA EG iV=0.65-0.85 Calendering Line ® ESPREE ®- DISCAGE MV... PET Technology Contents … what is PET Raw materials UIF's PET processes … Additives 2R - PET Technology Paste mixing ® Tower Reactor (2R) ESPREE ® Finisher DISCAGE (Polycondensation) Vacuum