(143g) Continuos Polymerization Process : Some Scale-up Issues

Over 92 billion pounds of thermoplastic resins were manufactured in USA in the year 2004. The lead products are LLDPE, LDPE, HDPE, PP, ABS, SAN, styrenics, polystyrene, nylon, PVC and thermoplastic polyester. Continuous polymerization process technology is being developed for many of these products. The continuous process offers the lowest cost and is found to be better from a environmental view point. Dow chemical has commercialized its Magnum ABS resin using the continuous mass polymerization process by introducing a new polymerization plant in Terneuzen, Netherlands. Bayer has closed its emulsion process made ABS plant in Muscatine, IA in USA. 15 process flow diagrams are reviewed to discuss continuous processes to manufacture ABS, SAN, PS, Nylon, PMMA, SMA and Polyolefins. The Dow process, GE process and Bayer process are compared side by side. The tower process of Dow and the three stage process with a finisher used by GE and the two CSTR process of Bayer are reviewed from a process performance and cost view point. The spheripol process and spherizone process commercialized by Basell polyolefins is discussed. The use of the circulating fluidized bed and the combination of the liquid pressurized process and gas phase Ziegler Natta catalyzed process is reviewed. The spherical polypropylene is manufactured in one of them. The continuous mass polymerization process to manufacture PMMA by the Rohm and Haas process is discussed. The azeotropic distillation separation method for separation of the unreacted monomer from the polymerized product and the helical ribbon agitated polymerization reactor is evaluated. The use of the decanter for separation of the unreacted monomers from the product is highlighted in the LG 2 CSTR process to manufacture SAN. The use of tube bundle reactor and geagasing extruder to prepare SAN by BASF is compared with the LG process. The reactor configuration to prepare polyglycolide is elloborated. The use of tubular reactor series for the manufacture of polystyrene is discussed. The use of a multistage rubber dissolver and a multistage reactor can be seen in the Hitachi process to prepare HIPS. Shaft horizontal reactors are used in the preparation of SMA copolymer in a continuous fashion. The continuous kettles for the preparation of nylon from hexamethylene diamine and adipic acid and directlr from aminonitrile are reviewed. The ethylene propylene copolymer preparation by continuous solution process developed by ExxonMobil is sketched. Some issues in developing a styrenic copolymer using the Bayer continuous process is discussed. The figure captions are as follows:

Figure 1.0 Dow Process to Manufacture ABS by Continuous Mass Polymerization using Plug Flow Reactor

Figure 2.0 GE Continuous Mass Polymerization Three Stage Process with a Prepolymerizer and Finisher to Manufacture ABS using Continuous Mass Polymerization

Figure 3.0 Spheripol Process Schematic to Manufacture Spherical Polypropylene Homopolymer, Random Copolymer and Terpolymer

Figure 4.0 Spherizone Process to Manufacture Spherical Polypropylene

Figure 5.0 Continuous MassPolymerization Process for PMMA

Figure 6.0 LG Continuous Mass Polymerization Process for Preparing Styrene-Acrylonitrile Copolymer

Figure 7.0 BASF Continuous Mass Polymerization Process for SAN

Figure 8.0 Reactor Configuration in the Continuous Solution Process for Biodegradable Polyglycolide

Figure 9.0 Continuous Bulk Polymerization of Styrene

Figure 10.0 Hitachi Contiuous Mass Polymerization Process For High Impact Polystyrene HIPS

Figure 11.0 Continuous Mass Polymerization of Stryene

Figure 12.0 Bayer Continuous Mass Polimerization Process for Styrenic Copolymer

Figure 13.0 Continuous Prepration of Polyamide

Figure 14.0 Continuous Process for Nylon 6,6 from Hexamethylene Diamine and Adipic Acid

Figure 15.0 Continuous Gas Phase Copolymerization Process With a Fluidized Bed Reactor