Aluminum alkyls technological applications

Two versions of the slurry process are most frequently applied. In the autoclave or Hoechst process (named after the former company Hoechst that introduced this version of the slurry process) the reaction temperature is 80-90 °C. Typical ethene pressures in the polymerization reactor are 5-10 bar, allowing the application of very large reactors (typically 100 m ). The catalyst compound and the aluminum alkyl activator are premixed in the catalyst preparation vessel with the diluent hexane. This mixture is fed to the polymerization reactor. Figure 6.20.3 shows a schematic view of the process with one polymerization reactor, but cascades of two or more polymerization reactors are also frequently found (allowing additional freedom in achieving specific molecular mass distributions of the PE product - see also picture at the beginning of the section, Hostalen ACP technology). 

Cumene capacity topped 9.5 million metric tons in 1998 and is projected to reach 10.4 million metric tons by the end of 2003 (19). Like ethylbenzene, cumene is used almost exclusively as a chemical intermediate. Its primary use is in the coproduction of phenol and acetone through cumene peroxidation. Phenolic resins and bisphenol A are the main end uses for phenol. Bisphenol A, which is produced from phenol and acetone, has been the main driver behind increased phenol demand. Its end use applications are in polycarbonate and epoxy resins. The growth rate of cumene is closely related to that of phenol and is expected to be approximately 5.1% per year worldwide over the next five years. Process technologies for both chemicals have been moving away from conventional aluminum chloride and phosphoric acid catalyzed Friedel-Crafts alkylation of benzene, toward zeolite-based processes. 

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