COMPUTER-SIMULATION STUDY OF ETHYLENE POLYMERIZATION RATE PROFILE CATALYZED OVER HIGHLY-ACTIVE ZIEGLER-NATTA CATALYSTS

Abstract

The polymerization rate profiles of the high-pressure slurry polymerization of ethylene with a silica-supported TiCl4/MgCl2/THF catalyst, activated by Al(C2H5)3, were studied. The polymerization rates were measured in the range of temperatures between 50 and 80-degrees-C, in the range of ethylene concentration between 128 and 428 mmol/L, and in the range of aluminum alkyl concentration between 0.92 and 4.35 mmol/L. The kinetic expression at the early stage of ethylene polymerization including k(p) (propagation rate constant) and k(i) (initiation rate constant) was proposed. k(p) and k(i) were estimated from the experimental data and incorporated into the simultaneous ordinary differential equations derived from the elementary polymerization steps to adequately simulate the polymerization rate profiles at various polymerization conditions.