An improved gas-phase polypropylene process

Abstract

Gas-phase polymerization of propylene to high isotactic homopolymers, random copolymers, and impact copolymers has been commercial in the U.S. since 1977. The process incorporates technological improvements including high activity, high stereospecific catalyst, and continuous in-process catalyst deactivation. It produces homopolymers with 97+% heptane insolubles, melt flow rates from fractional to 50+, and a wide range of copolymers.Rapid technological progress was made in developing these improvements through an integrated 1000-ton/year pilot plant in the U.S. to complement similar facilities in Germany. A process description and schematic flow plan for the process, typical product properties, and comparative economics are discussed.

Gas-phase polymerization of 1,3-butadiene with supported half-sandwich-titanium-complexes

“…2. [28,29] In comparison to the fluidized bed reactor the stirred bed reactor has the advantage that it is easier to construct and handle. Investigations were performed in this reactor to get a better insight into the heterogenization of the half-sandwich-titanium-complexes.…”

Gas-phase polymerization of 1,3-butadiene with supported half-sandwich-titanium-complexes

“…2. [28,29] In comparison to the fluidized bed reactor the stirred bed reactor has the advantage that it is easier to construct and handle. Investigations were per-formed in this reactor to get a better insight into the heterogenization of the half-sandwich-titanium-complexes.…”

Dynamic modeling of product grade transitions for olefin polymerization processes

“…Overshoot the hydrogen feed rate and reduce the comonomer feed during the first 100 s of the grade transition. rates (Brockmeier, 1991;Caracotsios, 1992;Byck et al, 1987;Hussein and Nemzek, 1989;Ross and Bowles, 1985;BASF Report, 1986;Weintritt and Burdett, 1989), with a supported Titanium Ziegler-Natta catalyst. For the liquid pool processes, a lower activity catalyst characteristic of these processes is used (Di Drusco and Rinaldi, 1984;Simonazzi et al, 1991;Galli and Ali, 1987;Miller, 1987;Brockmeier, 1983).…”

“…Gas-phasefluidized bed (such as UCC/Shell) (Hussein and Nemzek, 1989;Weintritt and Burdett, 1989;Choi and Ray, 1985;Goodenbour et al, 1989) Gas-phase vertical stirred bed (such as BASF/ICI/Quantum) (Ross and Bowles, 1985;BASF Report, 1986;Choi and Ray, 1988) Gas-phase horizontalstirred bed (such as AMOCO/Chisso) (Brockmeier, 1991;Caracotsios, 1992;Brockmeier and Koizumi, 1991;Brockmeier, 1983) Liquid pool loop (such as Himont) or CSTR (such as Mitsui) with two reactors in series (Di Drusco and Rinaldi, 1984;Simonazzi et al, 1991;Galli and Ali, 1987;Miller, 1987;Brockmeier, 1983).…”