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US 6,388,027 B1Granted
Transition strategy for the production of sticky polymers
AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsDaniel Paul Zilker, Jr., William David Vacek, Mark Edwin O'Rosky, Fathi David Hussein
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Abstract
The invention relates to a process for transitioning from polymerizing sticky polymer to polymerize another sticky polymer in gas phase fluidization bed production to decrease transition time, reduce off-grade material, and/or prevent operational difficulty.
Claims5
A process for transitioning from a first sticky polymer to a second sticky polymer in a gas phase fluidized bed polymerization, which process comprises the steps of:
- (a) terminating the feed of catalyst to a reactor, thereby allowing reaction rate to decrease;
- (b) terminating the polymerization using a reversible catalyst kill agent;
- (c) passivating the polymer with a gel inhibitor;
- (d) stopping polymer transfer from the reactor to post-reaction purging and polishing equipment, thereby recovering aim-grade product from the post reaction equipment;
- (e) flow and pressure purging to remove kill agent;
- (f) feeding cocatalyst and optional promoters to the reactor to establish concentrations of these components;
- (g) establishing reaction conditions for the second sticky polymer;
- (h) re-initiating catalyst feed;
- and
- (i) feeding fluidization aid and optional diene to the reactor.
7 more elements
Dependencies are inferred from the claim text.