Method for online estimation of reactor split for multimodal polyolefins
AssigneeUnivation Technologies, LLC
InventorsJohn R. Parrish, William H. Sachs, Mark G. Goode, Jeffrey Drabish
Life of this patent
Estimating the term…
Abstract
The present method is directed to techniques for estimating and periodically controlling the reactor split of alpha-olefin polymerizations using multiple catalysts that selectively incorporate monomers and other reactants into polymer compositions. The method provides for the rapid determination of instantaneous reactor split and cumulative split in polymerization reactors by the use of a novel linear relationship between Incorporation and Reactor Split.
Claims19
A method for calculating the instantaneous reactor split of a polymerization reaction, the method comprising the steps of:
- producing under separate reaction conditions at least two polymeric compositions, each composition comprising at least two different polymers, each polymer having at least one different monomer or reactant incorporation;
- determining for each polymeric composition:
- the incorporation of at least one monomer or reactant, a corresponding reactor production rate and reactor split;
- and
- determining a linear equation defined by the reactor splits and corresponding ratios of (monomer or reactant incorporation/production rate).
A method of controlling reactor split in a multimodal polymerization reaction, comprising the steps of:
- applying a predetermined linear relationship to control a polymerization reaction;
- polymerizing at least one monomer in the presence of at least two catalysts;
- obtaining periodic incorporation and production rate data from the reaction;
- and
- adjusting periodically at least one reaction variable to maintain a desired reactor split according to the predetermined linear relationship.
A method of producing a polymer composition by controlling the reactor split of a multimodal polymerization, comprising the steps of:
- determining a desired reactor split for a multimodal polymer composition based on at least one physical property of the composition;
- polymerizing at least one monomer in the presence of at least two catalysts under conditions that yield a composition having the desired reactor split;
- and
- periodically adjusting at least one reaction variable according to a predetermined linear relationship to maintain the desired reactor split.
Dependencies are inferred from the claim text.