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US 10,835,890 B2Granted
Polyolefin production with chromium-based catalysts
AssigneeUnivation Technologies, LLC
InventorsKevin J. Cann, Mark G. Goode, Kevin R. Gross, John H. Moorhouse
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Abstract
A method including contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a reduced chromium-based catalyst, drying the reduced chromium-based catalyst at a temperature, and adjusting the temperature to affect the flow index response of the reduced chromium-based catalyst.
Claims15
A method of preparing a chromium-based catalyst for the polymerization of an olefin into a polyolefin, the method comprising:
- contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a mixture of a reduced chromium-based catalyst and the solvent, wherein the chromium-based catalyst comprises a chromium oxide catalyst;
- drying the reduced chromium-based catalyst at a drying line-out temperature;
- and
- adjusting the drying line-out temperature to change the flow index response of the reduced chromium-based catalyst.
1 more element
Dependencies are inferred from the claim text.