Closed reactor transitions between metallocene catalysts
US10221254B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 2016 |
| Grant date | Mar 5, 2019 |
| Priority date | — |
| Expiry date | Apr 6, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F4/65916
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for transitioning a gas phase polymerization reactor between metallocene catalysts is provided. The method comprises first reducing the superficial gas velocity and increasing the height of the fluidized bed within the reactor prior to stopping a feed comprising a first metallocene catalyst. The method further comprises introducing a first polymerization neutralizer to the reactor, wherein the first polymerization reactor does not comprise water, and then introducing a second polymerization neutralizer to the reactor, wherein the second polymerization neutralizer is different from the first polymerization neutralizer. After this, the method comprises purging the reactor with an inert gas and then introducing a feed comprising a second metallocene catalyst to the reactor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.