Method for transitioning between ziegler-natta and metalocene catalysts in a bulk loop reactor for the production of polypropylene
US7960484B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 2008 |
| Grant date | Jun 14, 2011 |
| Priority date | — |
| Expiry date | Aug 24, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Polymerization processes in a bulk loop reactor are described herein. In particular, a method of contacting a flow of metallocene with a flow of propylene is provided. This method includes directing the flow of metallocene towards a junction, directing the flow of propylene towards the junction and maintaining a portion of the flow of metallocene separate from a portion of the flow propylene within a portion of the junction downstream of the flow of propylene into the junction. In another embodiment, a method of introducing a quantity of antifouling agent into a catalyst mixing system is provided. In this embodiment a portion of the antifouling agent is introduced at or downstream of a point of contact of a stream of propylene with a stream of catalyst. The antifouling agent may be a member, alone or in combination with other members, selected from Stadis 450 Conductivity Improver, Synperonic antifouling agent, and Pluronic antifouling agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.