Patent · US Expired

Processing C4 olefin streams for the maximum production of propylene

US7214841B2 · kind B2 · utility

94Cited by
7References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 15, 2003
Grant dateMay 8, 2007
Priority date
Expiry dateApr 10, 2024

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P20/10
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

In order to maximize the production of propylene when the external supply of ethylene is limited, the C4 cut from a hydrocarbon cracking process is first subjected to autometathesis prior to any isobutylene removal and without any ethylene addition. This favors the reactions which produce propylene and pentenes. The ethylene and propylene produced are then removed leaving a stream of the C4's and heavier components. The C5 and heavier components are then removed leaving a mixture of 1-butene, 2-butene, isobutylene, and iso- and normal butanes. The isobutylene is next removed preferably by a catalytic distillation hydroisomerization de-isobutyleneizer. The isobutylene-free C4 stream is then mixed with the product ethylene removed from the autometathesis product together with any fresh external ethylene needed and subjected to conventional metathesis producing additional propylene.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.