Patent · US Active

Process for making xylene isomer using a deheptanizer with a side draw recycle

US7371912B2 · kind B2 · utility

11Cited by
7References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 15, 2005
Grant dateMay 13, 2008
Priority date
Expiry dateNov 24, 2026

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C6/123
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

In processes for recovering one or more xylene isomers and isomerizing the remaining isomers for recycle, the isomerate is distilled to provide a toluene-containing overhead, a mid-boiling fraction containing C8 aromatics and a bottoms fraction containing C8 aromatics and C9+ aromatics. The mid-boiling fraction is recycled to the unit for recovering the sought xylene isomers and has sufficiently low content of C9+ aromatics that the separation feed to the unit for recovering the sought xylene isomers contains up to about 500 ppm-mass C9+ aromatics. The processes provide a high quality xylene isomer product while achieving at least one of debottlenecking, energy savings and capital savings.

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