Patent · US Active

Processes for the isomerization of normal butane to isobutane

US7638675B2 · kind B2 · utility

2Cited by
27References
7Claims
0Family size

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Inventors

Key dates

Filing dateSep 7, 2007
Grant dateDec 29, 2009
Priority date—
Expiry dateMar 15, 2028

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C7/144
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

In a normal butane isomerization process where the isomerization effluent (108, 114) is fractionated in a deisobutanizer (116) operated such that a lower boiling fraction (118) is provided containing at least 80 mass-% isobutane and a higher boiling fraction (122) containing normal butane and at least 10 mass-% isobutane. The higher boiling fraction (122) is contacted with a selectively permeable membrane (124) to provide a permeate (126) containing normal butane-containing and a retentate (128) containing at least 80 mass-% isobutane. The preferred membranes are sieving membranes having a C4 Permeate Flow Index of at least 0.01 and a C4 Permeate Flow Ratio of at least 1.25:1.

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