Patent · US Expired

Dehydration of maleic acid to form maleic anhydride

US4414398A · kind A · utility

0Cited by
2References
8Claims
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Assignee

Inventor

Key dates

Filing dateJun 11, 1981
Grant dateNov 8, 1983
Priority date
Expiry dateJun 11, 2001

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C51/56
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

In the dehydration of maleic acid to form maleic anhydride, comprising a first stage of concentrating an aqueous solution of maleic acid to 85-95% by maleic acid, and a second stage of dehydrating the concentrated maleic acid into maleic anhydride, in at least one of the stages, a falling film tubular evaporator is employed. Prior to the dehydration stage, about 15-35 parts by weight of maleic anhydride is added per 10 parts of concentrated acid.

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