Patent · US Expired

Recovery of alkali metal catalyst constituents with sulfurous acid

US4334893A · kind A · utility

90Cited by
3References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 24, 1980
Grant dateJun 15, 1982
Priority date
Expiry dateNov 24, 2000

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P20/52
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles primarily in the form of water-soluble alkali metal sulphites and bisulphites by treating the particles with a solution of sulfurous acid. During the treating process the water-insoluble alkali metal compounds in the alkali metal residues are converted into water-soluble alkali metal sulphites and bisulphites, which have been found to be catalytically active. The aqueous solution containing water-soluble alkali metal sulphites and bisulphites is then separated from the treated particles and any insoluble material formed during the treatment process, treated to remove soluble aluminum compounds and recycled to the gasification process where the alkali metal sulphites and bisulphites serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

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