Patent · US Expired

Process for upgrading coal

US5059307A · kind A · utility

9Cited by
69References
32Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 11, 1989
Grant dateOct 22, 1991
Priority date
Expiry dateOct 11, 2009

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S423/12
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

In a process for reducing the sulfur and ash contents of coal, coal is sequentially contacted with fused alkali metal caustic, water, carbonic acid, and a strong acid. Caustic removed from the coal by the water and the carbonic acid is recovered as anhydrous caustic for again contacting coal.

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