Process for upgrading coal
US5085764A · kind A · utility
12Cited by
69References
37Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1989 |
| Grant date | Feb 4, 1992 |
| Priority date | — |
| Expiry date | Dec 19, 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, wash water, and acid. Contacting the coal with the caustic produces water-soluble compounds. Sufficient wash water is used to reduce the temperature of the caustic treated coal and dissolve the bulk of the water-soluble compounds before the water-soluble compounds convert to water-insoluble compounds that precipitate on the caustic-treated coal. Caustic removed from the coal by the water is recovered as anhydrous caustic for again contacting coal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.