Sulfate reduction process useful in coal gasification
US4704136A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1986 |
| Grant date | Nov 3, 1987 |
| Priority date | — |
| Expiry date | May 16, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/14
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A carbonaceous material, such as coal, is gasified through the catalytic action of an alkali metal salt. The alkali metal is provided as a sulfate which is converted to a sulfide during gasification. In one embodiment, sodium sulfate is converted to sodium sulfide at a temperature effective to form a transitory melt condition at an interface which obtains coal gasification at relatively low temperatures and material residence times for the reaction. An alkaline earth sulfate, such as a gypsum, may be concurrently converted to a sulfide during gasification. The alkali metal sulfide may then be regenerated to a sulfate for process reuse while converting the alkaline earth to a carbonate for environmentally safe disposal with concurrent recovery of valuable sulfur. The evolved carbon gases may be used for fuel, for process feed chemicals, or the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.