Liquefaction process
US4351716A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1979 |
| Grant date | Sep 28, 1982 |
| Priority date | — |
| Expiry date | Mar 15, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S208/951
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a combination of pretreating agents comprising SO.sub.2 and an oxidizing agent. The pretreatment is believed to convert at least a portion of the scale-forming components and particularly calcium, to the corresponding sulfate prior to liquefaction. The pretreatment may be accomplished with the combination of pretreating agents either simultaneously by using a mixture comprising SO.sub.2 and an oxidizing agent or sequentially by first treating with SO.sub.2 and then with an oxidizing agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.