Process for heat treatment of coal
US4769042A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1987 |
| Grant date | Sep 6, 1988 |
| Priority date | — |
| Expiry date | Jun 24, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF26B3/08
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
There is provided a process for the heat treatment of coal which comprises heating and drying low grade coal such as subbituminous coal and brown coal containing less than 80% of carbon and more than 33% of volatile matter (dry mineral matter-free basis) and having a high moisture content and a particle diameter smaller than 2 inches, with a high-temperature gas containing less than 5% of oxygen in a fluidized bed for 2-10 minutes until the coal temperature reaches 180.degree.-400.degree. C., and subsequently cooling the coal by spraying water in a fluidized bed for 2-10 minutes until the coal temperature decreases to 60.degree. C. or below at which time the coal holds the maximum moisture given by wetting. The heating process may be performed in two steps, in which case coal is heated with a high-temperature gas to 80.degree.-150.degree. C. in the first step so that the moisture of coal is reduced below the inherent moisture. The cooling process may be performed in two steps, in which case heated coal is rapidly cooled to about 120.degree. C. with a cooling gas of high steam content in the first step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.