Process for upgrading lignitic-type coal as a fuel

Abstract

A process for upgrading lignitic-type coal including brown coals, lignite and subbituminous coals to render it more suitable as a solid fuel in which the moist lignitic-type coal in an as-mined condition is subjected to an autoclaving treatment at a controlled elevated temperature and under high pressure for a period of time to convert the moisture and a portion of the volatile organic constituents therein to a gaseous phase and to effect a controlled thermal restructuring of the chemical structure thereof. In accordance with a preferred practice, the autoclaved upgraded carbonaceous product during or after cooling is contacted with the gaseous phase to effect a deposition of at least a portion of the condensible organic constituents thereon. The upgraded carbonaceous product is stable and resistant to weathering, and is of an increased heating value approaching that of bituminous coal.

Dependencies are inferred from the claim text.