Thermochemical beneficiation of low rank coals

摘要

A process and apparatus for thermochemical beneficiation of carbonaceous solids, such as low rank coals and biomass, by countercurrently passing a moving bed of the solids in contact with a liquid in an amount sufficient to flush product liquids having dissolved and suspended products and make-water from the moving bed which is maintained within the wet carbonization reaction zone at about 400° to about 650° and an elevated pressure sufficient to prevent boiling of the liquid. The feed liquid may be preheated in a lower liquid preheat zone of the moving bed and a substantial portion of the liquid removed as heat recovery liquid for other process uses. External heat may be added in the lower portion of the wet carbonization reaction zone. The relatively high concentration of organic materials in the product liquid may advantageously be anaerobically digested producing methane containing gas to provide additional process heat and the liquid effluent vaporized to provide heat to the carbonization reaction zone. The process provides a continuously operating process capable of processing carbonaceous solids of about 1/4 inch to about 4 inches in diameter.