Ash-free coal production method

摘要

Provided is a production method for ashless coal whereby solvent recovery rate can be improved and ashless coal can be efficiently produced. The production method for ashless coal comprises: an extraction step in which slurry obtained by mixing coal and a solvent is heated and a coal component that is soluble in the solvent is extracted; a separation step in which the liquid solution part containing the coal component is separated from the slurry from which the coal component has been extracted; and an ashless coal capture step in which ashless coal is obtained by separating and recovering the solvent from the separated liquid solution part. Furthermore, the ashless coal capture step has a pressure reduction step in which, by reducing pressure to a pressure lower than the vapor pressure of the solvent, solid ashless coal is obtained by evaporating and separating the solvent from the liquid solution part, and a heating step in which the previously obtained solid ashless coal is heated to evaporate and separate solvent remaining in the ashless coal.