The extraction of coal liquefaction bottoms

Liquid yields from the liquefaction of coal and similar carbonaceous solids 10 are increased by extracting the heavy bottoms product 42 from the liquefaction zone 16 with a liquefied gas 53, selected from the group consisting of liquid sulfur dioxide, liquid carbon dioxide, and liquid ammonia at a temperature and pressure below the critical temperature and pressure of the liquefied gas. The high molecular weight reactive organic material 55 extracted from the heavy bottoms is converted into low molecular weight constitutents generally by either recycling to the liquefaction zone or by passing the material to a downstream conversion step.