There is a large reserve of low rank coals(LRC), such as brown coal and subbituminous coal in China, however, LRC is not so widely used because of the high water content and low heating value. If LRC is dried with conventional method, it maintains the ability of water reabsorption and the spontaneous combustion tendency. So, LRC is not fit to transport for long distances, and often combusted directly at power plants near the coal mines.
Hot water treatments can decrease the inherent water in LRC effecti...