Abstract:

This paper introduces the utilization status of low rank coal and the problems during thermal conversion,summarizes the influence of pretreatment technologies such as hydrothermal pretreatment,acid pretreatment,thermal pretreatment,solvent swelling,oxyalkylation and hydrogenation pretreatment to the structure,pyrolysis reactivity,tar quality and yield of low rank coal.It is proposed that with appropriate pretreatment technology,coal liquefaction conditions can be lowered,thermal conversion efficiency is increased,and tar quality is improved.Therefore,the goal of using low rank coal in a clean and efficient way can be achieved.