脱水干燥是对低阶煤进行深加工前的重要环节,介绍并比较了热空气干燥、热蒸汽干燥、微波干燥和太阳能干燥等蒸发干燥工艺,以及水热处理(HTD)、机械热压脱水(MTE)、有机溶剂脱水(DME)等非蒸发干燥工艺。蒸发干燥过程简单,设备成本较低;HTD和MTE等非蒸发干燥过程不消耗气化潜热,并能对低阶煤进行深度改性,将水分从低阶煤中不可逆地脱除,同时提高低阶煤的煤阶和热值,因此应用前景广阔。
The dewatering and drying of coal are important links before deep processing of low rank coal.The evaporative technologies,including use of hot air,hot steam,microwave,or solar enorgy,as well as the non-evaporative technologies,such as hydrothermal dewatering(HTD),mechanical thermal expression(MTE),and organic dissolvent dewatering etc.,have been presented and compared.The evaporative drying is simple in process,and lower cost for equipments,while in non-evaporative drying process HTD or MTE,the latent heat in gasification isn't cosumed,the characters of low rank coal can be deeply improved,and the moisture in low rank coal can be irreversibly dewatered,at the same time,the rank of coal and its calorific value can be enhanced,therefore,having wide prospect of application.