Dewatering can enhance the low-rank coal value in its industrial application

such as gasification

liquefaction and combustion

and improve the development of industries of energy

chemical and power.A view of evaporation technologies which applying flue gas

saturated steam and superheated stream as the drying media was presented.The flue gas drying technology commonly chooses the high temperature flue gas and directly heating.The saturated steam drying technology indirectly heats through the indirect rotary tube dryer and the exhaust carries less dust

this process has low requirement for the precipitator.The superheated steam drying technology comprises the WTA(Wirbelschicht-Trocknungmit-interner Abwrmenut-zung) technology

the PSFED(Pressurized Steam Fluidized Bed Theory) technology and so on

and has high energy efficiency

high heat efficiency

and safey.The low-rank coal was mainly dried by high temperature flue gas direct drying method in China.