Heat Treatment of the Hesigewula Lignite and Moisture Adsorption Experiment of its Solid Products

The Hesigewula lignite was studied by heat treatment in a fixed bed and moisture absorption experiment. The temperature of heat treatment was considered as a factor to investigate its influence on product yield. Under the gas carrier (N2) flow rate of 200 SCCM, 0.5 MPa and holding for 20 min, the yield of tar firstly increased and reached the maximum of 5.67 wt% at 500 °C, then came to a decrease with the increasing temperature. The proximate and ultimate analyses of the solid products had been measured. As to the moisture adsorption experiment, the equilibrium moisture content of the solid products at different humidity (30 °C) had been calculated. It was shown that the char of 600 °C adsorbed the least moisture with the minimum content of oxygen. It indicated that heat treatment can remove the oxygen-containing functional group and to some extent upgraded the coal rank.