Pyrolysis Process Of Baiyinhua Lignite And Analysis Of Coal Tar

The current situation of energy in our country determines the necessary of an effective utilization of coal resources. Different coal ranks have different utilization methods. Therefore effective classification use of coal resources is particularly important. Pyrolysis means an effective utilization for lignite, which belongs to low coal ranks.Experiments that study pyrolysis kinetics of Baiyinhua lignite are carried out by TGA. By analyzing the TG-DTG curves obtained under different heating rates, we identified the pyrolysis characteristic parameters, such as the starting pyrolysis temperature, the ending pyrolysis temperature and the maximum rate of weight loss temperature. We choose180℃to380℃and380℃to680℃as two temperature ranges to fit coal pyrolysis kinetic equation. Two-dimensional diffusion mechanism is utilized in the previous temperature range and chemical reaction control mechanism is adopted in the latter temperature ranges.In the fixed-bed experiment, we investigated the effects of different experimental conditions on pyrolysis products yields and components under nitrogen and hydrogen atmosphere respectively.The optimum conditions for Baiyinhua lignite pyrolysis are:reaction temperature500℃, pressure0.2MPa, nitrogen flow rate50mL/min and holding time20min under nitrogen atmosphere and temperature500℃, pressure1.0MPa, hydrogen flow rate100mL/min and holding time10min under hydrogen atmosphere. And the yield of coal tar is2.38%higher compared with that under nitrogen atmosphere.Coal tar is treated with pickling and alkaline cleaning first, and then separated into pure group components and analyzed by GC/MS finally. We compared the difference of coal tar obtained in the fixed-bed experiment that under different atmosphere, the results got by DG new pyrolysis and fixed-bed experiment is also discussed.The rod thin layer chromatography (TLC/FID) analysis method is applied to analysis the low temperature pyrolysis coal tar for the first time.The quality correct factor of coal tar group component is determined in the experiment, and the mass percentages of group components are calculated. We discussed the change of coal tar group components’ quality-through comparing the result of TLC/FID analysis to pickling and alkaline cleaning process.