Experimental study on kinetic characteristics of gas adsorption of coal with different degrees of metamorphism

WANG Menglu; SHEN Yongxing; ZHOU Dong; WANG Chen; WANG Jinxin; FENG Xuejian

doi:10.13347/j.cnki.mkaq.20221609

Abstract：In order to further reveal the dynamic characteristics of coal with different degrees of metamorphism under different ad-sorption pressures,the self-developed TQY-2 precision adsorption instrument and infrared thermal imaging device were used to con-duct macroscopic adsorption tests on lignite,coking coal and anthracite coal samples with a diameter of 8.5 mm at different pres-sures(0.2,0.4,0.6,0.8,1.0 MPa)and the adsorption test of the mesoscopic structure of the coal body with adsorption pressures of(0.3,0.6,0.9,1.2,1.5 MPa),using quasi-primary and quasi-secondary adsorption kinetic models such as intra-particle diffusion,Elovich and double constant analyze the law and mechanism of adsorption gas.The results show that compared with five adsorption kinetics models,the quasi-secondary adsorption kinetics model is suitable for characterizing the adsorption gas process of lignite and coking coal,while the optimal model for anthracite is the intra-particle diffusion model;with the increase of adsorption pressure,the quasi-secondary adsorption rate constant k2 of lignite and coking coal gradually increased,and the intra-particle diffusion rate con-stant kp of anthracite coal also gradually increased,all of which were positively correlated;adsorption pressure has little effect on the dynamic model suitable for coal samples;under the macroscopic adsorption experiment and the mesoscopic structure adsorption ex-periment of coal body based on infrared thermography,the dynamic models suitable for different degrees of metamorphism are con-sistent.