Experimental Study of Different Granularity on the Gas Absorption of Coal

To study the impact of different granularities on the gas adsorption of coal, the experimental system has been designed to apply dynamic constant pressure and the coal sample which is made from the same quality coal. The experimental data of the gas adsorption and desorption capacity with four different granularities coal sample under different initial pressure are obtained. Relative analysis to the different data shows the mathematical equation relationship among the capacity, rate and time of gas adsorption. The fitted curves of gas adsorption capacity with time in different granularities coal indicated how the size of granularities influences the time to reach the equilibrium of adsorption and desorption, the rate of gas adsorption. And the fitted curve showed the initial pressure had no influence on the rate of gas adsorption too. The smaller of the granularities, the faster of the adsorption rate, the shorter the time spent to adsorption equilibrium; the bigger of the granularities, the slower of the adsorption rate, the longer the time spent to adsorption equilibrium. It can be concluded that the rate of gas adsorption and desorption has scale effect.