The component fractionation effect in binary-component gas adsorption isotherm experiments on coal

Different gas adsorption isotherm experiments were carried out on the coal samples from Jincheng district, including N2, CH4, CO2, as well as the binary-component gas of CH4-N2 and CH4-CO2 of three different concentrations. In the binary-component gas adsorption isotherm experiments, the gas component with higher adsorption ability is adsorbed firstly. Thus the result in its relative concentration in the free phase shows a trend of decrease first and then increase, whereas the relative concentration of the gas component with lower adsorption ability shows a trend of increase first and then decrease. In the adsorption phrase, the relative concentration of the gas component with higher adsorption ability increases gradually, and the relative concentration of the gas component with lower adsorption ability decreases gradually. In the adsorption competition of the binary-component gas, the adsorption rate of the gas component with higher adsorption ability shows a trend of rapidity at first then slowness, but the adsorption rate of the gas component with lower adsorption ability shows a trend of slowness at first then rapidity. The component fractionation effect in the binary-component gas adsorption isotherm experiments is caused by the difference of the adsorption ability of coal of different gas components.