The adsorption thermodynamics and its application

A series of isothermal adsorption experimental data of Xiayukou#11 coal sample in Shaanxi Hanchengmine is transformed to fit a temperature-pressure-adsorption equation. In 20℃ to 50℃ temperature range, 0.0MPa to 14.0MPa pressure range, 0.0 cm3/g to 65 cm3/g adsorbed amounts range, all three kinds of Isobaric Adsorption, Isothermic Adsorption, and Isosteric Adsorption have been created and presented in figures.  The Clausius-Clapeyron indefinite integral equation and definite integral equation have been used to illustrate that the gas isosteric adsorption is an exothermic process if the lnP vs 1/T plot of gas adsorption is a straight line with a negative slope, or if P2＞P1, then T2＞T1.   The phenomenon of unit IAE being decreased with the increasing of adsorption amount indicates that the surface of the coal seam is not smooth, and the energy of the surface is uneven; and adsorption always occurs first at higher energy and more active positions.