Comprehensive studies on adsorption of CH4, N2, CO2 single gas and their multicomponent gas on coal are conducted by applying physical chemistry, interface chemistry, coal petrology and coal chemical engineering knowledge. Firstly, adsorption characteristics of methane on different rank coals are investigated and the diversities among CH4, N2 and CO2 are compared. Several classical adsorption models are evaluated and the optimal one is selected out for describing adsorption process of gas on coal...