Abstract:

Lignite, sub-bituminous coal, high volatile bituminous coal, low volatile bituminous coal and anthracite were chosen as models of coal surface, and the adsorption of six kinds of gases on coal surface were discussed, which were CO,O₂, H₂O(g), CO₂, CH₄ and H₂.The adsorption was described on the molecular level using the semi-empirical quantum chemistry intermediate neglect of differential overlap (INDO) method.The corresponding microscopic parameters, such as adsorption energies, adsorption distances, adsorption bond orders and changes of net charge of gases on coal surface were calculated.The curves of binding energies between gases and coal surface were fitted well using the Morse function.It was indicated that the adsorption of CO and O₂ on coal surface was the strongest, the next was H₂O and CO₂ , and the weakest was CH₄ and H₂.