Physical Simulation Experiment of Underground Gasification of Coal Samples at Hangjin Banner in the Ordos Basin
Hangjin Banner in northern Ordos Basin is rich in coal resources and underground gasification of coal seam is a potential way to develop and utilize coal resources safely,cleanly,and efficiently.Therefore,the underground ignition experiment and physical simulation experiment of gasification combustion were carried out by using the deep drilling coal samples in Hangjin Banner,which provided the basis for future field pilot experiments.The experimental results show that increase of the oxygen concentration of gasification agent under high pressure could significantly reduce the ignition point of coal seam,the ignition point of large coal sample can be reduced from 490℃to 390℃under the condition of 3 MPa and 30％oxygen-enriched concentration,the overall gasification reactivity of coal samples is quite good as well as the reactivity of water vapor is better than that of carbon dioxide,and both carbon dioxide and water vapor can be effectively reduced at 1 000℃.The oxygen concentration and water content have great influence on the composition of gasification products.The higher the water-oxygen ratio,the higher the H2 and CO2 contents in the produced gas,but the lower the CO content.The higher the oxygen concentration,the higher the effective components of the produced gas.The backward gasification process of gas injection point can effectively control the fire area to realize stable gasification,and the concentration of effective components in the produced gas can be stabilized between 55％ and 65％. The methane concentration increases obviously with the increase of gasification pressure. The laws and characteristics revealed in this experiment can provide reference for field test ignition,gasific ation agent ratio design,and gasification stability control.
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维普
