Modeling Binary CO2/CH4 Flow through Coal Media

Abstract

CO2 can be sequestered in coal seams considering the environmental issues. By means of injecting CO2 into the coal seams, both sequestration of CO2 and the enhanced recovery of methane inside the coal seam can be realized. One-dimensional simulation regarding the binary CO2/CH4 flow in a coal seam core was studied by using an analytical solution method. The simulation results were compared with experimental data by matching the effluent concentrations of CO2 and CH4. The transport parameters such as longitudinal dispersion coefficient, retardation factor, and distribution coefficient were determined. It was seen that the amount of CO2 captured inside the coal sample during binary displacement was much lower than the maximum adsorption capacity of the coal at the same pressure. Then the transport behavior of CO2 and CH4 inside the coal seam was simulated. The results of analytical solution were in good agreement with the measured ones within the acceptable error range.