The recovery rate of methane is usually limited by the coal seam gas pressure and diffusion rate and, as a result, not all the available gas can be recovered. By injecting gas into the seam, further methane can be liberated. This gas can be CO2, N2, flue gas or a combination thereof. The injection of captured CO2 to provide enhanced recovery of coalbed methane might serve to increase methane production whilst storing CO2, if the geography and economics are favourable. However, despite many pilot studies on ECBM, no projects have moved to the demonstration or commercial phase, due to both technical and economic issues.