However,
the effectiveness of this operation needs to be confirmed by
multi-component adsorption measurements since ECBM depends on the relative affinity of CO2 and CH4 in their mixture on coal
[11,12]. Also, the extent of preferential sorption of CO2 and CH4
cannot be derived from pure gas adsorption but requires experiments
with gas mixtures [13]. The measured isotherms of mixture
gas will be the firm basis for an effective design of injection strategies
and it can be used to describe the sorption dynamics in the
coal seams during ECBM.