CO2 Storage Mechanism in Coal and its Effect on Methane Production in Enhanced Coalbed Methane Recovery

In this study, we provided more theoretical method for estimation of dissolution amount and applied this method to enhanced coalbed methane recovery （ECBMR） simulator. Dissolution amount was measured by method of differential heat of adsorption. Akabira coal, a Japanese bituminous coal, was used for the experiment. The results showed that CO2 was stored in coal by both adsorption and dissolution. Using this result the methane production was calculated by ECBMR-simulator, enhanced coalbed methane recovery simulator, the University of Tokyo （ECOMERS-UT）. Total stored CO2 was separated into adsorption component and dissolution component. Only the former component contributes to the competitive adsorption. Coalbed methane （CBM） production simulation considering the dissolution showed later and smaller peak production and prolonged methane production before the breakthrough than the conventional competitive adsorption.