Estimation of CO2 sorption capacity onto coal : from laboratory to geological scale

Abstract : Nowadays, different methods are under development for storing CO2, one of which showing potential sequestration in coal seams. Laboratory sorption experiments of CO2 and CH4 were performed using a gravimetric experimental set-up, controlling different parameters, on a lignite samples from the Provence coal basin (Southeast of France). Our results evidenced that moisture and temperature are the most important parameters for controlling sorption capacities independent of their particle size. Gas adsorption capacities at equilibrium were estimated from the Langmuir theory applied to isotherm data. In addition, storage capacity were calculated by assuming experimental data, physical limits of the geological system, temperature and pressure conditions, presence of gas initially in place and porosity of coal. The estimation of CO2 storage capacity was computed for two main coal seams of an unexploited area in the Provence basin. Calculations show that CO2 storage from a coal-fired power plant would be relevant for 10 years.