Characteristics of CO ₂ gas permeability and adsorption of coal samples for CO ₂ sequestration into Japanese coal seams

This chapter describes adsorption capacity of CO2 on coal matrix and gas permeability necessary for a numerical modeling were measured with two sizes of core specimens and four sizes of coal specimens including crushed specimens, respectively. The effects of coal specimen sizes on CO2 gas absorption capacity and permeability are investigated. Coal seams have a significant ability of CO2 adsorption more than CH4 as approximately double based on some experiments reported. By utilizing this property, coal bed methane gas can be replaced with CO2 injected and produced as a clean energy. Furthermore, adsorption behaviors against saturated CO2 water have been measured to simulate CO2 adsorption in a coal seam with high water saturation.