Carbon dioxide sequestration effects on coal's hydro-mechanical properties: A review

Abstract

Carbon dioxide (CO 2) sequestration in deep un-minable coal seam causes the seam's permeability and strength to be significantly reduced because of CO 2 adsorption-induced matrix swelling. This paper reviews this swelling process in coal and its influence on coal's flow and strength properties. The amount of swelling depends on the properties of both the gas and the coal mass. The swelling caused by CO 2 adsorption is higher compared with that caused by CH 4 and N 2 and greatly depends on the state of the CO 2 phase. The super-critical state of CO 2 adsorption causes greater swelling compared with the sub-critical state. It has been observed that the swelling rate increases with increasing C..