Method for Simultaneous Measure of Sorption and Swelling of the Block Coal under High Gas Pressure

Carbon dioxide sequestration in unmineable coalbeds combined with enhanced coalbed methane recovery is attracting attention as one of the possible methods for carbon capture and storage. Sorption and swelling characterizations are important issues for forecasting the performance of aimed coalbeds. A method for simultaneously measuring the adsorption amount of gas and the corresponding swelling ratio of coal under high gas pressure (up to 18 MPa) is proposed. A high-pressure linear variable differential transformer displacement transducer is equipped with a manometric sorption apparatus. This intentional assembly provides an important opportunity to acquire the sorption and corresponding swelling data simultaneously, which is necessary to understand clearly the relationship between sorption and swelling of the block coal sample. Results unambiguously confirm that this method can be used under supercritical CO2 and moisture conditions, with relatively high reproducibility and accuracy.