High-pressure Sorption Behaviour Of CH₄ And CO₂ On Coals And Its Applications

Using a manometric experimental setup, experimental and modeling investigation of high-pressure CH4 and CO2 sorption thermodynamics and kinetics were performed on seven Chinese coals of different rank. The objective of this study was to explore the accuracy and reproducibility of the manometric method in the pressure and temperature range relevant for potential CBM and CO2-ECBM activities (P>8 MPa, T>35℃). Further, the upscaling and implementation of experimental results into reservoir simulation, CO2 coal seam sequestration and CO2-ECBM were discussed as well as maximum experimental errors were estimated using the Gauss error propagation theorem. The experimental data presented here was used to explicitly study the CO2 sorption behavior of Chinese coals in the elevated pressure range (up to 25 MPa) and the effects of temperature on supercritical CO2 sorption isotherms. To our knowledge the isotherms presented here are the first comprehensive sorption data of Chinese coal samples with pressure up to 25 MPa (250 bar) by manometric method which has not been explored previously. In order to assess and improve the quality of high-pressure sorption isotherms of carbon dioxide on coals, an inter-laboratory study ("Round Robin") was conducted among four European research laboratories. Supercrtical CO2 excess sorption isotherms were measured on Filtrasorb 400 (F400) activated carbon at 318 K. Inter-laboratory studies can help to identify and avoid pitfalls and to formulate standard procedures which can improve overall data quality significantly.