Geologic sequestration of carbon dioxide is an option for the mitigation of industrial emissions. However, considerable effort remains to shift this technology from its current status as potential solution to a safe, effective and trusted foundation to the global energy system. Characterization of gas movement and sorption capacity of coal at in-situ conditions is required. Using the volumetric method, measurements of CH4 and CO2 sorption and diffusion in coal have been made on powder and non-powder confined coal. Results obtained, emphasized that the sorption capacity and the kinetics of gas in coal are both influenced by the stress state of the sample. The application of 6.9 MPa confining stress contributed to about 30% and 80% of sorption capacity reduction for CO2 and CH4 respectively. The sorption and diffusion of CO2 in confined coal follow two distinct rates described with diffusion coefficients of 2.3×10-6 m2/s and 9.4×10-12 m2/s respectively. In contrast, the flow of methane is characterized by a continuous process with a diffusion coefficient of 3.8×10-7 m2/s. These observations confirms the complex interaction of CO2 with the coal structure and stressed that CH4 and CO2 sorption and transport in coal should be characterized differently, specifically when dealing with non-powder confined samples. Consequently, the use of information collected on pulverized coal samples for the simulation and prediction of long term underground sequestration and enhanced coalbed methane is not justified.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Feb 1 2009|
|Event||9th International Conference on Greenhouse Gas Control Technologies, GHGT-9 - Washington DC, United States|
Duration: Nov 16 2008 → Nov 20 2008
All Science Journal Classification (ASJC) codes