T215 Frontiers in Coal Science: From Basic Research to Applied Technology

Tuesday, 20 October 2009
1:30 PM - 6:00 PM
B114/115

MONITORING CO2 AND METHANE ADSORPTION INTO THE COAL: APPLICATION OF SMALL-ANGLE NEUTRON SCATTERING TECHNIQUES (SANS AND USANS)

Paper number: T215-5
Program: Technical Sessions
Time: 2:25 PM – 2:45 PM

Authors

Abstract

Carbon dioxide (CO2) is the greenhouse gas which makes the largest contribution to global warming and the vast majority of CO2 emissions are generated by fuel-burning power plants. Injection of CO2 in unmineable deep coal seams is one of the options of geologic CO2 sequestration. Whereas it has been demonstrated that organic matter has high gas adsorption capacity, the mechanisms and the consequences of this adsorption in subsurface conditions are poorly understood. Small-angle scattering techniques can provide unique, pore-size-specific insight into the density of adsorbed CO2. This study reports the results of the first small-angle neutron scattering (SANS) and ultra-small angle neutron scattering (USANS) studies on coal, using the Seelyville Coal from the Illinois Basin as an example [1,2]. Experimental conditions employed in this work were chosen to simulate a range of coal subsurface conditions including those at 518 feet depth (P,T) = (1-50 bar, 16ºC), and the coal was saturated with subcritical CO2. Experimental results illustrate that coal microstructure is unaffected by pressurised subcritical CO2 or Helium [3], and these findings suggest that depths of burial do not constitute a stability barrier to storage of CO2. The physical density of CO2, fluid phase adsorbed in the porous coal matrix exceeds by a factor of 3-4 the density of the bulk fluid at the same thermodynamic conditions. The applied methodology can be extended to studies of the sorption kinetics and capability of other naturally occurring porous materials of interest for carbon geological storage (saline aquifers, porous rocks, basalts, etc.) as well as investigations of supercritical fluid mixtures (e.g. CO2 and methane) in various coals and engineered porous materials such as carbon aerogels.

1. Y. B. Melnichenko, A. P. Radlinski, M. Mastalerz, G. Cheng and J. Rupp, Int. J. of Coal Geology, 77, 69-79 (2009).

2. A. P. Radliñski, T. L. Busbridge, E. MacA. Gray, T. P. Blach, Y. B. Melnichenko, G. Cheng, D. J. Cookson, M. Mastalerz, J. Esterle, Langmuir, 25, 2385–2389 (2009).

3. R Sakurovs, A. P. Radlinski, Y. B. Melnichenko, T. Blach, G. Cheng, H. Lemmel, and H. Rauch, Stability of coal microstructure on exposure to high pressures of helium, Energy & Fuels, in press.