HR: 1340h
AN: U43C-1401    [Abstracts]
TI: Numerical modeling of CO2 storage in gob areas of coal mines
AU: * Kempka, T
EM: kempka@lih.rwth-aachen.de
AF: RWTH Aachen University, Department of Engineering Geology and Hydrogeology, Lochnerstr. 4-20, Aachen, 52064, Germany
AU: Waschbuesch, M
EM: waschbuesch@lih.rwth-aachen.de
AF: RWTH Aachen University, Department of Engineering Geology and Hydrogeology, Lochnerstr. 4-20, Aachen, 52064, Germany
AU: Fernandez-Steeger, T
EM: fernandez-steeger@lih.rwth-aachen.de
AF: RWTH Aachen University, Department of Engineering Geology and Hydrogeology, Lochnerstr. 4-20, Aachen, 52064, Germany
AU: Azzam, R
EM: azzam@lih.rwth-aachen.de
AF: RWTH Aachen University, Department of Engineering Geology and Hydrogeology, Lochnerstr. 4-20, Aachen, 52064, Germany
AB: CO₂ storage in coal mines can offer a remarkable contribution to world-wide greenhouse gas control. Therefore, numerous technical approaches of CO₂ storage in coal mines especially considering sorptive storage on residual coal seams have been developed within the last decade.
The CO₂ storage concept discussed here considers the utilization of mining wastes from coal processing as CO₂ adsorbent resulting from their high content of organic matter. For that purpose a sorption reactor at the surface is used to capture CO₂ from flue gas originated by industrial combustion processes. CO₂ is separated from N₂ in that reactor, and a CO₂ mining waste suspension is established, involving a water content applicable for its pumping. The suspension is subsequently injected into remaining gob areas behind longwall workings providing efficient CO₂ storage accompanied by subsidence mitigation and underground mining waste disposal. The main aspect with respect to storage security is potential CO₂ outgassing from stowed gob areas into the longwall face as well as adjacent drifts and workings.
A software package for numerical simulation of multi- component flow and transport in porous media (MUFTE_UG) is used to investigate the interaction of gas flow parameters in terms of quantity, time and space. Different CO₂ storage scenarios are taken into account by the application of a parameterization based on laboratory experiments as well as knowledge and experience of German mining and mining research companies.
The low permeability of the mining wastes is the main criterion preventing CO₂ flow out of the stowed gob areas. Furthermore, the load of the roof compresses the injected CO₂ mining waste suspension leading to a consequent reduction of parameters like porosity and permeability. Therefore, implementation of a model considering CO₂ outgassing from stowed gob areas and a subsequent sensitivity analysis are conducted to evaluate interacting model parameters by their relevance and the overall CO₂ storage risks resulting from the application of the described sorptive CO₂ storage technology.
UR: http://www.co2trap.org
DE: 1694 Instruments and techniques
DE: 1699 General or miscellaneous
SC: Union [U]
MN: 2007 Fall Meeting