Carbon dioxide flow and interactions in a high rank coal

Carbon dioxide flow and interactions in a high rank coal: Permeability evolution and reversibility of reactive processes

Hadi Mosleh, Mojgan (Cardiff University; The University of Manchester)
Turner, Matthew (Cardiff University; IHS Global Limited)
Sedighi, Majid (Cardiff University; The University of Manchester)
Vardon, P.J. (TU Delft Geo-engineering; Cardiff University)

2018-03-01

Uncertainties exist on the efficiency of CO₂ injection and storage in deep unminable coal seems due to potential reduction in the permeability of coal that is induced by CO₂ adsorption into the coal matrix. In addition, there is a limited knowledge about the stability of CO₂ stored in coal due to changes in gas partial pressure caused by potential leakage. This paper presents an experimental study on permeability evolution in a high rank coal from South Wales coalfield due to interaction with different types of gases. The reversibility of the processes and stability of the stored CO₂ in coal are investigated via a series of core flooding experiments in a bespoke triaxial flooding setup. A comprehensive and new set of high-resolution data on the permeability evolution of anthracite coal is presented. The results show a considerable reduction of permeability above 1.5 MPa CO₂ pressure that is correlated with the coal matrix swelling induced by CO₂ adsorption. Notably studied in this work, the chemically-induced strain due to gas sorption into coal, that has been isolated and quantified from the mechanically-induced strain as a result of changes in effective stress conditions. The results of post-CO₂ core flooding tests using helium (He), nitrogen (N₂) and methane (CH₄) demonstrated a degree of restoration of the initial permeability. The injection of N₂ showed no significant changes in the coal permeability and reversibility of matrix swelling. The initial permeability of the coal sample was partially restored after replacing N₂ by CH₄. Observation of permeability evolution indicates that the stored CO₂ has remained stable in coal under the conditions of the experiments.

Anthracite coal
Carbon sequestration
CO adsorption
Core flooding
Matrix swelling
Permeability
South Wales coalfield

http://resolver.tudelft.nl/uuid:4b738d77-e0b9-4a01-ab40-b47e2cf036af

https://doi.org/10.1016/j.ijggc.2018.01.002

2018-09-01

1750-5836

International Journal of Greenhouse Gas Control, 70, 57-67

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2018 Mojgan Hadi Mosleh, Matthew Turner, Majid Sedighi, P.J. Vardon