Geologica Belgica Geologica Belgica -  volume 7 (2004)  number 3-4 - Proceedings of the 5th European Coal Conference 

FEASIBILITY OF CO2 SEQUESTRATION IN ABANDONED COAL MINES IN BELGIUM

Kris PIESSENS

Royal Belgian Institute of Natural Sciences - Geological Survey of Belgium, Jennerstraat 13, B-1000 Brussels, Belgium. E-mail: kris.piessens@naturalsciences.be

Michiel DUSAR

Royal Belgian Institute of Natural Sciences - Geological Survey of Belgium, Jennerstraat 13, B-1000 Brussels, Belgium. E-mail: michiel.dusar@naturalsciences.be

Abstract

The concept of storing gas in abandoned coal mines is proven technology (Anderlues, Péronnes). However, this was done for seasonal storage of natural gas in underpressured reservoirs, whereas CO2 sequestration preferably requires overpressured reservoir conditions for long-term storage. Marl and chalk apparently form a sufficiently tight seal in a number of coal mines, but this will need verification. Safety risks involved with the storage of CO2 in mines are low. Natural faults and induced fractures need detailed evaluation, especially with respect to changes in the stress-regime. Standard techniques to inject CO2into reservoirs involve the injection of liquid CO2. Excessive cooling of the reservoir and injection equipment can be avoided by depressurising CO2 and injecting it as a gas or, when the reservoir becomes partly fluid-filled, to apply custom-designed injection schemes for injection of liquid CO2. When CO2 is injected into a coal mine, it may be stored in free space, in solution in the formation water, or adsorbed in coal. These amounts can be calculated, but not all parameters are sufficiently known to produce reliable results. Therefore, the amounts are split into an ascertained capacity that can be calculated with a known accuracy, and an additional capacity, which is an estimated surplus that cannot be calculated accurately. CO2 sequestration in coal mines seems to be technically feasible and may be a useful option for Belgium to reduce the industrial emission of greenhouse gases into the atmosphere. A case study for the Beringen-Zolder-Houthalen collieries shows that sequestration is a viable option, even for the ascertained capacity alone. At an injection rate of 300 000 tons/y, sequestration can be operational for about 25 years. This is a conservative estimate, and it may prove possible to inject at 500 000 tons/y for 25 years. This could be a considerable contribution, approximately 3 to 6% of the mitigation required to reach the Kyoto target for Belgium. Petrochemical plants that produce nearly pure CO2 streams are prime candidates for early opportunity projects in abandoned coal mines.

Pour citer cet article

Kris PIESSENS & Michiel DUSAR, «FEASIBILITY OF CO2 SEQUESTRATION IN ABANDONED COAL MINES IN BELGIUM», Geologica Belgica [En ligne], volume 7 (2004), number 3-4 - Proceedings of the 5th European Coal Conference, 165-180 URL : https://popups.uliege.be/1374-8505/index.php?id=308.