Aquifer based carbon dioxide disposal in Denmark: Capacities, feasibility, implications, and state of readiness

Abstract

Electrical Power Generators in Denmark, as well as the rest of Europe, are under great pressure to limit their emissions of Carbon Dioxide gas to the atmosphere. In Denmark, there is an active debate as to whether CO 2 should be removed from stack gases from coal-fired power stations, and thereafter sequestered in an environmentally sound manner. In 1990 Danish electrical power generation produced 22.2 million tons CO 2, the removal of which would place an enormous technical and economical burden on the Power Generation Sector. Potential: Denmark has extensive deep lying salt water aquifers which are well suited as disposal facilities for CO 2. Existing information for three structures identified by hydrocarbon exploration and research wells indicates that Denmark has a disposal capacity for 30 years in Jutland and on Funen. This excludes potential repositories under Sealand. There exists a potential for sequestering carbon dioxide in North Schleswig, on Funen and Sealand; however, these structures are not described sufficiently to delineate a capcity or state their suitability to retain the CO 2 for long periods of time. Feasibility: The technology exists to pump CO 2 into deep lying aquifers. Problems arise in managing the repository. The physical states of carbon dioxide and water at depths greater than 800 meters below surface will cause difficulties in obtaining a high percentage utilization of a potential disposal information. This will probably require innovative reservoir modelling and simulation techniques and a careful management of the repository under operation. There are also physio-chemical processes to be considered: formation dissolution, cap rock alteration, etc. Implications: The implication of carbon dioxide disposal (excluding separation costs) is to increase the cost of producing electricity due to; wells, exploration costs, a transmission system, disposal facility, operational costs, environmental impact assessments/statements, monitoring systems, loss of efficiency, and closure costs. Further, public opposition can be expected to be associated with any installation which is designed to dispose of an unwanted product. The costs of a disposal facility will not cease with closure, as compressed carbon dioxide is denser than air any catastrophic leakage contains a serious damage for the local inhabitants. State of Readiness: A minimum of 10 years will be required to establish a disposal facility for carbon dioxide removed from stack gases. The constraining factors in this analysis will be construction of a pipe line to transport the gas, developing the repository (exploration, seismic, wells, modelling, etc.), and the work involved in obtaining political approval of the chosen site. Additional research is highly suggested before commencing the previous a activities and time expended for the must be added to the ten years.