Reducing Greenhouse Gas Emissions: Geological Storage of CO2

Abstract

Carbon capture and storage (CCS) is the collection of carbon dioxide (CO2) from industrial point sources such as power plants and its injection underground. Much of the technology necessary to capture and inject CO2 into the subsurface already exists and CCS will be an integral part of any strategy to combat anthropogenic climate change until we, as a society, are able to move away from our dependence on fossil fuels. There are three options for geological storage of CO2: deep saline aquifers, depleted oil reservoirs and unmineable coal beds. It is the purpose of this presentation to provide a general survey of each of these options. For each geological formation I review (1) The ways in which CO2 could escape into the atmosphere. (2) Current scientific knowledge and uncertainties about the behaviour of CO2 after it is underground -particularly the interactions of water, oil or gas initially present in the geological formation with injected CO2. (3) The overall advantages and disadvantages of each option in terms of technical challenges and cost.