Carbon capture and storage (CCS) is a technology with the potential to reduce emissions of carbon dioxide (CO2) and other greenhouse gases (GHG) to the atmosphere. This technology involves the combined processes of capture, transport and geological storage of CO2 and other GHG gases as shown in the diagram below.
Source: CO2CRC
The GHG may be produced by the combustion of fossil fuels, or co-produced through oil and gas extraction or some industrial processes. Instead of allowing the gases to be released into the atmosphere, they are captured at the emission site where they are separated from other substances. The separated stream is then compressed into a concentrated volume and transported from the source location (emission site) to the injection location. Geological storage comprises:
- the injection of the compressed stream into geological formations in the deep sub-surface
- its migration away from the immediate vicinity of the injection point
- its subsequent trapping in geological formations.
CCS offers the potential for Australia to reduce its GHG emissions while maintaining its international competitiveness through its competitive advantage in low cost and abundant fossil fuels (coal and gas). Australia is considering CCS as one of a suite of technologies to meet its future greenhouse objectives.
The electricity generation sector, which represents 35 per cent of net national GHG emissions, is potentially well placed to take advantage of CCS technologies given it is dominated by relatively few large emission sources. Before CCS can be applied commercially, there is however, a need to improve capture technologies, reduce associated costs, and firm up storage locations.
Some of Australia’s major natural gas reserves contain significant proportions of CO2. Gas projects may therefore be well placed to utilise CCS technology, given the capture and separation of CO2 is part of the gas processing.
Technically, the individual components of CCS are well understood through international and domestic experience, however, capture at a large scale and geological storage of CCS streams over the long term have not been fully and commercially demonstrated. As with any large scale industrial process, there are environmental and health and safety issues (both occupational and public safety) associated with CCS. However, experience to date of CCS technology indicates these risks can be managed with appropriate safeguards.
Further information on the technical aspects of CCS is in the Government submission to the House of Representatives Inquiry on Geosequestration Technology
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