The Commonwealth Scientific and Industrial Research Organisation (CSIRO), and Australian Petroleum Co-operative Research Centre (APCRC) are studying the geological disposal of CO2 in the Gladstone-Rockhampton region of Central Queensland which is experiencing rapid industrial growth. The process involves injecting the CO2 in a semi-liquid form into coal seams, depleted oil and gas fields, large voids and cavities, or into unusable or saline aquifers.

CSIRO will be exploring the existing range of capture and separation technologies for CO2, and to assess their suitability for the region, whilst the APCRC will research ways to dispose of the CO2 in the subsurface.

“CO2 is a major greenhouse gas and there is a growing view that geological disposal of CO2 could be one of the most environmentally acceptable ways to halt the rapid rise of CO2 emissions without adversely impacting on economic development,” said Dr Peter Cook, Executive Director of the APCRC.

“At this stage it appears possible to securely store CO2 underground for thousands of years,” said Cook.

There are six main methods of geological disposal, but preliminary studies suggest that there are three which are most suitable for Australia:

  • the use of CO2 from industry to extract methane from coal beds, where the CO2 adsorbs onto the coal, displacing the methane which is recovered and used in energy production;
  • CO2 could also be locked away through adsorption in deep, thick, unmineable coal seams;
  • disposal of CO2 in saline aquifers that are too deep or too saline to be used as a water source.

According to CSIRO, the last alternative is possibly the most favourable. “Overseas experience and our knowledge of Australian geology suggest this option may hold the greatest potential for Australia,” said Cook. “But we need to ascertain its technical applicability to Australia and most importantly define what the cost will be.”

Presently, the only methods of medium to large scale CO2 sequestration is through the use of forests, oceans or geological disposal, says Dr John Wright, CSIRO’s Energy Sector Co-ordinator.

“Australia’s Kyoto target from the Framework Convention on Climate Change held in Kyoto in 1997 allows for an eight percent grown in emissions above 1990 levels by 2008-2012,” said Wright. “Australia is already 16% above this target and major action needs to [be] taken such as large scale sequestration[see related story].”

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