An aerial view of all three Curtis Island LNG plants.
An aerial view of all three Curtis Island LNG plants. Ashley Roach - Fullframe Photogr

LANDMARK STUDY: Report shows benefits of gas over coal

A LANDMARK study by Australia's peak science body, using data from one of the three Curtis Island liquefied natural gas projects, has found new benefits of using gas as a power source.

The CSIRO report assessed greenhouse gas emissions of one of the three coal seam gas-LNG projects at Curtis Island, and the climate benefits of using natural gas in place of thermal coal for power generation.

Titled Whole of Life Greenhouse Gas Emissions Assessment of a Coal Seam Gas to Liquefied Natural Gas Project, it used commercial-in- confidence data from 2015-17 to provide the first accurate estimates of whole-of-life greenhouse gas emissions associated with the operation.

Undertaken by the CSIRO's Gas Industry Social and Environment Research Alliance, the study found switching black thermal coal to CSG for electricity generation using gas turbines could reduce greenhouse gas emissions by up to 50 per cent.

GISERA director Dr Damian Barrett said the results aligned with similar studies.

"(This) suggests that the fugitive emissions component of the total greenhouse gas emissions identified in this latest study are at the lower end of the scale," Dr Barrett said.

"Results of this latest research underline the potential climate benefits of using gas in place of coal to generate electricity, particularly when using high-efficiency closed-cycle gas turbines."

The report found greenhouse gas emissions associated with CSG production - compression, dehydration, water treatment and liquefaction - represented 1.4 per cent of likely future production for the CSG-LNG project (576PJ per year).

A comparison between greenhouse gas emissions from thermal coal power and natural gas found a reduction in emissions of 31 per cent using an open-cycle gas turbine, or 50 per cent using a closed-cycle gas turbine.

This was partly because theuse of domestic gas would avoid emissions caused with liquefaction, shipping and regasification, which represented 9.9 per cent of total life-cycle emissions.

The report has been lauded by gas industry groups as confirmation of the "key role" gas plays in lowering global greenhouse gas emissions.

Australian Petroleum Production and Exploration Association chief Andrew McConville said: "Australia's LNG industry is in a unique position to contribute substantially to the economic development of the nation and to reduce greenhouse gas emissions," he said.

However, the research alliance was unable to confirm if Curtis Island gas was having an impact on global emissions, because it could not determine if the exported gas was displacing the use of coal.

"In the present study, we cannot calculate directly the GHG emissions reduction of LNG exports from Curtis Island, Queensland relative to coal-fired electricity generation in Asia because we do not know the proportion of gas used to displace what would have been produced from coal," the report said.

The report does not address focuses solely on GHG emissions, and not on other potential environmental impacts of CSG production.