South Australia looks to trial underground coal gasification

In UCG mining, oxygen is pumped into the coal seam, which is then set on fire and allowed to burn underground.

The South Australian government has begun a public consultation on whether to hold a trial of underground coal gasification (UCG). The practice was banned in Queensland after it caused “irreversible” damage to hundreds of square kilometres of valuable Darling Downs farming land.

UCG is an experimental method of extracting gas from coal seams that are too deep to mine using conventional coal seam gas methods. In UCG mining, oxygen is pumped into the coal seam, which is then set on fire and allowed to burn underground. That combustion produces synthesis gas, or syngas, which is used in products such as aviation fuels and synthetic diesel.

It was banned in Queensland in April 2016 after flammable levels of carbon monoxide, hydrogen and hydrogen sulphide — three of the four main gases produced by the UCG process — were detected in soil near the Linc Energy plant at Hopeland.

A 320 square kilometre exclusion zone around the Linc plant continues to be enforced, engulfing the entire Hopeland agricultural community. Digging deeper than two metres is not permitted within the exclusion zone because of the risk of explosions triggered by sparks.

In South Australia, the trial would involve an experimental UCG plant operating at an old coalmine at Leigh Creek for three months to determine how well the process performed.

The Wilderness Society South Australia director Peter Owen said the South Australian government should opt for a renewable alternative.

"After Queensland has made it illegal in that state, how can minister [Tom] Koutsantonis think it is appropriate in South Australia?" he said.

"Allowing this dirty technology in our state is completely at odds with a government that regularly flies to Paris and New York to trumpet their climate change credentials."

Minister for mineral resources Tom Koutsantonis said the approval of the UCG trial was ultimately out of his hands.

"The approval or otherwise of coal gasification projects should be based on science and determined by expert regulators, not politicians," he said.

"We have a very effective regulatory framework in South Australia and the merits of future projects will be assessed against that framework, not the decision in Queensland.

"We trust the scientists and independent regulators, and proponents need to prove to these regulators that they will do no harm to the environment."

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