Galilee to marry geothermal and clean coal tech

GEOTHERMAL and carbon sequestration technologies could converge to create emission-free electricity in Queensland’s Galilee Basin with help from the University of Queensland.
Galilee to marry geothermal and clean coal tech Galilee to marry geothermal and clean coal tech Galilee to marry geothermal and clean coal tech Galilee to marry geothermal and clean coal tech Galilee to marry geothermal and clean coal tech

The Galilee Basin.

Blair Price

Both billionaire Clive Palmer and Australia’s richest woman Gina Rinehart are behind projects which could reach a combined 100 million tonnes per annum of thermal coal production in the undeveloped basin.

The university’s Queensland Geothermal Energy Centre of Excellence is researching green alternatives to fuel the power requirements.

QGECE director Professor Hal Gurgenci said a new 1000-megawatt power station might be needed in the emerging coal region.

“Is it possible to power the development of the present and future mining prospects in the Galilee Basin by zero-emission electricity? The research by the University of Queensland says yes,” he said.

“There are indications, which still need to be confirmed, that a significant geothermal heat source may exist in the Drummond Basin – the late Carboniferous granite structure underneath the Galilee Basin.”

Working with American and Japanese researchers, QGECE is aiming to develop a new geothermal technology known as “the supercritical CO2 thermosiphon”

Gurgenci said the new geothermal concept would send supercritical carbon dioxide down instead of water to extract heat from underground heat reservoirs.

“The hot CO2 rises to the surface and drives a turbo-generator to produce electricity, and then is cooled and sent back underground to repeat the cycle,” he said.

“The favourable thermodynamic properties of CO2 make it possible for the two wells to operate as a self-sustaining heat pump that brings the subterranean heat to the surface and transforms it to electricity.”

QGECE will pioneer the development of turbines, heat exchangers and other plant equipment to test the technology at the power conversion laboratory at UQ’s School of Mechanical and Mining Engineering.

“The concept has the potential to increase the geothermal power conversion efficiencies by up to 50 per cent,” Gurgenci said.

“Sequestration of CO2 captured from coal-fired power plants is an auxiliary benefit since access to large quantities of CO2 is essential, first, to start the reservoir and, then possibly, to make up for the fraction of CO2 trapped underground.

“All of our work and research is showing that the expected development in the Galilee Basin could be powered by a zero-emission CO2 geothermal siphon plant exploiting the heat of the Drummond geothermal resource by using the CO2 emissions captured from coal-fired power generation.”

QGECE is funded as part of Queensland’s ClimateSmart 2050 program.

Meanwhile, the US government provided a total of $US15 million to four projects pursuing other aspects of supercritical CO2 thermosiphon technology in its last round of geothermal stimulus funding.