The new CSIRO technology targets exhaust ventilation air from coal mines, which accounts for about 70% of all coal mining-related greenhouse gas emissions. These emissions have a greenhouse effect equivalent to more than 237 million tonnes of carbon dioxide.
CSIRO and the Australian Greenhouse Office together with China’s Shanghai Jiaotong University and Huainan Coal Mining Group will construct the demonstration unit at a Chinese mine.
The low heating value gas turbine will be powered by about 1% methane in ventilation air. It will generate green power while also consuming the mine’s fugitive methane, which is 23 times more potent than carbon dioxide as a greenhouse gas over a 100-year timeframe.
The project is being conducted under the Australian Government’s Bilateral Climate Change Partnerships Program along with support from an Australia-China special fund grant under the Australian Government International Science Linkage Program. The initial investigation of catalytic combustion performance was supported by a grant from the Australian Coal Association Research Program (ACARP).
The project is being led by Dr Shi Su from CSIRO Exploration and Mining.
“China is responsible for about 45 percent of total ventilation air methane emissions,” Dr Su said.
“Although gas drainage efficiency in China has increased from 15 percent in 1998 to 26 percent in 2004, much of the captured gas is poor in quality. It is estimated that more than 70 to 80 percent of the drainage gas has a methane concentration of less than 30 percent, which cannot be used by conventional technologies. So while China is the largest source of mine methane emissions, it is also the largest potential market for technologies mitigating those emissions.”
Su said that once the technology is proven at the mine, it will also have application in the mitigation and utilisation of methane from landfill, livestock and the combustibles in industrial offgas.
A prototype demonstration unit with a power output of 10-30 kilowatts will first be demonstrated in the Chinese mine. Operational performance data and experience gained from this small unit will be used for the design of a second-generation turbine with an output of at least one megawatt.
