New technologies are making natural gas a cheaper and greener fuel
Air quality in China’s cities is improving thanks to government initiatives to reduce urban coal burning. In Beijing, for example, homes, schools, hospitals and factories are switching from coal to gas for heating. As a result, demand for gas has quadrupled over the past decade. Now Australian researchers are partnering with Chinese industry to make gas production even cleaner and more efficient.
Both countries will benefit. China has large gas reserves but much of the gas is in unconventional sources such as coal seam gas and shale gas. The gases from these sources can contain less than 50 per cent methane so impurities such as carbon dioxide and nitrogen must be removed. For nitrogen that usually means cooling the gas to separate the valuable methane from the nitrogen in an energy-intensive process costing billions of dollars.
Australia has also stepped up to help China meet its demand for gas. About half of China’s gas imports come from Australia in the form of liquid natural gas (LNG). Some of that gas is from unconventional sources. In 2014 the world’s first shipment of LNG produced from coal seam gas left north Queensland for China.
“Separating methane and nitrogen is challenging due to their similar physical and chemical properties,” says Professor Eric May, from the University of Western Australia.
His research team have created molecular sponges using zeolite that can rapidly absorb methane, separating it from the contaminants. They’ve produced and tested a few kilograms of their zeolite sponge and are working with an Australian company Gas Capture Technologies. But industry will need thousands of tonnes.
“We’ve partnered with Sichuan DKT Energy Technology Company to bring these new separation technologies to the natural gas industry,” says Professor May. “DKT are specialists in gas separation so they’re working out how to produce the zeolites on a commercial scale,” he says.
The collaborative partners are also working on a second approach to the problem, taking inspiration from nature. Current processes for capturing nitrogen involve high temperatures and pressures.
But the bacteria in plants like clover can fix nitrogen using enzyme metal complexes. The team have developed similar technologies that also work at ambient temperature.
The project is supported by the Australian Government’s Global Innovation Linkages program.
Renergi is planning to turn crop waste and wood chips into gas and transport fuel, saving greenhouse emissions and landfill. They’re using technology developed at Curtin University and Taiyuan University of Technology.
Cheaper, stronger solar cells is the aim of a collaboration between the University of New South Wales and Chinese manufacturers. Twenty-five years ago UNSW demonstrated a new kind of solar cell with 25 per cent efficiency. But they were too expensive to produce. Now, using prototype laser tools from China’s DR Laser and others, the research partners have shown that they can cheaply hydrogenate silicon wafers to create affordable high-efficiency solar cells with 100 times the quality of previous approaches.
Underground mines are a significant source of methane, a powerful greenhouse gas. So CSIRO created a 25kW power generator demonstration unit that uses this waste gas to produce electricity, and trialled it at an underground coal mine of Huainan Coal Mining Group in China.
For further information visit www.china.embassy.gov.au
Header image: Solar cells developed at UNSW (Credit: UNSW).