More environmentally friendly aluminium refining is in the works, as researchers at the University of Adelaide partner with Alcoa to investigate the possibility of integrating concentrating solar thermal (CST) technologies into the Bayer alumina refining process.
The $15.1 million research project is getting $4.5 million in funding from the Australian Renewable Energy Agency (ARENA). The aim is to develop the technologies and process knowledge to enable the integration of both low and high temperature concentrating solar thermal, and solar reforming of natural gas into the existing Bayer aluminium refining process.
According to project leader Professor Gus Nathan, who is also Director of the Centre for Energy Technology in the University of Adelaide's Institute for Mineral and Energy Resources, aluminium refining utilises a lot of natural gas, which is increasing in price.
"Anticipated cost increases of natural gas and other non-renewable energy sources, and the carbon footprint associated with their consumption, mean that alternative, next-generation solar technologies are becoming more appealing to industry," he explained.
Natural gas usage also results in greenhouse gas emissions and higher carbon footprint.
According to the researchers, up to 45 percent of natural gas consumption can be displaced by using solar energy, helping reduce the carbon footprint of aluminium, and allowing Australia to meet greenhouse gas emission targets.
With a reduced carbon footprint, the aluminium produced by the hybrid process could be sold to new, carbon-conscious markets.
Alcoa is the world's leading producer of alumina (aluminium oxide), which is used in a wide range of industrial processes and products. Alcoa currently supplies 15 percent of the international alumina market.
The technology being developed is not primarily about solar panels and photovoltaics. Rather, the researchers are hoping to harness the power of the sun to generate alternative liquid fuels from carbon-rich sources, including agricultural residues.
Concentrated solar energy could also be used to create industrial process heat for the refining process, in conjunction with conventional energy sources.
"The University has been developing these technologies for many years now, and we believe such innovation in hybrid solar energy for the solarised production of mineral products and liquid fuels offers significant opportunities for industry," Professor Nathan says.
The funding from ARENA will enable the research team and its partners to identify a cost-effective way to integrate hybrid solar thermal technologies into one of Alcoa's Western Australian-based refineries and beyond.
“The knowledge gained from this project will also have the potential to benefit other mining and minerals processing operations in Australia and overseas,” said Professor Nathan.
Partners involved in this project are Alcoa, CSIRO, ETH Zurich, Hatch, IT Power, San Diego State University, and the University of New South Wales.