Rio Tinto and Alcoa announce world’s first carbon-free aluminum smelting process; Apple assist; Elysis JV to commercialize
Rio Tinto and Alcoa Corporation announced a revolutionary process to make aluminum that produces only oxygen as a by-product, eliminating all direct greenhouse gas emissions from the traditional smelting process. In Canada alone, use of the technology could eliminate the equivalent of 6.5 million metric tonnes of greenhouse gas emissions, if fully implemented at existing aluminum smelters in the country. That represents an amount roughly equal to taking nearly 1.8 million light-duty vehicles off the road.
The conventional Hall–Héroult process (invented in 1886) for smelting aluminum involves dissolving alumina (Al2O3) in molten cryolite, and electrolyzing the molten salt bath, typically in a purpose-built cell with carbon electrodes. The mixture is electrolyzed by passing a low voltage direct current at 100–300 kA through it, causing liquid aluminium metal to be deposited at the cathode. Oxygen from the alumina combines with carbon from the anode to produce mostly carbon dioxide.
The cells operate 24 hours/day; temperature in the cells is maintained via electrical resistance. Oxidation of the carbon anode increases the electrical efficiency at a cost of consuming the carbon electrodes and producing carbon dioxide.
The new Rio Tinto/Alcoa process eliminates the carbon, using proprietary materials instead; the only by-product is oxygen.
Québec is home to eight smelters with a combined production capacity of 2.9 million metric tons of primary aluminium. This represents 90% of Canada’s production, which ranks fourth in the world behind that of China, Russia and the Middle East.
Apple helped facilitate the collaboration between Alcoa and Rio Tinto on the carbon-free smelting process, and has agreed to provide technical support to the JV partners.
To advance larger scale development and commercialization of the new process, Alcoa and Rio Tinto are forming Elysis, a joint venture company to further develop the new process with a technology package planned for sale beginning in 2024. The name refers to the process at the center of aluminum smelting, the electrolysis of alumina; the new technology is also named the Elysis process.
Elysis, which will be headquartered in Montreal with a research facility in Québec’s Saguenay–Lac-Saint-Jean region, will develop and license the technology so it can be used to retrofit existing smelters or build new facilities. Alcoa, Rio Tinto, the Government of Canada, the Government of Québec and Apple agree to provide a combined investment of $188 million (CAD).
Canada and Québec are each investing $60 million (CAD) in Elysis. The provincial government of Québec will have a 3.5 percent equity stake in the joint venture with the remaining ownership split evenly between Alcoa and Rio Tinto.
Apple is providing an investment of $13 million (CAD). The company helped facilitate the collaboration between Alcoa and Rio Tinto on the carbon-free smelting process, and Apple has agreed to provide technical support to the JV partners.
Rio Tinto and Alcoa will invest $55 million (CAD) cash over the next three years and contribute specific intellectual property and patents.
When fully developed and implemented, the new process will eliminate direct greenhouse gas emissions from the smelting process and strengthen the closely integrated Canada-United States aluminum and manufacturing industry. The new joint venture company will also sell proprietary anode and cathode materials, which will last more than 30 times longer than traditional components, the partners said.
The technology represents the culmination of decades’ worth of research and development. Elysis will have access to a host of patents and intellectual property. The patent-protected technology, developed by Alcoa, is currently producing metal at the Alcoa Technical Center, near Pittsburgh in the United States, where the process has been operating at different scales since 2009.
The joint venture intends to invest up to $40 million (CAD) in the United States, which would include funding to support the supply chain for the proprietary anode and cathode materials.
Vincent Christ, with more than 30 years’ experience at Rio Tinto aluminum, has been named Chief Executive Officer of Elysis. Most recently, he has served as head of technology, research and development and automation programs. He holds an engineering degree in electronics and industrial information technology.