ZEAL - Development of novel technology with ZEro carbon emissions for primary ALuminium production

This process, named HalZero, shall eliminate CO₂ emissions from aluminium production. The traditional Hall-Héroult (HH) process gives CO₂ emissions (1.5-1.6 kg CO₂/kg Al) from the reaction between alumina and carbon anodes, giving more CO₂ emitted than aluminium produced. The HH-process requires that the CO₂ is mixed with large amounts of air leading to emissions with only ~1 vol% CO₂. The low concentration makes CO₂ capture and further handling technically challenging and costly. A significant increase of the CO₂ concentration has proven very difficult. The HalZero concept is to electrolyze anhydrous aluminium chloride (AlCl3) instead of alumina. The main gasses in the process will be handled in closed loops and thus not be emitted to the environment. Produced CO₂ is collected and converted for re-use. This makes HalZero a CO₂ emission free process given renewable energy sources. Initial studies show operating and capital costs comparable to the current HH process, making the HalZero process a promising zero CO₂ alternative.