The primary objective of ZEAL is to create knowledge needed to successfully develop and optimize an alternative process to produce primary aluminium. 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 oxide 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 oxide. 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.
The project is part of Hydro Aluminiums ongoing development of a novel process for aluminium production and will support the Hydro Aluminium strategy for a green transition. Hydro’s proprietary HalZero technology is a technology based on converting alumina to aluminium chloride prior to electrolysis in a process where chlorine and carbon are kept in closed loops, resulting in elimination of CO2 emissions from both electrolysis and anode baking.
Hydro has been working on lab-scale development of this technology for five years and has now developed a concrete roadmap for piloting this to industrial scale before 2030, and with a first industrial facility started in 2032. The ZEAL project will support the technology development with research on fundamentals aspects to increase the competence and knowledge needed to succeed with the industrialization.
Research partners are NTNU and SINTEF.