Turning Challenge into Opportunity 2025

Aluminium Technology Technology description Technology readiness level (TRL)TRL rationale Use cases Use case source(s) Electric calcination during alumina refiningNatural gas use in the calcination process is replaced by electric heating.7 IEA, 2025. ETP Clean Energy Technology GuideCalix has developed a technology called ZEAL (Zero Emissions Alumina), which is an indirectly heated electric calciner designed to replace combustion-based calciners in alumina refining. Calix has signed a memorandum of understanding (MoU) to jointly develop scalable electric alumina calcination systems (based on ZEAL) with an alumina company.Calix, 2023. Decarbonising alumina with Calix technology Heat exchangers during smeltingHeat exchangers control the loss of heat during aluminium smelting, allowing electricity consumption to be ramped up or down without impacting the production process. This allows smelters to consume electricity when prices are low, or store energy in molten aluminium when prices are high.8 IEA, 2025. ETP Clean Energy Technology GuideALUVATION is a developer of a mobile heat-treating system designed to optimize aluminium component usage and minimize CO2 emissions. The company’s system is connected to a data network and consists of standardized furnace modules for annealing and cooling down materials, enabling clients to get flexibility in application.Aluvation, 2015. Aluvation: modular heat treatment for aluminium Hydrogen calcination during alumina refiningNatural gas use in the calcination process is replaced by renewable hydrogen.4 IEA, 2025. ETP Clean Energy Technology GuideRio Tinto, in partnership with Sumitomo Corporation (via Summit Hydrogen Gladstone), is executing a Yarwun hydrogen calcination pilot demonstration programme. They are retrofitting one of their calciners to be able to run (partially or fully) with hydrogen burners, replacing natural gas in the calcination step. They are installing a 2.5 MW electrolyser on site to produce hydrogen (≈ 250–300 tonnes/ year) to fuel the retrofit calciner.Rio Tinto, 2024. Yarwun hydrogen calcination pilot for low-carbon alumina Inert anode during smeltingInert anodes replace carbon anodes which, when used, react with oxygen to produce CO2. A non-consumable (inert) anode avoids the formation of this CO2, producing only pure oxygen.7 IEA, 2025. ETP Clean Energy Technology GuideELYSIS is a joint venture between Alcoa and Rio Tinto focused on replacing carbon anodes with inert anodes in aluminium smelting. They are commissioning industrial prototype cells (450 kA) using inert anode technology.Alcoa, 2018. ELYSIS: zero-carbon aluminium smelting technology Turning Challenge into Opportunity: Supplier Voices from Heavy-Emitting Sectors 51