Green Hydrogen Production from Recycled Aluminum: A Review of Economic and Environmental Impacts and Opportunities for Quebec’s Energy Transition

This review analyzes hydrogen production through the aluminum–water reaction using recycled and postconsumer aluminum, with emphasis on its technical, economic, environmental, and regional implications for Québec’s energy transition. Aluminum can function as a solid energy carrier capable of generating hydrogen on demand, but its practical use is limited by the native oxide layer, feedstock variability, activation requirements, water quality, byproduct management, and system-level boundaries. Recent advances in chemical, mechanical, alloy-based, and high-temperature activation routes show that high hydrogen yields are possible under controlled conditions; however, scalable deployment requires more than maximizing laboratory performance. Activation methods must also be assessed in terms of cost, safety, reagent recovery, energy demand, byproduct quality, and compatibility with realistic aluminum scrap streams. The review shows that recycled aluminum can reduce the upstream energy and emissions associated with hydrogen production compared with primary aluminum, but the process should not be considered carbon-neutral by default. Reported hydrogen production costs vary widely, from approximately 4.5 to 21 USD/kg H2, depending on aluminum feedstock price, activation strategy, hydrogen yield, reagent recovery, process scale, and valorization or regeneration of aluminum oxide and hydroxide byproducts. Québec provides a relevant case for this pathway because of its low-carbon electricity, strong aluminum sector, and current challenges in local postconsumer aluminum valorization. The aluminum–water reaction may therefore complement electrolysis-based hydrogen production in specific decentralized or circular-economy applications, provided that future work validates realistic feedstocks, nonpure water sources, byproduct recovery routes, techno-economic assumptions, and life-cycle boundaries.