Aluminum as a Non-Carbon Metal-Fuel for Next-Generation Propulsion

As the propulsion sector seeks viable alternatives to hydrocarbon fuels, aluminum (Al) has emerged as a compelling non-carbon energy carrier. Its exceptional volumetric energy density (≈83.8 kJ cm-3), favorable cost, stable storability, and the potential for closed-loop recyclability of its combustion product, alumina (Al2O3), distinguish it from both conventional hydrocarbons and from gravimetrically denser carriers such as hydrogen and ammonia. Aluminum can, in principle, supply heat, work, or reactive intermediates across a broad range of propulsion architectures, from solid and hybrid rocket motors to internal combustion engines, metal–water and metal–air systems, and dual-fuel configurations co-combusted with hydrogen or ammonia.Realizing aluminum’s full energetic potential, however, remains technically challenging. The native Al2O3 passivation shell imposes a refractory transport barrier that delays ignition, promotes particle agglomeration, and constrains combustion efficiency across propulsion configurations. Persistent issues with two-phase flow losses, incomplete oxidation, condensed-phase product handling, and life-cycle sustainability further complicate deployment. Addressing these challenges calls for integrated progress across particle engineering, interfacial chemistry, combustion science, system-level engineering, and sustainability analysis.This Research Topic seeks to consolidate recent advances exploring aluminum as a non-carbon metal-fuel for next-generation propulsion. By bringing together contributions from metal-fuel chemistry, surface and interface engineering, combustion diagnostics, propulsion system design, and life-cycle assessment, the collection aims to position aluminum as a practical, scalable, and carbon-free contributor to the future of sustainable propulsion.Original Research articles, Reviews, Mini-Reviews, and Perspectives are welcomed on themes including, but not limited to:● Combustion kinetics, ignition behavior, and burn-rate phenomena of aluminum-based fuels across solid, hybrid, and internal combustion configurations● Co-combustion of aluminum with hydrogen and/or ammonia in hybrid and dual-fuel propulsion systems● Inorganic surface engineering of aluminum particles using hydride-, fluoride-, oxide-, and nitride-based coatings for enhanced ignition and reduced agglomeration● Atomic layer deposition (ALD) and plasma-enhanced chemical vapor deposition (PECVD) for reactive interfacial layer design on aluminum fuel particles● Aluminum–metal alloy and intermetallic fuels (Al–Mg, Al–B, Al–Ti, Al–Li) for improved energy release and propulsion efficiency● Thermite-type interfacial reactions and their role in propulsion ignition enhancement● Dual-fuel and multi-fuel propulsion architectures incorporating aluminum as a primary or supplementary energy carrier● Aluminum–water and aluminum–air propulsion systems for underwater, atmospheric, and dual-use platforms● Sustainable regeneration of aluminum fuel from recycled Al2O3, closing the energy carrier loop● Life-cycle assessment (LCA), emissions profiling, and environmental impact of aluminum-based fuels relative to conventional hydrocarbon propellants.Collectively, these themes are intended to articulate a mechanistic and systems-level understanding of aluminum combustion, and to identify scalable pathways toward carbon-free propulsion in which aluminum functions as a precisely engineered, high-efficiency metal fuel. Topic editors: Prawal P. K. Agarwal, Prithwish Biswas Source: https://www.frontiersin.org/research-topics/80821/aluminum-as-a-non-carbon-metal-fuel-for-next-generation-propulsion