The aviation sector must find solutions to reduce its greenhouse gas emissions. Considering the constraints of electric or hydrogen aircraft, sustainable non-fossil fuels represent an encouraging direction. Researchers from the University of Illinois at Urbana-Champaign have developed an ingenious method converting food waste into aviation fuel, fully compatible with contemporary engines. Their results, presented in
Nature Communications, establish the technical viability of an approach that fits within a circular economy logic.
Converting waste into fuel
The process begins with the collection of various organic residues, including food scraps, peels and other biowaste. These raw materials undergo a thermochemical treatment called hydrothermal liquefaction, which accelerates the reproduction of the natural petroleum formation mechanism. Under high pressure and elevated temperature, the biomass transforms into a crude biopetroleum still containing various undesirable elements.
Illustration image Pexels This bio-oil then requires an essential purification phase to meet the rigorous aviation standards. Scientists use a catalytic treatment employing cobalt and molybdenum to extract unwanted components such as oxygen, nitrogen and sulfur, as well as water, salts and ash. This refining step leads to the production of pure hydrocarbons suitable for aircraft engines.
The final fuel exhibits chemical properties almost identical to those of conventional kerosene. It meets all technical requirements defined by civil aviation authorities, making it immediately operational without modifications to engines or existing distribution networks.
Environmental and technical advantages
Life cycle assessment indicates that this biofuel could achieve up to an 80% reduction in greenhouse gas emissions compared to fossil kerosene. This significant reduction is explained by the renewable nature of the raw material and by waste treatment that prevents its decomposition into methane in landfill sites.
From a technical perspective, immediate compatibility with aircraft in service constitutes a decisive advantage for rapid implementation. Unlike other options requiring extensive modifications to aircraft or equipment, this fuel can be introduced directly into tanks without specific adaptation.
The variety of raw materials usable with the method represents another notable strength. Researchers specify that different organic sources can be used, from food waste to agricultural residues including sewage sludge, ensuring supply flexibility according to regions and seasons.
Going further: What is hydrothermal liquefaction?
This technology reproduces the natural geological process of petroleum formation under controlled conditions. It exposes organic matter to temperatures around 300°C (572°F) under high pressure, in the presence of water. In just a few hours, it transforms wet waste into usable biopetroleum.
Unlike other approaches, hydrothermal liquefaction does not require a preliminary drying phase of the waste. This characteristic significantly reduces the energy consumption of the overall process. The technique works with highly diversified raw materials, ensuring its versatility.
The energy efficiency of this process surpasses that of conventional biofuel production methods. Research continues to improve catalysts and further enhance transformation performance, with encouraging industrial prospects.
Article author: Cédric DEPOND