The fuel was produced using a co-solvent method that combines extracts from coconut oil with acetone and an alcohol. Unlike many biofuel production routes that require substantial heating, pressurization, or multiple purification stages, the Osaka Metropolitan University process operates at ambient temperature and pressure. This can reduce energy consumption during manufacturing and may also help preserve the chemical purity of the resulting fuel. The researchers prepared two types of coconut-derived aviation biofuel: fatty acid methyl ester, or FAME, made using methanol, and fatty acid ethyl ester, or FAEE, made using ethanol. Both belong to the broader family of fatty acid esters commonly associated with biodiesel, but their properties can be adjusted for use in aviation fuel blends.

Coconut oil is considered an attractive source for this purpose because its fatty acids contain relatively short carbon chains compared with many other vegetable oils. Jet fuel, including Jet A-1, consists primarily of hydrocarbons within a particular range of molecular sizes, and the chain lengths found in coconut-derived compounds are closer to this range than those in oils dominated by longer fatty acids. That chemical similarity does not automatically make untreated coconut oil suitable for a turbine engine. Raw vegetable oils are too viscous, thermally unstable, and chemically different from aviation kerosene to be used directly in most aircraft engines. Converting the oil into FAME or FAEE changes its physical and combustion properties, producing a fuel that can be mixed with conventional jet fuel and evaluated under controlled engine conditions.

To determine how the coconut-based fuels behaved, the research team created blends containing different proportions of FAME or FAEE and Jet A-1. They then tested the mixtures in a small turbojet engine, examining fuel consumption, thermal efficiency, and emissions. Thermal efficiency describes how effectively the engine converts the chemical energy in fuel into useful mechanical or propulsive output. Fuel consumption, meanwhile, depends not only on how efficiently the engine operates but also on the energy content of the fuel itself. The researchers expected the coconut-derived blends to consume more fuel because their heating values—the amount of energy released during combustion—differ from those of conventional Jet A-1.

The experiments confirmed that fuel consumption generally increased as the proportion of biofuel rose. This result was attributed primarily to differences in heating value rather than to a dramatic deterioration in engine operation. Even though the engine needed more of the blend to produce a comparable amount of energy, its thermal efficiency remained broadly similar to that observed with Jet A-1. In practical terms, the findings indicate that the engine was still converting the available fuel energy effectively. The result is important because a sustainable aviation fuel must do more than burn: it must deliver reliable energy without causing unacceptable changes in engine behavior, operating stability, or performance.

The emissions results were particularly significant. As the proportion of coconut-derived fuel increased, hydrocarbon emissions declined. Unburned hydrocarbons are released when fuel does not combust completely, and lowering them can indicate more complete combustion under the tested conditions. The researchers observed no significant changes in carbon dioxide or nitrogen oxide emissions compared with conventional Jet A-1. Carbon dioxide is the principal greenhouse gas associated with the combustion of aviation fuel, while nitrogen oxides contribute to air pollution and can affect atmospheric chemistry at cruising altitude. The absence of a significant increase in these pollutants suggests that the coconut-based blends did not create a new emissions penalty in the tested microturbine system.

“Our experiments showed that our fuel blend can operate in existing gas turbine engines without major loss of efficiency or engine performance, and without increasing emissions,” said Dr. Huynh Phuong Uyen Nguyen of Osaka Metropolitan University’s Graduate School of Sustainable System Sciences. The statement reflects the central appeal of drop-in or near-drop-in sustainable aviation fuels: they can potentially be introduced into existing engines and fuel infrastructure without requiring an entirely new generation of aircraft. However, the experiments were conducted in a small turbojet engine, not in a commercial airliner, and the findings should therefore be viewed as an early technical demonstration rather than proof of immediate large-scale aviation readiness.

The researchers also emphasize that combustion performance is only one part of the qualification process. Before a coconut-based fuel could be used widely in aviation, it would need to meet demanding requirements for long-term storage stability, cold-weather behavior, energy density, material compatibility, and safety. Jet fuel must remain stable during storage and transport, resist unwanted chemical reactions, and perform reliably across the extreme temperature range encountered in aviation. The compatibility of FAME and FAEE with seals, pumps, tanks, and fuel-control systems would also require extensive testing. In addition, a full life-cycle assessment would be necessary to determine whether the environmental benefits remain substantial after accounting for cultivation, harvesting, processing, transport, land use, and possible competition with food production.

The opportunity may be especially relevant in Southeast Asia, where approximately 30 percent of harvested coconuts are reportedly discarded because they do not satisfy commercial standards. These coconuts may not be suitable for conventional retail markets, yet they still contain oil that could serve as a chemical feedstock. Converting agricultural waste or rejected crops into fuel could provide an additional revenue stream for producers while reducing dependence on imported petroleum. The region’s vulnerability to fuel-price shocks further strengthens the appeal of locally sourced alternatives. At the same time, using waste coconuts rather than expanding plantations would be essential if the fuel is to avoid creating new environmental pressures through deforestation, excessive water use, or competition with food supplies.

The Osaka Metropolitan University team now plans to improve fuel-consumption performance and investigate technologies capable of operating engines on 100 percent coconut-derived biofuel. The researchers also intend to examine storage stability, material compatibility, and broader environmental impacts before pursuing practical deployment. Their study, published in the journal Fuel, provides evidence that coconut oil converted through a co-solvent process can function as a promising component of aviation fuel blends. It does not yet solve aviation’s emissions problem, but it points toward a potentially scalable pathway in which agricultural by-products become cleaner-burning energy sources for turbine engines. As airlines search for alternatives that can work with existing propulsion technology, an ingredient as familiar as coconut oil may be entering the conversation in a surprisingly technical new form.

Subject of Research: Aviation biofuel derived from coconut oil and its combustion and emission characteristics in a micro jet engine

Article Title: Combustion and emission characteristics of aviation biofuel derived from coconut oil using the co-solvent method: toward eco-friendly micro jet engines

News Publication Date: 8 June 2026

Web References: https://doi.org/10.1016/j.fuel.2026.140208

References: Fuel, DOI: 10.1016/j.fuel.2026.140208

Image Credits: Osaka Metropolitan University

Keywords: sustainable aviation fuel, coconut oil biofuel, FAME, FAEE, Jet A-1, co-solvent method, turbojet engine, aviation emissions, hydrocarbon emissions, renewable fuel

Professor Roland Dittmeyer, who heads the research activities at KIT’s Institute for Micro Process Engineering, emphasizes the importance of synthetic fuels produced through power-to-liquid processes. The methodology utilizes carbon dioxide sourced from either the atmosphere or biogenic sources, alongside water and green electricity. Such an approach aligns well with the pressing need for renewable energy solutions that do not easily convert to electrification. The significance of co-electrolysis technology cannot be understated, as it successfully couples water vapor and CO2 with a synthesis process, achieving an unprecedented scale in synthetic fuel production.

The co-electrolysis module stands poised at the heart of this innovative process, boasting an impressive output of 220 kilowatts. This level of efficiency marks a significant improvement and enables the production of syngas, which is a crucial precursor for creating synthetic kerosene. Notably, the co-electrolysis process operates differently than traditional methods, enabling the direct electrochemical conversion of water vapor and CO2 into syngas in a singular step. This innovation alone can recover up to 85 percent of the electrical energy utilized during the process, translating into a substantial reduction in energy costs overall.

An additional advantage of the co-electrolysis approach is its enhanced reliability and availability, as echoed by Hubertus Richter, a Senior Engineer in R&D at Sunfire. The option to eliminate the traditional production of hydrogen prior to syngas creation further streamlines the process, maximally utilizing input materials and thereby improving the overall energy conversion efficiency. This represents a crucial step towards realizing a sustainable and economically viable method for producing synthetic fuels.

Following the generation of syngas, the next phase of this production journey involves maintaining reaction pressure through a specialized compressor equipped with safety features to facilitate downstream applications. Once at the correct pressure, the syngas undergoes Fischer-Tropsch synthesis within a microstructured reactor that KIT has worked diligently to develop. This synthesis process translates the syngas into long-chain hydrocarbons, which includes the eventual production of kerosene and other essential chemicals.

The ongoing research positions KIT’s methods not only for immediate applications but also for future advancements. By capturing and utilizing the heat generated during synthesis, researchers can further minimize energy demands, underscoring the feasibility of this sustainable production process at a significant scale. Moreover, the innovative integration of these technologies allows for a robust recycling of material flows and the maximization of energy recovery, setting a new benchmark for sustainable synthetic fuel production.

Currently, researchers at KIT have successfully piloted the integration of co-electrolysis under real-world conditions, achieving a remarkable output of one hundred liters of syncrude per day. This operation is regarded as a pivotal step forward within the second funding phase of the Kopernikus P2X project, highlighting the advancements made toward the larger goal of producing a tonne of fuel daily. The enhanced facility is soon to be expanded to accommodate a capacity of up to 300 liters of syncrude each day, showcasing the scalability of this promising research.

In the ongoing third phase of the Kopernikus P2X project, researchers, alongside partners like INERATEC, are actively developing a larger production facility aimed at reaching tonne-scale operations in Höchst Industrial Park near Frankfurt. This ambitious project illustrates the commitment to advancing synthetic fuel technology, with products eventually intended for testing by aircraft engine manufacturers. They are poised to ensure that the resulting fuels align with stringent aviation industry standards.

The Kopernikus P2X project represents a collaborative effort that unites various organizations, including Climeworks and Sunfire, along with academic institutions such as KIT. Focused on the production of carbon-neutral fuels known as e-fuels, the project receives backing from Germany’s Federal Ministry of Education and Research (BMBF) and boasts a consortium of 18 partners spanning both industry and scientific sectors, as well as civil society entities.

This innovative approach towards the synthesis of synthetic fuels embodies a broader movement towards sustainability and carbon neutrality in energy production. As aviation and other sectors continue to grapple with the impacts of climate change, the advancements demonstrated at KIT signal a hopeful trajectory toward achieving substantial reductions in greenhouse gas emissions. Enabled by cutting-edge technology and collaborative efforts, the potential for broad adoption of synthetic fuels offers a promising glimpse into a lower-carbon future.

With ongoing research and development efforts aimed at refining and expanding this innovative technology, the potential for widespread application of synthetic fuels is growing. The work conducted at KIT exemplifies how dedicated research, industry partnerships, and advanced technology can converge to create viable solutions for some of the most pressing challenges of our time.

In conclusion, the advancements in co-electrolysis and synthetic fuel production at KIT represent a significant and necessary step towards sustainable aviation and energy solutions, demonstrating how interdisciplinary collaboration and technological innovation are essential in the face of climate change. The journey toward achieving carbon-neutral fuels is an evolving story, and the commitment to research such as that undertaken at KIT may soon bear fruit, illuminating the path to a more sustainable and renewable energy future.

Subject of Research: Co-electrolysis for Sustainable Synthetic Fuels
Article Title: Revolutionary Breakthrough in Synthetic Fuel Production at KIT
News Publication Date: October 2023
Web References: KIT Energy Center
References: Kopernikus P2X Project
Image Credits: Amadeus Bramsiepe, KIT

Keywords

Sustainable fuels, synthetic kerosene, co-electrolysis, Renewable energy, Climate change, KIT, Energy Lab, Fischer-Tropsch synthesis, Carbon neutrality, European aviation, Power-to-liquid processes.