The aviation industry, responsible for a significant portion of global carbon emissions, has long sought pathways to decarbonize its fuel supply. Jet fuel derived from fossil resources remains the dominant option, prompting extensive research into sustainable alternatives including biofuels and synthetic hydrocarbons. A particularly intriguing prospect involves converting abundant plastic waste—a growing environmental threat—into high-value jet fuel components. Historically, this conversion has required harsh reaction conditions, notably elevated pressures around 3 MPa and protracted reaction durations extending up to six days, which have limited scalability and economic viability.

Challenging these constraints, the research team designed a remarkable catalyst system based on atomically dispersed ruthenium species anchored on Co-Al oxide substrates. This single-atom catalyst exhibits unprecedented activity for benzene hydrogenation at atmospheric pressure, achieving turnover frequencies of 144 s^−1, which surpass conventional commercial Ru/C catalysts by more than two orders of magnitude. Such catalytic potency at ambient pressure marks a transformative leap toward more sustainable and accessible plastic upcycling technologies.

The tandem catalytic process exploits hydropyrolysis to fragment polymer chains in plastic feedstocks at elevated temperature (460 °C), producing intermediate hydrocarbon vapors enriched in unsaturated species. These vapors then transit downstream to a second stage maintained at a much lower temperature (160 °C), where the Ru_SA@CoAlO_x catalyst performs vapour-phase hydrogenation, saturating the molecules to yield cycloalkanes. This tandem reactor configuration integrates decomposition and hydrogenation seamlessly, optimizing conversion efficiency while maintaining mild operational pressure—ranging from atmospheric to a modest 0.15 MPa.

When tested on pure polystyrene feeds, this tandem catalytic system produced cycloalkane yields reaching an extraordinary 94.8 wt% at 0.15 MPa, and still an impressive 59 wt% even when operated at atmospheric pressure alone. The method’s versatility extends beyond single polymer types; mixtures of common plastic wastes undergo efficient conversion, yielding hydrocarbons within the jet-fuel boiling range at yields exceeding 82 wt%. This remarkable breadth points to broad practical applicability for diverse, heterogeneous plastic streams.

Equally notable is the catalyst’s stability under continuous operation. Over 110 hours of vapour-phase hydrogenation with the Ru_SA@CoAlO_x catalyst revealed sustained activity without significant degradation. This durability is critical for industrial viability, indicating that the catalyst can support sustained processing of plastic waste feedstocks without frequent replacement, reducing downtime and operational costs.

From an environmental perspective, the life-cycle assessment of the entire process underscores its transformative potential. Compared to conventional petroleum-derived jet fuel, the new method delivers an estimated 73% reduction in CO2 emissions over the well-to-pump lifecycle. This dramatic emissions cut arises from both the valorization of existing plastic waste and the energy efficiencies enabled by operating at low pressure and moderate temperatures, marking a meaningful stride toward climate targets in aviation fuel production.

Economic analysis further highlights the promise of this technology. The minimum selling price for jet fuel produced through this route is projected between US$1.0 and US$1.8 per kilogram, placing it in competitive range with fossil-based fuels. This is particularly relevant given fluctuating crude oil prices and growing regulatory pressures incentivizing greener alternatives, creating a favorable scenario for commercialization of this platform.

At the core of this innovation lies the concept of single-atom catalysis, a field gaining increasing traction for its ability to maximize atom efficiency and achieve superior reaction selectivity. By anchoring ruthenium atoms on carefully engineered cobalt-aluminum oxide supports, the research team capitalized on intimate metal-support interactions that stabilize active sites while enhancing hydrogen dissociation—key for high-performance hydrogenation under mild conditions.

The hydropyrolysis step in this tandem process cleverly exploits thermal cracking in a reducing hydrogen environment to generate reactive intermediates that are readily hydrogenated downstream. Operating hydropyrolysis at 460 °C balances conversion efficiency with thermal stability of the catalyst, while the downstream hydrogenation at 160 °C ensures effective saturation of unsaturated domains without undesired side reactions. This finely tuned temperature gradient within a single fixed-bed reactor system exemplifies elegant process engineering.

In contrast with prior high-pressure technologies, this ambient or near-ambient pressure operation not only reduces equipment and safety costs but also minimizes hydrogen consumption. Hydrogen is supplied in conjunction with plastic feedstock, enabling simultaneous polymer breakdown and hydrogenation in a continuous-flow system. This design presents a practical pathway for the integration of hydrogen sourced from renewables, further amplifying sustainability benefits.

Beyond polystyrene, the catalyst efficiently processed mixed plastic waste commonly found in municipal streams, such as polyethylene, polypropylene, and polyvinyl chloride blends. This adaptability is paramount for potential real-world deployment since plastic waste is notoriously heterogeneous. The ability to convert such varied feedstocks into consistent, jet-range hydrocarbons simplifies downstream fuel synthesis and distribution logistics.

The process’s integration compatibility with existing refinery infrastructure represents another advantage. The cycloalkane products can directly blend into conventional jet fuels without extensive upgrading, a factor facilitating regulatory compliance and adoption. Moreover, the high selectivity toward saturated hydrocarbons reduces the need for post-processing steps, contributing to overall process simplicity and cost reduction.

Looking forward, this innovation sets a new paradigm for plastic waste valorization, combining catalyst design, reaction engineering, and environmental consciousness into a single platform capable of addressing pressing challenges of waste accumulation and aviation emissions. The study’s authors articulate the potential for scale-up and industrial adoption, envisioning distributed conversion units near waste collection centers coupled with hydrogen production from renewable sources, creating circular and low-carbon fuel supply chains.

While challenges remain, including catalyst synthesis scalability and integrating hydrogen sourcing sustainably, this research provides a compelling blueprint for advancing beyond fossil-based jet fuel dependency. With plastic pollution and climate change exerting mounting global pressure, such technological breakthroughs exemplify how scientific ingenuity can transform environmental liabilities into valuable resources fueling a more sustainable future.

This work, published in Nature Energy in 2026, stands as a testament to interdisciplinary collaboration spanning materials science, catalysis, chemical engineering, and environmental assessment. Its implications resonate across sectors, promising impactful contributions to climate mitigation, resource conservation, and the emerging circular economy.

The unveiling of a single-atom Ru catalyst capable of ambient-pressure conversion of plastic waste into jet fuel cycloalkanes represents a pivotal step forward. By merging state-of-the-art catalyst innovation with process optimization, the research lays the groundwork for scalable, economically viable, and environmentally responsible aviation fuel solutions derived from problematic plastic waste streams. The path ahead integrates scientific discovery with global sustainability aspirations, illuminating a hopeful direction for tackling two of humanity’s most urgent crises simultaneously.

Subject of Research: Conversion of plastic waste to jet fuel cycloalkanes through tandem hydropyrolysis and vapour-phase hydrogenation enabled by a single-atom ruthenium catalyst.

Article Title: Ambient-pressure conversion of plastic waste to jet fuel cycloalkanes by tandem hydropyrolysis and vapour-phase hydrogenation.

Article References:
Wang, J., Zhang, Z., Wang, S. et al. Ambient-pressure conversion of plastic waste to jet fuel cycloalkanes by tandem hydropyrolysis and vapour-phase hydrogenation. Nat Energy (2026). https://doi.org/10.1038/s41560-026-02078-7

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41560-026-02078-7

In a landmark breakthrough, a research team led by Dr. Yun-Jo Lee at the Korea Research Institute of Chemical Technology (KRICT), in partnership with EN2CORE Technology Co., Ltd., has unveiled an integrated process that transforms landfill gas generated from organic waste—specifically food waste—into aviation fuel. This design not only addresses the pressing need for cleaner fuel alternatives but also presents new recycling opportunities for waste that would otherwise contribute to environmental degradation.

Traditionally, the SAF refining industry focuses primarily on repurposing used cooking oil, a resource characterized by its limited availability and alternative uses—such as biodiesel—which exacerbates both its cost and procurement difficulties. In contrast, landfill gas produced from food waste and livestock manure is both plentiful and cost-effective. This recent study marks a pioneering domestic demonstration of aviation fuel production utilizing landfill gas as its principal feedstock, potentially revolutionizing the approach to SAF creation.

Converting landfill gas into aviation fuel entails tackling two key challenges: purifying the gas to yield appropriate intermediates and increasing the efficiency of converting those gaseous intermediates into liquid fuel forms. Dr. Lee’s research team has addressed these challenges through an elaborately developed integrated process that encompasses the pretreatment of landfill gas, synthesis gas (syngas) production, and the catalytic conversion of syngas into liquid fuels.

EN2CORE Technology assumed a vital role in managing upstream operations. They collected landfill gas from waste disposal sites, undergoing a meticulous desulfurization process and subsequent membrane-based separation to eliminate excess carbon dioxide. The resultant purified gas is then transformed into synthesis gas, comprising carbon monoxide and hydrogen, via a proprietary plasma reforming reactor before delivery to KRICT for further processing.

At KRICT, the Fischer-Tropsch process is employed to convert this gaseous syngas into liquid fuels. This chemical reaction entails hydrogen and carbon reacting on a catalytic surface, subsequently forming hydrocarbon chains. These hydrocarbons are then assessed for chain length, wherein optimal lengths yield liquid fuels while longer chains produce solid byproducts, including wax. In a significant innovation, KRICT enhanced selectivity toward liquid fuels by utilizing zeolite- and cobalt-based catalysts, minimizing solid waste production.

A groundbreaking facet of this work is the microchannel reactor’s introduction. This reactor design combats excessive heat generation—an element that poses risks to catalysts and reduces the overall process stability. The microchannel reactor, crafted by the team, incorporates alternating layers of catalyst and coolant channels, facilitating efficient heat removal and averting thermal runaway. The reactor’s reduced volume—up to one-tenth of traditional systems—allows for straightforward capacity expansion through the addition of modules.

For demonstration purposes, the team has developed an integrated pilot facility located on a landfill site in Dalseong-gun, Daegu. This facility occupies approximately 100 square meters—equivalent to an average two-story detached house—and has successfully produced an impressive 100 kg of sustainable aviation fuel per day, achieving liquid fuel selectivity exceeding 75 percent. Currently, the team is focused on optimizing long-term operational conditions and enhancing both catalyst and reactor performance.

This advancement underscores the potential to convert everyday waste-derived gases from food waste and sewage sludge into valuable aviation fuel. It also highlights the feasibility of producing aviation fuel at local landfills or smaller waste treatment facilities, previously thought to be suitable only for larger centralized plants. Consequently, this innovative technology is poised to contribute significantly to the formation of decentralized SAF production systems, thereby boosting the competitiveness of South Korea’s SAF industry.

The significance of this research leads KRICT President Young-Kuk Lee to emphasize that the acclaimed development is pivotal in establishing integrated processing technology capable of converting organic waste into high-value fuels. The strong potential exhibited in this technology could serve as a cornerstone solution toward achieving both carbon neutrality and the principles of a circular economy.

The work surrounding the development of dual catalysts facilitating selective liquid fuel production has been published as an inside cover piece in ACS Catalysis (November 2025) and in the journal Fuel (January 2026). These meticulous endeavors reflect a seized opportunity to catalyze a greener future, fostering a transition within the aviation industry that prioritizes environmental sustainability and resource efficiency.

As the global context for energy sources shifts dramatically under climate-related pressures, technological advancements such as this integrated process represent an essential facet in the fight against climate change while reshaping the landscape of renewable fuels. By embracing such innovations, the aviation sector may soon reveal itself as a paragon of environmental accountability and sustainability.

In conclusion, integrating environmental responsibility within the aviation industry through the development of innovative processes such as this holds promise not just for fuel production but overall ecological well-being. By transforming waste into valuable fuel, we move toward a future where our energy sources are as sustainable as they are efficient, ensuring a greener planet for generations to come.

Subject of Research: Integrated process for producing sustainable aviation fuel from landfill gas
Article Title: Tailoring Zeolite-Supported Bifunctional Cobalt Catalysts for Direct Conversion of Syngas to Liquid Fuels
News Publication Date: 7-Nov-2025
Web References: http://dx.doi.org/10.1021/acscatal.5c03696
References: [Insert specific references if necessary]
Image Credits: Credit: Korea Research Institute of Chemical Technology(KRICT)

Keywords

Sustainable Aviation Fuel, Landfill Gas, Fischer-Tropsch Process, Renewable Energy, Greenhouse Gas Emissions, Carbon Neutrality, Environmental Innovation, Waste Management, Chemical Engineering, Technology Development.

At the heart of this research is a thermochemical conversion technique known as hydrothermal liquefaction (HTL). This innovative process replicates the natural formation of crude oil, applying high heat and pressure to wet biomass, specifically food waste, to synthesize biocrude oil. The versatility of HTL allows it to utilize a broad spectrum of organic materials, making it a promising solution for converting various waste products into valuable energy sources. The successful transformation of food waste into usable fuel exemplifies a crucial step toward sustainability in transportation.

Food waste itself is an alarming global issue, with over 30% of edible food discarded each year across the supply chain—from agricultural production to household waste. This not only exacerbates food insecurity but also contributes significantly to greenhouse gas emissions, especially when waste decomposes in landfills and contaminates water sources. By harnessing this waste through HTL, the researchers not only provide a method for reducing environmental impact but also promote the concept of sustainability in the aviation industry.

The research team meticulously crafted a three-step process to refine biocrude into aviable transport fuel. Initially, impurities such as moisture, ash, and salts are eliminated from the crude oil. Following this purification stage, catalytic hydrotreating is employed to remove unwanted constituents like nitrogen, oxygen, and sulfur. The result is a refined hydrocarbon mix suitable for aviation fuel. This breakthrough not only reutilizes food waste but also addresses the pressing need for cleaner energy alternatives in the aviation sector.

Lead author Sabrina Summers, who recently earned her doctoral degree from the Department of Agricultural and Biological Engineering, emphasizes that the effectiveness of their approach is rooted in the selection of suitable catalysts. After experimenting with various options, the researchers designated cobalt molybdenum as the most effective catalyst for facilitating the necessary reactions to refine biocrude into jet fuel. This strategic selection sets this research apart, showcasing the importance of catalyst efficiency in future developments within this field.

Their rigorous testing revealed that the sustainable aviation fuel produced from food waste passed advanced pre-screening tests set by the American Society for Testing and Materials (ASTM) and the Federal Aviation Administration (FAA). Impressively, this SAF sample adhered to all the specifications required for conventional jet fuel without the need for any additive or blending with fossil fuels. This not only validates their methodology but also positions their innovation as a legitimate contender for commercial aviation fuel.

The scalable nature of this technology bolsters its potential for widespread commercialization. Yuanhui Zhang, a co-author of the study and a professor in the same department, asserts that agriculture will play a critical role in providing the diverse renewable feedstocks necessary to meet aviation’s decarbonization goals. Their method can be utilized to produce various forms of sustainable fuels beyond just jet fuel, paving the way for a broader impact on the energy landscape.

In an era where sustainability is a primary concern, this research contributes meaningfully to the concept of the circular bioeconomy. Unlike conventional processes that adhere to a linear pattern of production and disposal, the approach employed by Zhang and Summers encapsulates the essence of circularity—taking waste materials and converting them into energy and usable products. This not only mitigates waste but also enhances resource efficiency in multiple industries, from aviation to plastics.

The implications of this research extend beyond immediate environmental concerns; they open doors for extensive commercial opportunities. As industry stakeholders grapple with climate change and the imperative to adopt greener practices, innovations like the conversion of food waste into aviation fuel could redefine how we perceive waste and energy production. The potential for growth in this sector is immense, especially as policymakers and the public become increasingly supportive of sustainable initiatives.

Moving forward, the expected impact of this study hinges on continued collaboration between academia and industry. The transition from laboratory successes to commercial viability involves addressing engineering and economic challenges that will arise during the scale-up of such processes. This transition is essential not only for the advancement of SAF but also for broader initiatives aimed at establishing a more sustainable energy economy.

In conclusion, the research conducted at the University of Illinois Urbana-Champaign stands as a beacon of hope for a future where aviation can coexist harmoniously with environmental sustainability. By harnessing food waste and turning it into a viable energy source, they have not only tackled an existing problem but have also positioned sustainable aviation fuel as a feasible option for the aviation industry’s future. As the world increasingly stands at the crossroads of climate action, innovations such as these are vital roadmaps showing the way forward.

The paper detailing this groundbreaking research, titled “From food waste to sustainable aviation fuel: cobalt molybdenum catalysis of pretreated hydrothermal liquefaction biocrude,” is published in Nature Communications, further legitimizing the methods and impacts discussed. With the backing of the U.S. Department of Energy and support from the National Science Foundation Graduate Research Fellowship Program, this research highlights the integral role that funding and collaboration play in driving scientific advancements.

As we navigate through the challenges posed by climate change, the importance of converting waste into valuable resources cannot be understated. The work at the University of Illinois is a prime example of how innovation and sustainability can blend seamlessly, forging a path toward a cleaner, more sustainable future.

Subject of Research: Conversion of food waste into sustainable aviation fuel
Article Title: From food waste to sustainable aviation fuel: cobalt molybdenum catalysis of pretreated hydrothermal liquefaction biocrude
News Publication Date: 30-Oct-2025
Web References: Nature Communications
References: DOI: 10.1038/s41467-025-64645-y
Image Credits: Credit: Marianne Stein