Illinois researchers convert food waste into jet fuel, boosting circular economy

University of Illinois College of Agricultural, Consumer and Environmental Sciences

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Sabrina Summers, University of Illinois, demonstrates hydrotreating biocrude oil from food waste.

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Credit: Marianne Stein

URBANA, Ill. — Airplane travel is more popular than ever, and our desire for fast transportation means jet fuel has become a major contributor to greenhouse gas emissions. Now, researchers at the University of Illinois Urbana-Champaign have discovered a novel way to address that problem—by converting food waste into sustainable aviation fuel (SAF) that meets industry standards without relying on fossil fuel blends. Their process, described in a new Nature Communications study, could help the aviation industry meet its ambitious goal of net-zero carbon emissions by 2050.

The process in a nutshell is this: The researchers convert food waste into biocrude oil through a thermochemical conversion process called hydrothermal liquefaction, or HTL. Next, they remove impurities from the biocrude oil, and finally, they refine it with the use of hydrogen and catalysts to turn it into aviation fuel. 

This approach can be applied to a variety of feedstocks and types of oil, potentially leading to a new direction for obtaining fuels.  

“HTL basically mimics the natural formation of crude oil in the Earth. It uses high heat and pressure to convert wet biomass into a biocrude oil. The goal of this work is to upgrade that biocrude oil into transportation fuels that can go directly into existing energy infrastructure,” said lead author Sabrina Summers, who recently graduated with a doctoral degree from the Department of Agricultural and Biological Engineering (ABE), part of the College of Agricultural, Consumer and Environmental Sciences and The Grainger College of Engineering at U. of I.

In this project, the researchers used waste from a nearby food processing facility. Globally, over 30% of food is wasted annually at all levels of the supply chain — from farm to transportation, processing, retail, food service, and households. Food decomposition in landfills and wastewater treatment plants further contributes to greenhouse gas emissions, and recycling waste helps promote sustainability. 

But HTL can process feedstock from a wide range of biowaste, including food, sewage sludge, algal bloom, swine manure, and agricultural residue. 

“To meet the aviation industry’s goals to decarbonate jet fuel, we need many different renewable sources, and agriculture is going to play a critical role in terms of providing the feedstocks,” said ABE professor and corresponding author Yuanhui Zhang. 

To convert biocrude oil into jet fuel, the researchers first removed impurities such as moisture, ash, and salt. They then used a process called catalytic hydrotreating to eliminate unwanted elements like nitrogen, oxygen, and sulfur—leaving behind only the hydrocarbons needed for fuel. After testing dozens of options, they identified cobalt molybdenum as the most effective commercially available catalyst to drive the necessary chemical reactions and refine the oil into sustainable aviation fuel.

To optimize the hydrotreatment process, the researchers adjusted variables such as temperature, catalyst and hydrogen loads, and retention time to identify the best conditions for producing jet fuel. They then tested their sustainable aviation fuel against rigorous standards set by the American Society for Testing and Materials (ASTM) and the Federal Aviation Administration. Their SAF sample passed Tier Alpha and Beta prescreening tests and met all specifications for conventional jet fuel—without requiring any additives or blending with fossil fuels.

The technology has the potential to be scaled up for commercial production, Zhang noted.

“Our research helps solve the science and engineering problems, and then the industry can step in. The process can be applied to other types of oils for SAF. It can also replace other materials, such as petroleum-derived compounds for making plastics. This has huge potential for business opportunities and economic development,” he said. 

Zhang has developed an index to measure circular bioeconomy, and he said SAF provides a valuable contribution to circularity.

“In a linear economy, we just produce something, use it, and throw it away. In this project, we take the waste and recover the energy and materials to make a usable product. This fills a missing link in the circular paradigm,” he concluded.

The paper, “From food waste to sustainable aviation fuel: cobalt molybdenum catalysis of pretreated hydrothermal liquefaction biocrude,” is published in Nature Communications [DOI:10.1038/s41467-025-64645-y]. Funding was provided by the U.S. Department of Energy (EE0009269) and the National Science Foundation Graduate Research Fellowship Program.

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Journal

Nature Communications

DOI

10.1038/s41467-025-64645-y 

Article Title

From food waste to sustainable aviation fuel: cobalt molybdenum catalysis of pretreated hydrothermal liquefaction biocrude

Article Publication Date

30-Oct-2025

 

We learn physical skills by feeling rewarded, even in the absence of a reward, finds new study

University of Surrey

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We learn physical skills by feeling rewarded, even in the absence of a reward, finds new study 

People master new physical skills, such as sports, crafts or controlling a vehicle while driving, by blending lessons learnt from both feedback on the amount of error they had in failures and the rewards of successes, even when reward cues are removed, according to a new study led by Dr Shlomi Haar from the University of Surrey. 

Using a high-tech virtual reality pool setup, researchers from Surrey and Imperial College London had 32 participants play pool on a physical table while wearing a virtual reality (VR) headset that slightly changed the cue ball’s trajectory, forcing players to adapt. 

In the study, published in npj science of learning, two different sessions took place, with different feedback given to each player taking part. In one session, players only got “error feedback”, with the balls disappearing before they could pocket them. In the other session, participants only got “reward feedback”, with successful shots being artificially shown pocketing, while failed shots gave no visual results. The goal was to see whether the brain would only use the type of feedback it was given. 

However, the brain behaved differently. Even when the reward – pocketing the ball – was taken away in the “error feedback” condition, players still showed strong signs of using reward-based learning. They were seen to be finding their own “mini rewards”, such as observing the ball taking a correct-looking path. The brain wouldn’t ignore that key information, much like seasoned basketball players can anticipate a good shot before it goes through the hoop.  

Measurements of brain activity confirmed this complex interaction, showing a mixed learning pattern, rather than separate processes as seen in past lab experiments. While players were seen to learn faster when focusing on errors, the underlying process in both conditions was always a blend of the two processes. 

Dr Shlomi Haar, lead author and Senior Lecturer in Cognitive Neuroscience at the University of Surrey, said: 

"The brain is a highly active detective, always seeking every available piece of information - whether it's seeing the mistake or anticipating success. Our findings suggest that the most effective learning embraces and strategically uses both error information and rewards together, and visual feedback interventions could be used to enhance it further.” 

[ENDS] 

Notes to editors 

• The full paper is available upon request. 

• Once published, the full paper will be available at: https://www.nature.com/articles/s41539-025-00373-8 

• DOI: 10.1038/s41539-025-00373-8 

• An image of Dr Haar is available upon request. 

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Journal

npj Science of Learning

DOI

10.1038/s41539-025-00373-8 

 

Electric vehicles outperform gasoline cars in lifetime environmental impact

Despite an initial higher emissions impact, electric vehicles result in a reduction in cumulative carbon dioxide emissions after two years of use.

PLOS

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The life cycle-based CO2 emissions from four technology-based categories of light-duty vehicles in GCAM/GLIMPSE from sales of new vehicles in 2030, (a) during lifetime, assumed to be 18 years (b) during first year (c) shows when the emissions from fossil fuel ICE surpasses BEV, plotted for first six years.

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Credit: Sadavarte et al., 2025, PLOS Climate, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

After two years of use, lithium-ion battery electric vehicles (BEVs) result in a reduction in cumulative carbon dioxide (CO₂) emissions compared to fossil-based internal combustion engine (ICE) vehicles, according to a new study published this week in the open-access journal PLOS Climate by Pankaj Sadavarte of Duke University, US, and colleagues.

The transportation sector accounts for 28% of US greenhouse gas emissions in the US and growing consensus supports electric vehicle adoption to address climate and air quality challenges. However, ongoing debate surrounds whether lithium-ion batteries are truly cleaner when considering their complete manufacturing and operational lifecycle.

In the new study, researchers used the Global Change Analysis Model (GCAM) integrated assessment model to evaluate CO₂ and air pollutant emissions across four scenarios of increasing electric vehicle adoption in the United States through 2050. The analysis included emissions from fuel production, battery manufacturing, vehicle assembly, and operation for both electric and gasoline vehicles.

The study concluded that during the first two years of operation, electric vehicles produce 30% higher CO₂ emissions than gasoline vehicles when all lifecycle factors are considered. The higher initial emissions stem from energy-intensive lithium mining and battery manufacturing processes. However, after the second year of on-road use, electric vehicles begin reducing cumulative emissions compared to gasoline alternatives. Moreover, as battery output increases over time, each additional kWh of lithium-ion battery output leads to an average reduction of 220 kg of CO₂ in 2030 and 127 kg of CO₂ in 2050. Accounting for both air pollution and climate change impacts, the economic value of environmental damage from ICE vehicles over their lifetime currently ranges from 2 to 3.5 times that of BEVs.

Co-author Dr. Drew Shindell summarizes: “Internal combustion vehicles lead to about 2-3 times more damage than EVs when considering both climate and air quality.”

The authors point out that several assumptions were made regarding the mileage of the passenger car, life of a vehicle, and average battery size of the passenger car in the US. Moreover, the study did not consider the associated emissions due to infrastructure required to meet the increasing demand for electric charging. However, they conclude that relative benefits of BEVs are expected to increase over coming decades as electricity generation becomes cleaner through reduced fossil fuel use.

Lead author Dr. Pankaj Sadavarte adds: “Our research shows that transitioning from fossil fuel vehicles to battery electric vehicles (BEVs) can significantly improve climate and air quality over time. While BEVs initially have higher lifecycle emissions due to extraction and battery production, our analysis using the Global Change Analysis Model demonstrates that they quickly outperform internal combustion vehicles—cutting carbon dioxide emissions and reducing harmful air pollutants. As the U.S. electricity grid becomes cleaner, the economic and environmental advantages of BEVs will only grow stronger.”

 

In your coverage please use this URL to provide access to the freely available article in PLOS Climate: https://plos.io/48u0I2t

Citation: Sadavarte P, Shindell D, Loughlin D (2025) Comparing the climate and air pollution footprints of Lithium-ion BEVs and ICEs in the US incorporating systemic energy system responses. PLOS Clim 4(10): e0000714. https://doi.org/10.1371/journal.pclm.0000714

Author Countries: United States

Funding: This work was supported by the Albemarle Corporation (to DS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Note that since Albemarle isn’t a government funding agency, they do not use grant numbers.

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Journal

PLOS Climate

DOI

10.1371/journal.pclm.0000714 

Method of Research

Computational simulation/modeling

Subject of Research

People

Article Publication Date

29-Oct-2025

COI Statement

Competing Interests: This work was supported by the Albemarle Corporation (to DS). This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents, products in development or marketed products associated with this research to declare.

 

Kilimanjaro has lost 75 percent of its natural plant species over the last century

Human-driven land use change is likely the primary cause of this biodiversity loss on Mount Kilimanjaro’s lower slopes

PLOS

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A century of biodiversity loss: Land use change on Mount Kilimanjaro.

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Credit: Anthony Lewis (www.anthony-lewis.com), PLOS, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

A new study suggests that, between 1911 and 2022, land-use change was the primary direct cause of the loss of 75% of natural plant species on the lower slopes of Mount Kilimanjaro. Andreas Hemp of the University of Bayreuth, Germany, and colleagues present these findings in the open-access journal PLOS One on October 29, 2025.

Kilimanjaro is a dormant tropical volcano in Tanzania and Africa’s tallest mountain. Millions of people living in the area rely on Kilimanjaro’s diverse ecosystems for such benefits as timber, food, and water regulation. But the variety of species found in these ecosystems—their biodiversity—is declining as a result of human-related pressures, such as climate change, pollution, introduction of invasive species, resource extraction, and land-use change.

Understanding which human activities are the main drivers of declining biodiversity on Kilimanjaro and other tropical mountains is necessary to inform mitigation efforts. However, most prior research has focused on climate change, without considering other drivers, and has typically explored the effects instead of the causes of environmental change.

To help clarify the main drivers behind Kilimanjaro’s decreasing biodiversity, Hemp and colleagues analyzed historical maps, census data, satellite imagery, and a high-spatial-resolution dataset of nearly 3,000 plant species found in different parts of the region. They focused on plant biodiversity, as it is closely related to the overall biodiversity of an ecosystem.

The analysis revealed that land-use change—for instance, expanding urban areas or converting savanna habitats to agricultural land—was the main cause of plant biodiversity loss between 1911 and 2022. In this time, the lower slopes of Kilimanjaro saw a loss of 75 percent of natural plant species per square kilometer. Land-use change stemmed from rapid population growth and economic development, with population density rising from 30 to 430 people per square kilometer between 1913 and 2022.

Meanwhile, the analysis showed, climate change was not a significant direct cause of biodiversity loss on Kilimanjaro.

These findings could help guide policies to mitigate biodiversity loss, the researchers say. As examples, they highlight specific locations in the Kilimanjaro region that have benefitted from sustainable traditional agricultural practices and establishment of protected areas.

The authors add: “Our research reveals that land-use change driven by rapid population growth—not climate change—was the primary direct driver of biodiversity loss on Mount Kilimanjaro over the past century, with up to 75% of natural species per km² lost on the lower slopes. Encouragingly, traditional agroforestry and protected areas emerged as promising strategies for mitigation.”

“Investigating a century of ecological change on Kilimanjaro allowed us to disentangle complex human and environmental impacts. This study was the first, to our knowledge, to link human population densities with plant species densities at a 1 km² scale in a tropical region—made possible by combining remote sensing with extensive ground-based species data. The process required cleaning and verifying ecological field data across diverse vegetation types, highlighting the critical role of biological collections and the taxonomic expertise of herbaria worldwide.”

“It was striking to find that, contrary to common narratives, climate change had no measurable effect on local biodiversity trends—emphasizing the urgent need to address socio-economic drivers like land use in conservation policy.”

 Mount Kilimanjaro - Wikipedia

In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/3J9oC91

Citation: Hemp A, Miyazawa M, Hurskainen P (2025) Gain and loss: Human and environmental wellbeing – drivers of Kilimanjaro’s decreasing biodiversity. PLoS One 20(10): e0334184. https://doi.org/10.1371/journal.pone.0334184

Author countries: Germany, Switzerland, Japan, Finland

Funding: German Research Foundation (DFG), (HE 2719/14-1), Dr. Andreas Hemp.

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Journal

PLOS One

DOI

10.1371/journal.pone.0334184 

Method of Research

Observational study

Subject of Research

People

Article Title

Gain and loss: Human and environmental wellbeing – drivers of Kilimanjaro’s decreasing biodiversity

Article Publication Date

29-Oct-2025