(Press-News.org) Agricultural plastic mulch films are widely used around the world to increase crop yields, conserve soil moisture, and suppress weeds. However, once these films are discarded, they can persist in the environment for decades, contributing to soil contamination and plastic pollution. A new study shows that these difficult to recycle plastics could instead be transformed into valuable chemical products using a biochar based catalytic process.
Researchers investigated a method for converting waste plastic mulch film into useful chemicals through catalytic pyrolysis. In this process, plastic is heated in the absence of oxygen, causing the long polymer chains to break down into smaller molecules that can be used as fuels or chemical feedstocks. The team used a catalyst made from walnut shell biochar activated with phosphoric acid, demonstrating a promising way to recycle both agricultural plastic waste and biomass residues at the same time.
Plastic mulch films are commonly made from low density polyethylene and are widely used in agriculture in countries such as China, the United States, and across Europe. Because these materials degrade extremely slowly and are often contaminated with soil after use, recycling them is challenging. Chemical conversion technologies such as pyrolysis offer an alternative approach by breaking plastics down into smaller molecules that can be reused.
In the study, scientists focused on a critical but often overlooked factor in catalytic pyrolysis: the temperature of the catalytic bed. The team tested how three different temperatures affected the conversion of waste plastic mulch film and the behavior of the catalyst. They found that temperature strongly influenced both the types of products produced and how quickly the catalyst became deactivated by carbon deposits known as tar.
At a catalytic temperature of 350 degrees Celsius, the process produced the highest yield of valuable olefins, which made up about 69 percent of the liquid products. Olefins are important chemical building blocks used in the production of plastics, fuels, and many industrial materials. Under these conditions, the total yield of pyrolysis oil reached about 72 percent, indicating highly efficient conversion of the plastic waste.
However, the study also revealed a trade off. Although 350 degrees Celsius maximized olefin production, it also promoted chemical reactions that generated oxygen containing tar on the catalyst surface. This tar gradually blocked the catalyst pores and reduced its activity.
At a higher catalytic temperature of 400 degrees Celsius, the reaction pathway shifted. Aromatic compounds became more abundant in the liquid products and the overall amount of tar decreased. More importantly, the carbon deposits formed under these conditions were easier to remove because they had lower thermal stability. Kinetic analysis showed that the activation energy required to decompose the deposited tar decreased to around 40 to 50 kilojoules per mole at this temperature, indicating that the catalyst could be regenerated more easily.
According to the researchers, these findings highlight a fundamental balance in catalytic plastic recycling systems.
“Our results show that catalytic temperature controls not only the product distribution but also the long term stability of the catalyst,” said the study’s authors. “While 350 degrees Celsius is ideal for maximizing olefin production, a higher temperature of 400 degrees Celsius produces carbon deposits that are easier to regenerate. Understanding this trade off is essential for designing practical plastic upcycling technologies.”
The researchers also demonstrated that walnut shells, an abundant agricultural by product, can be converted into effective catalysts for plastic recycling. Using biomass derived catalysts could help reduce costs and improve sustainability compared with conventional catalyst materials.
By linking product chemistry, tar composition, and kinetic analysis, the study provides new insights into how catalysts behave during plastic pyrolysis. The findings offer guidance for developing more efficient and durable catalytic systems that can convert agricultural plastic waste into valuable chemical resources.
As plastic waste continues to accumulate globally, technologies that combine waste recycling with renewable materials could play an important role in building a more circular and sustainable chemical industry.
===
Journal reference: Tan C, Lan X, Chen X, Wang Y, Dai L, et al. 2026. Controlling catalyst deactivation: temperature regulation for the directed synthesis of easily regenerable and refractory tar in the pyrolysis of waste films. Sustainable Carbon Materials 2: e008 doi: 10.48130/scm-0026-0004
https://www.maxapress.com/article/doi/10.48130/scm-0026-0004
===
About Sustainable Carbon Materials:
Sustainable Carbon Materials (e-ISSN 3070-3557) is a multidisciplinary platform for communicating advances in fundamental and applied research on carbon-based materials. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon materials around the world to deliver findings from this rapidly expanding field of science. It is a peer-reviewed, open-access journal that publishes review, original research, invited review, rapid report, perspective, commentary and correspondence papers.
Follow us on Facebook, X, and Bluesky.
END
Turning agricultural plastic waste into valuable chemicals with biochar catalysts
2026-03-05
ELSE PRESS RELEASES FROM THIS DATE:
Hidden viral networks in soil microplastics may shape the future of sustainable agriculture
2026-03-05
Microplastics are widely recognized as pollutants in oceans and waterways, but scientists are increasingly discovering that they are also accumulating in agricultural soils. A new scientific review highlights a largely overlooked dimension of this problem: the complex interactions between soil microbes and viruses that occur on the surface of microplastic particles. The study reveals that these microscopic relationships may influence soil health, ecosystem recovery, and the long term sustainability of agriculture.
Microplastics are tiny plastic fragments smaller than five millimeters that enter farmland ...
Americans don’t just fear driverless cars will crash — they fear mass job losses
2026-03-05
Key Takeaways
More than 60% of Americans said they would probably or definitely avoid riding in a driverless car.
About 85% said widespread AVs would cause job losses in ride-hailing, ridesharing and delivery work.
More than 46% said AVs would widen the income gap (vs about 6% who said it would narrow).
The survey found a social and geographic divide: tech-aware, educated groups show strong adoption interest but economic concern, while lower-income and non-metro respondents remain unwilling and skeptical.
While much of the public debate about self-driving cars focuses on safety, a new national study from the University of California San Diego ...
Mayo Clinic researchers find combination therapy reduces effects of ‘zombie cells’ in diabetic kidney disease
2026-03-05
JACKSONVILLE, Fla. — Mayo Clinic researchers have identified a drug-and-supplement combination therapy that is capable of reducing the harmful effects of senescent cells – also known as "zombie cells" – in diabetic kidney disease. In eBioMedicine, a publication of The Lancet, the team reported that the combination of the cancer drug dasatanib and a naturally occurring substance known as quercetin decreased inflammation and boosted protective factors in the kidney.
Diabetic kidney disease affects more than 12 million people in the U.S. and is the leading cause ...
Preventing breast cancer resistance to CDK4/6 inhibitors using genomic findings
2026-03-05
Researchers at Memorial Sloan Kettering Cancer Center (MSK) have made an important discovery about how genetic mutations in breast cancer patients can interact and drive resistance to certain drugs called CDK4/6 inhibitors. This finding, published in Nature, suggests a new strategy for predicting and preventing resistance to specific therapies based on the tumor’s genetic profile.
“This represents a major advance in understanding and predicting cancer behavior in response to treatment,” says physician-scientist Pedram Razavi, MD, PhD, who led the study with physician-scientist Sarat Chandarlapaty, MD, PhD. The study’s first author ...
Carbon nanotube fiber ‘textile’ heaters could help industry electrify high-temperature gas heating
2026-03-05
A cross-disciplinary team at Rice University has developed a new type of electric heating element — one that looks less like a traditional metal coil and more like a high-performance thread.
In a study published in Small, the researchers demonstrated that wires and fabrics made from carbon nanotube fibers (CNTFs) can deliver substantially more heating power per unit mass than conventional metal-alloy heaters when placed directly in flowing gases. The findings point to a potential new pathway for electrifying industrial heating, a critical but technically challenging step toward reducing carbon emissions.
“Electrifying industrial heat is one of the most important, and most difficult, ...
Improving your biological age gap is associated with better brain health
2026-03-05
Highlights:
Improving the gap between your biological age and your actual age is associated with a lower risk of stroke and better brain health.
The study involved 250,000 people. Researchers measured 18 biomarkers in their blood to determine their biological age. A subset of people also had brain scans.
People who improved the gap between their biological and chronological ages during the study were 23% less likely to have a stroke afterward than those who did not.
The study does not prove that improving the age gap is the cause of the lower risk of stroke and brain health improvements. It only shows an association.
Researchers say eating a healthy diet, ...
Learning makes brain cells work together, not apart
2026-03-05
When you get better at a skill—recognizing a familiar face in a crowd, spotting a typo at a glance, or anticipating the next move in a game—sensory neurons in your brain become more coordinated, sharing information rather than acting more independently. That’s the conclusion of a new study by researchers at the University of Rochester and its Del Monte Institute for Neuroscience, published in Science, which challenges a long-held assumption in neuroscience that learning improves efficiency ...
Engineers improve infrared devices using century-old materials
2026-03-05
After decades of intense research, surprises in the realm of semiconductors – materials used in microchips to control electrical currents – are few and far between. But with a pair of published papers, materials engineers at Stanford University debut a promising approach to using a well-studied semiconductor to improve infrared light-emitting diodes and sensors. They say the approach could lead to smaller, sleeker, and less expensive infrared technologies for environmental, medical, and industrial uses.
“We taught an old dog new tricks,” ...
Physicists mathematically create the first ‘ideal glass’
2026-03-05
Scientists led by a physicist at the University of Oregon have taken a major step in solving an enduring mystery that we encounter every time we look through a window or stare at a phone screen.
For centuries, scientists have studied how and why glass forms from a molten state into a rigid, solid material, while still maintaining an amorphous or disordered internal structure like a liquid.
UO physicist Eric Corwin and a team of current and former students have now created on a computer the first “ideal ...
Microbe exposure may not protect against developing allergic disease
2026-03-05
ITHACA, N.Y. – The “hygiene hypothesis” suggests exposure to diverse types of microbes may protect against developing diseases caused by allergens, but a new Cornell University study in mice reveals that adults’ exposure to diverse microbes and allergens may in fact worsen certain allergic conditions.
“Our data suggests that it’s important to think about how we go through the world and protect ourselves from exposure to microbes, because depending on your condition, if you’re moving from a clean to a dirty environment, or dirty to clean environment, you might have a different response in terms of developing allergic ...