Agricultural waste from the global sugar industry could become a powerful tool for clean energy, pollution control, and sustainable materials, thanks to new research showing how microwave technology can dramatically improve biochar production.
In a study published in Sustainable Materials and Chemicals, researchers report that microwave-assisted pyrolysis can be precisely optimized to convert sugarcane bagasse, the fibrous residue left after sugar extraction, into highly porous biochar with exceptional surface properties. By fine-tuning key processing conditions, the team achieved biochar with a surface area exceeding 1,150 square meters per gram, making it well suited for applications such as pollutant adsorption, wastewater treatment, and energy storage.
Sugarcane is one of the world's most widely grown crops, with more than two billion tons produced each year. Processing this crop generates hundreds of millions of tons of bagasse annually, much of which is burned or discarded, creating environmental burdens and wasting valuable resources.
"Sugarcane bagasse is often treated as a low-value by-product, but it actually has enormous potential as a sustainable carbon material," said corresponding author Wenke Zhao. "Our work shows that with the right microwave-assisted process, this waste can be transformed into high-performance biochar with carefully controlled pore structure."
Unlike conventional pyrolysis, which heats biomass from the outside inward, microwave-assisted pyrolysis delivers energy directly into the material. This results in faster, more uniform heating and greater control over the chemical reactions that shape the final product.
To identify the best conditions for producing high-quality biochar, the researchers systematically studied the effects of three key variables: pyrolysis temperature, the amount of potassium hydroxide used as an activating agent, and the flow rate of carbon dioxide gas during processing. They then applied response surface methodology, a statistical optimization approach, to model how these factors interact and to predict optimal operating conditions.
The analysis revealed that potassium hydroxide addition had the strongest influence on biochar properties, followed by carbon dioxide flow rate, while temperature played a smaller but still important role. Under optimized conditions, the team produced biochar with an exceptionally high specific surface area and a finely tuned balance of micro- and mesopores.
"These pores are critical," Zhao explained. "They determine how well biochar can trap pollutants, store charge in energy devices, or interact with chemicals in environmental applications."
The researchers also showed that their predictive models closely matched experimental results, confirming that the optimization strategy can reliably guide biochar production without extensive trial-and-error experimentation.
Beyond sugarcane bagasse, the findings offer broader insights for converting many types of agricultural and biomass waste into valuable carbon materials. Microwave-assisted pyrolysis, combined with advanced statistical modeling, could help scale up sustainable biochar production while reducing energy use and processing costs.
"This study provides a practical roadmap for designing efficient, high-value biochar systems," Zhao said. "By turning agricultural waste into functional materials, we can reduce environmental pressure while creating new opportunities in clean energy and environmental protection."
The research highlights how innovative processing technologies can support circular economy goals by transforming waste streams into advanced materials with real-world impact.
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Journal reference: Cao W, Jing H, Araya DT, Zhao WK. 2026. Optimization of microwave-assisted pyrolysis parameters for sugarcane bagasse biochar using response surface methodology. Sustainable Carbon Materials 2: e003 doi: 10.48130/scm-0025-0014
https://www.maxapress.com/article/doi/10.48130/scm-0025-0014
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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.
