TNAU scientists eye cosmetic uses for glycerol from used cooking oil biodiesel
Researchers at Tamil Nadu Agricultural University (TNAU) in Coimbatore have taken up a project to refine glycerol, a by-product generated during the conversion of leftover cooking oil into biodiesel, for potential use in cosmetic products. The work, being carried out at the Department of Renewable Energy Engineering (DREE), Agricultural Engineering College and Research Institute, aims to unlock the economic value of crude glycerol, which is currently underutilised.
Biodiesel is produced through a chemical process called transesterification, in which oils or fats react with an alcohol in the presence of a catalyst. The process yields biodiesel alongside glycerol, a thick, sweet-tasting liquid that is widely used in industries ranging from pharmaceuticals to food processing. However, the glycerol obtained from this process contains impurities such as methanol, soap, and residual catalysts, requiring extensive purification before it can be used in high-end applications like cosmetics.
According to D. Ramesh, Head of DREE, the crude glycerol produced during biodiesel conversion has not been adequately refined for commercial use. “We will be working on the processes for purification of glycerol,” he said, indicating that the focus would be on removing residues and improving the quality of the by-product to meet industrial standards.
The research gains significance in the backdrop of increasing efforts to recycle used cooking oil. The Food Safety Department has been monitoring major restaurants and food establishments to prevent the re-use of cooking oil, which poses health risks. This has led to a modest but steady supply of leftover oil for biofuel conversion. Previously, the collection of such oil was sparse, limiting research and production.
Another aspect highlighted by Ramesh is the quality of biodiesel derived from leftover cooking oil. He noted that it is superior to biodiesel made from non-edible oil sources, making it a more efficient and environmentally friendly alternative. Biodiesel produced through transesterification of used cooking oil has a viscosity comparable to petroleum diesel, with over 90% similarity, allowing it to be used in engines without major modifications.
The university also marked World Biofuel Day on Tuesday, where researchers and students demonstrated the utility of biodiesel. P. Rajkumar, institute dean, and students of the department participated in the event, lighting lamps using biodiesel to showcase its practical application. The demonstration was intended to promote awareness about renewable energy sources and their role in reducing dependence on fossil fuels.
If successful, the refinery process developed by TNAU could provide a sustainable pathway for managing waste from biodiesel production. It would also add value to the entire biofuel supply chain, making it more economically viable for small-scale producers. The purified glycerol could find applications not only in cosmetics but also in pharmaceuticals and food additives, contributing to a circular economy.
The project underscores the broader potential of agricultural research in addressing environmental challenges. By converting waste into valuable resources, institutions like TNAU are helping to build a more sustainable future. However, scientists acknowledge that laboratory-scale success will need to be followed by pilot studies and industry partnerships to translate the technology into real-world applications.
As the research progresses, the findings are expected to be published in peer-reviewed journals and shared with stakeholders, including biodiesel producers and cosmetic manufacturers. Further details regarding the purification methods and their efficiency are awaited.
