Orange peel hydrochar used by IIT-Mandi researchers to make biofuel precursors

Researchers at the Indian Institute of Technology (IIT) Mandi employed hydrochar made from orange peels as a catalyst to convert biomass-derived compounds into biofuel precursors, a development that could help alleviate global concerns about depleting petroleum supplies.

The research team’s findings were just published in the Green Chemistry journal. Venkata Krishnan, associate professor at IIT Mandi’s School of Basic Sciences, conducted the study, which was co-authored by his students Tripti Chhabra and Prachi Dwivedi.

“One of the main objectives among the renewable energy sector is the development of relatively clean and energy efficient techniques to convert biomass into valuable compounds, including fuel,” Krishnan said of the research.

After coal, oil, and natural gas, biomass-derived products from naturally existing materials are now the country’s fourth most important energy source for fulfilling energy demand. Lignocellulosic biomass, such as that derived from forestry and agricultural waste, can be transformed to a range of valuable compounds using a variety of methods.

The researchers catalyzed the conversion of biomass-derived compounds into biofuel precursors utilizing hydrochar made from orange peels. The researchers used a hydrothermal reactor (a lab-level “pressure cooker”) to heat dried orange peel powder with citric acid under pressure for several hours. Other compounds were used to introduce acidic sulfonic, phosphate, and nitrate functional groups to the hydrochar that was produced.

“We used these three types of catalyst to bring about hydroxyalkylation alkylation (HAA) reactions between 2-methylfuran and furfural, compounds that are derived from lignocellulose, to produce fuel precursors,” Tripti Chhabra stated.

The scientists discovered that the sulfonic functionalized hydrochar catalyst could successfully catalyse this process, resulting in high yields of biofuel precursors.

“We were able to synthesize the biofuel precursors under solventless and low temperature conditions, which decreases the overall cost of the process and also makes it environment friendly and attractive from an industry point of view,” said Krishnan.

To learn more about the catalytic activity of sulfonic, nitrate, and phosphate functionalized hydrochar generated from orange peels, the researchers used green metric calculations and temperature programmed desorption (TPD) investigations.