Professor Saikat Chakraborty, lead researcher and faculty at the department of chemical engineering and P K Sinha Centre for Bioenergy at IIT-Kharagpur. has used sunn hemp, the non-toxic annual cover crop, to make biofuel. In what is being called a “kitchen to cosmos” effort, Chakraborty and his team have used microwave for mass use of hemp biofuel by tapping the radiation to create clean energy.
Even though biofuel from the high-energy non-edible plant source has been possible, the main obstacle to its large scale use as a future fuel was its highly crystalline structure and long polymer chains, which make the fibres inaccessible to enzymatic and chemical treatments.
The IIT scientists addressed the issue through the use of microwave radiation and converted non-edible lignocellulosic fibres of sunn hemp into biofuel precursors. The entire conversion which would have taken eight to 10 hours — has been completed in only 46 minutes using the microwave reactors in their labs.
“The research gives the hemp’s chemical composition the necessary stability for conversion and deployment as liquid biofuels, which can be used for large-scale production by the transport industry,” said Chakraborty.
Fellow researcher Souvik Kumar Paul explained, “A kg of sunn hemp fibres containing 756g cellulose produces 595g glucose, at 160°C, and 203g hydroxymethylfurfural (HMF), at 180°C, in 46 minutes. The glucose is then separated and fermented, using yeast to produce 230g of ethanol-based biofuel which is used in automobiles as a biofuel-additive for gasoline. The platform chemical (HMF) can also be hydrogenated to furanic biofuels like dimethylfuran, which can be used as replacement for diesel.”
The scientists have filed for a patent and their findings have also appeared in ‘Bioresource Technology’ Jnl published by Elsevier.