One-Pot Process to Convert Sugarcane Waste to Jet Fuel

(University of Queensland) Converting sugarcane waste to biofuel could become more environmentally friendly and cost effective, thanks to a joint project at The University of Queensland and the Indian Institute of Technology Delhi.

PhD candidate Ms Neethu Joshikumar has successfully tested a process to simplify the preparation of sugarcane waste, known as bagasse.

“As most countries begin the transition to sustainable fuel, the focus has turned to creating biofuels from agricultural waste but there are still challenges we need to overcome,” Ms Joshikumar said.

“A key problem in making biofuels from bagasse is the presence of lignin, a stubborn component that makes it harder to access the fermentable sugars in bagasse.

"Conventional ethanol production involves soaking the bagasse to remove the lignin and isolate the cellulose, which requires toxic and expensive acids plus a lot of water.

“My research focuses on an alternative pre-treatment to see if we can cut costs and reduce the environmental impact of the conversion process.

“Unlike the acids it doesn’t kill the enzymes and the yeast needed for fermentation allowing me to complete the entire step in one pot without separation or water washing.

Ms Joshikumar also analysed different sugarcane varieties and found that higher cellulose and lower lignin content gave the best ethanol yield.

Modelling shows when integrated with a sugar mill, the DES-based one-pot bioethanol production is both economically competitive and environmentally sustainable.

Ms Joshikumar said taking a significant step forward to solve a major problem was extremely gratifying.

“Where I’m from in India, farmers burn the agricultural waste every year to get the land ready for the next crop and that causes extensive air pollution,” she said.

“It’s very rewarding to know that my research could result in a better use for that waste and help solve climate issues, as well as speed up the conversion of biofuel.”

The Queensland Alliance for Agriculture and Food Innovation is a research institute at The University of Queensland, established with and supported by the Department of Primary Industries. READ MORE

Excerpt from Agriculture Communications/Queensland University: When anyone talks about the future of sustainable aviation fuel, one question dominates: how do we replace fossil carbon without compromising food security or biodiversity? My (Emeritus Professor Robert Henry) experience leads me to believe the answer is sugarcane.

Our mission is ambitious: create economically viable, renewable aviation fuel at the scale this huge industry needs. Plants are the best current source for renewable carbon, and all available evidence suggests sugarcane is the plant offering the best chance of success.

Sugarcane is the only crop currently produced at the tonnage demanded for this purpose.

Other options, like algae, sound promising in theory, but the economics don’t add up. Algal systems are expensive, and unless you can generate a high-value co-product, they will not be cost-effective.

Canola is another option being considered internationally. A lot of Australia’s canola is being exported into Europe and turned into fuel rather than food, so that is a food issue. But more than that, it’s a scale issue. The yield of canola is a few tonnes per hectare, so the land you’d need to grow enough to replace jet fuel is more than the area of Australia.

Land use is a critical consideration. So, what crops can you scale? Sugarcane is productive and grown on a relatively small proportion of land. Its small footprint and exceptional productivity make it the standout choice.

Our research at the Hub focuses on improving plant biomass to convert it into fuel. We’re exploring genetic changes in rice, sorghum and sugarcane to increase the proportion of biomass that can be converted without sacrificing yield. READ MORE