Agave could generate efficient biofuel for transport

The agave plant is known for being the base ingredient of Tequila, but now scientists have found it could be used as an environmentally friendly solution to Australia’s transport fuel shortage and hand sanitiser production.

The agave plant used to make Tequila is more efficient for producing biofuel than sugarcane or corn

A team of researchers from the University of Sydney, University of Adelaide and the UK’s University of Exeter analysed the potential to produce bioethanol from the agave plant, the high-sugar succulent commonly grown in Mexico.

The agave plant is now being grown as a biofuel source in the Atherton Tablelands in Queensland, Australia, by agribusiness company MSF Sugar. University of Sydney agronomist associate professor Daniel Tan, who led the project, said the plant “promises some significant advantages over existing sources of bioethanol such as sugarcane and corn”.

Tan, of the university’s institute of agriculture, explained: “Agave is an environmentally friendly crop that we can grow to produce ethanol-based fuels and health care products.

“It can grow in semi-arid areas without irrigation; and it does not compete with food crops or put demands on limited water and fertiliser supplies. Agave is heat and drought-tolerant and can survive Australia’s hot summers.”

The University of Exeter’s Dr Xiaoyu Yan, who ran the life-cycle assessment, said: “Our analysis highlights the possibilities for bioethanol production from agave grown in semi-arid Australia, causing minimum pressure on food production and water resources.

“The results suggest that bioethanol derived from agave is superior to that from corn and sugarcane in terms of water consumption and quality, greenhouse gas emissions, as well as ethanol output.”

‘Environmental winner’

Tan said the study is the first thorough life-cycle assessment and economic analysis of bioethanol produced from a five-year agave field experiment in north Queensland.

“Our analysis shows a bioethanol yield of 7,414 litres a hectare each year is achievable with five-year-old agave plants,” said Tan.

The study also found that sugarcane yields 9,900 litres per hectare each year. However, agave beats sugarcane on a number of measures, including fresh water eutrophication, marine ecotoxicity and water consumption.

The project noted agave uses 69% less water than sugarcane and 46% less water than corn for the same yield. “This shows agave is an economic and environmental winner for biofuel production in the years to come,” Tan added.

In addition, agave’s efficient, low-water process could also help produce ethanol for hand sanitiser, the researchers said, which is currently in high demand due to the covid-19 pandemic.

“The economic analysis suggests that a first generation of bioethanol production from agave is currently not commercially viable without government support, given the recent collapse in the world oil price,” said Tan.

“However, this may change with the emerging demand for new ethanol-based healthcare products, such as hand sanitisers.”