Sweet sorghum is no longer just a source for table syrup. Now, scientists see a future in which sorghum is converted into biofuels rather than relying on fossil fuels.
That potential grew as University of Florida researchers found three sorghum varieties -- developed at the Institute of Food & Agricultural Sciences (IFAS) -- that could produce up to 1,000 gal. of ethanol per acre.
“Sweet sorghum has the potential to be an effective feedstock for ethanol production,” said Wilfred Vermerris, a IFAS professor of microbiology at the University of Florida and cell science and a co-author on the study.
Ethanol produced from sweet sorghum can be used for automotive and jet fuels, the researchers said.
The IFAS researchers see big potential for sorghum as fuel, partly because it’s so abundant. Sorghum is the fifth-largest cereal crop in the world and the third-largest crop in the U.S., according to the U.S. Department of Agriculture. In 2014, the U.S. was the largest producer of sorghum in the world.
The scientists like sorghum because it can be cultivated twice a year in Florida, requires little fertilizer, uses water efficiently and can be drought resistant, according to IFAS research.
For a newly published study, the IFAS scientists wanted to see if they could use the three sweet sorghum cultivars as raw material for bio-ethanol production.
Eulogio Castro, a former visiting assistant professor at IFAS and lead author of the study, worked with other IFAS researchers to grow the sorghum cultivars at the IFAS Plant Science Research & Education Unit in Citra, Fla. Castro is now a researcher at the University of Jaén in Spain.
Once the researchers grew and harvested the sorghum, they took it to the IFAS Stan Mayfield Biorefinery Pilot Plant in Perry, Fla. There, they processed the crop and collected the sugar-rich juice from the stems, which could be fermented directly to fuel ethanol. The bagasse — the dry, pulpy residue left after extracting the juice from the plant — was processed to generate an additional source of fermentable sugars that could also be converted to ethanol.
They found the potential for the crop to produce up to 1,000 gal. of ethanol per acre from the combined juice and bagasse-derived sugars.
The new study was published in the journal Industrial Crops & Products.