By LRC Public Relations
FRANKFORT, Ky. (Oct. 18, 2013) — Kentucky state lawmakers, biofuel experts, and farmers met today in Frankfort to discuss the feasibility of converting sweet sorghum to ethanol.
The Special Subcommittee on Energy was told by Dr. Michael Montross of the University of Kentucky’s Food and Bioprocess Engineering Department that the juice of sweet sorghum—a stalk-like plant used primarily to make food syrup in North America—is simple to convert to ethanol, adding that fermentation of sweet sorghum into ethanol right on the farm is possible.
“We’ll end up with a stable product” at 10-percent ethanol concentration, said Montross, adding some water would have to be removed from the product to “make it economical to transport.”
While processing ethanol from the juice of sweet sorghum is easy, Montross said there are some issues to consider. First, Kentucky’s window to process juice from sweet sorghum stalks is relatively short, running from around August until frost. Storage of the stalks is also problematic since storing them in a silage pile creates high sugar losses, said Montross.
It is the sugar in the plant’s stalk (derived from the stalk’s stem juice) that allows sweet sorghum to be used as fermentation material for producing ethanol, according to biofuel researchers.
Transportation costs are another issue, Montross explained. While a semi truck can hold roughly 900 bushels of corn—which can produce around 3,300 gallons of ethanol—one semi truck can “optimistically” hold enough sweet sorghum stalks to produce 600-900 gallons of stem juice, he told lawmakers.
“That quickly gets expensive trying to truck that,” he said.
Using sweet sorghum to make ethanol is still a fairly new concept in the U.S, according to researchers. The process is more widespread in nations like China and India.
Montgomery County farmer Danny Townsend’s family has been growing sweet sorghum for over 100 years, he told the subcommittee. While syrup production is still the primary use of the crop, Townsend said there are many other uses, including production of ethanol, rubber, carpeting—even water bottles.
Townsend said sweet sorghum is fast-growing (some varieties can be grown in 120 days, he said) and inexpensive to grow: The total cost to seed, fertilize, and apply herbicide on an acre of sweet sorghum is around $125, he said. Comparably, Townsend said the seed alone for an acre of corn costs about that much.
Former state lawmaker and fellow Montgomery County farmer Adrian Arnold said he appreciates the subcommittee’s effort to look at Kentucky sweet sorghum as a possible fuel source. He explained that sweet sorghum is a good crop for older farmers in particular to grow.
“A lot of our farmers are getting older and all they have to do is plant the seed and get a field chopper to harvest it,” said Arnold.
The subcommittee also received testimony today on developments in energy efficiency for manufactured housing. Representatives from East KY Power Cooperative, Nextstep Housing, and the Kentucky Energy and Environment Cabinet were on the agenda to speak on the topic.