Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: September 29, 2010
Publication Date: December 4, 2010
Citation: Lingle, S.E. 2010. Opportunities and challenges of sweet sorghum as a feedstock for biofuel. In: Eggleston, G., editor. Sustainability of the Sugar and Sugar-Ethanol Industries, ACS Symposium Series 1058. Washington, DC: American Chemical Society. p. 177-188. Technical Abstract: Sorghum (Sorghum bicolor L. Moench) is a grass crop with thick stalks adapted to warm climates. Sweet sorghum (SS) has a juicy, sweet stalk. The juice can be pressed from the stalks, directly fermented or boiled down to make syrup. The plant residue remaining can be burned to run the mill or cogenerate electricity, or used as feedstock for cellulosic ethanol. SS has wide environmental adaptation, rapid growth, high productivity, tolerance to marginal growing conditions, and high concentrations of the easily fermentable sugars glucose, fructose and sucrose. The sugars in SS start to deteriorate once the stalk is harvested. Leaves and leaf sheaths are difficult to remove from the stalk. They are a source of microorganisms, organic acids and starch. Microorganisms deteriorate the sugars, organic acids react with the sugars when the juice is heated, and starch thickens during boiling. Ideas for addressing these challenges will be discussed.