Sugar Beet (Beta vulgaris L) as a Biofuel Feedstock in the United States

Authors: Panella, Leonard; KAFFKA, STEPHEN - University Of California

Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: 10/1/2010
Publication Date: 12/14/2010
Citation: Panella, L.W., Kaffka, S.R. 2010. Sugar Beet (Beta vulgaris L) as a Biofuel Feedstock in the United States. American Chemical Society Symposium Series. pp. 163-175 In: Eggleston, G. (ed.) Sustainability of the Sugar and Sugar-Ethanol Industries.

Interpretive Summary: Sugar beet produces an enlarged root in the first year, in which it stores the sugar that provides energy used to flower in the next season. Technically, conversion of sugar to ethanol is a simple process requiring only yeast fermentation. A 2006 USDA study calculated it would be possible to produce about 25 gallons ethanol from one ton of sugar beet root. Life cycle analysis (LCA) indicates that, ethanol from sugar beet reduces green house gases as well or better than ethanol from corn. Sugar beet, and potato, followed by sugar cane were found to be the best ethanol feedstock crops based on their water requirements. Even though LCA may indicate that beet is a better feedstock than corn, because area of sugar beet cultivation in the United States in 2009 was about 465 thousand hectares and the area of corn cultivation about 32 million hectares, sugar beet most likely will not displace corn as the primary feedstock for ethanol. More likely, co-products like pulp and molasses will find use as bioenergy feedstocks, probably for high value specialty fuels or as a feedstock for a whole generation of petroleum plastic substitutes.

Technical Abstract: Sugar beet is a biennial plant, which produces an enlarged root and hypocotyl in the first year, in which it stores sucrose that provides energy used to flower in the next season. Technically, conversion of sugar to ethanol is a simple process requiring only yeast fermentation. A 2006 USDA study calculated the yield of ethanol from the sucrose in a sugar beet was 103.5 L per tonne of root (wet weight). Life cycle analysis (LCA) indicates that, bioethanol from sugar beet reduces green house gases as well or better than maize. Sugar beet, and potato, followed by sugar cane were found to be the most advantageous bioethanol feedstock crops based on their water footprint. Even though LCA may indicate that beet is a better feedstock than maize, because area of sugar beet cultivation in the United States in 2009 was about 465 thousand hectares and the area of maize cultivation about 32 million hectares sugar beet cannot displace maize as the primary feedstock for bioethanol. More likely, co-products like pulp and molasses will find use as bioenergy feedstocks, probably for high value specialty fuels or as a feedstock for a whole generation of petroleum plastic substitutes.