Steam Explosion and Fermentation of Sugar Beets from Southern Florida and Minnesota

C. Dorado, R.G. Cameron, K. Cooper
United States Department of Agriculture - Agricultural Research Service,
United States

Keywords: sugar beet, fermentation, pectin, ethanol, steam explosion

Summary:

Sugar beets have been grown primarily in the Midwest for the production of table sugar and have recently gained interest for planting and harvesting in other areas of the U.S. for use as cattle feed, ethanol production and phytoremediation. Florida has a total of 1.69 million cattle and calves whose feed can be supplemented with sugar beets. Ethanol from sugar beets has great economic potential in Florida where 18.9 billion barrels of ethanol were consumed in 2013 but none was produced in the state. Algae blooms on the Florida Treasure Coast could be mitigated by the use of barrier crops, such as sugar beets, on agricultural land to prevent nutrient rich run-off from entering the waterways. Sugar beets, therefore, have the potential to serve as a new source of income to farmers in the state of Florida based on their use as cattle feed and as a feedstock for ethanol production as well as serve as a method to improve the quality of water via soil nutrient accumulation. Sugar beets grown in southern Florida and Minnesota were subjected to steam explosion using a continuous steam explosion pilot scale system located at the U.S. Horticultural Research Laboratory in Ft. Pierce, FL. Analysis of soluble and insoluble sugars as well as pectin from raw and steam exploded sugar beet were completed. Fermentations of raw and steam exploded sugar beets, with and without enzymes, were conducted. There was no significant difference for ethanol production in the fermentation of steam exploded sugar beets with and without enzymes indicating that addition of enzymes are not necessary for fermentation. Pilot scale fermentations of the steam exploded sugar beet gave 6.7-9.7 percent ethanol by volume.