Kentucky State University
Analyzing the Viability of Sweet Sorghum Bagasse as a Biofuel Feedstock
Institution
Kentucky State University
Faculty Advisor/ Mentor
Michael Bomford; Jon Cambron; Anthony Silvernail
Abstract
Kentucky is the largest producer of sweet sorghum (Sorghum bicolor) in the United States. It is grown for the sugar-rich sap, which can be processed into syrup or ethanol, and for the grain, which can be used for human or animal food. Bagasse, the fibrous material that remains after extraction of the sap, may have potential as a fuel source for gasification or combustion. Before the bagasse can be used in gasification or combustion systems it must be dried to less than 30% moisture by mass. Pelletization of this dried material can make it easier to handle, and improve its characteristics as a fuel source. We compared greenhouse and field drying methods for bagasse preparation prior to pelletization. Oven dried subsamples served as a control to calculate final moisture content. Initial moisture content of bagasse ranged from 24% to 59% of fresh weight. Bagasse was air dried in a greenhouse and outdoors at densities of 2 to 8 kg m-2. A week of air drying reduced bagasse moisture content to an appropriate level for pelletization in either environment, and at all densities tested. The combustion potential of the dried bagasse was assessed using a calorimeter before and after pelletization. Our results can be applied by sweet sorghum growers needing low input pre-processing methods for waste bagasse destined for energy production through combustion or gasification.
Analyzing the Viability of Sweet Sorghum Bagasse as a Biofuel Feedstock
Kentucky is the largest producer of sweet sorghum (Sorghum bicolor) in the United States. It is grown for the sugar-rich sap, which can be processed into syrup or ethanol, and for the grain, which can be used for human or animal food. Bagasse, the fibrous material that remains after extraction of the sap, may have potential as a fuel source for gasification or combustion. Before the bagasse can be used in gasification or combustion systems it must be dried to less than 30% moisture by mass. Pelletization of this dried material can make it easier to handle, and improve its characteristics as a fuel source. We compared greenhouse and field drying methods for bagasse preparation prior to pelletization. Oven dried subsamples served as a control to calculate final moisture content. Initial moisture content of bagasse ranged from 24% to 59% of fresh weight. Bagasse was air dried in a greenhouse and outdoors at densities of 2 to 8 kg m-2. A week of air drying reduced bagasse moisture content to an appropriate level for pelletization in either environment, and at all densities tested. The combustion potential of the dried bagasse was assessed using a calorimeter before and after pelletization. Our results can be applied by sweet sorghum growers needing low input pre-processing methods for waste bagasse destined for energy production through combustion or gasification.