Nitrogen Use Efficiency of Biomass Crops and Their Processability for Ethanol Conversion.

Use of biomass to produce bioenergy is an option to reduce the environmental impact and increase energy independence of energy management and production. A field experiment was conducted during 2011 at Arkansas State University to determine the nitrogen uptake patterns during the crop cycle for eastern gamagrass, switchgrass and high biomass sorghum. We compared the nitrogen use efficiency and dry matter yield with three different sources of nitrogen: urea, municipal biosolids and poultry litter. Dry matter yields for the nitrogen sources were not significantly different and all three nutrient sources produced significantly greater yield than the control. Switchgrass produced significantly greater yield than gamagrass and high biomass sorghum. Switchgrass biomass from different nitrogen sources was tested for bioethanol production using cellulose solvent-based lignocellulose fractionation (CSLF) pretreatment and enzymatic (cellulase) hydrolysis. Switchgrass with no nitrogen applied resulted in a lesser amount of glucose on a biomass dry weight basis than switchgrass with the other nitrogen sources applied.  Fermentation was conducted using a self-flocculating yeast strain (SPSC01) to ferment the lignocellulosic biomass hydrolysates. The expected outcomes include nitrogen use efficiency factors and ethanol production for these biomass crops and the alternative nitrogen sources.