Evaluation of Four Cellulosic Energy Crops for Biomass and Ethanol Production in Georgia.

Encouraging progress in commercial production of cellulosic biofuels, together with the mandate of cellulosic biofuels consumption by the Energy Independence Security Act of 2007, makes cellulosic biomass production more attractive than ever. Switchgrass (Panicum virgatum L.) and miscanthus (M. × giganteus) as two dedicated cellulosic energy crops have been extensively evaluated for biomass production in the United States and Europe, respectively, both with very favorable results. Energycane (Sacharum spontaneum) and napiergrass (Pennisetum purpueum) are another two potential, perennial cellulosic energy crops with high yield potential. Georgia as one of the ideal states for cellulosic feedstocks production in the Southeast could play a leading role in biomass production to meet the mandate. However, truly comparative performance data of the four potential cellulosic energy crops is lacking in Georgia. Therefore, the purpose of this study was to evaluate biomass and ethanol production of four cellulosic energy crops grown in Georgia as affected by irrigation and delayed harvest, and to provide comparative performance data for the four perennials. Ethanol production was estimated by using a benchtop dilute acid pretreatment and simultaneous saccharification and fermentation procedure. Results indicated that napiergrass and energycane provided significantly higher biomass yield as well as ethanol yield than switchgrass and miscanthus, regardless of irrigation and harvest treatments. Irrigation enhanced biomass and ethanol yields of the four energy crops, with yields of energycane and miscanthus increasing relatively higher. Compared to harvest in December, delayed harvest in February resulted in significant reduction in biomass and ethanol yields of all four energy crops except miscanthus and switchgrass. In this study, napiergrass and energycane showed high potential for biomass and ethanol production in Georgia.