Tuesday, May 3, 2011
Angele Djioleu1, Elizabeth M. Martin1, Evan Childress1, Casey Johnson1, Matthew Pelkki2, James Smith1, Carl Griffis1 and Danielle Julie Carrier3, (1)Biological and Agricultural Engineering, University of Arkansas, Fayetteville, AR, (2)School of Forest Resources, University of Arkansas, Monticello, Monticello, AR, (3)Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, AR
In the southeastern United States, pines represent the main source of produced timber. Unfortunately pine understories are composed of hardwoods, including
Liquidambar styraciflua L. (sweetgum), that compete for forest resources. Hardwood understories are currently eliminated from pine dominated forest by an excessive use of herbicide. This practice is both a threat for the environment and an additional cost in the production of softwood in the southeastern United States. The possibility of using this sweetgum hardwood understory as feedstock in a biochemical-based biorefinery represents an alternative use for this biomass.
A chemical analysis of sweetgum samples showed that sweetgum heartwood is composed of 37.5% cellulose and 15.7% xylan. Therefore, sweetgum wood represents a potential carbohydrate source. The current study examined the xylose recovery of sweetgum heartwood pretreated in dilute acid at 140 °C for 10, 60 and 90 min; recoveries of 4, 56 and 58%, respectively were obtained. Xylose recoveries of sweetgum heartwood pretreated at 160 °C for 10, 60, and 90 min were 50, 30 and 44%, respectively. Pretreatment of the heartwood at 140 °C for 90 min, resulted in the significantly highest xylose recovery. However, this pretreatment condition resulted in the production of 0.45% furfural, which could possibly inhibit the ensuing enzymatic hydrolysis step.
