466651 Understanding the Effects of Ammonia and Organosolv Pretreatments on Physicochemical Characteristics of Lignin

Thursday, November 17, 2016: 4:05 PM
Union Square 17 & 18 (Hilton San Francisco Union Square)
Chang Geun Yoo1, Mi Li1, Yunqiao Pu2 and Arthur J. Ragauskas3, (1)Oak Ridge National Laboratory, Oak Ridge, TN, (2)University of Tennessee, (3)Chemical and Bimolecular Engineering & Forestry, Wildlife, and Fisheries, University of Tennessee-Knoxville, Knoxville, TN

Pretreatment is an important step in biological conversion of biomass. It renders structural changes of biomass to reduce the biomass recalcitrance, thus enhancing its sugar release performance. Lignin is one of major barriers for lignocellulosic biomass utilization; therefore, various pretreatment methods have been studied to reduce the recalcitrance of biomass by removal and/or modification of lignin in the biomass. Among many pretreatment methods, two pretreatment methods using ammonium hydroxide and organic solvents were selected to understand how these methods reduces the recalcitrance and improves sugar release. In this study, the crude lignins isolated from poplar and switchgrass were subject to aqueous ammonia and organosolv pretreatments, and the effects of each pretreatment on lignin structural changes were investigated. Physicochemical characteristics of the lignins during the pretreatments were analyzed by diverse analysis methods. Chemical compositions of soluble fraction and residual solid fraction were analyzed by HPLC and GCMS. Molecular weights of both fractions were investigated using GPC. 2D 13C-1H HSQC NMR and 31P NMR analyses were conducted to reveal the structural and chemical transformation of lignin. Adsorption of enzymes on the pretreated lignin was also investigated.

Extended Abstract: File Not Uploaded