Effect of particle size based separation of milled corn stover on AFEX pretreatment and enzymatic digestibility

Citations Over TimeTop 1% of 2006 papers

Abstract

Abstract Particle size and compositional variance are found to have a substantial influence on ammonia fiber explosion (AFEX) pretreatment and enzymatic hydrolysis of lignocellulosic biomass. Corn stover was milled and fractionated into particle sizes of varying composition. The larger particle size fractions (rich in corn cob and stalk portions) were found to be more recalcitrant to hydrolysis compared to the smaller size fractions (rich in leaves and husk portion). Electron spectroscopy for chemical analysis (ESCA) and Fourier transform infrared spectroscopy (FTIR) were used for biomass surface and bulk compositional analysis, respectively. The ESCA results showed a 15–30% decrease in the O/C (oxygen to carbon) ratio after the pretreatment indicating an increase in the hydrophobic nature of biomass surface. FTIR results confirmed cleavage of the lignin–carbohydrate complex (LCC) for the AFEX‐treated fractions. The spectroscopic results indicate the extraction of cleaved lignin phenolic fragments and other cell wall extractives to the biomass surface upon AFEX. Water washing of AFEX‐treated fractions removed some of the hydrophobic extractives resulting in a 13% weight loss (dry weight basis). Phenolic content of wash stream was evaluated by the modified Prussian blue (MPB) method. Removal of ligno‐phenolic extractives from the AFEX‐treated biomass by water washing vastly improved the glucan conversion as compared to the unwashed samples. Reduction in substrate particle size was found to affect the AFEX process and rate of hydrolysis as well. Implications of the stover particle size, composition, and inhibitory role of the phenolic fragments on an integrated biorefinery are discussed. Biotechnol. Bioeng. 2007;96: 219–231. © 2006 Wiley Periodicals, Inc.

Related Papers

• → Effect of Lignin Chemistry on the Enzymatic Hydrolysis of Woody Biomass(2014)186 cited
• → Comparative study on enzymatic digestibility of acid-pretreated poplar and larch based on a comprehensive analysis of the lignin-derived recalcitrance(2020)94 cited
• → Structure alteration of lignin in corn stover degraded by white-rot fungus Irpex lacteus CD2(2009)63 cited
• → The dual effects of lignin content on enzymatic hydrolysis using film composed of cellulose and lignin as a structure model(2015)40 cited
• → Comparison of Ultrasonic and CO2 Laser Pretreatment Methods on Enzyme Digestibility of Corn Stover(2012)17 cited