Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia

PP-29STUDY ON THE PRETREATMENTS OF BIRCH WOOD SAWDUSTFOR ETHANOL PRODUCTIONKosheleva D.A., Volkhin V.V.Perm State Technical University, Perm, Russia, E-mail: vvv@purec.pstu.ac.ruEthanol is one of the most important renewable fuels derived mainly from sugarcane and corn grain. The lignocellulosic biomass is a potential feedstock for low-costethanol production, but it must be pretreated before enzymatic hydrolysis [1-3]. Nowchemical processes are considered as the most comprehensible pretreatments [4].The effectiveness of dilute sodium hydroxide (NaOH) and sulfuric acid (H 2 SO 4 )pretreatments of wood wastes for conversion of carbohydrates to fermentable sugarswas investigated. Birch wood sawdust at a solid loading of 10% (w/v) were pretreatedwith NaOH and H 2 SO 4 by autoclaving at 121 °C for 20, 40, and 60 min. H 2 SO 4pretreatment promoted the increase of soluble sugars content (the highest sugarsyield was 15.8% at 60 min). The FTIR-spectra of pretreated samples provedessential solubilization of xylan due to H 2 SO 4 activity and indicated the increase oflignin content. Solids from NaOH pretreatment (at 2%, 60 min, 121 °C) showedsignificant lignin degradation and small decomposition of xylan, but no changes incellulose cristallinity were detected. Moreover NaOH hydrolysis resulted in thedecrease of main soluble sugars yield. Probably this phenomenon was caused by theformation of phenolic and heterocyclic compounds, like furfural, during heat alkalipretreatment. Therefore, comparative analysis of the two pretreatment methodsdemonstrated that H 2 SO 4 pretreatment is more suitable for wood splitting. Further theinfluence of 1% and 2% H 2 SO 4 concentrations on soluble sugars yield was examined(solid loading was 10% (w/v), 121 °C, residence times of 20-360 min). The kineticcurves of the soluble sugars yield from acid concentrations were obtained. Inaddition, a process directed on the intensification of H 2 SO 4 hydrolysis in an autoclavewas studied. It can serve as a step towards the optimization of birch sawdustpretreatment.References:[1]. Kumar R. [et al.]. Bioconversion of lignocellulosic biomass: biochemical and molecularperspectives// Ind. Microbiol. Biotechnol. – 2008. – V. 35. – P. 377-391.[2]. Mosier N. Futures of promising technologies for pretreatment of lignocellulosic biomass //Bioresourse Technology. – 2005. – V. 96. – P. 673-686.[3]. Sun Y., Cheng J. Hydrolysis of lignocellulosic materials for ethanol production: a review //Bioresource Technology. – 2002. – V. 83. – P. 1–11.[4]. Hamelinck C.N. [et al.]. Ethanol from lignocellulosic biomass: techno-economic performance inshort-, middle- and long-term // Biomass and Bioenergy. – 2005. – V. 28. – P. 384-410.118