Effects of biopretreatment of corn stover with white-rot fungus on low-temperature pyrolysis products Xuewei Yang a , Fuying Ma a , Hongbo Yu a , Xiaoyu Zhang a,⇑ , Shulin Chen b,⇑ a Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science & Technology, Luoyu Road 1037, Wuhan, PR China b Biological Systems Engineering Department, Washington State University, WA 99164, USA article info Article history: Received 27 July 2010 Received in revised form 2 November 2010 Accepted 3 November 2010 Available online 12 November 2010 Keywords: Biopretreatment White-rot fungi Biomass Py–GC/MS DAEM abstract The thermal decomposition of biopretreated corn stover during the low temperature has been studied by using the Py–GC/MS analysis and thermogravimetric analysis with the distributed activation energy model (DAEM). Results showed that biopretreatment with white-rot fungus Echinodontium taxodii 2538 can improve the low-temperature pyrolysis of biomass, by increasing the pyrolysis products of cel- lulose, hemicellulose (furfural and sucrose increased up to 4.68-fold and 2.94-fold respectively) and lig- nin (biophenyl and 3,7,11,15-tetramethyl-2-hexadecen-1-ol increased 2.45-fold and 4.22-fold, respectively). Calculated by DAEM method, it showed that biopretreatment can decrease the activation energy during the low temperature range, accelerate the reaction rate and start the thermal decomposi- tion with lower temperature. ATR-FTIR results showed that the deconstruction of lignin and the decom- position of the main linkages between hemicellulose and lignin could contribute to the improvement of the pyrolysis at low temperature. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Renewable energy sources have received great interest from the international community during the last decades (Antonopoulou et al., 2008), driving the worldwide efforts to develop environmen- tally benign and efficient technological process for producing renewable energy and transportation fuels (Muradov et al., 2010). Biomass is one of the most promising energy sources including agri- cultural residues that can be used for the production of biofuels (Jorquera et al., 2010), which could reduce the dependency on fossil fuels and provide significant advantage in terms of less greenhouse effect (Chew and Bhatia, 2008). And pyrolysis is a possible thermo- chemical conversion rout, converting biomass to a huge number of chemical compounds that can be used as conventional biofuels (Kraxner et al., 2009). Biomass pretreatment has become an important tool for biofuel production. The pretreatment of biomass prior to the fast pyrolysis process has been shown to alter the structure and chemical composition of biomass feed stocks leading to a change in the mechanism of biomass thermal decomposition, rendering it more accessible to release sugars (Mosier et al., 2005). This provides the potential to vary bio-oil chemical and physical properties for specific applications. Numerous pretreatment methods for this purpose have been investigated, including physical (Kumar et al., 2009a), chemical (Misson et al., 2009), and a combination of both (Sun and Cheng, 2002). For example, steam explosion (Taniguchi et al., 2010), hot compressed water treatments (Johnson et al., 2009), and applications of dilute acids (Chaiwat et al., 2008) have been utilized. Various pretreatment processes were also used prior to fast pyrolysis to improve bio-oil characteristics, produce useful selected chemicals, and increase the yield of sugars (Dobele et al., 2003). However, physical and chemical processes require high temperature and operating pressure, and the usage of acid and alkali might cause serious environment consequences. Thus, the green and effective biopretreatment with mild condition and low energy consumption exhibits great superiority. Biological pretreatment employs wood degrading microorgan- isms, including white- (Lee et al., 2007), brown- (Tewalt and Schilling, 2008), soft-rot fungi (Papadopoulos et al., 2010), and bacteria (Masai et al., 2007) to modify the chemical composition and the structure of the lignocellulosic biomass. Fungi (Dinis et al., 2009) have the distinct deconstruction characteristics on lignocellu- losic biomass. And white-rot fungi are more active and effective in deconstructing the biomass (Wan and Li, 2010). Thus white-rot fungi were considered the most promising basidiomycetes for bio- pretreatment of biomass and were the most studied biomass degrading microorganisms. As a result, biological pretreatments, a safe and environmentally-friendly method which does not require high energy and expensive equipment for lignin removal, attract more and more interests and show a promising future for the biofuel production. Recently most of the research work focused on the biopretreat- ment for ethanol production to improve the cellulase hydrolysis 0960-8524/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.biortech.2010.11.021 ⇑ Corresponding authors. Tel.: +86 (0) 27 87792108; fax: +86 (0) 27 87792128. E-mail address: paperimerhust@gmail.com (X. Zhang). Bioresource Technology 102 (2011) 3498–3503 Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech