International Journal of Hydrogen Energy, Vol.43, No.49, 22116-22125, 2018
Enhancing saccharification of Agave tequilana bagasse by oxidative delignification and enzymatic synergism for the production of hydrogen and methane
Agave tequilana bagasse is a suitable lignocellulosic residue for energy production. However, the presence of lignin and the heterogeneous structure of hemicellulose may hinder the availability of polysaccharides. In this work, the pretreatment of A. tequilana bagasse with alkaline hydrogen peroxide (AHP) followed by enzymatic saccharification with hemi-cellulases and cellulases was assessed for the removal of lignin and extraction of fermentable sugars, respectively. Results of the AHP pretreatment indicated that it is possible to attain up to 97% delignification and recover 88% of cellulose and hemicellulose after only 1.5 h of treatment. Regarding the saccharification process, the total sugar yield and productivity were both increased by 2-fold using an enzymatic mixture (cellulases + hemicellulases) compared to single enzyme hydrolysis (cellulases), evidencing synergism. Further evaluation of the hydrolyzates as substrate for hydrogen and methane production, resulted in yields 1.5 and 3.6-times (215.14 +/- 13 L H-2 and 393.4 +/- 13 L CH4 per kg bagasse, respectively) superior to those obtained with hydrolyzates of non-pretreated bagasse processed with a single enzyme. Overall, using AHP pretreatment and subsequent hydrolysis with enzymatic mixtures improves the saccharification of A. tequilana bagasse enhancing the production of hydrogen and methane. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Agave bagasse;Anaerobic digestion;Dark fermentation;Delignification;Enzymatic synergism;Lignin