Enzymatic pretreatment of steam-exploded birch wood for increased biogas production and lignin degradation

Abstract

Lignocellulose is readily available biomass for biogas production; however, due to its rigid structure, it requires pretreatment to obtain a maximum energy extraction. In this study, steam explosion (SE) (220 °C and 10 minute retention time) has been employed to increase the biogas production potential from birch wood. Although the biogas production increased by over two times after SE, the SE of birch wood negatively affects the structure of C5/C6 sugars and doubled the concentration of non-degradable lignin in all the samples. In this work, SE birch wood has been further pretreated by novel lignin-degrading enzymes cocktail to convert lignin into degradable sugars and increase the biogas production rate. The proposed hybrid pretreatment could increase the biogas production by up to 25% (from 450.5 mL/g VS to 566 mL/g VS), and reduced the lignin concentration by up to 48%.