Title:
Boosting Biogas with Hydrolytic Enzymes - Effect of Cellulase Pretreatment of Wheat Straw on Sugar Release, Onset and Ultimate Gas Production
Author(s):
Christensen, E.Y., Strætkvern, K.O.
Document(s):
Paper
Poster
Abstract:
In biogas reactors, hydrolysis of fibrous substrate can be improved by supplementing hydrolytic enzymes, however, reports are not conclusive on this claim. In this study, two commercial preparations consisting of cellulases and hemicellulases, were characterized and tested for their effect on biogas yield. Milled wheat straw was incubated with enzymes in a pretreatment step, prior to mixing with cow’s manure. Following anaerobic digestion (AD), improved gas yield and increased volatile fatty acids (VFA) was demonstrated in small-scale batch syringe reactors (100 ml) under various conditions. As a further verification, enzyme pretreatment step and AD was scaled up (1.0 L) with optimized conditions. Monitored for extended time, both enzyme-treated reactors performed 16 - 23 % better on gas yield compared to the control (no enzyme). Although the increased release of fermentable sugar shortens lag time and lowered volatile solids (VS), enzyme hydrolysis can also cause microbial imbalance compromising reactor pH due to rapid acid accumulation.
Keywords:
anaerobic digestion, enzymatic hydrolysis, modelling, sugar, pretreatment, wheat straw
Topic:
Biomass Conversion Technologies for Heating, Cooling and Electricity
Subtopic:
Anaerobic digestion for biogas production and biogas upgrading
Event:
26th European Biomass Conference and Exhibition
Session:
2CV.5.31
Pages:
809 - 810
ISBN:
978-88-89407-18-9
Paper DOI:
10.5071/26thEUBCE2018-2CV.5.31
Price:
FREE
