Use of a Pulsed Electric Field to Improve the Biogas Potential of Maize Silage

Some types of biomass require great inputs to guarantee high conversion rates to methane. The complex structure of lignocellulose impedes its penetration by cellulolytic enzymes, as a result of which a longer retention time is necessary to increase the availability of nutrients. To use the full biogas potential of lignocellulosic substrates, a substrate pretreatment is necessary before the proper methane fermentation. This article discusses the impact of the pretreatment of maize silage with a pulsed electric field on biogas productivity. The experiment showed a slight decrease in cellulose, hemicellulose and lignin content in the substrate following pretreatment with a pulsed electric field, which resulted in a higher carbohydrate content in the liquid substrate fraction. The highest biogas production output was obtained for the pretreated sample at the retention time of 180 s for 751.97 mL/g volatile solids (VS), which was approximately 14% higher than for the control sample. The methane production rate for the control sample was 401.83 mL CH4/g VS, and for the sample following disintegration it was 465.62 mL CH4/g VS. The study found that pretreatment of maize silage with a pulsed electric field increased the biogas potential.