Biological Pretreatment of Lignocellulosic Agricultural Waste for Enhanced Methane Production in Digesters

Abstract

Lignocellulosic agricultural waste represents an abundant renewable biomass resource with significant potential for biogas production; however, its complex structural composition and resistance to microbial degradation limit methane generation during anaerobic digestion. The present study investigates the biological pretreatment of lignocellulosic agricultural waste for enhanced methane production in anaerobic digesters under controlled operational conditions. The research focuses on evaluating the effectiveness of microbial and enzymatic pretreatment methods in improving biomass biodegradability, hydrolysis efficiency, and methane yield. Experimental analysis was conducted to examine the influence of pretreatment duration, microbial inoculum type, temperature, substrate composition, moisture content, and lignocellulosic structure on digestion performance and biogas generation. Results demonstrate that biological pretreatment significantly enhances the breakdown of lignin and hemicellulose components, thereby increasing cellulose accessibility and improving subsequent anaerobic digestion efficiency. The study further reveals that optimized pretreatment conditions substantially accelerate hydrolysis reactions and volatile solids degradation, resulting in enhanced methane production and improved process stability. Increased microbial activity and enzymatic degradation contributed to reduced digestion lag phase and enhanced conversion of organic matter into biogas. Comparative assessment with untreated agricultural residues confirms the advantages of biological pretreatment, including lower energy requirements, reduced chemical consumption, and improved environmental sustainability compared with physicochemical pretreatment techniques. In addition, the process supports efficient utilization of agricultural waste for renewable energy generation and nutrient recycling applications.