Biomethane Production through Anaerobic Digestion of Lignocellulosic Biomass and Organic Wastes

Abstract

Biogas generation via anaerobic digestion of lignocellulosic biomass entails a developed technology and a cost-effective pathway. The technology may add further appeal to lignocellulosic waste management owing to the surplus availability and nonedibility of the precursors in rural areas. The biogas generated from anaerobic digestion contributes significantly to the ever-increasing demand for sustainable and affordable energy and products. The current review is an attempt to present the state-of-the-art of anaerobic digestion of biogenic solid wastes, the impact of different chemical pretreatment processes and products and the influence of operating parameters on biomethane yields. In this regard, various pretreatment strategies like acidic, alkaline, oxidative, and ionic liquid have been developed to overcome the inherent recalcitrance and complex crystallinity of cellulose and lignin to simpler forms like monomer. The present review 62highlights the use of chemical agents including mild alkali, dilute acid, ionic liquid, and oxidants which trigger solubilization and degradation of lignocellulosic wastes and utilization for enhanced biogas generation than the pristine substrate. The comparison of different chemical pretreatment strategies for enhanced biogas yield is presented. Additionally, the influence of the operational parameters like temperature, pH, reactor type, hydraulic retention time, carbon/nitrogen ratio and chemical loading on the performance of anaerobic digestion towards the quality and quantity of biogas yield are inherently reviewed. Lastly, the emphasis is also placed on the global biomethane market towards a sustainable future.