An Overview of Biomass Conversion from Agricultural Waste

Bioenergy is considered as an integral part to address climatic menace as well as environmental, economic, and social security challenges. Biofuels, in this regard, ensure a sustainable and low-carbon alternative to fossil fuels because of cleanliness and renewable nature. Biofuel production, in particularly, from agricultural residue/waste is very advantageous since agricultural residues are cheap, readily available, renewable in nature, and highly biodegradable. Agricultural wastes become one of the most alternative energy sources for both non-renewable and renewable energy sources recently, since their lignocellulose (lignin, cellulose, hemicelluloses, etc.) content proved as promising substrate for biofuel production. Apart from these, the economic aspect (lower production cost due to cheaply available materials) and environmental concern (environmental deterioration due to phenolic compounds) of agricultural waste can be minimized through its utilization during biofuel production. Accordingly, this review paper focuses on various aspects of biofuel production such as agricultural waste types, their sources, and different economic conversion technologies for biofuel production. In particular, thermochemical techniques (pyrolysis, liquefaction, and gasification) and biochemical technologies (anaerobic digestion, photobiological hydrogen production, and alcoholic fermentation) were critically evaluated. Additionally, the role of different regulatory factors, namely pH, temperature, pressure, amount of biomass, and microbial actors, are discussed. Finally, the outcomes of this review paper will provide clear picture about various aspects of agricultural waste-based biofuel production in economical and environmentally beneficial way and will provide valuable information to researchers and scientific community.