ABSTRACT
The residues from agricultural and forestry industries, such as field residues/wastes (e.g., stems and stalks) and process residues (e.g., bagasse, husk, and molasses), are increasingly being utilized for energy generation through a multitude of routes, such as thermochemical conversion to form syngas and bio-oils, and biochemical conversion to bio-alcohols, biodiesel, biohydrogen, biomethane, etc. Among the available options, lignocellulosic (second-generation) biofuels like bioethanol offer a number of benefits such as reduced competition with food production, carbon sequestration, and ecological benefits, in addition to possessing several desirable qualities like a high octane number, low boiling point and heat of vaporization, and sufficient energy density. For such second-generation biorefineries, the choice of feedstock and the conversion route is decided by the biomass type and availability, available technology, economics, and demand, among other considerations. However, biofuel production will become viable only if the cost and energy needed for its generation are appreciably lower than the energy yielded. This chapter outlines the types of agro-residue-based fuels and their production routes, together with the challenges that need to be addressed, such as those regarding feedstock procurement and logistics, development of energy-efficient technologies for conversion, the generation of by-products, and designing efficient strategies for waste management.
