Thermochemical conversion of agricultural waste to hydrogen, methane, and biofuels: A review

With the depletion of fossil fuels, the energy crisis can now be visualized shortly. At the same time, waste production in various fields is also on the rise. This has led to a global waste management challenge. Agricultural wastes are produced in abundant amounts in various parts of the world, and they offer a potential substitute for fossil fuels. Agricultural wastes can be used to produce Methane, Hydrogen and biofuels along with various useful chemicals. This review provides insight into the composition of agricultural waste, the process of gasification, gasification agents, and challenges in the process. The fuels made from agricultural wastes, the pretreatment of agricultural waste and its challenges and future of energy production from agricultural waste are also discussed. The paper discusses in depth the reactions involved in the gasification process and the various types of gasifiers, their advantages and disadvantages. Energy production from agricultural waste is already being employed in few countries, but further research needs to make the processes more environmentally benign and eco-friendly. The logistics cost to transport the agricultural waste to biofuel plants is a major challenge that needs to be tackled. The feasibility of installing biofuel plants closer to agricultural fields is much better. For a smart usage of agricultural waste and to meet the sustainability criteria, it is necessary to integrate the available waste streams with local technical solutions.