Agricultural Waste as a Source of Fine Chemicals Through Thermochemical Methods

The escalating demand for sustainable sources of fine chemicals has drawn attention towards utilising agricultural waste as a valuable resource. This chapter explores the potential of agricultural waste conversion through thermochemical methods to yield fine chemicals. Thermochemical processes, including solvolysis, hydrolysis, hydrogenation, pyrolysis, gasification and hydrothermal liquefaction through conventional and non-conventional heating methods including microwave, ultrasonic, radiative heating, etc., stand out as transformative technologies for converting agricultural waste into biofuels like bio-oil, biochar and syngas. This chapter presents the key catalysts used for hydrolysis and solvolysis, including zeolites, heteropolyacids, metals, metal oxides, carbon-based catalysts, etc. Additionally, the importance of effective characterisation techniques for feedstock and the analysis of resulting biofuels, laying the foundation for proper utilisation in multiple applications, are highlighted. The potential of agricultural waste as a renewable feedstock for producing green fuels and value-added chemicals aligns with the goals of circular bioeconomy and sustainability. Furthermore, the utilisation of agricultural waste biomass in the context of a circular bioeconomy is explored. This approach emphasises the generation of bioenergy and value-added products through biorefinery processes, mitigating the environmental impact of conventional fossil fuels. This chapter highlights the transition towards eco-friendly practices that harness organic waste for the production of biofuels and chemicals.