Chapter 7: Converting Agricultural Waste Biomass Into Value-added Fuels Via Thermochemical Processes

Due to the rapid increase in population and modernization, the daily consumption of fossil reserves is rising, posing a severe threat to their continued existence. In addition, the combustion of fossil-based fuels causes specific environmental issues, which is why developed nations are transitioning to carbon-neutral fuel sources. Carbon neutral fuels are derived from biomass, the combustion of which conserves the environment, and are regarded as viable alternatives to fossil-derived fuels. Over the past few decades, specific biomass sources have been recommended for biofuel production; however, it is believed that non-edible biomass is most suitable for biofuel production, as it does not cause the food versus fuel controversy and is thought to be more cost-effective than biofuels derived from edible biomass feedstock. Several types of non-edible biomass exist, including agricultural waste (biomass leftover from edible crops) and wild-grown biomass (which does not produce an edible product, such as rubber plants and jatropha plants, among others). Non-edible agro-waste is regarded as the most viable alternative to fossil-based fuels. By utilizing thermochemical and biological processes, agro-waste can be converted into biofuel. Biological methods are deemed unsuitable compared to thermochemical methods due to several benefits, including a higher biofuel yield and higher-quality products obtained via the thermochemical method. There are three thermochemical processes: gasification, pyrolysis, and direct combustion. This chapter discusses viable agro-waste for biofuel production and provides a comprehensive analysis of the thermochemical methods for biomass conversion to biofuel.