Agri-food Waste to Biofuels: Current Trends and Challenges

Nowadays, the health and quality of life in the ecosystem are heavily influenced by waste quantities that are steadily increasing. Globally, the agro-industry produces valuable materials such as agri-food wastes with well-known potential. These wastes have natural bioactive compounds that can be used in various applications, especially in renewable energy or the so-called biofuel production. Biofuels, which are renewable and carbon-neutral, are being considered one of the possible solutions to reduce transportation emissions and human reliance on fossil fuels. Agricultural food wastes are promising feedstocks for the biofuel industry because they are produced in large quantities, are inedible, and are currently underutilized. The biotechnological approach in the bioconversion of agricultural food waste into biofuels will be a great strategy to improve their applicability in order to avoid environmental problems and could help the economy and society. In this chapter, these approaches are covered in detail as a valorization approach to these agricultural food waste for biofuel production. Regarding the production of bioethanol and biobutanol, mature biofuel biotechnologies will be discussed in this chapter. In addition, this chapter also provides recent trends and innovations in lignocellulosic agricultural food waste valorization treatment and hydrolysis in sustainable biofuel production. The current trends and challenges are also investigated, considering future perspectives. This strategy is consistent with the benefits of the circular economy model of reducing, reusing, and recycling, and it promotes the possibility of establishing and optimising new supply chains for biorefineries of agri-food wastes.