Biomass feedstocks for advanced biofuels: Sustainability and supply chain management

Circular economy is increasingly being seen as a sustainable route to development. The utilization of traditional waste streams for wealth generation is experiencing increased focus from policymakers. Agricultural activities globally generate billions of metric tons of waste biomass annually, which includes solid, liquid, and gaseous residues. Valorization of such agro-waste as feedstock for bioethanol production seems to be the only feasible route toward the achievement of the national blending target of 20% ethanol-blending with petrol. The cellulosic agro-wastes offers a more sustainable option compared to 1st generation biofuels which were dependant on food crops such as sugarcane, corn, and oil seeds. Particularly, in geographies with limited land and water resources, the dilemma to choose between food crop and energy crop has led to food vs fuel and sustainability issues. Major energy sources of feedstock may be switchgrass, miscanthus, high biomass, or energy sorghum, as well as crop residues, such as rice straw, wheat straw, corn stover, and corn cobs. Governmental policies that regulate agriculture, industry, and trade significantly influence the profitability of biofuels and play an important role in the development of a country's energy sector. However, there needs to be an increased awareness about these policies at the grass root level. While doing site selection for any advanced biofuel plant, one of the key criteria is sustainable availability of feedstock with an efficient and robust biomass supply chain management system. Biomass is a sustainable low carbon source that can replace fossil carbon via multiple thermo-chemical and biochemical technologies to produce almost all advanced biofuels for road/aviation transport. This chapter reviews the various feedstocks available for advanced biofuel production, supply and process chain analysis, sustainability, and industrial optimization. Though examples for bioethanol are given, but the discussed biomass can also provide fungible fuels, methanol, and Hydrogen by various technology platforms