Sustainable approaches toward the production of bioethanol from biomass

In the coming future, natural energy sources such as diesel and petrol are going to be diminished. Therefore, interest in alternate sources of reliable, affordable, and sustainable energy has prompted much attention in the past three decades. Bioethanol is one of the promising alternatives, which is obtained from different biomass feedstocks. Bioethanol production from biomass is a well-established technology. This chapter provides a detailed insight on the current technologies for sustainable production of bioethanol from Indian bamboo using enzymatic saccharification technique, sweet sorghum bagasse through microwave irradiation approach, oil palm frond through ultrasonic irradiation method, sweet sorghum stalk via advanced solid-state fermentation system (ASSF), lignocellulosic through low-intensity pulsed ultrasonic methodology, sugarcane bagasse through hydrolysis approach using yeast cellulolytic enzymes, water hyacinth Eichhornia crassipes using an approach based on the preparation of the saccharified solution, sugarcane bagasse through sono-mediated enzymatic saccharification protocol, reed straw and corn stover using liquid hot water (LHW) pretreatment method, wheat straw using gamma irradiation approach, sugarcane bagasse through consolidated bioprocessing technique using Phlebia sp. MG-60, waste of date palm fruit using solar energy, and mandarin peel wastes using steam explosion method. Further, the chapter discusses industrial scale formation processes of bioethanol from sugar-, lignocellulosic-, and starch-mediated feedstocks. Moreover, the chapter also summarizes the commonly used feedstocks for sustainable and cost-effective bioethanol production and the biochemical reactions involved in the transformation of vegetative biomass to bioethanol. Pros and Cons of each sustainable approach for bioethanol production are discussed in detail, which will be very fruitful for the research community to get knowledge about the finest technologies, improve traditional methods, and develop further new more reliable, affordable, and sustainable methodologies for bioethanol production.