Bioethanol: An overview of production possibilities

Bioethanol production mainly from sugarcane juice and corn, called first generation ethanol (1G), has already presented consolidated worldwide technology in the current scenario. Within this context, novel approaches are pivotal for development of technologies regarding bioethanol production from different renewable biomass. In this chapter, besides a global review of the 1G ethanol production from different carbon sources, the all steps and challenges for the ethanol 2G production, based on use of lignocellulosic materials (such as sugarcane bagasse and leaves, corn cobs, woods, agricultural wastes and others) are presented in detail. Among these steps, the biomass availability and bioprocess including pretreatments, detoxification, enzymatic hydrolysis, fermentation of pentose and hexose sugars, as well as different process configuration such as Separate (or Sequential) Hydrolysis and Fermentation (SHF), Simultaneous Saccharification and Fermentation - (SSF) and Simultaneous saccharification and cofermentation (SSCF) are presented. Moreover, the third generation ethanol production (3G), from microalgae are also described. Additionally, new advances and emerging technologies such as strain improvement, biomass improvement (genetically modified) are elucidated, highlighting their real potential. Future prospects and economical scenario are also presented. In all sections of this chapter, content are discussed according to their real feasibility for Bioethanol production.