Bioethanol wastes: Economic valorization

Abstract

The valorization of solid, liquid, and gaseous wastes from industrial activities is important to achieve positive economic and environmental balances.The ethanol industry is one of the biggest examples of biorefineries around the world, generating enormous amounts of wastes and reusing them within the industry.New technologies to add value to these residues are underdevelopment and will chance the panorama of the sector.This chapter describes technologies to reuse and valorize the solids, liquids, and gaseous wastes generated during the production of ethanol through the fermentation of sugarcane.Special attention is given to the liquid and gaseous wastes, more specifically vinasse and CO2, which can be used in microalgal and cyanobacterial cultures for the production of biomolecules such as lipids (to biodiesel), proteins, and pigments.Technologies to produce biogas and biohydrogen from vinasse are also presented and discussed.Finally, a chemical process that promotes vinasse treatment (COD, BOD, and turbidity reduction) coupled to the mitigation of CO2 are presented.All these technologies promote the valorization of the ethanol industry wastes, bringing economic advantages to the segment and immensurable environmental benefits.