The development of new technologies to increase the production of biofuel without directly competing with food production is required. Microalgal biomass has recently been in the highlight in this regard. In this chapter, the role of this biomass for bioethanol production is discussed within the concept of biorefinery and industrial sustainability. The process of cultivation in order to accumulate around 50-60% of carbohydrates in the biomass (dry weight) and the importance of water and nutrient recycling are reviewed. Saccharification of biomass using enzymes or acids is addressed together with alternative operations (such as hydrothermal liquefaction and flash hydrolysis) that aim at recovering additional products (i.e. biocrude). Since the main monosaccharide in microalgal biomass is glucose, high rates of hydrolysis and fermentation are possible achieving more than 80% of the efficiency as a sum of these two processes. Anaerobic digestion to treat vinasse after distillation and the recycling of CO2 from the ethanolic fermentation and from biogas combustion could increase the process sustainability. Finally, the advantage of using microalgae rather than other sources of biomass in bioethanol production is estimated with reference to the production rate, even though the cultivation costs remain still high.

Chapter 17: Bio-refinery as a promising approach to promote ethanol industry from microalgae and cyanobacteria

Carlos Eduardo de Farias Silva
Writing – Original Draft Preparation
;
Elena Barbera
Writing – Original Draft Preparation
;
Alberto Bertucco
Supervision
In corso di stampa

Abstract

The development of new technologies to increase the production of biofuel without directly competing with food production is required. Microalgal biomass has recently been in the highlight in this regard. In this chapter, the role of this biomass for bioethanol production is discussed within the concept of biorefinery and industrial sustainability. The process of cultivation in order to accumulate around 50-60% of carbohydrates in the biomass (dry weight) and the importance of water and nutrient recycling are reviewed. Saccharification of biomass using enzymes or acids is addressed together with alternative operations (such as hydrothermal liquefaction and flash hydrolysis) that aim at recovering additional products (i.e. biocrude). Since the main monosaccharide in microalgal biomass is glucose, high rates of hydrolysis and fermentation are possible achieving more than 80% of the efficiency as a sum of these two processes. Anaerobic digestion to treat vinasse after distillation and the recycling of CO2 from the ethanolic fermentation and from biogas combustion could increase the process sustainability. Finally, the advantage of using microalgae rather than other sources of biomass in bioethanol production is estimated with reference to the production rate, even though the cultivation costs remain still high.
Bioethanol Production from Food Crops
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3254098
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