Recovery and characterization of cellulosic ethanol from fermentation of sugarcane bagasse

Industrial production of ethanol by fermentation using renewable feedstock such as sugarcane stalks has been demonstrated as a sustainable fuel chain in Brazil. This work focused on the production of cellulosic ethanol from sugarcane bagasse in a pilot scale unit by applying the current bioprocessing strategies with the aim of recovering and characterizing the end products. The feedstock was pretreated at 190 & DEG;C and a residence time of 10 min. Enzymatic hydrolysis was performed with commercial cellulolytic enzymes. Fermentation's substrates were formulated with hydrolysate and supplemented with 8%wt sugarcane molasses. The fermentations were set up to mimic the conventional industrial fermentation in Brazil's ethanol distilleries at high cell density with cell recycling. The fermentation resulted in a reproducible performance by the yield of 0.49 g/g, productivity of 6.96 g/(L & BULL;h), and cell viability of 95.3%. Ethanol was recovered in a lab-scale distillation batch system. Distilled fractions showed higher content of higher alcohols and sulfur content than the standard specification of ANP (National Agency of Petroleum Brazilian Agency) for ethanol fuel. The distillation bottom product (vinasse) presented most characteristics suitable for fertilizer or biogas applications, except for sodium and sulfate content. Therefore, for a successful technology, transference processing adjustments should be made to make the product commercially suitable and the side stream compatible for disposal as fertilizer or digestion for biogas production.& COPY; 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

Automated summary

This work focused on the production of cellulosic ethanol from sugarcane bagasse in a pilot scale unit by applying current bioprocessing strategies, with the aim of recovering and characterizing the end products. The fermentation resulted in a reproducible performance, with a yield of 0.49 g/g, productivity of 6.96 g/(L·h), and cell viability of 95.3%. However, the distilled fractions showed higher content of higher alcohols and sulfur than the standard specification for ethanol fuel.