Economic and environmental assessment of n-butanol production in an integrated first and second generation sugarcane biorefinery: Fermentative versus catalytic routes

n-Butanol produced from renewable resources has attracted increasing interest, mostly for its potential use as liquid biofuel for transportation. Process currently used in the industry (Acetone-Butanol-Ethanol fermentation - ABE) faces major technical challenges, which could be overcome by an alternative production through ethanol catalysis. In this study, both routes are evaluated by means of their financial viabilities and environmental performance assessed through the Virtual Sugarcane Biorefinery methodological framework. Comparative financial analysis of the routes integrated to a first and second generation sugarcane biorefinery shows that, despite the drawbacks, ABE process for fermentation of the pentoses liquor is more attractive than the catalysis of ethanol to n-butanol and co-products. n-Butanol use as fuel demonstrated favorable environmental results for climate change as figures showed over 50% reduction in greenhouse gas emission compared with gasoline.