IMPACT OF TECHNOLOGICAL VARIABLES ON THE PROFITABILITY OF AN ETHANOL PRODUCTION PLANT FROM SUGARCANE BAGASSE

Abstract

Introduction:
The production of bioethanol from lignocellulosic biomass faces economic challenges due to technological and market uncertainties.
Objective:
To evaluate the impact of the main technological and economic variables on the profitability of a second-generation (2G) ethanol plant, considering different capacities and process variants.
Materials and Methods:
A base plant with a capacity of 500 hL/day of ethanol was designed, including four variants. Investment and operating costs were estimated, applying univariate sensitivity analysis and the Plackett–Bürman design. Profitability (NPV, IRR, PBP) was assessed for ethanol production capacities of 500, 3500, and 5000 hL/day.
Results and Discussion:
At 500 hL/day, none of the variants are profitable, although Variants 3 and 4 (175 °C, furfural as a coproduct) show better indicators. Fixed capital is the most significant variable. Fractionation and enzymatic hydrolysis account for 85–95% of equipment costs. At 3500 and 5000 hL/day, Variants 3 and 4 are highly profitable (positive NPV, IRR > 60%, PBP of 1.5–2 years).
Conclusions:
Ethanol production from sugarcane bagasse is not profitable at a small scale without high-value coproducts. Furfural (pretreatment at 175 °C) is key to economic viability. Fixed capital is the most influential variable; therefore, the design and energy integration of the fractionation and enzymatic hydrolysis stages must be optimized. Variants with integrated saccharification and fermentation are technically and economically superior.