Techno-economic analysis of the production of 2G ethanol and technical lignin via a protic ionic liquid pretreatment of sugarcane bagasse

Abstract

The increasing demand for renewable energy, fuels, and chemicals encourages the development of new biorefinery processes. This work presents a techno-economic analysis of the pretreatment of sugarcane bagasse using the protic ionic liquid 2-hydroxyethylammonium acetate ([MEA][OAc]) considering four washing methods to remove it from the pretreated pulp. In the best scenario, the increased enzymatic hydrolysis yield and the more efficient counter-current washing method contributed to an increased ethanol yield of 33 %. Despite the lower increment in ethanol yield compared with other second-generation processes, the production of technical lignin increased the reaction mass efficiency of the biorefinery by 5.6 % and led to an internal rate of return two percentage points higher. However, wastewater and vinasse production increased by 26 % and 50 %, respectively. These results indicate that protic ionic liquids are potentially good pretreatment agents to produce fuels and chemicals from biomass, thus underpinning the establishment of new biorefinery processes. • Process development to produce ethanol and technical lignin from bagasse. • Different washing steps yielded different hydrolysis and fermentation yields. • Techno-economic analysis indicates the importance of using protic ionic liquids. • Protic ionic liquid pretreatment has better economic results because of lignin. • Recycling of ionic liquid plays an important role in process economic feasibility.