Ethanol from residual biomass of banana harvest and commercialization: A three-waste simultaneous fermentation approach and a logistic-economic assessment of the process scaling-up towards a sustainable biorefinery in Brazil

Abstract

This work performs the ethanol production by a fermentation approach based on three banana residues simultaneously (banana pulp and peels, and banana pseudostem) in the realistic proportion (1:2:10) as generated at harvest and commercialization. A process model was developed using a commercial simulator to assess the energy consumption, inputs, and ethanol production, aiming to carry out a preliminary economic analysis for large-scale production in Brazil. Five scenarios for large and medium-sized plants installed in the state of Santa Catarina were created, seeking the lowest logistic cost. Two types of inoculums were chosen in the fermentations: with a monoculture of Saccharomyces cerevisiae, and with a coculture of Saccharomyces cerevisiae and Pachysolen tannophilus (ATCC32691). The highest ethanol yield (0.4 g/g), volumetric productivity (1.1 g/L h), and annual production (32.713 m3) with lower energy expenditure (138.4 GJ/m3) were obtained with fermentation by co-culture with wet pseudostem in the composed broth. Massaranduba is considered the most appropriate municipality of Santa Catarina state for the installation of a biorefinery. In an optimistic scenario, where the energy cogeneration would meet the plant's energy demand, the proposed process is economically viable, with the lowest payback time of 12.4 yr.