Vinasse treated with charcoal as a molasses diluent for ethanol fermentation

The demand for new products derived from agro-industrial residues has increased recently. Furthermore, vinasse, a wastewater from ethanol production, needs treatment to be reused in the sugarcane industry, reducing industrial water consumption. This study performed vinasse filtration with charcoal from industrial sugarcane residues and used the filtered molasses dilution in ethanol fermentation. There were five treatments in randomized blocks with three repetitions. The treatments were deionized water and natural vinasse as positive and negative controls, respectively, and filtered vinasse from charcoal made from bamboo, sugarcane bagasse, and straw. Hence, fermentation for ethanol production was performed. The filtered vinasse with all types of charcoals showed lower soluble solids, total residual reducing sugar, higher ethanol concentration, and fermentative efficiency compared to in-nature vinasse in the wine. Filtered vinasse from bagasse and straw charcoals shows 81.14 and 77.98% efficiency in ethanol production, respectively, close to deionized water (81.49%). For an industrial proposal, vinasse filtration may occur in a continuum process with recovery of charcoal by regeneration. Charcoal renewal should increase porosity for subsequent vinasse filtration. The process is feasible to apply using a product of sugarcane residue to treat wastewater and reduce industrial water consumption and vinasse disposal.