Bioethanol Production from Mulberry Molasses Waste with Ohmic-Assisted Hydrodistillation

In this study, the fermentation process of bioethanol production conditions were optimized by response surface methodology. Mulberry molasses production waste was used as the only carbon source for yeast fermentation to produce bioethanol. Hydrodistillation (HD) and ohmic-assisted hydrodistillation (OAHD) methods were employed to concentrate the bioethanol. Fermentation time (48–168 h), waste matter rate (5–45%) and pH (5–7) were selected as independent variables. Alcohol concentration was treated as the response. Optimum fermentation conditions were determined as 96.894 h fermentation time, 45% waste ratio and pH 7. At these optimum conditions, alcohol concentration was determined as 3.77 ± 0.33%. While the distillate obtained in the HD method contained 22.50 ± 1.89% alcohol, it showed 27.72 ± 0.24% in the OAHD method. The energy consumption values for OAHD and HD was 2.92 ± 0.51 and 53.24 ± 1.74 Wh/mL bioethanol, respectively. Results of study showed that the OAHD could be a cost-effective and green method to distillation of bioethanol from mulberry molasses waste.