Utilization of molasses Wastewater for enzymatic fermentation in bioethanol production and residual glucose recovery

Abstract

Molasses liquid waste (MLW) is a byproduct of the bioethanol production process from sugar cane molasses, typically containing approximately 10 % v/v glucose. This study investigates the use of enzymatic fermentation with turbo yeast to enhance bioethanol production from MLW while minimizing fermentation time. Various volumes of MLW, ranging from 500 to 2500 mL, were pretreated to remove impurities and then stirred for 30 min prior to fermentation. Fermentation was carried out using turbo yeast concentrations of 2 to 6 % v/v over durations of 4 to 12 days, with the pH maintained at 4.5 to achieve a bioethanol content of 21.92 % v/v. Optimization of the fermentation process was performed using Response Surface Methodology (RSM). Results indicated that an optimized condition of 3 % v/v turbo yeast and an 8-day fermentation period yielded the highest bioethanol content while minimizing residual glucose to approximately 2.04 % v/v. These findings provide valuable insights for optimizing fermentation parameters to maximize bioethanol yield from MLW.