Optimization of Glucose Levels from Alcohol Industry Liquid Waste on the Fermentation Process Using Response Surface Methodology

The liquid waste generated by the alcohol industry is PT. Energi Agro Nusantara, which is a company in the alcohol sector, includes a significant amount of glucose, around 10%, as well as starch and other by-products. This waste has the potential to be used for the production of bioethanol by increasing the glucose levels and undergoing additional processing. The objective of this study is to achieve elevated concentrations of glucose and bioethanol through the processes of alkaline hydrolysis and anaerobic fermentation. The liquid waste undergoes an alkaline hydrolysis procedure using an 8N NaOH solution under pH 4 conditions. The fermentation procedure is conducted without the presence of oxygen, using 0.3 grams per milliliter of turbo yeast pure 48. The fermentation durations range from 4 to 12 days, with increments of 2 days. The optimization results acquired by RSM (Response Surface Methodology) indicated that the most favorable outcomes were achieved when the turbo yeast pure 48 concentration was 0.419 gr/ml, the fermentation time was 11.978 days, the glucose content was 21.231%, and the bioethanol content was 4.087%. The research findings can help decrease waste produced by the alcohol industry. The research also shows that the anaerobic fermentation process yields higher glucose levels. However, not all of the glucose obtained from this process is converted into bioethanol. The liquid waste from the alcohol industry contains residual glucose rather than reduced glucose. Therefore, the glucose produced during anaerobic fermentation can be utilized as an additional component in the flavoring alcohol industry taste.