مهدي نوروزي

Ethanol produced from sugar, compared to other carbon sources such as molasses, starch, and others, has a high quality and percentage due to the lack of environmental waste. The main goal of this research is to optimize the production of bioethanol from sugar. To achieve this, the biological synthesis of ethanol using Saccharomyces cerevisiae yeast with white sugar as the substrate was conducted using a continuous method. Various factors affect ethanol production, including pH, aeration time, temperature, sugar concentration, yeast amount, urea phosphate concentration, and vitamin concentration. This thesis eva‎luates the effect of these different factors, which were controlled at various levels, on ethanol production. To reduce the number of experiments required to examine these factors, experimental design was performed using the Taguchi method. A fractional factorial L27 Taguchi design was used in Minitab software with variations in 6 parameters at three levels. Since the ambient temperature could not be adjusted to a specific number due to available resources, this factor was not considered, and the yeast growth and multiplication temperature was set at approximately 28°C, while the fermentation temperature was set at approximately 35°C. The experimental design results showed that optimal ethanol production occurs at pH 5, aeration for 8 hours, 30 grams of sugar, 0.6 grams of yeast, 2.366 grams of urea phosphate, and 0.002 grams of vitamin. Based on the optimal point provided by Minitab software, experiments were conducted under the suggested conditions. Since the results showed minimal effect with variations in the parameters, the experiments were repeated after removing less influential parameters such as aeration time, urea phosphate, and vitamin. The highest result from the conducted experiments according to the Taguchi table was an ethanol production of 12%, and the lowest result was 4%.

بيواتانول، ساكارومايسيس سرويزيه، بهينه سازي فرآيند تخمير، طراحي تاگوچي

Bioethanol, Saccharomyces cerevisiae, Fermentation process optimization, Taguchi design

Mahdi norouzi

Dr.Omid vahidi