Effect of pH and Temperature on Bioethanol Production: Evidences from the Fermentation of Sugarcane Molasses using <i>Saccharomyces cerevisiae</i>

Abstract

Bioethanol is increasingly seen as a competitive alternative to gasoline due to rising concerns about the greenhouse effect, the price of crude oil, and other issues. Due to improvements in the agricultural sector, millions of tons of trash and byproducts are produced annually, with the potential to be used as inexpensive energy sources and raw materials for energy production. In the sectors that produce sugar, sugarcane molasses is widely available as a feedstock for the commercial generation of low-cost bioethanol. In order to examine the impact of temperature and pH on the output of bioethanol, this study fermented sugarcane molasses to make bioethanol. In the experiment, fermentation was accomplished using the fungus Saccharomyces cerevisiae (yeast). Following fermentation, ethanol was extracted using distillation at a temperature of 78^oC. The impact of pH on the ethanol yield was studied using five samples at five different pH levels (3.0, 3.5, 4.0, 4.5, and 5.0) at a temperature of 35^oC. Five more samples were utilized to investigate the impact of temperature on the production of ethanol; the pH was maintained at 4.0 while the temperature was changed (25, 30, 35, 40, and 45^oC). The percentage of ethanol yield was observed to grow with increasing pH and temperature until the optimum conditions were attained, at which point it began to decline. The study also found that the best conditions for Saccharomyces cerevisiae to make ethanol were pH 4.5 and temperature 35^oC, yielding the highest amount of ethanol (81%).