Effect of Pretreatment, Fermentation Medium and Solid Loading Rate on The Production of Bio- Ethanol from Fruit Waste Using Saccharomyces cerevisiae

Abstract

Rapid increase in world’s population and growing industrialization are major sources of energy consumption, therefore energy demand is expanding continuously. The first-generation feedstock like maize, sugarcane, wheat etc. can be used to produce bioethanol, but due to food and feed security issues first generation feedstock cannot be used to produce bioethanol. To overcome the feed and food security issue related to first-generation feedstock, waste fruit can be used to produce bioethanol. In this experiment, firstly the effect of pretreatment technique on glucose generation is observed. Simultaneous saccharification and fermentation (SSF) experiment carried out at a pH of 4.5 and temperature of 30°C for 48 h with fermentation helping nutrients using Saccharomyces cerevisiae. Nearly equal amount of glucose concentration is observed from sample treated with hot water, 1% H2SO4, 5% H2SO4 and without any pretreatment. SSF results also revealed that fermentation helping nutrients has no significant effect on the production of bioethanol at same concentration. Second part of the experiment deals with the effect of solid loading rate, that is directly proportional to glucose concentration 10-20% (w/w) and time for fermentation (48-96 hours) on generation of bioethanol from fruit waste. Solid loading rate and reaction time for SSF had significant effect on production of bioethanol. Optimized 41.19 gL-1 bioethanol concentration was observed with solid load rate of 20% (w/w) and fermentation period of 58.8 h. High yield of bioethanol can be achieved using fruit waste at domestic scale with minimum operational requirements.