Optimization of Ethanol Production from Mango Peels using Response Surface Methodology

Environmental concern as well as escalating of fossil fuel price and demanding for renewable energy is the main reasons why bioethanol technology being developed. Bioethanol can act as alternatives energy and reduce dependencies on fossil fuel alone. Recently, research has been done to produce bioethanol by utilization of agricultural waste. Production of bioethanol from mango peels is examples of utilization of agricultural waste. Mango fruit is grown naturally in over 90 countries
worldwide and is known to be the second largest produced tropical fruit crop in the world. This shows that the amount of waste that will produce will be significant. The focal point of this project is to optimize production of bioethanol from mango peels using Response Surface Methodology (RSM) and to studies the effects of temperature, yeast concentration and fermentation time towards production of bioethanol. Mango peels will undergo hydrolysis and fermentation in order to
produce bioethanol. To achieve these objectives, experiment was conducted which consist of four stages; preparation of mango peels, hydrolysis of mango peels,
preparation of yeast and optimization using RSM. The first part of experiment, mango peels is manually peeling off using knife and the underlying pulp was removed. Then, the mango peels is treated with sulphuric acid with concentration of 0.25 % to 1 % (w/v). At acid concentration of 0.25 % (w/v) was the highest amount
of glucose yield. Fermentation is conduct according to experimental design layout that is generated by Design Expert software and the range for temperature, yeast
concentration and fermentation time is 25-40°C, 6-14 g/ml and 48-96 hours respectively. RSM using three factors and two level central composite designs was employed to optimize production of ethanol from mango peels. Based on the results obtained, the concentration of ethanol yield ranged from 5.28-7.34 g/ml. The
optimize condition to produce 7.34 g/ml is 38 °C, 6 g/ml yeast and 48 hours fermentation time. Therefore, this finding portray that the production of ethanol from
mango peels can be scale up for large production industry.