నైరూప్య

Production of Bioethanol from hitherto underutilized agro waste (Field beans/Green Pea pods waste) incorporating zero waste generation technique

Upendra R.S, Pratima Khandelwal, Priyanka.S, Jagadish M L, Nandhini N J

With the inevitable depletion of world’s energy supply, there has been an increasing interest worldwide in alternative sources of energy. Unlike fossil fuels, ethanol is a renewable energy source produced through fermentation of sugars and can be used as a partial gasoline replacement. Bioethanol market is expected to reach 100 x10^9 liters in 2015. Currently, bioethanol is being commercially produced only from edible feedstock such as corn-starch and sugarcane juice. These bioethanol production systems pose a concern about the rising competition with food and feed supplies. Agro-waste wastes are generated in large amounts throughout the year, and are the most abundant renewable resources on earth. Due to the large availability and rich in composition of polymers that could be used in other processes, there is a great interest on the reuse of these wastes, both from economical and environmental view points. Very scanty research documents were reported on using alternative sources like Agro- waste for the production of bioethanol. With these lacunae the present investigation aimed in using agro-waste, a rich energy source to produce bioethanol. A suitable low cost anaerobic fermenter was designed and fabricated for bioethanol production under submerged culture conditions using Yeast (Saccharomyces cerevisiae). Agro waste biomass (field bean pods, field bean seed coat and green peas pods) was pre-treated (physical and mild acid treatment) and saccharified using consortium of fungal strains (Aspergillus sp.). On completion of the process, 90g of glucose/ kg was obtained. Glucose obtained was taken for the SmF process using Saccharomyces cerevisiae and the end product ethanol was estimated qualitatively and quantitatively by specific gravity method, 7.725g in comparison with the weight of pure ethanol 7.639 and Gas Chromatography (70.2% ethanol). A Conversion rate of, 250 ml of ethanol /kg of agro waste calculated. The spent yeast was dried (50g/litre) and used as peptone.