Devendra Pratap Singh, Rakesh Kumar Trivedi
Abstract: Biomass is a renewable energy resource derived from the carbonaceous waste of various human and natural activities. Bio-fuels such as ethanol, biodiesel are important because they replace petroleum fuels. Production of bio-ethanol from kinds of biomass is one way to reduce both consumption of crude oil and environmental pollution. Using bio-ethanol blended gasoline fuel for automobiles can significantly reduce petroleum use and exhaust greenhouse gas emission. Biofuel production from renewable sources is widely considered to be one of the most sustainable alternatives to petroleum sourced fuels and a viable means for environmental and economic sustainability. Microalgae are currently being promoted as an ideal third generation biofuel feedstock because of their rapid growth rate, CO2 fixation ability and high production capacity of lipids; they also do not compete with food or feed crops, and can be produced on non-arable land. Lignocellulosic biomass and algae are the rich source of carbohydrates and lipids, which may converted in to biofuels. Microalgae have broad bioenergy potential as they can be used to produce liquid transportation and heating fuels, such as biodiesel and bioethanol. The Spirogyra biomass was selected as a substrate for bioethanol production in the process of work, as it is rich in polysaccharides- starch and cellulose. In this content experiment were done in two ways for comparative study. (a) Pretreatment with acid and scarification of algal biomass by Aspergillus Niger (b) Direct scarification of algal biomass. In the first case ethanol concentration was found 4 % (w/w). While in case of direct scarification of algal biomass using Aspergillus Niger, 6 % (w/w) of alcohol was produced. Saccharomyces cerevisiae and Zymomonasmobilis was comparatively used to ferment the saccharified algal biomass. Addition of lactose and -amylase were taken for the effective improvement. (i) On addition of 0.12g of lactose maximum alcohol was found 6.6 % for direct scarified biomass, while 4.7 % ethanol was found in case of acid treated biomass in 6 days. (ii) Presence of 0.09 grams of -amylase enzyme ethanol production is recorded maximum by fermentation using Zymomonasmobilis than Saccharomyces cerevisiae.
Keywords: Pretreatment, Algal biomass, Biofuel, Saccharification, Fermentation