Municipal secondary sludge as carbon source for production and characterization of biodiesel from oleaginous bacteria

Abstract

Rising level of CO2, increasing demands and price of fossil fuel, generation of waste are the major challenges of the modern society. Biorefinery approach for production of biodiesel using waste as feedstock could be an alternative of these problems. The present research demonstrates the use of municipal secondary sludge as growth media for production of biodiesel by chemolithotrophic, oleaginous bacteria Serratia sp. ISTD04. The characterization of bacteria and biodiesel was performed by TEM and GC–MS, NMR respectively. The hydrocarbon range, C-7 to C-25 and suitable saturated and unsaturated fatty acid composition, makes it an impending fuel. Optimization of in-situ transesterification process parameters increased the yield by 25% and similarly increases in transesterification efficiency from 74% to 94%. The fuel properties (Total acid value, Cetane number, Cloud point, Pour point, Heating value, Kinematic viscosity) of 5% blended biodiesel was analyzed by ASTM standard methods and its shows good fuel behavior.