Extraction of Algal Oil and Its Utilization in DI Diesel Engine

Abstract

The biofuels derived from plant biomass may overcome the problems associated with fossil fuels, but the difficulty associated with biofuels is the feed stocks and fertile land for their growth. So algae can be considered as the best and promising resource for the production of the biofuel, particularly microalgae biomass is much reliable source for the biofuel production because they do not require fertile land for its growth and they are non edible. Accordingly in this research investigation the bio-oil was extracted from Heterotrophic chlorella protothecoides (HCP) microalgae biomass by solvent extraction method using hexane as solvent along with Soxhlet apparatus. The yield of the HCP microalgae oil was 52% by weight with this solvent extraction method. Alkali catalyzed transesterification process was used to convert HCP microalgae oil into HCP microalgae biodiesel with biodiesel yield of 92 % by volume. Physiochemical characterization of HCP microalgae biodiesel was carried out and most of the results obtained were comparable with biodiesel properties and ASTM biodiesel standard. FAMEs content of the HCP microalgae biodiesel was analyzed using Gas chromatography. The results from this analysis show that HCP microalgae according to its fatty acid content is an ideal biomass resource for biodiesel production. newlineHCP-B100 (100% biodiesel blend) shown a reduction of 4.2, 6.7, 10.8, 20, 4.9, 10.56 and 10.34% in torque, brake power, brake thermal efficiency, CO, CO2, HC and NOx emissions, respectively, and an increase of 14.8 and 9.75 % in O2 and BSFC, respectively compared to petroleum diesel (PD) at 200 bar injector opening pressure (IOP) and 230bTDC injection timing (IT) . HCP- B20 blend at the 80% engine load shown higher BTE and lesser CO, HC, BSFC,NOx and smoke opacity at 240 bar IOP and 270bTDC compared to 200 bar IOP and 230bTDC IT. Statistical analysis shown that the ANN predicted and experimental results are in close agreement with each other. The ANN predicted values of BTE, BSFC, CO, HC and NOx are 31.83%, 0.362 Kg/KWh, 0.006 (%vol), 19 ppm and 144 ppm respectively. A little improvement in the diesel engine performance and minor reductions in the exhaust emissions was observed. Assessment of newlineiii newlinethe engine out responses for HCP-B20 operation at optimum IOP and optimum IT with neat diesel operation at rated IOP and IT at the 80% engine load gives sufficient indications to promote 20% blend of the HCP microalgae biodiesel in neat diesel for running the diesel engine. newline