Assessment of Combustion, Performance, and Emission Phenomenon of a CI Engine Fuelled with Algal and Cottonseed Biodiesel

The present study investigates the effect of algal and cottonseed biodiesel in a single-cylinder compression ignition engine. Oil extraction was achieved through grinding operation and Soxhlet lipid extraction from cottonseed and S. marginatum macro-algae, respectively, which was followed by a single-stage transesterification process. Gas chromatography-mass spectrometry analysis revealed the presence of linoleic acid in prominent proportion for algal biodiesel. The physiochemical properties of cottonseed and algal biodiesel were comparative and found to be within American Society for Testing and Materials (ASTM) D6751 standards. At rated load, neat algal biodiesel showed elevated in-cylinder pressure, rate of pressure rise, and rate of heat release. Higher ignition delay with neat biodiesel resulted in prolonged combustion duration. Algal biodiesel produced higher brake thermal efficiency than cottonseed biodiesel along with 16.67% of lower brake-specific fuel consumption (BSFC) at full load. Furthermore, lower unburned hydrocarbon, smoke, and carbon monoxide were evidenced especially at full load with significant increase in oxides of nitrogen.