Assessment on Performance, Combustion and Emission Characteristics of Diesel Engine Fuelled with Blends of Diesel, Algae Biodiesel and Heptanol

Because of higher NO_x and PM emissions Compression Ignition (CI) engines are slowly being replaced by gas engines in metro cities though CI engine have better thermal efficiency and emit less Carbon monoxide (CO) and Unburned Hydrocarbons (UHC) emission than SI engines. Pollutants formed during combustion, depleting fossil fuels and continuous raising fuel price pushes the research community to find new alternative fuels which can be used along with diesel or replace the diesel without making major modifications in the current engine. The objective of this research work is to derive bio-diesel fuel from the source of algae and use it as a fuel by blending with commercially available diesel fuel. Heptanol is added along with algae bio-diesel and diesel blend to improve the ignition quality of the blend. Tests were conducted on a single cylinder constant speed, water cooled stationary diesel engine with different blends proportions of heptanol-biodiesel-diesel. The experimental results obtained for seven different types of blend proportions were compared with baseline diesel values. This research study reveals significant decrease in HC, CO, CO₂ and NO_x emission with marginal rise in smoke level. Amongst these seven samples, maximum of 14.7% NO_x emission was reduced with S6 blend. At full load maximum Brake Thermal Efficiency (BTE) of 34.96% is also achieved with the same S6 blend which is a combination of 10% heptanol, 20% biodiesel and rest diesel. On overall comparison, sample S6 found to be better to operate in conventional diesel engine without any prior modification.