Impact of n-butanol as an additive with eucalyptus biodiesel-diesel blends on the performance and emission parameters of the diesel engine

Abstract

The rising demands of energy and strict regulations of government associated with toxic gases emitted from utilization of conventional fuels are motivating towards biofuels mainly biodiesel. However, some constraints for employing biodiesel as substitution fuel are higher viscosity, nitrogen oxides (NOx) and carbon dioxide (CO2) emissions. The main intention of this work is to explore biodiesel production and examine the influence of butanol (Bu)-biodiesel (B)-diesel fuels on the diesel engine. In present work, biodiesel (B) is prepared from eucalyptus oil and B20 (20%biodiesel-80%diesel), B100 (neat biodiesel), B20-5Bu (20%biodiesel-75%diesel-5%butanol), B20-10Bu (20%biodiesel-70%diesel-10%butanol) and B20-15Bu (20%biodiesel-65%diesel-15%butanol) prepared fuel samples are tested with varying engine load at 1500 rpm in diesel engine. Approximately 92% yield of biodiesel is obtained with base-catalyzed transesterification method at pre-determined methanol-oil ratio (8:1) and 0.1% (wt) sodium hydroxide (NaOH) catalyst at 65 °C reaction temperature for 3 hrs. It is found that slight increase in brake power (BP) and higher brake specific fuel consumption (BSFC) are attained with butanol-biodiesel-diesel fuels, while brake thermal efficiency (BTE) is decreased. At full load, the results are indicated that 10% and 20% average reduction in carbon mono-oxide (CO); 36.7% and 46% unburnt hydrocarbon (HC) emissions are declined for B20 and B100 respectively. Moreover, the NOx and CO2 emissions are found to be increased than diesel. B20-5Bu, B20-10Bu and B20-15Bu shows 23.55%, 21.9% and 25.16% average decrease in NOx emission at great extent, due to cooling effect of butanol. Finally, it is proclaimed that butanol-diesel-biodiesel can become a promising fuel as same as diesel.