Eco-Friendly Additives: Performance and Emissions Analysis of a Diesel Engine With Jojoba Methyl Ester and CNT Blends

Abstract

Diesel engines have extensive use in vehicles, power plants, and agriculture, but they pose significant challenges due to both regulated and unregulated emissions. As fossil fuel supplies diminish and pollution levels increase, it has become crucial to shift from conventional fuels to biodiesel and alternative additives. This experimental study investigates the emission and performance characteristics of a water-cooled, three-cylinder, four-stroke compression ignition engine operating on blends of Jojoba methyl ester (JME) combined with additives such as carbon nanotube (CNT). JME was mixed with pure diesel in concentrations of 5% and 15% by volume, creating blends referred to as J5 and J15. CNT was added to these blends at a concentration of 20, 40, and 60 ppm. Emission and performance metrics were evaluated across engine speeds varying from 1200 to 2200 rpm. The findings revealed significant improvements, with brake thermal efficiency (BTE), brake power (BP), and torque increasing by 6.7%, 3.8%, and 3.8% respectively. A 2.6% reduction in brake-specific fuel consumption (bsfc) was observed at 1600 rpm with the J5CNT60 blend. The introduction of Jojoba biodiesel into neat diesel resulted in reductions of 12.8%, 14.56%, 15.25%, and 7.27% in nitrogen oxide (NO_x), carbon monoxide (CO), carbon dioxide (CO₂), and unburned hydrocarbon (UHC) emissions, respectively. Although Jojoba biodiesel resulted in a slight increase in smoke opacity (SO) emissions by less than 1%, the addition of CNT led to a 2% decrease in SO emissions at 2000 rpm.