Effects of stably dispersed carbon nanotube additives in yellow oleander methyl ester-diesel blend on the performance, combustion, and emission characteristics of a CI engine

In the present investigation, we studied the influence of carbon nanotubes (CNTs) on the overall performance of a diesel engine using 20% (by volume) of yellow oleander methyl ester and 80% diesel (Y20) with and without CNT nano additives. The surface modification of CNT nanoparticles was observed, using ultraviolet–visible spectrometry, in the Y20 with different concentrations of QPAN 80 surfactant. The optimal concentration is determined to be 1:4. Nano additives were blended in Y20 blends at concentrations of 25, 50, and 75 ppm employing an ultrasonicator with optimal ratio. These samples were examined for physicochemical properties and tested in a compression ignition (CI) engine. Significant enhancements in performance and emission parameters were observed for the Y20C50 blend: Brake thermal efficiency improved by 15.5%, and we observed a reduction in brake-specific fuel consumption by 20.57%, carbon monoxide by 26.8%, unburnt hydrocarbon by 35.7%, and nitrogen oxides by 13.2%. Similarly, the addition of CNTs in the Y20 blend improved cylinder pressure, heat release rate, and rate of pressure rise and reduced ignition delay and combustion duration. In summary, CNTs were discovered to be suitable fuel additives for the Y20 blend to improve overall engine performance and reduce emissions.