Effect of multi-walled carbon nanotubes and alumina nano-additives in a light duty diesel engine fuelled with schleichera oleosa biodiesel blends

In the present research, the efforts have been lodged to improve the combustion and performance characteristics along with exhaust emissions of diesel-schleichera oleosa biodiesel blends by adding nanoparticles of alumina and multi-walled carbon nanotubes. The nanoparticles (np's) were synthesized and their morphologies were characterized by using Field-Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction spectroscopy (XRD) techniques. Test fuels containing 50 ppm and 100 ppm dosage of nanoparticles were dispersed with diesel-biodiesel blends and were labelled as D80B20A50, D80B20A100 (alumina (Al2O3) nanoparticles) and D80B20C50, D80B20C100 (multi-walled carbon nanotubes (MWCNT)). The droplet size of test fuels was analysed by using a laser-diffraction based Malvern Spraytec set-up. Interestingly, nano-additive dispersed test fuels showed smaller droplet size due to the higher force of collision between the nanoparticles. Moreover, the engine trial showed up to a 2-13% increase in brake thermal efficiency and upto 5-60% drop in exhaust emissions for nanoparticles dispersed test fuels. Also, alumina showed better results than MWCNT in terms of higher thermal efficiency, lower specific energy consumption and lower exhaust emissions as compared to diesel. However, due to the superior sorbent of nitrogen oxides, the (100 ppm) MWCNT has resulted in a maximum reduction of NO emissions.