Experimental assessment on characteristics of premixed charge compression ignition engine fueled with multi-walled carbon nanotube-included Tamanu methyl ester

Abstract

The premixed charge compression ignition (PCCI) engine is developed to develop combustion at low temperatures to enhance engine efficiency and decrease exhaust emissions. This study was performed to compare the performance and emission characteristics of the PCCI mode-based engine operated with induction of ethanol in the inlet manifold and direct injection of multi-walled carbon nanotube (MWCNT)-blended Tamanu methyl ester (TME) at various proportions such as 10, 40, 70, and 100 ppm in comparison with the conventional CI engine fueled with diesel and TME. It was found that adding 100 ppm of MWCNT could provide significant improvements in the performance and emission characteristics of the PCCI engine because of its superior atomization, catalytic behavior, and high surface-to-volume ratio. As a result of comparison with conventional CI engine, brake thermal efficiency and brake-specific fuel consumption of PCCI engine running on MWCNT-blended TME was reduced by 4.12% and increased by 4.28%, respectively. Besides, emissions of hydrocarbon, carbon monoxide, nitrogen oxide, and smoke were reduced by 3.3%, 3.27%, 75%, and 45%, respectively. For combustion analysis, the CI engine has a higher in-cylinder pressure and heat release rate than the PCCI mode, which could be due to the PCCI mode's lower combustion and lean charge mixture. ICP and HRR of PCCI engines running on MWCNT-blended TME were reduced by 7.5% and 3.8%, respectively. In general, this current study reveals a significant reduction in pollutant emissions and an increase in engine performance by using a combined strategy between MWCNT-blended TME and low-temperature combustion mode like PCCI, which was previously unexplored.