Influence of injection timing on performance and combustion characteristics of compression ignition engine working on quaternary blends of diesel fuel, mixed biodiesel, and t-butyl peroxide

The objective of the present work is to examine the effects of adding t-butyl peroxide (TB) additive with diesel fuel and biodiesel originated from Mahua oil and waste Palm oil in form of quaternary blends with varying injection timing (21^obTDC (before Top Dead Centre), 23^obTDC, and 25^obTDC) on performance, emission, and combustion characteristics of a diesel engine. In this experimentation, all the quaternary blends were prepared by keeping the volume percentage of diesel fuel at 50% v/v, while concentrations of Mahua oil-based biodiesel, waste Palm oil-based biodiesel, and t-butyl peroxide were varied by volume. The prepared blends were utilized on a constant-speed single-cylinder 4-stroke turbocharged diesel engine for comprehensive analysis in contrast to diesel fuel. The obtained results depicted that the quaternary blend of 50% diesel fuel (D)/20% mixed biodiesel (MB)/30% t-butyl peroxide (TB) (D50-MB20TB30) at advanced injection timing of 25°bTDC has shown a 2.66% increment in exhaust gas temperature and a 2.12% reduction in brake thermal efficiency compared to diesel fuel. At peak load, emission parameters such as carbon monoxide, unburnt hydrocarbon, and smoke opacity for D50-MB20TB30 were found to be respectively 4.59%, 3.47% and 5.03% lower than those of diesel fuel, although there was a slight increment by 0.83% of nitrogen oxide compared to diesel fuel. Considering combustion behaviours, heat release rate, cylinder pressure, and ignition delay were also observed to be 1.14%, 2.21%, and 8.34% lesser than conventional diesel fuel at 100% load, respectively. In closing, using the D50-MB20TB30 quaternary blend combined with advanced injection timing of 25°bTDC could offer a significant efficiency in improving the engine performance and reducing pollutant emissions, contributing to sustainable development and environment protection.