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 (21obTDC (before Top Dead Centre), 23obTDC, and 25obTDC) 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 degrees 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 D50MB20TB30 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 degrees bTDC could offer a significant efficiency in improving the engine performance and reducing pollutant emissions, contributing to sustainable development and environment protection.