Influence of Propyl gallate antioxidant on performance and emissions of a compression ignition engine fueled with Madhuca Indica B20 ester blends

Biodiesels have received much attention due to depletion of world fossil reserves and increased environmental concerns. However, the biodiesel has lower oxidation stability which degrades its properties. Hence, biodiesel is treated with antioxidants to enhance the oxidation stability which also affects the performance and emission characteristics of biodiesel. In this investigation, the influence of synthetic antioxidant Propyl Gallate (PG) on the diesel engine performance and emissions was studied at 1,500 rpm by varying the engine load from no load to full load by using non-edible Mahua biodiesel, and PG was added to the B20 biodiesel blend with the concentrations of 0, 250, 500, and 750 ppm. The addition of PG marginally decreases the brake-specific fuel consumption and significantly reduces the NOx emission. This is because of free-radical scavenging property of PG which reduces the combustion temperature. However, hydrocarbon and carbon monoxide emission levels are higher than the B20 blend without antioxidant.