The influence of natural and synthetic antioxidant on oxidation stability and emission of sapota oil methyl ester as fuel in CI engine

Abstract

In this present study oxidation stability of sapota oil methyl ester with synthetic and natural antioxidant additives using Rancimat test is investigate. The performance and emission characteristics of the B20 blend of sapota oil methyl ester with different antioxidant additive are evaluated in a Diesel engine. The natural antioxidants namely citric acid, rosemary extract and leaf extract and synthetic antioxidants namely pyrogallol, propyl gallate and butylated hydroxylanisole are selected. Addition of all the antioxidant additive found to have improved the oxidation stability of the biodiesel to the required level. Pyrogallol is found to be the best among the synthetic antioxidant, while leaf extract is the best among the natural antioxidant. From the emission test it is found that B20 has better emission characters compared to diesel except NOx. Further the addition of leaf extract slightly reduces the NOx emission of B20 and appreciably suppresses smoke emission.