The main reason for the limited usage of biodiesel is it tends to oxidize when exposed to air. It is anticipated that the addition of an antioxidant along with graphene nano particle improves combustion of diesel-biodiesel blend. In the present research biodiesel made from the transesterification of waste cooking oil is used. Three synthetic antioxidants butylated hydroxytoluene (BHT), 2(3)-t-butyl-4-hydroxyanisole (BHA) and tert butylhydroquinone (TBHQ) along with 30 ppm of graphene nano particle were added at a volume fraction of 1000 ppm to diesel–biodiesel blends (B20). The performance and emission tests were performed at constant engine speed of 1500 rpm. Because of the inclusion of graphene nano particles, surface area to the volume ratio of the fuel is augmented enhancing the mixing ability and chemical responsiveness of the fuel during burning causing superior performance, combustion and emission aspects of compression ignition engine. The results revealed that there was a slight increase in brake power and brake thermal efficiency of about 0.29%, 0.585%, 0.58% and 6.22%, 3.11%, 3.31% for B20GrBHT1000, B20GrBHA1000 and B20GrTBHQ1000, respectively, compared to B20. Additionally, BSFC, HC and NO_x emissions were reduced to considerable levels for the reformed fuel.

This article is concerned with the study of effect of addition of Carbon Nano Tube (CNT) on the physiochemical properties of Biodiesel and to investigate its effect on the performance and emission of a single cylinder direct injection CI engine. The fuel selected for the present study were Diesel, Biodiesel blends (B20), and CNT blended –biodiesel. The Biodiesel used is Honge Oil Methyl Ester (HOME). Biodiesel Blends were prepared by adding 80% Diesel and 20% Biodiesel by volume with the help of mechanical homogenizer. CNT blended Biodiesel contains 50 ppm of CNT in one liter of biodiesel blends. The experimental studies were carried out in a single cylinder 4 stroke direct injection CI engine connected to an eddy current dynamometer with computerized test rig facility to measure the performance and emission. The experimentations were carried at a constant speed of 1500 rpm and varying the load on the engine. The results shows that increase in the Brake thermal efficiency with the inclusion of CNT to Biodiesel. The brake thermal efficiency of CNT added Biodiesel fuels were 2.24% better as compared to that of Biodiesel without the addition of nano particle at full load calculation. Also the reformulated fuel (Inclusion of CNT's in the Biodiesel blends) shows considerable reduction in the pollutant emission.