Investigation of low heat rejection diesel engine run on N,N'-diphenyl-p-phenylenediamine antioxidant doped Jatropha methyl ester-diesel blend

Low heat rejection (LHR) diesel engines help increase engine performance and reduce engine emissions, but they increase air-polluting nitrogen oxide (NOx) emissions. Different types of antioxidants or additives can be added to fuels to reduce NOx emissions and improve engine performance. In this investigation, N,N'-diphenyl-p-phenylenediamine (DPPD) is used as an antioxidant. Different concentrations of DPPD namely, 500, 1000, 1500, and 2000 ppm are mixed with Jatropha Methyl Ester (JME)-diesel blend (JME20), and the fuels are tested in an engine fitted with a TBC piston. The piston crown is coated using a mixture of Yttria-stabilized zirconia (YSZ) and cerium oxide (CeO2) with a coating thickness of 0.3 mm. The novelty of this research work is the comprehensive assessment of the engine characteristics of an LHR diesel engine run on a synthetic antioxidant doped biodiesel-diesel blend. Results indicate that the peak heat release rate (HRR) and the peak cylinder pressure are lesser by about 5.6% and 5.1% for JME20B(4), respectively, at maximum engine load, in the coated engine (CE). The nitric oxide (NO), hydrocarbon (HC), and carbon monoxide (CO) emissions are reduced by about 6.5%, 17.4%, and 34.6%, respectively, at full load for the JME20B4 fueled LHR diesel engine. Smoke opacity decreases up to 15.3% in the coated diesel engine fueled with JME20B4 at full load.

Automated summary

In this study, the engine characteristics of an LHR diesel engine running on a synthetic antioxidant doped biodiesel-diesel blend were comprehensively assessed. The results showed that the coated engine had lower peak heat release rate and peak cylinder pressure, as well as reduced NO, HC, CO emissions and smoke opacity.