Aftermarket exhaust gas emissions analysis of a direct injection CNG-Diesel dual fuel engine

In the present paper an experimental research was carried out on a laboratory two cylinder, four-stroke, direct injection diesel engine, designed mainly to run on diesel fuel and converted with minor modifications to run on CNG-Diesel dual fuel mode. The aim is to analyze the emission characteristics of pure diesel first and then CNG-Diesel dual fuel mode. The measurements were recorded at CNG substitution rates of 10%, 20% and 30% and varying the load from 1.5 to rated load of 9kW in steps of 1.5. The results reveal that, there is drastic reduction in CO, CO2, HC, NO and smoke in the exhaust of dual fuel engine at all loads and for 10%, 20% and 30% CNG substitution rates. From the positive results obtained in this experimental research, it can be concluded that it is a promising technology for achieving controlling on emissions in conventional compression ignition engines with minor engine modifications, thus great saving the human and plant life from the hazardous effects of exhaust gas pollutants from the conventional diesel engines.