**2.5 Role of selected oxygen enriched additive in the emulsified fuel**

Cherng – Yuan Lin and Kuo-Hua Wang, (2004) have given their report on the effects of an oxygenated additive in the emulsion field. Emulsified fuel characteristics have also been discussed, after adding the additives. They have shown the oxygenated additive to the diesel fuel which improves the combustion characteristics of the diesel engines. For the purposes of comparison, the emulsification characteristics of the two phases of emulsified fuels with additive have been analyzed. The chemical structures, HLB values and specific gravity of the surfactants Span-80 and Tween-80, have been given in detail. Also, they have stated that the efficiency and combustion properties of the CI engine have been improved by adding oxygenated additives in the emulsified fuel.

Mark.P.B.Musculus and Jef Dietz, (2005) have stated the effects of additives in the emulsion field on in-cylinder soot formation in a heavy duty DI diesel engine. Report states that the additives could potentially reduce in–cylinder soot formation by altering combustion chemistry. Chemical and physical mechanisms of the additives may affect soot formation in diesel engines. From the investigation, they have concluded that the effect of ignition delay on the soot formation and ethanol containing fuels display a potential for reduction of in – cylinder soot emission.

## **2.6 Role of best selected additive in the emulsified fuel (performance and emission)**

M.P.Ashok., et., al., (2007) have studied about identifying an alternate fuel, for the current existing engines without any modification, with better performance and less emission. Emulsion technique is the best method to solve the above mentioned problems. Emulsified fuel with a surfactant is familiar nowadays. Addition of oxygen enriched additives in the emulsified fuels gives good results than the previous one. Usually NOx emission is high for the emulsified fuels, when compared with diesel fuel. But additive added emulsified fuels emit less NOx than diesel. Based on this, the present work has been carried out using oxygen enriched additives: Diethyl Ether (DEE), Hydrogen Peroxide (H2O2) and Dimethyl Ether (DME). The W/O type emulsion method is used to prepare the emulsified fuel. The test results have shown that DME has given the best performance and less emission, with the selected emulsified fuel ratio of 50D: 50E, comparing with the other two additives.
