**2.3 Use of surfactant to prepare the emulsified fuel**

Santhanalakshmi.J and Maya.S.I, (1997), state about Span-80 and Tween-80 as the two non ionic surfactants, which could be used for preparing the emulsified fuel. Micellisation of surfactants in solvents of low dielectric constant differs from those in aqueous media due to the differences in the solute-solute, solute-solvent and solvent-solvent interactions. They have also explained about the solvent effects of the non ionic surfactants. They have stated that surfactants in non aqueous and non polar solution form reverse in order the micelles with hydrophilic core.

### **2.4 Selection of best emulsified fuel ratio**

M.P.Ashok., et al., (2007) have conducted a research to identify the best ratio from the emulsified fuel ratios and compare with diesel fuel, based on its performance and emission characteristics. Water–in–Oil type emulsion method has been implemented to produce the

Role of Emulsified Fuel in the Present IC Engines –

Need of Alodine EC Ethanol Corrosion Resistant Coating for Fuel Injection System 11

the best result based on the performance and less emission than the other fuel ratios. By keeping the selected fuel 50D: 50E, the same performance and emission tests are conducted by varying their injection angles at 18º, 20º, 23º and 24º. The outcome shows better performance and less emission by the fuel 50D: 50E at 24º Injection Angle (IA). Further, ignition delay, maximum heat release and peak combustion pressure tests have been conducted. These results show that increase in IA decreases the delay period thus increasing the pressure obtained at the maximum output. Also, P-θ diagram is drawn between crank angle and cylinder pressure. The maximum value is attained by the fuel 50D: 50E at 24º IA. All the tests have been conducted by maintaining the engine speed at 1500 rev/min. The result shows that 50D: 50E ratio fuel has been identified as a good emulsified fuel and its better operation is obtained at 24º IA based on its best performance and less emissions.

M.P.Ashok., et. al., (2007) have studied about the best performance and less emission of 50% diesel and 50% ethanol [(50D/50E); 100% proof] emulsified fuel. Oxygen-enriched additive Dimethyl ether has been added to the selected best ratio of 50D: 50E emulsified fuel. Then, the performance and emission tests for diesel, 50D: 50E emulsified fuel ratio and oxygenenriched additive-added emulsified fuel have been conducted. Finally, it has been found that the oxygen-enriched additive-added emulsified fuel has given the best performance and less emission when compared to the other two fuels. In comparison to diesel and the selected best ratio of the emulsified fuels, the oxygen-enriched additive-added emulsified fuel shows an increase in brake thermal efficiency and a decrease in SFC, PM, SD, and NOx. Jae W.Park, et.al, [11] (2000) have done an experimental study on the combustion characteristics of emulsified fuel in a Rapid Compression and Expansion Machine (RCEM). Water–in–Oil emulsion type has been implemented and shows the best performance with respect to the better thermal efficiency. In the emission part, it is observed that NOx and Soot have been decreased. Also, the emulsified fuel has been characterized by a longer

**2.8 Role of emulsified fuel in the CI engine (performance and emission)** 

ignition delay and a lower rate of pressure rise in a premixed combustion.

emulsified fuel.

**2.9 Role of water added emulsified fuel in the CI engine (performance and emission)**  Svend Henningsen, (1994), has investigated that NOx emission has been reduced by adding water to the emulsified fuel. The result shows that NOx is reduced with the addition of water, without deterioration in the SFC and the NOx behaviour is correlated, with the injection intensity as well as the water amount in the fuel. The report explains the result of the parameters such as injection valve opening, closing, duration, combustion starts and ignition delay. The concluding result is that the NOx emission and Specific Fuel Consumption (SFC) have been reduced considerably, because of water added to the

Wagner U., et.al, (2008), have described the possibilities of simultaneous in-cylinder reduction of NOx and soot emissions, for the DI diesel engines. They have stated that diesel engines with direct fuel injection give the highest thermal efficiency. Optimization of the injection process and the addition of water to the emulsified fuel are the two different possibilities for the reduction of NOx and soot emission, which have been discussed. Result of water addition gives increase in the value of thermal efficiency and reduction of NOx and

emulsified fuel. Emulsified fuels have been prepared with different ratios of 50D: 50E (50 Diesel: 50 Ethanol - 100% Proof), 60D: 40E, 70D: 30E, 80D: 20E and 90D: 10E. From the investigation, it is observed that the emulsified fuel ratios have given the best result than diesel fuel. Also, 50D: 50E has given the best performance result than the other emulsified fuel ratios and diesel fuel. It has been observed that there is reduction in Smoke Density (SD), Particulate Matter (PM) and Exhaust Gas Temperature (EGT) with an increase of Oxides of Nitrogen (NOx) and Brake Thermal Efficiency.
