EXPERIMENTAL AND ANALYTICAL INVESTIGATION ON THE EMISSION AND COMBUSTION CHARACTERISTICS OF CI ENGINE FUELED WITH TAMANU OIL METHYL ESTERS

The emission and combustion characteristics of a four stroke multi fuel single cylinder variable compression ratio engine fueled with tamanu oil methyl ester and its blends 10%, 20%, 40%, and 60% with diesel (on volume basis) are examined and compared with standard diesel. Biodiesel produced from tamanu oil by trans-esterification process has been used in this study. The experiment has been conducted at a constant engine speed of 1500 rpm with 50% load and at compression ratios of 16:1, 17:1, 18:1, 19:1, and 20:1. With different blend and for selected compression ratio the exhaust gas emissions such as CO, HC, NOx, CO2, and the combustion characteristics are measured. The variation of the emission parameters for different compression ratios and for different blends is given, and optimum compression ratio which gives best performance has been identified. The results indicate higher rate of pressure rise and minimum heat release rate at higher compression ratio for tamanu oil methyl ester when compared with standard diesel. The blend B40 for tamanu oil methyl ester is found to give minimum emission at 50% load. The blend when used as fuel results in reduction of polluting gases like HC, CO, and increase in NOx emissions. The previously mentioned emission parameters have been validated with the aid of artificial neural network. A separate model is developed for emission characteristics in which compression ratio, blend percentage and load percentage were used as the input parameter whereas CO, CO2, HC, and NOx were used as the output parameter. This study shows that there is a good correlation between the artificial neural network predicted values and the experimental data for different emission parameters.