Flame temperature analysis of biodiesel blends and components

Abstract

Providing sustainable energy demand with minimum environmental impact is a major area of concern in energy sector. Alternative fuels such as biodiesel, ethanol etc. have been quite promising in both aspects. Biodiesel reduces emissions significantly with an exception on oxides of nitrogen (NOx). The propensity for the production of NOx emissions while using biodiesel is an important problem that requires extensive research. NOx emission from a direct-injection diesel engine is mainly due to formation of thermal NO that is described by Zeldovich mechanism. Thus, studying temperature profile during biodiesel combustion can provide useful insight into the formation and destruction of NOx. The main objective of this work is to investigate the effect of blending biodiesel with diesel, ethanol and methyl acetate. This objective is achieved by obtaining thermocouple measurements and thermal infrared imaging of local flame temperatures of wick-generated open air flames. A relationship between blend proportion and relative flame temperatures was obtained. In addition, separate analysis of relative flame temperatures of different components of biodiesel was performed. In general, it was found that blending ethanol and methyl acetate tends to increase the flame temperature in comparison with straight diesel. It was also found that the saturated methyl esters result in greater flame temperatures in compare to unsaturated methyl esters.