Physical and combustion characteristics of rice bran oil biodiesel in an oil burner

Abstract

The concept of biodiesel as an alternative fuel is not an overnight thought, but high prices, pungent gas emissions and non-ecological behaviour of fossil fuels has constrained the researchers to take the step. Biodiesels which are renewable in nature and having environmental friendly attitude have shown the potential to be the perfect replacement for the diesel fuels. Similarly, this study demonstrates the characteristics of Rice Bran Oil (RBO) which can be used as a latent substitute for diesel products. RBO is the vegetable oil, which is extracted from the rice bran (by-product of rice grain). As the rice is the steeple diet for more than half of the population of the world, the quantity of RBO that can be extracted is enormous. In this study, RBO is converted to the biodiesel first and then it is blended with diesel to produce B5, B15 and B25 to study the physio-chemical properties and exhaust emissions. Conversion of RBO into biodiesel is compared by altering the amount of different catalysts i.e. KOH and NaOH. At catalyst amount of 1% (w/w to crude RBO), KOH converts 5.55% more RBOBD than NaOH thus keeping other parameters i.e. methanol amount, reaction time and reaction temperature constant. Owing to highly packed molecules of RBOBD, the properties such as density, specific gravity, viscosity and surface tension are higher in RBOBD blends than diesel. In contrast, calorific value is lower. In combustion test, the highest wall temperature is achieved at stoichiometric fuel mixture, while among the fuels, the wall temperature gets lower as biodiesel proportion increases in diesel. Moreover, in B25, emissions such as CO and SO2 are 68% and 50% lower than diesel respectively. However, due to the additional oxygen present in the biodiesel structure, NOx emission of B25 is 15.668% higher than CDF.