Performance and emission of swirl burner with different swirl numbers using palm, coconut and jatropha oil biodiesel

Abstract

Biodiesel is used as an alternative invaluable fuel in reducing the effect of global warming, greenhouse-gas emissions, and severe climate changes. It is also considered as promising global green energy that can replace fossil fuel, which causes severe pollution to the environment. Biodiesel blend fuel can mitigate pollution towards greener emission in many heavy combustion industries, however, the appropriate axial swirler in burner needs to be identified. The aim of this research is to determine the most suitable percentages of biodiesel fuel blends to be combined with the swirler vane angle in the liquid fuel burner. Therefore, experimental works were conducted in this study by using swirl burner. Three different biodiesel fuel feedstocks of palm, coconut, and jatropha oils were chosen and produced through the transesterification method according to ASTM and EN Standards. The isothermal studies were also conducted via Computational Fluid Dynamics analysis to examine the characteristics of swirl number of axial swirler used in the burner. Experimental results showed that high swirl number yielded the highest center toroidal recirculation zone which could help air and fuel mixing prior to ignition and leads to complete combustion. This test also indicated that, a high swirl number reduces carbon monoxide, sulfur dioxide and unburned hydrocarbon emissions for diesel and jatropha oil biodiesel (JOB) fuels significantly. The different types of neat biodiesel fuel and their blends; B10, B15, B20, and B25 were tested and compared with diesel fuel performances in terms of lean, stoichiometric, and rich mixtures. The biodiesel fuel blends also exhibited better emissions of nitrogen oxides, carbon monoxide, sulfur dioxide and unburned hydrocarbon with high SN effect in certain mixtures depending on the types of biodiesel feedstock and blend percentage. In overall, JOB also produced better carbon monoxide emissions in any blend percentages with a maximum reduction of 60% with JOB B25. Meanwhile, COB B25 and COB B10 blends were found able to reduce sulfur dioxide and unburned hydrocarbon emissions by 35% and 33%, respectively, relative to diesel fuel. JOB B25 is the most appropriate biodiesel blend because it is a type of non-edible oil and does not compete with human food consumption. In conclusion, biodiesel fuel blends with high SN is a viable alternative for swirl burner applications that effectively reduce greenhouse gases, adverse climate changes and more greener environmental.