Dual fuel soy biodiesel and natural gas swirl combustion for toxic emissions reduction

Abstract

The dual fuel swirl combustion of soy biodiesel and natural gas was investigated using a generic gas turbine combustor. Liquid fuel spray was generated using air-assisted atomiser with air-to-liquid ratio 2.50. An axial swirler with a vane angle of 45° was utilised to produce the swirling air flow at burner outlet. Liquid fuel spray was then blended with swirling air to form a flammable mixture and setup the flame. The flame colour of soy biodiesel/natural gas was mostly blue, similar to pure biodiesel. When compared to diesel, biodiesel/natural gas combustion reduced nitric oxide emissions by a factor of averaging 3. Empirical model for estimating NO emission was also proposed. Predicted results were closed to experimental data, denoted by R2 greater than 0.95. This study demonstrates that biodiesel/natural gas combustion with a 20–30% natural gas input power fraction is a promising way to reduce toxic emission, offering a tactical approach to minimise hazardous emissions from neat biodiesel swirl combustion.