Mixture Temperature-Controlled combustion of different biodiesels and conventional fuels

Abstract

Mixture Temperature-Controlled combustion is a novel concept featuring ultra-low pollutant emission. Since the resulting distributed combustion is highly homogeneous, NOX emission can be kept below 10 ppm. The available renewable fuels worldwide vary a lot in their characteristics. Three renewable hydrocarbon fuels: coconut oil, palm oil, and waste cooking oil-rapeseed oil methyl esters were tested along with three conventional fuels: standard jet fuel (JP-8), standard diesel oil, and natural gas. The ultimate goal of the present study was the comparison of the flame structures, chemiluminescent, and pollutant emissions of various fuels, exploiting distributed combustion offered by the novel burner concept. As mixture preparation is highly sensitive to fuel vaporization, distillation curves of the five investigated liquid fuels were measured and evaluated. Density, surface tension, and viscosity were also measured to compare the estimated atomization characteristics. The tests were uniformly performed at 13.3 kW thermal power and an equivalence ratio of 0.8, varying atomizing pressure and air preheating temperature. It was found that jet fuel, diesel fuel, and coconut biodiesel bear the highest potential for distributed combustion in gas turbines, while incorrect burner setup may lead to unacceptably high emissions.