- An experimental study comparing air and oxy-fuel combustion

It is well known that combustion of biomass derived fuels may lead to problems with high-temperature corrosion (HTC). The HTC process is largely based on the release and transformation of chlorine, sulphur and alkali components during the combustion process. However, these components may also interact with other critical parts of the combustion chemistry and the present work focuses on how potassium chloride and sulphur dioxide influence the oxidation of carbon monoxide. This is investigated during combustion of propane (80 kW) applying both air and oxy-fuel combustion conditions. The experiments were carried out in Chalmers 100 kW oxy-fuel test facility in which sulphur dioxide and potassium chloride was added to the flame. The experimental results are also supported by modelling work including a detailed reaction mechanism of the related alkali-S-Cl chemistry. The results show that KCl promotes CO-oxidation in oxy-fuel combustion. However, for the experimental conditions tested in the present work, no significant effect was detected in air combustion. In addition, when adding water as well as SO2 to the flames, there were no significant effects on the measured CO concentrations in the respective flames