Pollutant concentrations from two-stage thermal conversion of pine wood logs in a 25 kW boiler with fixed air supply

A study and further analysis of the two-stage process of burning pine wood logs (gasification and wood gas combustion) in a 25 kW heating boiler were performed. The air stream for combustion was set manually and was constant throughout the given test run. The values of the carbon monoxide, hydrocarbons and nitric oxide in the flue gas were measured. The correlation between the concentration level of these pollutants and the temperature in the wood gas firing nozzle was established, as well as the link between the nitric oxide and carbon monoxide concentrations and the influence of the oxygen concentration in the combustion air on the carbon monoxide emission