Insights into the Effects of Atmosphere and Chlorine on Potassium Release during Biomass Combustion: Temporal Measurement and Kinetic Studies

Abstract

The effect of atmosphere and chlorine on potassium release under air and oxy-fuel combustion conditions of biomass in a fluidized bed was investigated using a temporal measurement system. The results showed that the release proportion of potassium in air atmosphere was bigger than oxy-fuel environment at the temperatures below 900 °C. The overall activation energy for potassium release under air atmosphere is less than that under oxy-fuel atmosphere. The influence of chlorine on potassium release behavior also revealed an obvious difference in the two kinds of combustion environments. In general, the enhancement degree of chlorine to potassium release under air atmosphere was higher than the case under oxy-fuel atmosphere, probably caused by variations produced in chlorine species by massive CO2 under oxy-fuel atmosphere. Thermodynamic analysis was performed to determine final potassium species in air and oxy-fuel environment. The impact of mass CO2 under oxy-fuel condition on release mechanism of potassi...