Release of gas phase potassium during combustion of biomass - experimental and modelling observations

Pulverised fuel furnaces fired with biomass or co-fired with coal and biomass commonly operate at temperatures above 1,600 K. Such temperatures affect the partitioning of inorganic components through phase transformations. In most biomass fuels, potassium is a significant component present as inorganic species or bound to organic molecules. At temperatures approaching 1,600 K KOH and KCl become volatilised and are released to the gas phase. These gases condense out in cooler parts of the furnace and lead to increased corrosive deposits and adhesion of ash. In order to model these processes and predict the likely fate of potassium during the combustion process, it is necessary to understand the release mechanisms and patterns of release.