Characteristics of aerosol particles formed during grate combustion of moist forest residue

The characteristics of aerosol particles formed during combustion of moist forest residue were studied as a function of load in a 1 MW moving grate boiler and at almost full load in a similar larger 6 MW boiler. The coarse (1 μm12) were K, S and Cl in the fine mode and Ca, K and S in the coarse mode. The dominant ions in the fine mode were K+, SO42− and CO32−. The fine mode particles had hygroscopic growth factors of around 1.65 at RH=90%, with a deliquescence point at a relative humidity between 30% and 60%. It was assessed that K2CO3 is responsible for the low deliquescence point. Fine mode particles of a given dry diameter had similar chemical composition.