Properties of PM and gaseous products generated by low-power domestic boiler after wood combustion and removed by electrostatic precipitator

In this paper, the elemental composition and morphology of fly ash particles after wood pellets combustion in low-power domestic boiler and removed by electrostatic precipitator were investigated by EDS, XRD and SEM methods. The gaseous products discharged into the atmosphere were identified by the FTIR method. Because fly ash particles are usually exhausted to the atmosphere, new constructions of small electrostatics precipitators for domestic use were proposed in recent years in the literature, for the collection of fly ash particles emitted by such boilers fired by biomass fuel (wood pellets) or by coal. The goal of this study was to characterize the combustion products retained at various places from boiler to stack, i.e., beneath the grating (as bottom ash), on heat exchanger, inner walls of stack, and the collection electrodes of electrostatic precipitator. It was shown that the precipitated biomass fly ash comprises of large irregular particles, which were the agglomerates of primary nanoparticles or unburned fragments of fuel (biomass pieces). These particles were composed mainly of K, Cl, Ca, C, O, P and S (>1 at.%).