Emission of fine particles from residential combustion of wood: Comparison of automatic boiler, manual log feed stove and thermo-gravimetric analysis

Abstract

The emission of fine particles (FP) generated by biomass combustion poses a substantial health risk. The immediate emissions from biomass boilers are mainly influenced by the operating parameters. The authors of this article present the results of an experimental identification of the real FP emissions from small biomass boilers and residential stoves in Central Europe. A single method was used in the study to measure the FP emissions from an automatic boiler burning spruce pellets and from a manual stove burning beech logs. The measurement is extended by a thermo-gravimetric analysis of samples of the fuels used, supplemented with an analysis of the emitted particles. The boilers were tested in an operating cycle that included the phases of fuel ignition, steady combustion, and afterburning. The paper presents the concentrations and size distributions observed of the emitted FP ranging from 17 to 544 nm in size. Operating cycles including a “cold start” and “warm start” are compared. The results achieved are summarized by the expression of the nominal FP emission presenting the number and mass emission corresponding to burning 1 kg of fuel. The tested automatic boiler fed by spruce pellets produced a nominal FP emission of 173 mg kg−1 in the size range of 17–544 nm during the testing operation cycle. The tested manual stove, fed by beech logs, produced a nominal emission of 1043 mg kg−1 in the same size range of particles during the similar testing cycle.