Particle mass and gaseous emissions from small scale modern wood stoves

Abstract

The objectives of the paper were to evaluate particle mass concentrations of PM1 (size <1 µm) and PM2.5 (size <2.5 µm), mass size distributions and CO emissions under standard laboratory conditions obtained from two commercially available modern residential wood stoves with capacity 10 kW and 20 kW. Four combustion batches with minor modification of primary air flows into the combustion chamber for each stove were conducted to evaluate the emission results. Particle mass concentrations and size distributions were measured in real time using an Electrical Low Pressure Impactor Plus (ELPI+) instrument, which measures particles with a fast response time in a wide particle size range from 6 nm to 10 µm aerodynamic diameter. Gaseous concentrations of O2 and CO2 were measured continuously using a Horiba PG-250 analyzer and CO emissions were measured using a Siemens Ultramat 6 gas analyzer. The measurement protocols of each combustion test were conducted according to the European standard EN 13229. The combustion experiments were conducted in a laboratory of a stove manufacturing plant in Belgium. The results showed that PM1 and PM2.5 concentrations of all the batches of both stoves varied from 116 to 327 mg/Nm3 and 139 to 413 mg/Nm3, respectively in the combustion cycle. Particle mass size distribution for all batches from both stoves is very similar showing a maximum in the fine mode at a particle size of around 330 nm to 500 nm. The CO emissions from all the batches varied from 447 to 1184 mg/Nm3 for the 10 kW stove and 958 to 1545 mg/Nm3 for the 20 kW stove. The experimental results of PM1, PM2.5 concentrations and CO emissions from combustion measurements could be useful for the improvement of the combustion process as well as the reduction of gaseous and particle mass emissions from these residential biomass combustion appliances.