Fine particle generation, evolution and control by small biomass combustion.

Purpose – The aim of the paper is to present the results of investigations of fine particle generation by small biomass combustion and the possibility of reducing the emissions by electrostatic precipitation. Design/methodology/approach – The grains, wood-logs, wood-, mixed- and straw-pellets were combusted in two stoves and two boilers. The set-ups were operated according to DIN-4702. Particle number concentration in the gas flow was measured by Scanning Mobility Particle Sizer and particle mass concentration was measured according to the Guidelines VDI-2066 upstream and downstream a novel space charge electrostatic precipitator (ESP). The ESP consists of an ioniser and a grounded brush inside of a tube form grounded collector electrode. Findings – The ESP ensures stable operation at gas temperatures up to 350°C. The use of sharp-points high voltage electrode ensures effective particle charging at high particle number concentrations. The combustion of wood-pellets is characterized by lower particle mass concentrations. The highest particle mass concentrations were observed by the straw-pellets combustion. The ESP ensures particle collection with mass collection efficiency 87±3% for wood-logs and 82±2% for wood-pellets combustion. Practical implications – The novel ESP is recommended for exhaust gas cleaning from small scale biomass combustion facilities and domestic heating units. The use of the ESP would reduce the emissions of fine aerosol into the atmosphere and improve the air quality. Originality/value – The paper presents the comparative analysis of particle size distribution and particle mass concentrations in the exhaust gas from small-scale combustion units for different types of biomass. The study confirms the possibility to reduce particle emissions by electrostatic precipitation. The originality of the technology and apparatus is patently protected. [ABSTRACT FROM AUTHOR]