Specifics of Electrostatic Precipitation of Fly Ash from Small-Scale Fossil Fuel Combustion

• Published in: Processes Vol. 11; no. 3; p. 808
• Main Authors: Molchanov, Oleksandr, Krpec, Kamil, Horák, Jiří, Ochodek, Tadeaš, Dej, Milan, Kubonová, Lenka, Hopan, František, Ryšavý, Jiří
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.03.2023
• Subjects: Aerosols; Air pollution; Air quality management; Back corona; Boilers; Coal-fired power plants; Combustion; Design; Efficiency; Electric currents; Electric field strength; Electric fields; Electrodes; Electrostatic precipitation; Electrostatic precipitators; Emissions; Emissions control; Energy minerals; Equipment and supplies; Fly ash; Fossil fuels; Fuel combustion; Gas flow; Gases; Heating; Industrial plant emissions; Lignite; Nucleation; Outdoor air quality; Parameters; Particle size; Particulate emissions; Particulate matter; Precipitators; Product design; Smog; Sulfuric acid; Massachusetts
• ISSN: 2227-9717; 2227-9717
• DOI: 10.3390/pr11030808

This paper investigates the removal efficiency of a honeycomb electrostatic precipitator (ESP) applied to control particulate matter (PM) emissions from a small-scale boiler with combustion lignite and hard coal. The specifics of the precipitation of emissions from small-scale boilers are discussed, and the design principles for relevant ESPs are presented and used. The ion-induced nucleation of sulfuric acid occurred, causing the drastic penetration of 19 nm particles through the ESP. Despite this, the overall collection efficiency was sufficient to meet the EU’s Ecodesign Directive requirements. Back corona was not detected. The optimal ESP performance is defined with further parameters: a current density of 0.5 mA/m2 at an electric field strength of about 2.7 × 105 V/m; a minimal specific collecting area of ESP (SCA) of 60 m2/(m3/s); and Nt-product of 4.5 × 1014 s/m3. Such parameters of ESPs should ensure adequate PM emissions control for any type of boiler with similar emissions characteristics. The composition of collected fly ash particles was analysed, and a method for fly ash utilisation was proposed. This research may be helpful for designing ESPs to control PM emissions for small-scale units with fossil fuel combustion.