Tests on catalytic wall flow filters for PM abatement from biomass boilers

Wall flow catalytic filters may represent an efficient solution for PM emission control of biomass-fired boilers and stoves, as they combine physical filtration processes with catalytic oxidative reactions. Moreover, such solution may be applied both in new equipment and in retrofit of existing appliances, and may be easily scaled according to the size of the boiler. The presented results were obtained from experimental tests carried out on filters with a silicon carbide matrix loaded with 20%wt of copper ferrite, and they aimed at evaluating the filter performance on fine PM abatement and the regeneration efficacy. The filters were tested in a customised sampling line at the exhaust of a 30 kW pellets boiler, and regeneration was specifically obtained by a high-temperature electrical heater. PM concentration in the flue gas was monitored by means of a real-time continuous detector and a cascade impactor. Tests showed high efficiency, over 90%, in PM reduction, and allowed to investigate in details the dynamics of regeneration and the effect of successive cycles, providing useful information in order to improve the service life and the performance of the catalytic filters. © 2016 ETA-Florence Renewable Energies.