Performance analysis of different scrubber systems for removal of particulate emissions from a small size biomass boiler

Biomass boiler plants of small thermal power (under 35 kW thermal), in particular for domestic heating, have greatly contributed to the rise in particulate emissions. Several technologies, like fabric filters or electrostatic precipitators, can achieve high particulate removal efficiency, over 99%. However, the application of these technologies is limited by excessive prices and operational problems, since the high cost does not allow their use in small size plants. The paper shows a comparative performance analysis of different scrubber systems which have been designed, realized and tested with flue gas produced by biomass combustion in a 25 kW thermal boiler. The experimental campaigns were realized in the laboratory of the Department of Industrial Engineering of the University of Bologna. Experimental results demonstrate the achievements of particulate removal efficiency which is comparable with the efficiency of industrial technologies. Moreover, a preliminary energy balance was carried out to assess the energy cost of the different scrubber systems tested.