Combined removal of particulate matter and nitrogen oxides from the exhaust gas of small-scale biomass combustion

Abstract

The utilization of various solid biofuels in combustion plants often requires the application of secondary emission reduction measures in order to meet legal requirements. Since common multi-stage exhaust cleaning methods are too expensive for the application in decentral biomass combustion, new approaches have to be investigated which can be applied economically in small- and medium-sized plants. The combined removal of particulate and gaseous emissions in one unit can save investment and operation costs. In this context, a method for simultaneous reduction of particulate matter (PM) and nitrogen oxides (NOX) was developed and tested. The investigations focused on the alignment of the system components and the determination of optimal operating parameters for use in decentralized biomass furnaces. Experiments with wood chips and different non-woody biomass pellets at a 120-kW pilot plant showed significant reduction of PM and NOX. There is still a need for optimization with regard to the NH3 slip and the degree of particle separation.