Investigations on the Influence of Catalyst Geometry on Emission Reduction in Small‐Scale Combustion System

Abstract

Legal regulations for exhaust gas treatment in small‐scale combustion systems demand both emission and dust reduction. Simultaneously removing both pollutants using catalysts presents a significant challenge due to constraints on the very low allowed pressure drop over the catalyst. It can be demonstrated that the total oxidation of CO, as one of the main pollutants in the combustion of biogenic materials, in small‐scale combustion systems can be quantitatively achieved using precious metal‐based catalysts based on Pt/CeO2/TiO2. The highest CO conversion rate can be observed with a 233 cpsi honeycomb catalyst, whereas the foam ceramic catalysts with 30, 20, and 10 ppi show progressively decreasing activity. However, concerning dust reduction, it can be demonstrated that the ceramic foam with 10 ppi is superior, as evidenced in real‐world experiments conducted on an Leda Novia W small‐scale combustion device with 8 kW combustion capacity. Particle deposition on the catalysts is observed with all catalysts, whereby catalysts with small pores show rapid pore blockage. It is observed that only with the 10 ppi foam catalyst, dust deposition does not lead to pore blockage, allowing a reduction in dust of more than 50% over the measurement cycle.