Thermal and chemical degradation behavior of a catalytic ceramic filter for dust/NOx removal

Abstract

The thermal and the chemical degradation characteristics of a catalytic ceramic filter were investigated using various stresses. The stress factors with modes and levels were designed in consideration of the pseudo-real environmental conditions for hot gas cleaning. The apparent porosity and the compressive strength of the filters, which were prepared using cordierite powder and coated with V2O5 catalyst were 58% and 10 MPa, respectively. The failure mechanism of the ceramic filter was cracking due to thermal shock. The crack formation gave an increase in baseline differential pressure by the depth filtration of dust. With thermal stress tests of catalytic filters, the peak intensity for active sites of the V2O5 catalyst was decreased due to the weak bond strength of the V = 0 double bond against the thermal stress. Moreover the degradation of the catalyst was accelerated by sulfur adsorption during thermal durability tests.