Integration of dedusting and denitration in V2O5-WO3/TiO2/PTFE-based catalytic bag-filter materials: Lab- and pilot-scale testing and development of SCR models

Abstract

Removal of dust and NOx from flue gas is highly significant for air pollution control, and integration of these two functions in one unit can greatly improve process efficiency. In this study, a functional catalytic bag-filter material (CBFM) was fabricated from commercial PTFE felt and cheap catalyst V2O5-WO3/TiO2 via a simple immersion-fixation procedure. The attachment of catalysts on PTFE was confirmed, and the material properties of CBFM of various loadings were determined. Their denitration and dedusting performances were investigated individually in lab-scale experiments. Compared to the original PTFE, CBFMs exhibited superior denitration activities, which were positively correlated with temperature (60–90% under 150–210 °C) and negatively correlated with filtration velocity (50–90% under 0.5–0.9 m min−1). On the other hand, introduction of catalysts in PTFE felt did not compromise its filtration efficiency, and almost complete dust removal was achieved. A simplified kinetic model was developed based on Eley-Rideal mechanism, to correlate the materials' denitration efficiency with various operational conditions. The model's accuracy was verified in both lab and pilot environments, where real flue gas from a waste incineration plant was treated with a scaled-up CBFM. In a six-day continuous test, the CBFM maintained >70% NO removal and >99.8% dust removal, confirming its stability and applicability in industrial settings. Therefore, this study offers a low-cost and functional bi-functional filter material capable of efficient simultaneous dedusting/denitration, as well as a simple and practical procedure for its manufacture. In addition, the kinetic model could be applied to speed up production and process optimization, and direct future application of similar materials in real environments.