中国有色冶金

The emission levels of dust, nitrogen oxides (NO_x), and dioxins serve as critical indicators for evaluating flue gas purification efficiency in waste incineration power generation. By integrating the capabilities of a deNO_x catalyst and a dust collector, the pursuit of a multifunctional material that can simultaneously and efficiently eliminate dust, NOx, and dioxins can significantly streamline the flue gas purification process. Drawing upon the concept of composite structures, a novel composite functional filter material was developed, combining a VMo/CeTi-based low-temperature deNOx catalyst with a PTFE filter cloth. This study investigated the impact of the composite structure on the catalytic performance of low-temperature NH₃-SCR, the degradation of dioxin model compounds such as furan and 1,2-dichlorobenzene, and the efficiency of dust removal. Particular attention was given to the material's stability in the presence of moisture and sulfur compounds. The findings reveal that the composite functional filter material exhibits excellent performance in low-temperature NH₃-SCR and the degradation of dioxin model compounds, along with a strong tolerance to water vapor and SO₂. Upon conducting a series of characterization analyses, it was determined that the catalyst supported on the functional filter material with a composite structure exhibited excellent stability. The catalysts shedding rate was merely 0.2% following 500 injections, indicating a robust adherence to the substrate. Additionally, the catalyst powder was uniformly distributed, facilitating the exposure of more active sites. Consequently, the catalyst maintained its deNO_x performance and the degradation of dioxin model compounds. Simultaneously, the electron transfer, consumption, and regeneration of hydroxyl radical structures, along with the water generation resulting from the valence state cycling of active components during NH₃-SCR reactions, were found to enhance the hydrolysis and ring-opening of dioxin model compounds. This, in turn, achieved a synergistic elimination of NO_x and dioxins.The flexible PTFE filter cloth (PTFE fiber) matrix offers superior dispersion for catalyst powder while also leveraging its surface hydrophobicity to minimize the impact of water vapor on the catalyst. This reduction in turn decreases the production of toxic sulfites (sulfates), enhancing the water resistance of the composite structure functional filter media and extending the lifespan of the materials. Furthermore, experiments on SO₂ tolerance have demonstrated that the incorporation of Ce additives can effectively suppress the formation of nitrates and ammonium sulfates, exhibiting a high level of SO₂ tolerance. Hence, the development of advanced composite functional filter materials capable of removing dust, nitrates, and pollutants is crucial for advancing the market adoption of short-process flue gas purification technology.