Study On Catalyst Loading Process And Performance Of Polyphenylene Sulfide Needled Filter Felt Based On SCR Technology

With the rapid development of modern industry and the large-scale use of fossil fuels,humans emit large amounts of dust and nitrogen oxides into the atmosphere each year,leading to haze and severe air pollution.Due to the high filtration efficiency,more and more heavy industries use bag filter dust removal devices.The dedusted tail gas enters the denitrification(nitrogen oxide)process,and the selective reduction method(SCR)is widely used due to its low operating cost and high denitrification efficiency.The commonly used denitration catalysts are oxides of manganese(Mn)and cerium(Ce).This project has developed two routes to load Mn and Ce oxides onto a PPS fiber mat to achieve a dust/denitrification integrated removal process for high temperature dust.First,the impregnation method,the commonly used catalyst active components-Mn,Ce oxides attached to the carrier polyphenylene sulfide(PPS)fiber mat;Second,the catalyst in situ by the redox reaction in situ deposition method attached to the manganese dioxide On the PPS fiber mat,the optimum load process for two catalyst loads was tentatively explored.The Mn and Ce oxides of the metal catalysts are loaded on the PPS high-temperature needle felt using the impregnation loading process.Single factor tests are performed on the conditions affecting the loading rate to determine the factors and levels of the orthogonal test.The experimental load rate and filtration efficiency were the evaluation indexes.The final optimized schemes were: Ce molar concentration 0.07 mol/L,Mn/Ce molar ratio 6:1,sodium alginate mass fraction 0.8%,and immersion time 60 min,rolling margin 150%.The manganese dioxide catalyst was loaded onto the PPS heat-resistant needle felt by an in-situ deposition method.First,the appropriate orthogonal test level was selected by controlling the molar concentration of potassium permanganate and the dropping rate of the manganese nitrate solution.Then the orthogonal test load rate and filtration efficiency were used as evaluation indicators.The final optimized in-situ deposition method loading conditions were as follows: the molar concentration of potassium permanganate was 0.30 mol/L,and the reaction time was 0.3 ml/liter.Min(Note: 1 drop is about 0.05 ml).The physical properties of PPS needled felts loaded with catalysts by impregnation and in-situ deposition methods were characterized by PSM 165 pore size analysis and SEM testing.The results show that the average pore size of the loaded needle felt is smaller than that of the PPS needle punch felt;the catalyst adheres to the surface of the needle felt fiber.Through the physical performance test and filtration performance test of the PPS needle felts after impregnation and in-situ deposition,the experimental results of the two different catalysts developed in this paper were found to be the same for the PPS high temperature resistant needle felts.The physical and mechanical properties have a slight influence,but there is basically no effect on the filtration performance.Compared with the two loading methods,the in-situ deposition method provided better catalyst distribution uniformity.