Preparation Methods Investigation Of Polyphenylene Sulfide Composite Filter Materials

PM2.5 and PM10 particulate pollutants emitted from stationary sources will cause numerous environmental problems.Bag filter has many advantages,such as high dust removal efficiency.、stable performance and suitable for acid and alkali,so it is widely used in flue gas dust control.Polyphenylene sulfide(PPS)has been selected as the first choice material for bag filter because of its excellent thermal stability and chemical and physical properties.There are still NO:(x=1,2)pollutants in the stationary sour.If the catalyst with SCR activity can be loaded to the surface of the bag filter,the integration of dedusting and denitrification can be realized,the purification system of tail gas is simplified and the cost of treatment can be saved.But there are two problems at present.The first is that the use temperature of PPS is below 190 C,and the preparation temperature window of the catalyst is generally 300 C to 400 C;second is the current commonly used load methods such as ultrasonic、impregnation and vacuum method.These load methods inevitably result in the poor bonding strength of the catalyst with the fiber,it will clog the hole in the fiber.Therefore,developing the preparation technology that combines excellent denitrification catalyst and filter material has become the focus of this research.Hydrothermal method can control the degree of crystallization of the catalyst by controlling the temperature and time of the hydrothermal reaction,and because of the high temperature and pressure of the hydrothermal method,the catalyst can get more pressure than the other physical methods between the catalyst and the PPS.Therefore,two element Mn-MoOx/PPS(H)composite filter material was prepared by high temperature and high pressure hydrothermal method and two element Mn-MoOx/PPS(U)composite filter material was prepared by traditional ultrasonic load method.The results of characterization analysis show that the composite filter prepared by hydrothermal method has the best reaction temperature of 160 C,and the reaction time is 12h,the NO conversions could reach 81.5%when the temperature is 180 C,and the NO conversions is obviously better than that of the traditional ultrasonic method,and the tensile,bonding strength and the stability of the catalyst have been better improved.Using the mechanism of related redox reaction,three kinds of different catalyst components were grown on the surface of PPS fiber in situ,and Mn-CeOx/PPS,Mn-SnOx/PPS and Mn-Ce-SnOx/PPS composite filter materials were prepared.The results show that the best deactivation activity of the three different composite filters at the mass ratio of KMnO4/PPS is 0.6,and the denitrification activity reach 100%at the temperature of 180°C,and it is worth mentioning that the denitrification rate is up to 100%when the Mn-Ce-SnOx/PPS composite filter is 120℃.And Mn-Ce-SnOx/PPS FESEM shows that the Mn-Ce-SnOx component of the composite filter is composed of three-dimensional network structure on the surface of PPS,so its bonding strength,denitrification activity and air permeability are better than Mn-CeOx/PPS and Mn-SnOx/PPS composite filter material.Polyacrylamide(AM)was grafted on the surface of activated PPS filter by grafting copolymerization reaction mechanism.Package has the denitration activity MnO2 at the same time,and MnO2/PAM@PPS composite filter material was prepared.The results show that the denitrification activity of the composite filter is best when the mass ratio of AM/PPS is 3,but the NO conversions at 180℃ is only 60.5%.FESEM shows that only part of the surface of PPS filter material graft copolymerization of AM and encapsulates manganese dioxide,which is related to the incomplete surface activation of PPS and the agglomeration of PAM.