Preparation method of low-sulfur dioxide oxidation rate high-activity honeycomb SCR denitration catalyst

Abstract

The application discloses a preparation method of a low-sulfur-dioxide-oxidation-rate high-activity honeycomb SCR denitration catalyst, and comprises the following steps: S1, preparing materials; S2, adding a tungsten source and a phosphorus source into a mixing machine containing denitration titanium dioxide, uniformly stirring, and obtaining mixed dry powder; S3, adding deionized water, glass fiber, kapok pulp, glycerol and a vanadium source into the mixed dry powder, and uniformly mixing; S4, adding polyvinyl alcohol and carboxypropyl methyl cellulose, stirring, adjusting pH to 8.5, and obtaining a mud; S5, extruding and shaping the mud to obtain a catalyst blank; S6, wrapping the catalyst blank, and placing the catalyst blank in a normal-temperature and sunlight-free environment for more than 48 hours, and then drying; and S7, roasting the dried catalyst blank. The application realizes uniform dispersion of vanadium and modification of the catalyst, so that the SO2 oxidation rate of the catalyst is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of denitration catalysts, in particular to a preparation method of a low-sulfur-dioxide-oxidation-rate high-activity honeycomb SCR denitration catalyst. BACKGROUND

[0002] The selective catalytic reduction (SCR) denitration technology is the most widely used technology in the field of denitration at present, and the SCR denitration catalyst is the core of the technology, and at present, a V2O5-WO3 (MoO3) / TiO2 catalyst is more commonly used in industry, wherein V2O5 is the main active component of the catalyst, and in the denitration process, V2O5 inevitably oxidizes SO2 to generate SO3, and the generated SO3 combines with NH3 to generate ammonium bisulfate, which can easily cause problems such as shortening of the service life of the catalyst, blockage and corrosion of the air preheater and the dust collector, and bag jamming of the bag-type dust collector.

[0003] Therefore, it is urgent to develop a denitration catalyst suitable for high-sulfur coal, low-load operation conditions and low SO2 oxidation rate, so as to reduce the SO2 oxidation rate while ensuring that the nitrogen oxides meet the emission standard, prolong the service life of the catalyst, and slow down the blockage and corrosion of the equipment. SUMMARY

[0004] The application aims to overcome the defects of the prior art, and provides a preparation method of a low-sulfur-dioxide-oxidation-rate high-activity honeycomb SCR denitration catalyst, which reduces the content of the active component vanadium of the catalyst, improves the dispersity of vanadium on the carrier, introduces phosphate to form a VOPO4 structure, occupies the sites of SO2 on V, thereby inhibiting the adsorption of SO2 on the species, combines the two methods to realize the uniform dispersion of vanadium and the modification of the catalyst, and thereby reduces the SO2 oxidation rate of the catalyst.

[0005] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0006] A preparation method of a low-sulfur-dioxide-oxidation-rate high-activity honeycomb SCR denitration catalyst, comprising the following steps:

[0007] S1, raw materials are prepared according to the following weight proportions: 60-70 parts of denitration titanium white powder, 0.3-1 part of a vanadium source, 2-8 parts of a tungsten source, 0.5-2 parts of a phosphorus source, 0.5 part of polyvinyl alcohol, 0.5-1 part of carboxypropyl methyl cellulose, 4 parts of glass fiber, 0.5 part of cotton pulp, 0.2 part of glycerol, and 25-30 parts of deionized water;

[0008] S2, the tungsten source and the phosphorus source are added to a mixer containing the denitration titanium white powder, and are stirred uniformly to obtain mixed dry powder;

[0009] S3, the deionized water, the glass fiber, the cotton pulp, the glycerol and the vanadium source are added to the mixed dry powder prepared in step S2, and are stirred and mixed uniformly;

[0010] S4, adding polyvinyl alcohol and carboxypropyl methyl cellulose, stirring, adjusting pH to 8.5, obtaining a non-granular paste;

[0011] S5, using a vacuum screw extruder to extrude the paste into a catalyst body;

[0012] S6, wrapping the catalyst body and placing it in a normal temperature, non-sunlight irradiation environment for more than 48h, and then drying;

[0013] S7, calcining the dried catalyst body, obtaining a catalyst product.

[0014] The vanadium source is ammonium metavanadate; the tungsten source is ammonium tungstate or ammonium metatungstate; and the phosphorus source is at least one of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate and di-ammonium hydrogen phosphate.

[0015] The stirring speed in step S2 is not more than 25 rad / min, and the stirring time is not less than 20 min.

[0016] The stirring speed in step S3 is not less than 700 rad / min, and the stirring time is not less than 1h.

[0017] In step S6, the drying is performed in a drying oven, the drying temperature is 60-70℃, the humidity is 50-55%, and the drying time is not less than 72h.

[0018] In step S7, the calcination is performed at 550-650℃, and the calcination time is not less than 10h.

[0019] The beneficial effects of the present application are:

[0020] 1. By controlling the content of active component vanadium in the catalyst to be 0.3-1wt%, the dispersibility of vanadium on the carrier is improved, thereby reducing the SO2 oxidation rate of the catalyst.

[0021] 2. The vanadium-titanium-based catalyst is modified by using phosphorus element to form VOPO4 structure, occupying the V site of SO2, thereby inhibiting the adsorption of SO2 on the species, not only improving the denitration performance of the catalyst, but also reducing the SO2 oxidation rate of the catalyst.

[0022] 3. By combining the two means, the denitration activity of the catalyst is improved and the SO2 oxidation rate is reduced, and the denitration efficiency can be as high as 98.5% at 380℃ and 120000h -1 of space velocity, while the SO2 / SO3 conversion rate can be as low as 0.20%. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The structure diagram of the improved mixer of the present application;

[0024] Figure 2 for Figure 1 enlarged view of A in the middle;

[0025] Figure 3 perspective view of the improved pusher in the mixer of the present application;

[0026] Figure 4 structural view of the connection between the stirring paddle and the pusher in the improved mixer of the present application;

[0027] Figure 5 structural view of the mixer after the scraper moves outward and the stirring paddle moves downward.

[0028] In the figure: kettle body 1, side kettle part 11, bottom kettle part 12, shaft cylinder 2, screw rod 21, guide rod 22, pusher 3, pusher plate part 31, connecting plate part 32, sliding groove 33, main sliding groove 331, side sliding groove 332, screwing part 34, stirring paddle 4, shaft part 41, stirring part 42, stirring rod 421, stirring blade 43, pin shaft 44, scraper 5, straight rod part 51, inclined rod part 52, partition plate 6, first motor 7, second motor 8. DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with the drawings and specific embodiments:

[0030] The preparation method of the low-sulfur-dioxide oxidation rate high-activity honeycomb SCR denitration catalyst of the present application comprises the following steps:

[0031] S1, prepare materials according to the following weight proportions: 60-70 parts of denitration titanium dioxide, 0.3-1 parts of vanadium source, 2-8 parts of tungsten source, 0.5-2 parts of phosphorus source, 0.5 parts of polyvinyl alcohol, 0.5-1 parts of carboxypropyl methyl cellulose, 4 parts of glass fiber, 0.5 parts of kapok pulp, 0.2 parts of glycerol, and 25-30 parts of deionized water; the vanadium source is ammonium metavanadate; the tungsten source is ammonium tungstate or ammonium metatungstate; the phosphorus source is at least one of phosphoric acid, ammonium phosphate, dihydrogen ammonium phosphate, and hydrogen diammonium phosphate.

[0032] S2, add the tungsten source and the phosphorus source to a mixer containing the denitration titanium dioxide, and stir uniformly (stirring speed not more than 25 rad / min, stirring time not less than 20 min) to obtain a mixed dry powder;

[0033] S3, add deionized water, glass fiber, kapok pulp, glycerol, and vanadium source to the mixed dry powder obtained in step S2, and stir to mix uniformly (stirring speed not less than 700 rad / min, stirring time not less than 1 h);

[0034] S4, add polyvinyl alcohol and carboxypropyl methyl cellulose, stir, and adjust the pH to 8.5 to obtain a non-gritty paste;

[0035] S5, extruding the mud into a catalyst body by using a vacuum screw extruder;

[0036] S6, wrapping the catalyst body and placing it in an environment with normal temperature and no sunlight for more than 48 hours, and then drying; the drying is performed in a drying oven, the drying temperature is 60-70℃, the humidity is 50-55%, and the drying time is not less than 72 hours.

[0037] S7, roasting the dried catalyst body at 550-650℃ (the roasting time is not less than 10 hours), to obtain a catalyst product.

[0038] Example 1

[0039] Put 70 parts by mass of denitration titanium dioxide, 2 parts by mass of ammonium metatungstate and 0.5 parts by mass of phosphoric acid into a mixer and stir for 20 minutes; add 25 parts by mass of deionized water, and then add glycerol, ammonium metavanadate, glass fiber and kapok pulp in sequence, and continue to stir for 1 hour, wherein the ammonium metavanadate is 1 part by mass, the glass fiber is 4 parts by mass, the kapok pulp is 0.5 parts by mass, the glycerol is 0.2 parts by mass; then add polyvinyl alcohol 0.5 parts by mass and hydroxypropyl methyl cellulose 0.5 parts by mass for stirring, and finally add ammonia water to adjust the pH to 8.5 to obtain a mud without obvious grain feeling; a honeycomb catalyst body with 5x5 holes is extruded by using a vacuum extruder; the catalyst body is wrapped and placed in an environment with normal temperature and no sunlight for more than 48 hours, and then dried (the drying is performed in a drying oven, the drying temperature is 60-70℃, the humidity is 50-55%, and the drying time is 72 hours); after the body is dried, it is sent into a tunnel kiln for roasting at 550℃ for 10 hours to obtain a honeycomb denitration catalyst. The V2O5 content of the catalyst is 1wt%, the WO3 content is 2wt%, and the P2O5 content is 0.5wt%.

[0040] Example 2

[0041] 68 parts by mass of denitration titanium dioxide, 0.5 parts by mass of ammonium metatungstate and 2 parts by mass of diammonium hydrogen phosphate were placed in a mixer and stirred for 20 min, 25 parts by mass of deionized water was added, and then glycerol, ammonium metavanadate, glass fiber, kapok pulp were added in sequence, and stirring was continued for 1 h, wherein the ammonium metavanadate was 0.5 parts by mass, the glass fiber was 4 parts by mass, the kapok pulp was 0.5 parts by mass, the glycerol was 0.2 parts by mass; then polyvinyl alcohol 0.5 parts by mass and hydroxypropyl methyl cellulose 0.5 parts by mass were added and stirred, and finally ammonia water was added to adjust the pH to 8.5, to obtain a mud without obvious grain feeling; a honeycomb catalyst body with 5x5 holes was extruded by using a vacuum extruder; the catalyst body was wrapped and placed in an environment at room temperature without sunlight for more than 48 h, and then dried (drying was carried out in a drying oven, the drying temperature was 60-70℃, the humidity was 50-55%, and the drying time was 72 h); after the body was dried, it was sent into a tunnel kiln at 550℃ for calcination for 10 h, to obtain a honeycomb denitration catalyst. The V2O5 content of the catalyst was 0.5wt%, the WO3 content was 3wt%, and the P2O5 content was 2wt%.

[0042] Example 3

[0043] 67.2 parts by mass of denitration titanium dioxide, 5 parts by mass of ammonium metatungstate and 1 part by mass of ammonium dihydrogen phosphate were placed in a mixer and stirred for 20 min; 25 parts by mass of deionized water was added, and then glycerol, ammonium metavanadate, glass fiber, kapok pulp were added in sequence, and stirring was continued for 1 h, wherein the ammonium metavanadate was 0.3 parts by mass, the glass fiber was 4 parts by mass, the kapok pulp was 0.5, the glycerol was 0.2 parts by mass; then polyvinyl alcohol 0.5 parts by mass and hydroxypropyl methyl cellulose 0.5 parts by mass were added and stirred, and finally ammonia water was added to adjust the pH to 8.5, to obtain a mud without obvious grain feeling; a honeycomb catalyst body with 5x5 holes was extruded by using a vacuum extruder; the catalyst body was wrapped and placed in an environment at room temperature without sunlight for more than 48 h, and then dried (drying was carried out in a drying oven, the drying temperature was 60-70℃, the humidity was 50-55%, and the drying time was 72 h); after the body was dried, it was sent into a tunnel kiln at 550℃ for calcination for 10 h, to obtain a honeycomb denitration catalyst. The V2O5 content of the catalyst was 0.3wt%, the WO3 content was 5wt%, and the P2O5 content was 1wt%.

[0044] Example 4

[0045] The 67.7 parts by mass of denitration titanium dioxide, 4 parts by mass of ammonium metatungstate and 1.5 parts by mass of ammonium phosphate were stirred in a mixer for 20 min, 25 parts by mass of deionized water was added, and then glycerol, ammonium metavanadate, glass fiber, kapok pulp were added in sequence, and stirring was continued for 1 h, wherein the ammonium metavanadate was 0.3 parts by mass, the glass fiber was 4 parts by mass, the kapok pulp was 0.5 parts by mass, the glycerol was 0.2 parts by mass; then polyvinyl alcohol 0.5 parts by mass and hydroxypropyl methyl cellulose 0.5 parts by mass were added for stirring, and finally ammonia water was added to adjust the pH to 8.5, to obtain a mud without obvious grain feeling; a honeycomb catalyst body with 5x5 holes was extruded by using a vacuum extruder; the catalyst body was wrapped and placed in an environment at room temperature without sunlight for more than 48 h, and then dried (drying was carried out in a drying oven, the drying temperature was 60-70℃, the humidity was 50-55%, and the drying time was 72 h); after the body was dried, it was sent into a tunnel kiln at 550℃ for calcination for 10 h, to obtain a honeycomb denitration catalyst. The V2O5 content of the catalyst was 0.3wt%, the WO3 content was 4wt%, and the P2O5 content was 1.5wt%.

[0046] Comparative Example 1

[0047] The 69.5 parts by mass of denitration titanium dioxide and 2 parts by mass of ammonium metatungstate were stirred in a mixer for 20 min, 25 parts by mass of deionized water was added, and then glycerol, ammonium metavanadate, glass fiber, kapok pulp were added in sequence, and stirring was continued for 1 h, wherein the ammonium metavanadate was 1 part by mass, the glass fiber was 4 parts by mass, the kapok pulp was 0.5 parts by mass, the glycerol was 0.2 parts by mass; then polyvinyl alcohol 0.5 parts by mass and hydroxypropyl methyl cellulose 0.5 parts by mass were added for stirring, and finally ammonia water was added to adjust the pH to 8.5, to obtain a mud without obvious grain feeling; a honeycomb catalyst body with 5x5 holes was extruded by using a vacuum extruder; the catalyst body was wrapped and placed in an environment at room temperature without sunlight for more than 48 h, and then dried (drying was carried out in a drying oven, the drying temperature was 60-70℃, the humidity was 50-55%, and the drying time was 72 h); after the body was dried, it was sent into a tunnel kiln at 550℃ for calcination for 10 h, to obtain a honeycomb denitration catalyst. The V2O5 content of the catalyst was 1wt%, the WO3 content was 2wt%.

[0048] Comparative Example 2

[0049] The 70 parts by mass of denitration titanium dioxide and 3 parts by mass of ammonium metatungstate were stirred in a mixer for 20 min, 25 parts by mass of deionized water was added, and then glycerol, ammonium metavanadate, glass fiber, and kapok pulp were added in sequence and stirred for 1 h. The ammonium metavanadate was 0.5 parts by mass, the glass fiber was 4 parts by mass, the kapok pulp was 0.5 parts by mass, and the glycerol was 0.2 parts by mass. Then, 0.5 parts by mass of polyvinyl alcohol and 0.5 parts by mass of hydroxypropyl methyl cellulose were added and stirred. Finally, ammonia water was added to adjust the pH to 8.5, and a mud material without obvious granular feeling was obtained. A honeycomb catalyst body with 5x5 holes was extruded by using a vacuum extruder. The catalyst body was wrapped and placed in an environment at room temperature without sunlight for more than 48 h, and then dried (drying was performed in a drying oven, the drying temperature was 60-70℃, the humidity was 50-55%, and the drying time was 72 h). After the embryo was dried, it was sent into a tunnel kiln at 550℃ for 10 h, and a honeycomb denitration catalyst was obtained. The V2O5 content of the catalyst was 0.5 wt%, and the WO3 content was 3 wt%.

[0050] Comparative Example 3

[0051] The 68.5 parts by mass of denitration titanium dioxide and 5 parts by mass of ammonium metatungstate were stirred in a mixer for 20 min. 25 parts by mass of deionized water was added, and then glycerol, ammonium metavanadate, glass fiber, and kapok pulp were added in sequence and stirred for 1 h. The ammonium metavanadate was 3 parts by mass, the glass fiber was 4 parts by mass, the kapok pulp was 0.5 parts by mass, and the glycerol was 0.2 parts by mass. Then, 0.5 parts by mass of polyvinyl alcohol and 0.5 parts by mass of hydroxypropyl methyl cellulose were added and stirred. Finally, ammonia water was added to adjust the pH to 8.5, and a mud material without obvious granular feeling was obtained. A honeycomb catalyst body with 5x5 holes was extruded by using a vacuum extruder. The catalyst body was wrapped and placed in an environment at room temperature without sunlight for more than 48 h, and then dried (drying was performed in a drying oven, the drying temperature was 60-70℃, the humidity was 50-55%, and the drying time was 72 h). After the embryo was dried, it was sent into a tunnel kiln at 550℃ for 10 h, and a honeycomb denitration catalyst was obtained. The V2O5 content of the catalyst was 3 wt%, and the WO3 content was 5 wt%.

[0052] The denitration catalysts prepared in Examples 1-4 and Comparative Examples 1-3 were tested for denitration performance and SO2 oxidation rate. The test conditions were as follows: test temperature 380℃, NH3 concentration 500 ppm, NH3 / NO = 1, SO2 concentration 500 ppm, H2O concentration 8%, GHSV = 120000 h-1, and catalyst wall thickness 0.85. The denitration efficiency of each denitration catalyst is shown in Table 1. -1

[0053] Table 1 Denitration efficiency and SO2 oxidation rate of different denitration catalysts

[0054] ​

[0055] The present application prepares the mud in a mixer, but uses the traditional mixer, and the components of the mud are easy to adhere to the inner wall of the mixer during mixing, which leads to uneven mixing of the materials, affecting the denitration efficiency and SO2 oxidation rate of the final catalyst; after mixing, the materials adhere to the inner wall of the mixer, causing loss of the mud and affecting the yield. The present application also improves the mixer.

[0056] As shown in Figures 1-4 The improved mixer includes a kettle body 1, a shaft cylinder 2, a pushing piece 3, a stirring paddle 4 and a scraper piece 5. The kettle body 1 includes a partition 6 fixed to the upper inner cavity thereof. The shaft cylinder 2 rotates through the partition 6. The pushing piece 3 is arranged in the inner cavity of the shaft cylinder 2. The pushing piece 3 can rotate with the shaft cylinder 2 and move back and forth left and right. The pushing piece 3 includes a pushing plate part 31 and a connecting plate part 32 connected to one side of the pushing plate part 31. The lower part of the pushing plate part 31 is provided with an inclined sliding groove 33. The stirring paddle 4 includes a shaft part 41 and a stirring piece 42 fixed to the bottom end of the shaft part 41. The shaft part 41 slides through the bottom part of the shaft cylinder 2 and is in sliding connection with the sliding groove 33. The connecting plate part 32 slides transversely out of the side wall part of the shaft cylinder 2. The outer end of the connecting plate part 32 is vertically fixed to the scraper piece 5. When the pushing piece 3 moves, it can drive the stirring paddle 4 to move up and down and the scraper piece 5 to move in and out. When the pushing plate part 31 moves to abut against the side part of the shaft cylinder 2 through which the connecting plate part 32 passes, the stirring paddle 4 moves down to abut against the inner wall of the bottom part of the kettle body 1, and the scraper piece 5 moves out to abut against the inner wall of the kettle body 1.

[0057] The kettle body 1 includes a cylindrical side kettle part 11 and an inverted conical bottom kettle part 12 connected in sequence. The scraper piece 5 includes a vertical straight rod part 51 and an inwardly and downwardly inclined inclined rod part 52 connected to the lower end of the straight rod part 51. The bottom surface of the inclined rod part 52 is horizontally arranged. The stirring piece 42 includes a pair of stirring rods 421 connected in an angle shape and having an angle opening facing upward. The upper end surface of the stirring rod 421 is horizontally arranged. Initially, the inclined rod part 52 is parallel to the inner side of one stirring rod 421 (the inclination of the inclined rod part 52 is the same as that of the stirring rod 421). When the pushing plate part 31 moves to abut against the side part of the shaft cylinder 2 through which the connecting plate part 32 passes, the straight rod part 51 moves horizontally outwards to abut against the inner wall of the side kettle part 11, the inclined rod part 52 moves horizontally outwards to abut against the inner wall of the bottom kettle part 12, and the pair of stirring rods 421 move downwards to abut against the inner wall of the bottom kettle part 12, and the lower end of the inclined rod part 52 abuts against the upper and lower ends of one stirring rod 421, as shown in Figure 5 .

[0058] The stirring paddle 4 further includes stirring blades 43 installed on the shaft part 41 and located above the stirring piece 42.

[0059] The shaft cylinder 2 is driven to rotate by a first motor 7.

[0060] The pushing member 3 further comprises a screwing part 34 connected to the upper end of the pushing plate part 31, a screw rod 21 is transversely arranged in the upper part of the shaft cylinder 2, the screw rod 21 is driven to rotate by the second motor 8, and the screwing part 34 is screwed with the screw rod 21. A transverse guide rod 22 is further arranged in the shaft cylinder 2, and the screwing part 34 is slidingly connected with the guide rod 22.

[0061] The pushing plate part 31 is in the shape of a transverse trapezoid as a whole, and the bottom surface of the pushing plate part 31 is arranged to be inclined upwardly towards the connecting plate part 32. The chute 33 is arranged to be inclined upwardly towards the connecting plate part 32, and the chute 33 transversely penetrates the pushing plate part 31. The chute 33 comprises an A chute 331 formed by the bottom surface of the pushing plate part 31 being recessed, and side chutes 332 formed by the front and rear side surfaces of the A chute 331 being recessed, respectively. The A chute 331 and the side chutes 332 are both arranged to be inclined upwardly towards the connecting plate part 32. The upper end of the shaft part 41 is provided with a pin shaft 44, and the front and rear ends of the pin shaft 44 are slidingly inserted into the side chutes 332, respectively.

[0062] Initially, the first motor 7 drives the shaft cylinder 2 to rotate, thereby driving the stirring paddle 4 and the scraper member 5 to rotate to stir the mud in the kettle body 1. After a period of stirring, some mud is adhered to the inner wall of the kettle body 1, the second motor 8 is started to drive the pushing member 3 to move, the pushing member 3 drives the scraper member 5 to move outward to abut against the inner wall of the kettle body 1, and at the same time, the pushing member 3 drives the stirring paddle 4 to move downward to make the stirring member 42 abut against the inner wall of the kettle body 1, so that the mud adhered to the inner wall of the kettle body 1 can be scraped off when the stirring paddle 4 and the scraper member 5 rotate, and then the second motor 8 drives the pushing member 3 to move back, and the stirring paddle 4 and the scraper member 5 return to the initial state to stir the mud in the kettle body 1. The device can scrape off the mud adhered to the inner wall of the kettle body 1 in time while stirring the mud, thereby promoting the full mixing of the components of the mud.

[0063] The improved mixer is used to mix the low-sulfur oxidation rate and high-activity honeycomb SCR denitration catalyst according to the method of Example 1 (the mixers used in Examples 1-4 and Comparative Examples 1-3 are all traditional mixers). It is found that the NO conversion rate of the catalyst is 95.63% and the SO2 oxidation rate is 0.51% at 380℃.

[0064] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a low-sulfur-oxidation-rate high-activity honeycomb SCR denitration catalyst, characterized by, It comprises the following steps: S1, preparing materials by weight ratio: denitration titanium dioxide 60-70 parts, vanadium source 0.3-1 parts, tungsten source 2-8 parts, phosphorus source 0.5-2 parts, polyvinyl alcohol 0.5 parts, carboxypropyl methyl cellulose 0.5-1 parts, glass fiber 4 parts, kapok pulp 0.5 parts, glycerol 0.2 parts, deionized water 25-30 parts; S2, adding tungsten source, phosphorus source into the mixing machine containing denitration titanium dioxide, stirring uniformly to obtain mixed dry powder; S3, adding deionized water, glass fiber, kapok pulp, glycerol and vanadium source into the mixed dry powder prepared in step S2, stirring and mixing uniformly; S4, adding polyvinyl alcohol and carboxypropyl methyl cellulose, stirring, adjusting pH to 8.5 to obtain a non-gritty paste; S5, using a vacuum screw extruder to extrude the paste into a catalyst body; S6, wrapping the catalyst body and placing it in a normal temperature, sunlight-free environment for more than 48 hours, and then drying; S7, roasting the dried catalyst body to obtain the finished catalyst product; The mixing machine for paste mixing comprises a kettle body (1), a shaft cylinder (2), a pushing piece (3), a stirring paddle (4) and a scraper piece (5). The kettle body (1) comprises a partition plate (6) fixed to the upper inner cavity thereof. The shaft cylinder (2) penetrates through the partition plate (6) and rotates. The pushing piece (3) is arranged in the inner cavity of the shaft cylinder (2) and can rotate with the shaft cylinder (2) and move back and forth left and right. The pushing piece (3) comprises a pushing plate part (31) and a connecting plate part (32) connected to one side of the pushing plate part (31). The lower part of the pushing plate part (31) is provided with an inclined sliding groove (33). The stirring paddle (4) comprises a shaft part (41) and a stirring piece (42) fixed to the bottom end of the shaft part (41). The shaft part (41) slides through the bottom of the shaft cylinder (2) and is slidingly connected with the sliding groove (33). The connecting plate part (32) transversely slides out of the side wall part of the shaft cylinder (2). The outer end of the connecting plate part (32) is vertically fixed with the scraper piece (5). When the pushing piece (3) moves back and forth, it can drive the stirring paddle (4) to move up and down and the scraper piece (5) to move in and out. When the pushing plate part (31) of the pushing piece (3) abuts against the side part of the shaft cylinder (2) through which the connecting plate part (32) penetrates, the stirring paddle (4) moves downward to abut against the inner wall of the bottom of the kettle body (1), and the scraper piece (5) moves outward to abut against the inner wall of the kettle body (1). The scraper (5) comprises a vertical straight rod part (51) and an inward and downward inclined inclined rod part (52) connected to the lower end of the straight rod part (51), and the bottom surface of the inclined rod part (52) is horizontally arranged, the stirring part (42) comprises a pair of angular stirring rods (421) connected and with the angular opening upward, the upper end surface of the stirring rod (421) is horizontally arranged, and initially the inclined rod part (52) is located inside a stirring rod (421) in parallel; when the pushing plate part (31) moves to the side of the shaft cylinder (2) through which the pushing plate part (31) abuts against the connecting plate part (32), the straight rod part (51) moves outward horizontally to abut against the inner wall of the side kettle part (11), the inclined rod part (52) moves outward horizontally to abut against the inner wall of the bottom kettle part (12), a pair of stirring rods (421) move downward to abut against the inner wall of the bottom kettle part (12), and the lower end of the inclined rod part (52) abuts against the upper and lower stirring rod (421) on one side; The shaft cylinder (2) is driven to rotate by the first motor (7); the pushing part (3) further comprises a screw part (34) connected to the upper end of the pushing plate part (31), a screw rod (21) is transversely arranged in the upper part of the shaft cylinder (2), the screw rod (21) is driven to rotate by the second motor (8), the screw part (34) is screwed with the screw rod (21), and a transverse guide rod (22) is further arranged in the shaft cylinder (2), and the screw part (34) is slidably connected with the guide rod (22). The pushing plate part (31) is in the shape of a transverse trapezoid, the bottom surface of the pushing plate part (31) is arranged to be inclined upward toward the connecting plate part (32), the chute (33) is arranged to be inclined upward toward the connecting plate part (32), the chute (33) transversely penetrates the pushing plate part (31), and the chute (33) comprises a main chute (331) formed by recessing the bottom surface of the pushing plate part (31) and side chutes (332) formed by recessing the front and rear surfaces of the main chute (331), respectively, and the main chute (331) and the side chutes (332) are arranged to be inclined upward toward the connecting plate part (32). Initially, the first motor (7) drives the shaft cylinder (2) to rotate, thereby driving the stirring paddle (4) and the scraper (5) to rotate to stir the mud in the kettle body (1); after stirring for a period of time, the mud adheres to the inner wall of the kettle body (1), the second motor (8) is started to drive the pushing part (3) to move, the pushing part (3) drives the scraper (5) to move outward to abut against the inner wall of the kettle body (1), and the pushing part (3) also drives the stirring paddle (4) to move downward to make the stirring part (42) abut against the inner wall of the kettle body (1), so that the stirring paddle (4) and the scraper (5) can scrape off the mud adhered to the inner wall of the kettle body (1) when rotating, and then the second motor (8) drives the pushing part (3) to move back, the stirring paddle (4) and the scraper (5) return to the initial state, and the mud in the kettle body (1) is stirred.

2. The method for preparing a low sulfur dioxide oxidation rate high activity honeycomb SCR denitration catalyst according to claim 1, characterized in that, The vanadium source is ammonium metavanadate; the tungsten source is ammonium tungstate or ammonium metatungstate; and the phosphorus source is at least one of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate and di-ammonium hydrogen phosphate.

3. The method for preparing a low sulfur dioxide oxidation rate high activity honeycomb SCR denitration catalyst according to claim 1, characterized in that, The stirring speed in step S2 is not more than 25 rad / min, and the stirring time is not less than 20 min.

4. The method for preparing a low sulfur dioxide oxidation rate high activity honeycomb SCR de-NOx catalyst according to claim 1, characterized in that, The stirring speed in step S3 is not less than 700 rad / min, and the stirring time is not less than 1 h.

5. The method for preparing a low sulfur dioxide oxidation rate high activity honeycomb SCR denitration catalyst according to claim 1, characterized in that, In step S6, the drying is performed in a drying oven, the drying temperature is 60-70℃, the humidity is 50-55%, and the drying time is not less than 72 h.

6. The method for preparing a low sulfur dioxide oxidation rate high activity honeycomb SCR de-NOx catalyst according to claim 1, characterized in that, In step S7, the calcination is performed at 550-650℃, and the calcination time is not less than 10 h.

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