KR810000778B1 - Process for production of sintered cataysts - Google Patents

Abstract

TiO2 solid was sintered by treatment with Mo oxide vapor at 460-650≰C in the presence of an active component(catalyst or adsorbent). These active materials were V2O3, V2O5, Fe2O3, WO3, or CuO. The products were used as catalysts and adsorbents in treatment of exhaust gases. Precursors of TiO2(ortho titanic acid or metatitanic acid), precursors of Mo oxide(molybdic acid or NH4 molybdate), and precursors of the catalytic oxides(e.g., NH4VO3 precursor for V oxide) may be used. The sintered products were mixed with H2O, formed, and calcined. In an example, metatitanic acid, NH4VO3, and NH4 molybdate were mixed with H2O, dried at 150≰C, and treated at 530≰C to obtain the sintered products.

Description

Manufacturing method of gold network adhesion catalyst

1 and 2 are process diagrams illustrating a system for sintering titanium oxide and active ingredients oxidized according to the present invention.

3 is a characteristic diagram illustrating the relationship between the amount of molybdenum oxide added and the amount of water to be added.

4 is a characteristic diagram illustrating the relationship between the preliminary calcination temperature and the amount of water to be added.

5 is a characteristic diagram illustrating the relationship between the amount of molybdenum oxide added and the peering.

6 is a perspective view of a honeycomb structure illustrating one embodiment according to the present invention.

7-11 is a perspective view of a plate structure illustrating another embodiment of the present invention.

12 is a perspective view of a catalytic reactor stacked in at least 4 units in accordance with the present invention.

The present invention relates to a method of sintering a mixture of oxidized titanium powder and an active metal component and an article produced by the method. Sintered products made by calcining powder mixtures of oxidized titanium and metal oxides are used as catalysts or adsorbents to effectively remove harmful substances from exhaust gases. In many cases, dry-type treatment using catalysts or adsorbents can be carried out using various types of gases containing harmful substances, for example nitrogen oxides such as No and No2 (hereinafter referred to as Nox) and sulfur oxides (hereinafter referred to as Sox). It is used to treat Kraus dwelling gases, emissions from paper mills and other types of emissions, including many kinds of odorous substances such as combustion emissions, emissions from nitric acid, emissions from steel mills and hydrogen sulfide. It is widely used because the process is simpler and there is no secondary consumption.

When carrying out dry processing, fixed bed reactors are generally used by the optional filling of catalysts or adsorbents in the form of columns, cylindrical annular, spherical or granular ferrets. In this case, the large amount of off-gas to be treated needs to be large in order to fill the reactor with catalyst or adsorbent. Under these conditions, the catalyst and the adsorbent may be destroyed by their own gravity, so sufficient mechanical strength is required for the catalyst or the adsorbent.

Many solids and intact materials are included in the off-gases along with harmful substances. For example, off-gases from chemical fuels such as coal, heavy petroleum and impure petroleum contain incombustibles such as oil fumes and from coke ovens or sinter ovens. Exhaust gases contain large amounts of dust, such as heavy metals and ash, and exhaust gases from furnaces and paper mills that melt glass contain strong viscous mirabilite or alkaline vapors.

When this gas is injected into a ferret-filled stationary bed reactor, the same deposit first increases the pressure loss in the reactor, blocks the flow of gas, and in severe cases seals the reactor.

Therefore, the use of a process using a parallel reactor consisting of a small size and a low pressure loss filled with a catalyst of a honeycomb structure with a base plate made of a metal plate or a wire mesh or a structure of a panic structure has been proposed. However, technical problems exist for formability and mechanical strength when sintered products that can be used in either fixed bed reactors or parallel reactors are made primarily from oxidized titanium powder.

Sintered products used as catalysts or adsorbents need to have a larger surface area to increase practicality. The higher the sintering temperature, the higher the strength of the catalyst and adsorbent, but the smaller the surface area, the lower the functionality. In order to improve the functionality, the sintering temperature is lowered, but this method reduces the mechanical strength as well as the adsorption power of the catalyst and the adsorbent to the base.

In addition, oxidized titanium powder is used to create a honeycomb structure through a wet method, which requires a large amount of water to mix or knead the oxidized titanium powder into a viscous material, which takes a long time to remove the contained water. And mechanical strength is lowered. If a large amount of water is used to form the structure, the adsorption and mechanical strength are reduced even if the water is removed to form a porous catalyst or adsorbent.

The Titanium system catalyst described in US Pat. No. 4, 085, 193, issued to Nakajima, which produces a catalyst for the removal of Nox from the off-gas, produces a mixture of titanium and molybdenum, which are then molded into tablets and then molded. The tablets were then calcined in a furnace at 500 ° C. for 4 hours. However, this patent does not describe how to increase the mechanical strength as well as the adsorption power of the catalyst or adsorbent.

It is therefore an object of the present invention to provide a method for producing a sintered product comprising oxidized titanium and active ingredients and a product capable of providing high mechanical strength and adsorptivity.

It is another object of the present invention to provide a method of making a product which can provide a strong bond between sintered product comprising oxidized titanium and an active ingredient and calcined titanium granules.

Another object is to provide a method of making a product which can provide a sintered product comprising oxidized titanium and an active ingredient and a strong binder connecting the oxidized titanium particles.

It is yet another object of the present invention to provide a process for the manufacture of articles having improved formability by reducing the amount of water when making sintered articles and viscous materials comprising oxidized titanium and active ingredients.

Another object is to provide a solvent or adsorbent that can remove harmful substances from the exhaust gas.

According to the present invention, molybdenum oxide vaporized in a molybdenum atmosphere at a temperature of 460-650 ° C. is deposited on oxidized titanium powder: comprising the deposited molybdenum oxide and the titanium oxide powder oxidized together with the active ingredient. The powder mixture consists of: adding sufficient water to make the viscous material to the powder mixture: kneading the powder mixture: molding the desired object using the viscous material and then calcining the molded object to produce the product A method of sintering an active ingredient comprising oxidized molybdenum as a binder for oxidized titanium powder and oxidized titanium particles.

According to another aspect of the invention there is provided a sintered product comprising 3.1-99% oxidized titanium and 1-69% active ingredient by weight, wherein the active ingredient is a binder of oxidized titanium particles, at least 1% by weight. Oxidized molybdenum was deposited on the oxidized titanium particles. The active ingredients are V ₂ O ₃ , Fe ₂ O ₃ , WO ₃ , CO ₂ O ₃ , NiO, Cr ₂ O ₃ , CeO ₂ , SuO ₂ , CuO, MoO ₃ , Pt, Pd, Rh, Ru, I'r and It contains one or more materials selected from Re.

The inventors have found a binder for oxidized titanium particles to reduce the amount of water added to mix and knead the oxidized titanium powder and thereby increase the mechanical strength and adsorptivity of the sintered product. The inventors tested organic binders such as methylcellulose and fortivinyl alcohol, which not only increase the amount of water but also reduce the mechanical strength of the sintered products and also test the inorganic binders such as alumina and silica. There was no effect of reducing the amount and adversely affected the activity of the catalyst.

Finally, the inventors found that oxidized molybdenum was effective in binding oxidized titanium particles.

According to the invention it is possible to produce a sintered product having an excellent bonding effect by the function of oxidized molybdenum. In particular, the mechanical strength or the destructive stress of the sintered product is 76 kg / cm ² in the absence of a binder effect by oxidized molybdenum while 224 kg / cm ² in the case of a binder effect by oxidized molybdenum. By depositing oxidized molybdenum on oxidized Titanium Isolates, it can be used as a catalyst or adsorbent in reactors in parallel and stationary phases to produce mechanically strong sintered products that can withstand vibration, shock and friction in pieces. can do.

When the mechanical strength of the catalyst or adsorbent is increased, the opening ratio of the cross section in the catalyst bed, which means the ratio of the useful area of gas flow to the cross section of the catalyst bed, becomes larger, even though the reactor contains a large amount of dust. Large amounts of off-gas can be safely treated for a long time without pressure loss.

As shown in FIG. 1, a slurry of meta titanate TiO (OH) ₂ or ortho titanate TiO (OH) ₄ is prepared, and ammonium metavanadate and ammonium molybdate are added to the slurry. The resulting mixture is mixed and kneaded while heating until the amount of water is 30% or less, and then the kneaded mixture is pulverized by drying at a temperature of 110 ° C. or higher, particularly 110-180 ° C. The particle size of the mixture is different depending on the following molding method, and it is generally preferable to grind it to a particle size powder of 60 mesh or less.

The powder is heat treated for several hours at a temperature of 460-650 ° C. for the preliminary calcination process.

The precalcination process deposits oxidized molybdenum on the oxidized titanium powder. The choice of preliminary calcination temperature is important for obtaining good performance as described below.

Instead of metanitanate TiO (OH) ₂ or ortho titanate TiO (OH) ₄ , active oxidized titanium, TiO ₂ can be used, in which case the oxidized titanium ammonium meta vanadate and ammonium molybdate are mixed directly The mixture is kneaded in the same manner as above under heating.

Water is precisely added to the pre-calcined powder, mixed and kneaded with viscous materials that can be used to shape the desired object or structure, and finally calcined through the steps of maturation and drying.

As shown in FIG. 2, instead of the above-described process, ammonium moridate is added to metatitanic acid or ortho titanic acid mixture, mixed, the mixture is heated to kneading, the kneaded mixture is dried, and the dried mixture is pulverized to powder After making a mixture, ammonium metavanadate is heated to form vanadium pentoxide, and the powder mixture prepared above and vanadium pentoxide are mixed and kneaded by adding water to make a viscous substance, and the obtained viscous substance is a desired object or structure. It is also possible to use another process consisting of the steps of molding and drying and calcining in the same manner as described in FIG. Molybdate may be added to the precalcined powder mixture after heating instead of vanadium pentoxide for the purposes of the present invention.

The precalcined oxidized titanium powder contains 1-20% by weight of oxidized molybdenum and 3-20% by weight when the particle size of the oxidized titanium is less than μ. The pre-calcined powder deposits oxidized molybdenum in its phase to form an increase in thickness of several tens to hundreds of microns.

The presence of the layer results in a smaller mechanically sintered product when calcining the space between the titanium particles. Oxidized Titanium particles and oxidized products in the product obtained when the oxidized Titanium powder and the oxidized Molybdenum powder were simply calcined without undergoing a preliminary calcination process for depositing the oxidized Molybdenum on the oxidized Titanium powder. The molybdenum particles present are individually present so that the oxidized molybdenum has no binder effect. On the contrary, according to the present invention as described above, the surface, especially the concave portions, of the oxidized titanium particles are coated to make the space between the oxidized titanium particles smaller when they are finally calcined. Titanium powder oxidized in the present invention is treated under a high vapor pressure atmosphere of molybdenum, such as about 10 ^-6 10 ^-4 atm, within a certain temperature range.

Titanium oxide powder treated in the vessel of molybdenum was deposited on the oxidized titanium oxide powder to be mixed and kneaded by treating a small amount of water. Thus, a small amount of water is added to form a mixed and kneaded viscous material which is then dried and calcined to produce a high density and high strength final product without reducing walking surface area. Preliminary calcination of the oxidized titanium powder can form an oxidized titanium or oxidized molybdenum in a closed vessel under heating with a titanium compound capable of forming oxidized titanium through oxidized titanium or heat treatment. The compound of molybdenum present is made by heat treatment at a temperature of 460-650 ℃ especially 500-610 ℃ 2-10 hours.

Another method of treating oxidized titanium is to pass the oxidized titanium to an oven having a temperature difference introduced with vaporized molybdenum oxide for deposition on oxidized titanium. When the oxidized molybdenum is calculated as molybdenum trioxide MoO ₃ , the amount of oxidized molybdenum deposited on the titanium oxide powder is 1-20%, especially 3-20%, based on the weight of the finally calcined product. to be. Higher amounts of molybdenum may be included when oxidized molybdenum is used as the active component of the catalyst or adsorbent. The amount of molybdenum is preferably 49% or less by weight as the active ingredient, and when molybdenum is used as the binder, 20% by weight of molybdenum may be used up to 69% by weight in total. The oxidized titanium powder on which oxidized molybdenum is deposited becomes viscous by kneading with the addition of water, and the obtained viscous material is easily formed in the form of pellets or in structures such as porous plates and metal meshes. I can make it. The most suitable amount of water added is 20-30% by weight when forming viscous material into honeycomb structure, 25-35% by weight when making viscous material into plate, and when it is made into pellet form. 13-30% by weight. The oxidized titanium powder becomes viscous by the addition of an extremely small amount of water, since the oxidized titanium powder with the oxidized molybdenum forms a capillary region by the addition of an extremely small amount of water. This is the reason that the oxidized molybdenum is deposited on the oxidized titanium powder by repeating the vaporization and melting of the oxidized molybdenum.

As a raw material of oxidized titanium, a titanium compound such as ortho titanic acid or metatitanic acid capable of forming oxidized titanium by heat treatment with annatase or rutile titanium oxide may be used.

As a raw material of oxidized molybdenum, molybdenum compounds such as molybdenum and ammonium molybdate, which can form molybdenum oxide through heat treatment with oxidized molybdenum, can be used. When using oxidized titanium powder and oxidized molybdenum powder as raw materials, 30-60% water by weight is added in a kneading machine, uniformly mixed and kneaded, and then injected into a preliminary calcination process.

Although there is no limit to the particle size of the powder during preliminary calcination, it is preferable to form a particle size suitable for mixing and satisfaction after the preliminary calcination process, so that the size of 80% of the powder passing through the 50 mesh sieve is appropriate.

The preliminary calcination treatment is carried out in a gas oven or an electric oven under ordinary air winding, but is preferably carried out under the above-mentioned temperature range in a sealed container.

Curve A in FIG. 3 illustrates the relationship between the amount of molybdenum oxide added and the most suitable amount of water added to shape the honeycomb structure using viscous material. Curve B illustrates when forming a viscous material into a metal mesh. Curve A represents a measured value when the honeycomb structure has a cross section of 43 mm in one side in a square, and each unit is molded to have 49 system units with an inner diameter of 5 mm, and curve B represents a SUS material having a size of 45 mesh. The actual measured value when unfolded on a metal mesh made of 304 is shown. In both cases the most suitable amount of water is extremely less than the amount of water required without the addition of oxidized molybdenum. When the added amount of oxidized molybdenum was less than 1% by weight, the binding effect was not expected much, and the binding effect was satisfied when the added amount of oxidized molybdenum exceeded 20% by weight. It is therefore not advisable to add more than 20% by weight of oxidized molybdenum as a binder for the titanium particles.

4 relates to the relationship between the most suitable amount of water added and the preliminary calcination temperature when 10% oxidized molybdenum by weight is added to the oxidized titanium powder as a binder. In the drawings, A and B are the same as those shown in FIG. The amount of water represents the performance of the sintered product. The smaller the amount of water, the stronger the mechanically sintered product.

As shown in FIG. 4, the preliminary calcination temperature is appropriately in the range of 460-650 ° C., especially 500-610 ° C., although the amount of oxidized molybdenum increases or decreases by weight in the range of 1% -49%. The trend remains unchanged.

Determination of TiO ₂ when a transition metal oxide is added to the catalyst or adsorbent to form a composition comprising three components such as TiO ₂ , V ₂ O ₅ , M ₀ O ₃ and TiO ₂ , Fe ₂ O ₃ , M ₀ O ₃ Is generated and a decrease in activity as a catalyst or adsorbent is observed above 610 ° C.

When oxidized molybdenum is added, a large amount of oxidized molybdenum leaks out of the system due to the high vapor pressure above 610 ° C. Therefore, it is appropriate to perform preliminary calcination below 610 ° C from the point of view of production.

5 shows the relationship between the amount of molybdenum oxide added and the rate of peeling of the sintered body calcined at a temperature of 500 ° C. by forming a viscous material into a metal mesh. It is obtained by a test method of sticking on one part of the sintered body, removing the tape, and comparing the sintered part covered with the tape and the part without the tape.

As shown in FIG. 5, when the amount of oxidized molybdenum is increased, the bonding force in the sintered body is gradually increased by increasing the binding effect, but if the amount of oxidized molybdenum is increased by more than 20% by weight, the bonding effect is no longer It is not improved.

Sintered products containing active ingredients including oxidized titanium and oxidized molybdenum deposited on oxidized titanium particles are used as catalysts or adsorbents: M ₃ O ₃ , Fe ₂ O ₃ , WO ₃ , Catalysts for removing Nox from various gases including active compounds selected from CO ₂ O ₃ , NiO, Cr ₂ O ₃ , CeO ₂ , SnO ₂ , CuO and M ₀ O ₃ : Pt, Pb, Rh Ru, Ir and Catalysts for removing carbon compounds, such as carbon monoxide and carbon dioxide, from combustion and exhaust gases from automobiles, including active ingredients selected from Re: selected from V ₂ O ₃ , Fe ₂ O ₃ , WO ₃ and M ₀ O ₃ Catalyst for dissociating hydrogen emulsifier in gas, including active ingredient: Active ingredient including binder and catalyst effect for removing sulfur oxides from various exhaust combustion gases, including active ingredient selected from Fe ₂ O ₃ and CuO Adsorbent for adsorbing and removing hydrogen sulfide from exhaust gas, including 10-50% oxidized molybdenum in an amount.

As shown in FIG. 6, the honeycomb structure is formed by extruding a viscous material formed by adding 20-30% of water by weight to a mixture of oxidized titanium powder and active ingredient powder with oxidized molybdenum. do.

As shown in FIG. 7, the plate structure is made by spreading a viscous material on a stainless steel sheet formed by adding 20-35% by weight, in particular 24-28% by weight of water.

Other plate structures, as shown in FIGS. 8-11, also create viscous materials formed by adding 20-30% water by weight onto various metal meshes.

As shown in FIG. 12, a parallel reactor is made by using a plurality of honeycomb structures or plate structures. In order to make experiments, repairs, replacements and regeneration of the device easier, it is necessary to make a unit using a plurality of honeycomb structures or plate structures and stack several units to produce a final parallel reactor having a specific capacity. desirable,

Such a device is particularly useful for treating large quantities of exhaust gases. By spreading the viscous material on the base having various shapes, a plate structure having various shapes such as a wave shape or a rolling shape can be made, and thus a reactor having various shapes can be manufactured.

The parallel reactor was equipped with many gas passages, one of which had a cross-sectional area of 4-400 mm 2. When the cross-sectional area is 4 mm 2 or less, it is larger than the pressure loss, which is not suitable for treating the exhaust gas containing a large amount of dust. When the cross-sectional area exceeds 400 mm 2, it is impossible to form a large geometric surface of the catalyst per volume of the catalyst, so that the performance for removing harmful substances is reduced, resulting in a larger reactor.

Table 1 shows the compressive burst strength of the honeycomb structure and the sintered ferret with or preliminarily calcined.

TABLE 1

Table 2 shows the peening speed of the catalyst plate according to the Peeling test in the same manner as in Table 1.

TABLE 2

Table 3 shows the peeling rate of the catalyst plate according to the 1m drop test results in the same manner as in Table 1. The specimens were 400 mm x 200 mm x 1 mm high.

The following examples illustrate the invention in more detail.

TABLE 3

The following examples illustrate the invention in more detail.

Example 1

10 kg of metatitanic acid sludge, 395 g of ammonium metavananate and 8.6% of oxidized molybdenum by weight, calculated on the basis of the total amount of the manufactured product by weight 40% oxidized titanium TiO ₂ 496 g of ammonium molybdate was mixed and kneaded in a kneading machine, taken out, dried in an oven at a temperature of 140 ° C., and then pulverized in a grinder to a particle size of 60 mesh or less. Time heat treatment. 80% of the raw powder by weight is mixed by adding 2% of Avicel by weight, and again 17% of water by weight, and then mixed and kneaded in a kneading machine to form a viscous material.

The viscous material is made into a honeycomb structure having a square cross section by a vacuum extruder, and then dried to sinter at a temperature of 500 ° C. for 2 hours to obtain a honeycomb structure made of a sintered body. The honeycomb structure has an overall cross section of 49 mm in one axial plane and 49 units, each of which has an inner diameter of 5 mm in one axial plane and a wall thickness of 1 mm.

The mechanical strength of the structure is 224 kg / cm 2 in the direction of the cross section.

Addition of Oxidized Molybdenum for Comparison To this, 68% of the raw powder by weight made similar to the above example is mixed with 2% of Avicel and 30% of water by weight is mixed and kneaded well. The honeycomb structure of the sintered body is made in the same manner as in the above embodiment except that there is no binder.

The mechanical strength of the structure was 76 kg / cm 2 in the cross-sectional direction.

As shown in the examples, the mechanical strength of the structure including the binder is three times greater than that of the structure without the binder and exhibits a strong binding force to the titanium particles.

This indicates that the structure is extremely useful as a catalyst.

Example 2

7500h^-1)의 배출가스를 NH₃/NO=1.1의 반응조건과 350℃의 반응 온도하에 암모니아를 주입함에 의하여 가스로부터 Nox를 제거하기 위하여 촉매적 반응기(11)에 주입한다.One unit of the reactor is fabricated by arranging the 36 structures obtained in Example 1, with every six structures arranged vertically and at right angles to the horizontal. The length of the unit is 150 mm and as shown in FIG. 12, the entire catalytic reactor 11 has four units 12A, 12B, 12C and 12D in a vessel 13 having an exhaust gas inlet 14 and an exhaust gas outlet 15. Makes by stacking. As described above, the unit includes six 36 honeycomb structures. 300 Nm ³ / h (space velocity SV) from coal fired boilers with

The exhaust gas of 7500 h ⁻¹ ) is injected into the catalytic reactor 11 to remove Nox from the gas by injecting ammonia under a reaction condition of NH ₃ /NO=1.1 and a reaction temperature of 350 ° C.

As a result, the initial removal rate of Nox was about 85%, the pressure loss in the catalytic reactor was 36mmAq, after 1,000 hours the removal rate was 84% and the pressure loss was 43mmAq.

Since the removal rate and pressure loss of Nox remained almost unchanged for a long time, it became clear that there was no problem as a catalytic reactor.

Example 3

1,000 g of metatitanic acid slurries, 27.5 g of ammonium metavanadate and 70.8 g of ammonium molybdate (NH ₄ ) ₆ M ₇ , O ₂₄ , ₄ H calculated as 35% by weight oxidized titanium ₂ O is well mixed and kneaded in a kneader for 2 hours, dried at 150 ° C. for 5 hours, and ground to a particle size of 90% of the powder passing through a 60 mesh sieve. The mixture powder was calcined at 530 ° C. for 3 hours to deposit oxidized molybdenum on oxidized titanium and then kneaded in a kneader for 2 hours by adding 20% water by weight to obtain a paste-like viscous material. Part of the viscous material spread over a mesh of 45 mesh of 200mm × 1,000mm size, and the mesh with excess viscous material was formed by two stainless steel plates equipped with cutters at the contact with the mesh. The excess viscous material is removed from the net by passing through a scraping device with a space of mm. The mesh net filled with the viscous material spread out in this way is left at room temperature for 10-20 minutes and then pressurized with a roller mill coated with Teflon to dry the molded structure at 150 ° C. for 3 hours and finally calcined at 450 ° C. for 2 hours. The calcined product had a thickness of 0.5 mm, including titanium, Ti, vanadium V and molybdenum in a molar ratio of 87: 6: 7. The specimens were cut from 50 mm x 50 mm in size and the results of the Peeling test indicated that the Peering speed was 0.9%. According to the drop test from the height of 1m, the peering speed is less than 0.5%.

Example 4

Into the kneading machine with 1.5 kg of oxidized titanium, 116 g of Ammonium metavanadate and 624 g of Ammonium molybdate, calculated as 10% by weight M ₀ O ₃ based on the total amount of product, Knead well at and then dried at 150 ℃ calcined at 530 ℃ to make a powder. Water is added to the powder and mixed and kneaded under heating by a kneader. The water is reduced to 22% by weight to obtain a viscous material. The viscous material is then spread on a porous stainless steel sheet for 1 day by air and dried at 120 ° C. for 5 hours and finally calcined at 500 ° C. for 2 hours.

Peeling tests are carried out to evaluate the adsorption properties of sintered products. According to the test results, the peering rate was 0.5% by weight.

Example 5

The viscous material obtained in Example 4 was spread on a stainless steel mesh of 255 mm x 400 mm and pressed by a Teflon-coated roll mill to dry the resulting structure, and finally calcined at 530 ° C. for 2 hours to obtain a catalyst plate. The plate thickness is 0.5 mm and the catalyst plates are arranged in sequence at a distance of 6 mm to form a reactor unit of 252 mm square length and 400 mm length.

The entire catalytic reactor is made up of four units, with an open percentage of 95%.

The total weight of the plate was about 13 kg, which is 1/10 compared to that made with the conventional catalyst ferret, and the amount of catalyst was reduced to 1/25 compared with the case with the conventional catalyst ferret.

1000h^-1)의 배출가스를 NH₃/NO=1.1의 반응조건과 350℃의 반응 온도하에 암모니아를 주입함에 의하여 가스로 부터 Nox를 제거하기 위하여 촉매 반응기에 주입한다.From coal-only combustion boilers containing 1,000 Nm ² / h (SV

The exhaust gas of 1000h ^-1 ) is injected into the catalytic reactor to remove Nox from the gas by injecting ammonia under a reaction condition of NH _{3 /} NO = 1.1 and a reaction temperature of 350 ° C.

As a result, the initial removal rate of Nox was about 89%, the pressure loss in the catalytic reactor was 18mmAq, after 1,000 hours the removal rate was 87%, and the pressure loss was 23mmAq.

It is evident that there is no problem as a catalyst because the scrap rate and pressure loss do not change over a long time. In addition, since the catalyst is not poisoned by SOx in the gas, it shows stable performance over a long time.

Example 6

A viscous material was prepared in the same manner as described in Example 4 except that Fe ₂ O ₃ was used as an active ingredient instead of TiO ₂ at a Ti: Fe ratio of 95.5 and 5% M ₀ O ₃ by weight was added as the binder. Make it.

The viscous material obtained is spread out on a 100 mesh metal network, pressurized with a mill, and the resulting catalyst plate is dried and finally calcined. Peel the calcined catalyst plate.

According to the test results, the peeling rate is 0.8% by weight, which is extremely small.

Example 7

The WO ₃ Ti of 95.5: in the Fe used as active ingredient instead of TiO ₂ and to obtain the described viscous material in the same manner as in the embodiment except that there is added as the binder M0O ₃ Example 4.

The resulting viscous material is spread over a 200 mesh metal network and pressed by a mill to dry the calcined catalyst plate. Pyring test of the calcined catalyst plate, and the test results show that the peering speed is 0.8% by weight, which is extremely small.

[Comparative 1]

A viscous material is made in the same manner as described in Example 4 except for using 10% alumina. The calcined product is obtained in the same manner as described in Example 4 by using the prepared viscous material.

The test results for the sintered product show that the peering speed is 65% by weight and therefore the adsorptivity is very bad compared to that of Examples 4, 5, 6 and 7.

Example 8

The meta titanate TiO (OH) ₂ slurry is mixed and kneaded in a kneader, is present at a temperature of 150 ° C. for 1 week, and then calcined at 400 ° C. for 2 hours. The resulting 1 kg of oxidized titanium, 43 g of ammonium molybdate and 428 g of copper nitrate are mixed and 1 kg of water is added and heated to knead. The obtained dough was dried at a temperature of 150 ° C., ground to a particle size of 60 mesh or less by a grinder, and preliminarily calcined at a temperature of 500 ± 20 ° C. for 3 hours.

150 ml of water is added to the obtained powder and kneaded for 3 hours by a kneader to obtain a viscous substance. The pellet obtained by extruding the viscous material into a columnar shape having a diameter of 4 mm by an extruder was dried at 150 ° C. for 1 day and then calcined at 400 ° C. for 2 hours. The resulting composition contains 87% TiO ₂ , 3% M ₀ O ₃ and 10% CuO, so that the strength of the composition is 45 kg peret in the direction of the diameter.

Compositions comprising TiO ₂ M ₀ O ₃ and CuO are suitable for use as adsorbents for adsorbing and removing sulfur dioxide and sulfur trioxide from gases.

The chemical reaction is as follows.

CuO + SO ₂ + 1 / 2O ₂ → CuSO ₄

CuO + SO ₃ → CuSO ₄

Copper oxide has the activity of absorbing sulfur oxide and oxidized molybdenum acts as a binder. Adsorption and removal of SOx generally takes place at temperatures of 350-450 ° C.

Example 9

The ortho titanate Ti (OH) ₄ was calcined at a temperature of 400 ° C. to make oxidized titanium, and 1 kg of oxidized titanium and 1050 g of ammonium molybdate were mixed in a kneader, and 500 ml of water was added and heated to knead the dough. After drying for 1 day at 150 ℃, pulverized to powder and preliminarily calcined at a temperature of 480 ± 20 ℃ for 5 hours. 140 ml of water per 1 kg of powder is added to the obtained powder and kneaded in a kneader for 2 hours to obtain a viscous material. It is made of viscous material in the form of 1.5mm diameter column, dried at 150 ℃ for 1 day, and then calcined at 450 ℃ for 2 hours to complete the sintered product. The product comprises 54% TiO ₂ , 46% M ₀ O ₃ by weight.

The strength of the product was measured with a compression burst strength meter and the measured strength was 5 kg / Peret in the radial direction.

In this embodiment, the sintered product including oxidized titanium and oxidized molybdenum has the ability to adsorb and remove hydrogen sulfide in the gas. The chemical reaction for adsorption is as follows.

M ₀ O ₃ + H ₂ S = M ₀ O ₂ S + H ₂ O

Adsorption is effective at 80-180 ° C.

The adsorbent can be easily regenerated by treatment with a gas containing oxygen and can be used repeatedly for adsorption of hydrogen emulsion.

Oxidized molybdenum not only adsorbs hydrogen sulfide but also acts as a binder.

Claims (1)

Depositing molybdenum oxide vaporized in a molybdenum atmosphere at a temperature of 460-650 ° C. on oxidized titanium powder; Making a powder mixture comprising an oxidized titanium active ingredient deposited with molybdenum oxide; After adding sufficient water to make a viscous substance to the powder mixture: kneading the powder mixture; Molding the article using a kneaded powder mixture: by sintering an active ingredient comprising oxidized titanium powder and oxidized molybdenum as a binder for oxidized titanium, comprising steps of calcining the molding to produce a product. Preparation method of gold network impregnated catalyst.

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