KR20030068905A - The removal catalyst for CO, SOx, NOx at a time. - Google Patents

Abstract

PURPOSE: Provided is a catalyst activated at low temperature and maintaining its activity at high temperature for removing CO, SOx, and NOx simultaneously and further provided is a method for manufacturing the same catalyst. CONSTITUTION: The method comprises the steps of preparing catalyst carrier by mixing alumina powder and silica powder to make powder mixture, adding activated carbon powder and binder to the powder mixture, compressing and plastic working the final mixture; preparing mixture of aqueous solution by dissolving titanium dioxide and tartar dioxide into ammonia liquor and water from which anions are eliminated; dipping the catalyst carrier into the mixture of aqueous solution; and rinsing and drying the catalyst.

Description

A catalyst that simultaneously removes carbon monoxide, sulfur oxides and nitrogen oxides {The removal catalyst for CO, SOx, NOx at a time.}

It is an object of the present invention to provide a catalyst which simultaneously converts a complex gas of carbon monoxide, nitrogen oxides and sulfur oxides into nitrogen and sulfur and does not lose activity for a long time.

Conventionally, a technique has been provided for removing a mixed gas of carbon monoxide, nitrogen oxides, sulfur oxides, or gases in which the above gases are separately present with separate conversion catalysts.

However, the prior art has a lot of economic burden because each installation a separate facility. At the same time, a technique for removing the above mixed pollutants has been developed, but it does not penetrate the active ingredient into the inside of the carrier and does not adhere evenly in attaching the active ingredient to the surface. I can't.

Therefore, the present invention has been proposed for the purpose of solving the above-mentioned problems. As a catalyst for simultaneously removing a mixture of carbon monoxide, nitrogen oxides and sulfur oxides, active coarse powder is evenly and firmly attached to the epidermis and activated at low temperature. It is an object to provide a catalyst that does not lose activity even in.

The catalyst for achieving the above object is a catalyst for simultaneously removing carbon monoxide, nitrogen oxides, and sulfur oxides. The composition is rutile TiO ₂ , which is a complex oxide of titanium dioxide (TiO ₂ ) and tin oxide (SnO ₂ ). Is done.

The catalyst preparation method of the present invention is a carrier prepared by compression molding and calcining by mixing the silica powder and the alumina powder in a weight ratio and adding activated carbon powder as a pore-forming agent to the blender in the above powder, or kaolin or ocher or elvan Activated carbon is mixed with a pore-forming powder by mixing 2-4 kinds of zeolite or carbon or silicon carbide alone or powders selected from the above-mentioned materials by weight ratio, and then mixing into spherical, tubular, honeycomb, cyclic, cylindrical, The carrier is prepared by compression molding and firing into fine spherical powder, plate shape, and various seed types.

Titanium dioxide (TiO ₂ ) and tin dioxide (SnO ₂ ) 20% -80% titanium sulfate (Ti ₂ (SO ₄ ) ₂ ) and tin chloride (SnCl ₄ , SnCl ₄ · 5H ₂ O) 20% -80% Was dissolved in anionized water to form a mixed aqueous solution. Then, water is ionically separated to make anion-free cationic water to dissolve citric acid in the above mixed solution, ammonia water (ammonia NH ₃ ) and water from which the anion is removed, and the above two solutions are mixed in the above dissolved solution, and the carrier is vacuum vessel. It is put in the vacuum container, and the vacuum container is evacuated to remove impurities and air present in the pores of the carrier, and then the above-mentioned mixed solution is injected into the vacuumed container. Then, the above-mentioned mixed solution is injected in a vacuum state and precipitated for 1 hour to 2 hours at normal pressure.

At this time, care should be taken to maintain the pH of the above-mentioned mixed solution 7-8.

And the precipitate impregnated in the mixed solution is washed with cationic water. At this time, the washings are washed until no chlorine ion (Cl ⁻ ) and sulfate ion (SO ₄ ^2- ) are detected.

The washed precipitate carrier was dried by drying for 10 hours-20 hours at 90 degrees Celsius-150 degrees Celsius and then heated for 2 hours-5 hours in an indirect heat of 400 degrees Celsius-700 degrees Celsius. A composite oxide catalyst composed of titanium (TiO ₂ ) and tin dioxide (SnO ₂ ) is obtained. As described above, the composition ratio of tin dioxide and titanium dioxide of the linguistic catalyst is 1: 1 by weight.

The surface ratio of the catalyst product prepared in the above manner is 95m ² g ^-1 -120m ² g ^-1 and has a tetragonal rutile structure of rutile (with rutile TiO ₂ ).

In addition, the catalyst of the present invention converts sulfur oxides and nitrogen oxides into S and N at 95% -100% with carbon monoxide as a reducing agent.

The catalyst of the present invention should be used with caution because the activity may be stopped in the presence of oxygen and water.

Example 1.

Select the powder of activated carbon as a pore-forming agent and mix it with the powder mixed with Silica and alumina in a weight ratio of 1: 1.2-2.5, and mix the above mixture into the binder, spherical, tubular, honeycomb, cyclic, cylindrical, plate, micro-spherical powder, The carrier is formed by compression molding into various seed types.

Alternatively, the activated powder is mixed with kaolin, ocher, and elvan, or kaolin, ocher and elvan, and mixed with pore and spherical, tubular, honeycomb, cylindrical, micro, spherical powder, plate, and various seeds. To form a carrier.

Alternatively, activated carbon is mixed with zeolite or powder of silicon carbide or carbon to have a large porosity, and then mixed in a binder and molded and compressed into each of the above forms to form a carrier.

In the above, the size of activated carbon as pore-forming agent is 1-100 mesh size depending on usage. And the mixing ratio of kaolin, loess, and elvan powder is 3: 2: 1 by weight.

And the above-mentioned carrier is fired by oxidative indirect heat of 1000 degrees Celsius-1600 degrees Celsius.

Example 2.

139.5804 g of titanium sulfate (Ti ₂ (SO ₄ ) ₂ ) and 180.2256 g of tin chloride (SnCl ₄ , SnCl ₄ · 5H ₂ O) are dissolved in 2,400 ml of deionized water. A solution of 25% ammonia was dissolved in 1800 ml of anion-free water.

Example 3.

Two solutions described above in Example 2 were added to a solution obtained by mixing citric acid 4 / 1-4 / 3 in 1200 ml of deionized water to prepare a solution of PH 7-8.

Example 4.

1.5 kg of the carrier described in Example 1 was placed in a sealed container and vacuumed to remove impurities and air present in the pores formed in the carrier. Then, the solution of Example 3 is first injected in a vacuum state, then the solution of Example 2 is injected, mixed uniformly, and precipitated for 1 hour to 2 hours at atmospheric pressure.

Example 5.

The precipitate described in Example 4 was washed with deionized water until no Cl ⁻ and SO ₄ ^2- were detected in the precipitate, dried at 90 ° C. to 150 ° C. for 10 hours to 20 hours, and then continued at 400 ° C. -Firing for 2 hours-5 hours with reducing indirect heat of 700 degrees Celsius.

Example 6.

200 ml of the microspherical powder catalyst prepared by the method described above in Example 1-5 was added to the reactor to react a material containing SO ₂ 525ppm, NOx 520ppm, CO 2085ppm and some Ar at 250 degrees Celsius to 500 degrees Celsius. Let's do it.

At this time, the air velocity of 2400hr ^-1 showed conversion of SO _{2 over} 96% and NOx 100% at a temperature of 350 degrees Celsius-400 degrees Celsius, and selectivity to select S and selectivity to select N ₂ were 100%. And even if the reaction time proceeded for 50 hours, the activity of the catalyst did not decrease.

According to the catalyst made according to the present invention as described above, the effect of removing the carbon monoxide, sulfur oxides, nitrogen oxides at the same time, there is an effect of reducing the installation cost and operating costs. And even when used for a long time does not wear and break effect.

Claims (9)

In the catalyst which removes carbon monoxide, sulfur oxides and nitrogen oxides simultaneously as a waste product as a pollutant, a mixed oxide mixed aqueous solution of titanium dioxide and tin dioxide is mixed and mixed with water having ammonia and anion removed to form a mixed solution to form a porous carrier. Carbon monoxide, sulfur oxides, characterized in that the catalyst product is prepared by impregnating the mixed solution in a vacuum in the pores formed inside and outside the carrier, and washed, dried and baked to form a rutile Catalyst for simultaneous removal of nitrogen oxides. The mixed oxide mixed aqueous solution of titanium dioxide and tin dioxide according to claim 1 is titanium sulfate (Ti ₂ (SO ₄ ) ₃ ) and tin chloride (SnCl ₄ , SnCl ₄ · 5H ₂ O), and the blending ratio is 20% by weight titanium sulfate. 80%: A catalyst for simultaneously removing carbon monoxide, sulfur oxides and nitrogen oxides, characterized in that the mixture is a mixture of 20% -80% tin chloride. The method of claim 1, the carrier is a powder containing a mixture of silica and alumina in a weight ratio of 1: 1.2-2.5, and the activated carbon is mixed with a pore-forming agent, or activated carbon is added to a single powder of kaolin, elvan, loess, zeolite, carbon, and silicon carbide. The mixture or the mixture of kaolin, loess, and albite is activated by oxidizing indirect heat of 1000 degrees Celsius to 1600 degrees Celsius by compression molding the mixture in which activated carbon is mixed into a mixed powder having a weight ratio of 3: 2: 1. A catalyst that simultaneously removes carbon monoxide, sulfur oxides and nitrogen oxides. The method of claim 1, the drying and firing of the precipitate is to dry the precipitate for 10 hours-20 hours at an indirect heat temperature of 90 degrees Celsius-150 degrees Celsius and then calcined for 2 hours-5 hours with oxidative indirect heat of 400 degrees Celsius-700 degrees A catalyst for simultaneously removing carbon monoxide, sulfur oxides, and nitrogen oxides. The mixed solution of claim 1, wherein the mixed solution of titanium dioxide and tin dioxide and an anion-free water in ammonia water is blended in the gastric mixture solution such that citric acid is 1 / 4-4 / 3 of the gastric mixed solution to PH 7-8. A catalyst for simultaneously removing carbon monoxide, sulfur oxides, nitrogen oxides, characterized in that the solution is maintained. The catalyst of claim 1, wherein the washing of the impregnated carrier is simultaneously performed by removing anion-free water until Cl ⁻ and SO ₄ ^2- are not detected. The method of claim 1, wherein the carrier is impregnated with the mixed solution in a vacuum. The carrier is placed in a sealed container and vacuumed, the mixed pressure solution is injected while removing impurities and air in the pores of the carrier, and the vacuum is released for 1 hour at normal pressure. A catalyst for simultaneously removing carbon monoxide, sulfur oxides and nitrogen oxides, which is a method of precipitation for 2 hours. The method according to any one of claims 1 to 3, wherein the carrier is a spherical, tubular, honeycomb, cyclic, cylindrical, microspherical powder, plate, various seed-like carbon monoxide, sulfur oxides, nitrogen oxides at the same time Catalyst to remove. It catalyst product according to claim 1 is a surface ratio of 95m ² g ^-1 -120m ² g ^-1 as rutile carbon monoxide, characterized in that it is a tetragonal crystal system rutile structure (TiO ₂ in rutile), removing sulfur oxides, nitrogen oxides, at the same time Catalyst.