JPH02276891A - Removal of carbonyl sulfide in gas - Google Patents

Abstract

PURPOSE:To easily, safely and economically accomplish the desulfurization by hydrolyzing a carbonyl sulfide-contg. gas using a catalyst with e.g. potassium carbonate carried on alumina to effect conversion into hydrogen sulfide. CONSTITUTION:Using a catalyst with potassium carbonate and/or sodium carbonate carried on gamma- or eta-type alumina, a carbonyl sulfidecontg. gas also containing NOx, unsaturated hydrocarbons and aromatic hydrocarbons is brought into contact with said catalyst at normal temperature to 100 deg.C under ca. normal pressure to effect hydrolysis of the carbonyl sulfide into hydrogen sulfide, thus removing said carbonyl sulfide.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to dry process gases such as coke oven and blast furnace gas in the steel industry, various generated gases in the oil refining industry, and flue gas in various industries. The present invention relates to a method for removing carbonyl sulfide in.

<Prior art and problems to be solved by the invention> Methods for removing carbonyl sulfide from gas include a dry method and a wet method.

As a wet method, MAL is suitable for practical use.
There is an APROP process (McCIure.

G,P,,and Marrow,D,C,,”MA
LAPROP process removes CO5
”, Hydrocarbon Processing
, Vol.

58, No 5. May 1979. P, 231
-33. ), this process is characterized by using the following reaction:

CO3+2DGA:BHEEU+H2SCOS+
H20#CO2+ H2SD G A
: DilycolamineBHEEU
: N, N-B15 (hydroxy ethoxy
ethyl)ureaFrom this formula, DGA acts as a catalyst and can be evaluated as an effective process. However, wet methods, including this process, are complicated;
Depending on the amount of gas to be processed, this is very disadvantageous economically.

For the dry method, metal oxides, molecular sieves,
It can be directly adsorbed and removed using activated carbon, or it can be converted into an easily removed compound using hydrogen, water vapor, oxygen, etc. in the gas, and then absorbed and removed. This method requires processing at relatively high temperatures or under pressure, which poses a problem.

Among these dry methods, Japanese Patent Laid-Open No. 49-22375 discloses a method that can remove the particles at a relatively low temperature. This method proposes that organic sulfur compounds are removed using a porous carrier carrying a secondary amine or its organic solvent solution as an absorbent. According to this method,
Secondary amines have a problem in that they have a short life due to their low carbonyl sulfide absorption performance, and therefore require frequent regeneration operations.

To overcome the problems of the conventional system,
A technique disclosed in Japanese Patent No. 645 was developed. This uses activated alumina containing silicon oxide as a catalyst to generate io at room temperature or higher.
The catalytic reaction below 0° C. is intended to hydrolyze and remove carbonyl sulfide in the gas at a low temperature. However, the technology shown in this publication, as shown in the claims thereof, uses hydrogen, C, and -C.

It is effective only for removing carbonyl sulfide from gases containing only hydrocarbons, and is effective for removing carbonyl sulfide from gases containing higher hydrocarbons with higher carbon numbers, such as aromatic hydrocarbons such as benzene and naphthalene. has not passed.

That is, there is a problem in that the aromatic hydrocarbons are adsorbed and deposited on the catalyst, which lowers the initial activity of the catalyst and significantly increases the rate of deterioration of its activity.6 To solve the above problems, Japanese Patent Publication No. 63-224
A technique disclosed in Japanese Patent No. 736 was proposed. This method uses a catalyst consisting of alumina and potassium hydroxide and/or sodium hydroxide to hydrolyze and remove carbonyl sulfide in a gas containing aromatic hydrocarbons such as benzene and naphthalene derivatives.

However, the technology disclosed in this publication poses safety problems because it uses potassium hydroxide and sodium hydroxide, which are designated as deleterious substances under the Poisonous and Deleterious Substances Control Law.
Both are highly deliquescent and generate significant heat when dissolved in water, which poses great danger in handling. Another fundamental problem is that potassium hydroxide and sodium hydroxide are strongly basic substances and dissolve silicon oxide, which is usually contained in alumina at an impurity of about 0.1% or more. As a result, the structure of alumina's crystals and pores changes, causing problems such as deterioration of performance as a catalyst and catalyst carrier, reduction in strength, and collapse.

That is, according to this method, although the rate of performance deterioration is suppressed, the initial activity is low, and therefore carbonyl sulfide in the gas cannot be sufficiently removed unless the reaction temperature is increased. Solving this problem by increasing the purity of the alumina results in significant costs and introduces new problems in industrial scale implementation.

Generally, the process gas is a reaction product and therefore has a high temperature, and in order to recover the effective components in the gas, it is cooled to around room temperature by spraying water like coke oven gas. Therefore, the dew point of the processing gas often rises to 25 to 35 degrees Celsius,
Its moisture concentration increases to 3-6%.

In low-temperature hydrolysis, as mentioned above, a large amount of water causes an irreversible decrease in activity, and as shown in Figure 5, the degree of activity is significantly reduced in potassium hydroxide-supported alumina compared to potassium carbonate-supported alumina. ing. Therefore, when desulfurizing a general processing gas and using potassium hydroxide-supported alumina, it becomes necessary to newly install a dehumidifying device for the processing gas in order to maintain the activity to some extent.

This also applies to sodium hydroxide-supported alumina.

As described above, the influence of water on low-temperature hydrolysis performance is large, and when the amount is large, it causes irreversible performance deterioration. In the case of potassium hydroxide-supported alumina, the degree of dehumidification is significantly greater than that of the catalyst according to the present invention, and in order to use this for general gas treatment and put it into practical use, a new gas dehumidification device must be installed. There are many problems such as nara.

Desulfurization treatment is generally unproductive and is used for pollution prevention,
This is done to protect other catalysts or prevent product quality deterioration (for example, coloring of polyurethane) due to sulfur.
Therefore, it is desirable that the processing cost be as low as possible, and therefore low-temperature desulfurization that does not require heating is strongly desired. Even if you try to maintain it, new problems will arise, such as the need for a gas dehumidifier.

Furthermore, JP-A-61-46244 discloses a technique for hydrolyzing and removing organic compounds (carbonyl sulfide, carbon disulfide) and hydrogen cyanide contained in CO gold-containing process gas.

This is an attempt to hydrolyze the above substance at high temperature (100 to 350°C) and high pressure (5.1 to 41.8 atmospheres in the examples) using an alkalized chromium oxide-aluminum oxide catalyst.

In the technology disclosed in this publication, as is clear from the description of the main points of the invention, the main premise for catalyst preparation is to immerse the aluminum oxide support in a chromium salt solution, then dry and calcinate it. Therefore, when manufacturing a catalyst, a large amount of man-hours and costs are required for supporting and firing chromium oxide.

Further, the conditions for using the catalyst are a high temperature of 100° C. or higher and a high pressure of 5 atmospheres or higher. If it is attempted to hydrolyze carbonyl sulfide, etc. under such high temperature and high pressure conditions, serious new problems will arise as described below.
In other words, when removing carbonyl sulfide from gas such as coke oven gas, which contains a large amount of unsaturated hydrocarbons such as nitrogen oxides and dienes, if the reaction temperature is raised, the nitrogen oxides and unsaturated hydrocarbons in the gas will be removed. Hydrocarbons or unsaturated hydrocarbons undergo a polymerization reaction to produce a gum-like substance.

High pressure further accelerates the reaction. The gummy material adheres to the catalyst in the catalyst bed, clogging the catalyst bed and making it impossible to operate the reactor. Many experimental studies have been conducted in the past to solve this problem (for example, Japanese Patent Application Laid-Open No. 59-2
32174, Japanese Patent Application Laid-open No. 59-232175)
However, it seems that a low-cost and easy solution has not yet been found. As described above, the technique disclosed in Japanese Unexamined Patent Publication No. 61-46244 causes new serious problems, and the object of the invention according to the present application cannot be achieved.

The present invention aims to solve the problems of the prior art, and has high activity at a reaction temperature as close to room temperature as possible, and a low rate of performance deterioration even when a relatively large amount of water is present in the processing gas. An object of the present invention is to provide a method for removing carbonyl sulfide from a gas containing nitrogen oxides and/or unsaturated hydrocarbons and/or aromatic hydrocarbons such as benzene and naphthalene derivatives by using a catalyst.

Currently, hydrogen sulfide in gas is generally absorbed and removed at room temperature using iron-based absorbents (for example, Japanese Patent Application No. 62-123023), and various types are commercially available.

Therefore, if carbonyl sulfide can be converted to hydrogen sulfide at the above-mentioned low temperature, the generated hydrogen sulfide can be removed easily and inexpensively by conventional methods, making it a very promising industrial process.

Means for Solving the Problems The present inventors impregnated alumina with various metal compounds and conducted intensive research on the effect of removing carbonyl sulfide in gas. and ease,
The present invention was developed by considering ease of acquisition, price, etc.

That is, the present invention provides a method of hydrolyzing carbonyl sulfide and converting it into hydrogen sulfide by using a catalyst in which potassium carbonate and/or sodium carbonate is supported on alumina, and bringing a gas containing carbonyl sulfide into contact with the catalyst. It is something.

The present invention will be explained in more detail below.

As mentioned above, the technology using activated alumina alone, activated alumina supported with potassium hydroxide or sodium hydroxide, or alkalized chromium oxide-aluminum oxide that has been proposed for removing carbonyl sulfide in gases is as follows:
It has disadvantages such as a high rate of performance deterioration, a low initial activity, and therefore the reaction temperature must be raised to 100° C. or higher, and clogging of the catalyst layer by polymerized gum, which is likely to occur under high temperature and high pressure conditions.

Carbonyl sulfide is an acidic gas, and in order to remove it, activated alumina with basicity is effective, and metals with low electronegativity such as cesium, francium,
It is theoretically predicted that if activated alumina is impregnated with potassium, rubidium, sodium, barium, radium, lithium, calcium, strontium, lanthanum, actinium, magnesium, etc., the removal effect will be improved.

As a result of repeated searches for the various metals mentioned above, in the present invention, a catalyst consisting of potassium carbonate and/or sodium carbonate and alumina is used, and a gas containing carbonyl sulfide is brought into contact with the catalyst to hydrolyze carbonyl sulfide. By using the method of converting hydrogen sulfide into hydrogen sulfide, it is possible to eliminate relatively large amounts of moisture and/or nitrogen oxides and/or unsaturated hydrocarbons and/or aromatic hydrocarbons such as benzene and naphthalene derivatives in the target gas. However, the performance deterioration rate of the catalyst is small, and the initial activity is high, making it possible to lower the reaction temperature from room temperature to 100°C, which suppresses the generation of polymerized gum and prevents clogging of the catalyst layer. Furthermore, it has been found that this method is advantageous in terms of catalyst production since no deleterious substances are used.

It has been found that, as the active metal compound, in addition to carbonates and hydroxides, organic acid salts such as hydrogen carbonates, acetates, and oxalates can also be used, although their performance deteriorates.

The alumina support used in the present invention has seven types of modified forms: α type, θ, δ, γ, η, χ, and ρ types. It is preferable to use molded alumina.

Note that if the alumina content in the carrier is 3 to 5% by weight or more, it will be effective as a carrier for the carbonyl sulfide removal catalyst, and preferably the alumina content should be 20% by weight or more.

The catalyst used in the present invention is prepared by immersing the alumina in an aqueous solution of potassium carbonate and/or sodium carbonate.
~! It can be easily prepared by drying at 50°C for several hours. There are various methods for impregnating the alumina with potassium carbonate or sodium carbonate, such as mixing it with alumina powder and granulating it, but the easiest method is to impregnate it by immersing it in an aqueous solution as described above.

The aqueous solution of potassium carbonate or sodium carbonate to be impregnated is
The concentration used is 0.5 to 40% by weight, preferably 2 to 201% by weight. If it is smaller than this range, the amount of potassium carbonate or sodium carbonate impregnated will be too small to be effective, and the drying time and cost will be increased.

If it is larger than this range, it is not preferable because the effect may be diminished due to pore clogging of alumina or suppression of diffusion within the pores.

The time for immersing alumina in the aqueous solution varies greatly depending on the alumina used and the amount of impregnation, from several seconds to several hours, so select an appropriate time according to the alumina used and the target amount of potassium carbonate or sodium carbonate to be impregnated after drying.

The alumina that has been immersed in the aqueous solution for an appropriate time and impregnated with an aqueous solution of potassium carbonate or sodium carbonate is dried preferably at a temperature of 250°C or lower, more preferably at a temperature of 100°C to 14°C.
It is carried out at a temperature of about 0 tl. At this time, heating above 300°C is not preferable because it causes transformation of the alumina and decreases the activity.

The amount of potassium carbonate and/or sodium carbonate to be impregnated into alumina is 0.5 to 0.5 to the weight of alumina.
401% by weight, preferably in the range from 5 to 15% by weight. If an amount outside this range is impregnated, a problem similar to that which occurred when selecting the concentration of the aqueous solution described above will occur, which is not preferable.

The method for removing carbonyl sulfide from gas according to the present invention is carried out in the following steps using the aforementioned potassium carbonate and/or sodium carbonate supported on alumina as a catalyst.

First, the potassium carbonate and/or sodium carbonate supported on alumina is used as a catalyst and packed into a packed column. Next, the gas containing carbonyl sulfide is allowed to flow into the packed column. At this time, the catalytic reaction operating conditions are as follows:
The temperature is preferably from room temperature to 100°C, particularly from 40 to 80°C, which is close to room temperature. If the temperature exceeds 100°C, the reaction rate will increase, but as mentioned above, nitrogen oxides and unsaturated hydrocarbons will react, and gum-like substances will begin to form, causing clogging of the catalyst bed in the packed column, so this is not preferred. Moreover, since the pressure can be set around normal pressure (it can be used even under increased pressure), the method of the present invention has a feature of great practical value.

Here, in the packed bed, carbonyl sulfide is converted to hydrogen sulfide by the following reaction (1).

COS+H20-H2S+CO2 (1) Reaction (1) has occurred by detecting hydrogen sulfide in the gas after treatment by the method of the present invention in an amount approximately equivalent to the carbonyl sulfide contained in the gas before the reaction. It has been proven that there is.

The amount of water required for the reaction should be at least the reaction equivalent to the carbonyl sulfide contained in the gas to be treated.
There is no need to add a considerable amount of water, unlike the operating conditions used in water-splitting reaction catalysts (ratio of water vapor to process gas of about 0.3:1); on the contrary, excess water will not condense on the catalyst. Not inviting.

As mentioned above, the hydrogen sulfide produced by reaction (1) is
It can be easily absorbed and removed at room temperature using an iron-based absorbent.

Note that the shape and dimensions of the catalyst used in the present invention may be selected appropriately by considering the pressure loss in the packed column, the dust concentration in the treated gas, etc. , ring shape, etc. may be used.

As mentioned above, by using the catalyst according to the present invention,
In a simple packed bed, carbonyl sulfide in a gas containing a relatively large amount of water and/or nitrogen oxides and/or unsaturated hydrocarbons and/or aromatic hydrocarbons such as benzene and naphthalene derivatives is heated at room temperature to 100% It can be removed with high efficiency at a low temperature of ℃ for a long period of time.

<Examples> The present invention will now be described in more detail with reference to Examples and Comparative Examples.

(Example 1 and Comparative Example) Alumina impregnated with potassium carbonate or sodium carbonate according to the present invention and alumina alone as a comparative example were used as catalysts to investigate carbonyl sulfide removal performance. In this example, a catalyst was prepared by immersing alumina (γ type) in a 10% by weight potassium carbonate or sodium carbonate aqueous solution for about 1 minute, and then drying it at 110° C. for 1 hour.

The reaction conditions are as follows.

(1) Gas: Coke oven gas (main component) H2: 54-57%, 02: 0.11-0
．． 3%, N: 3-4%, CH4: 24-27%, Co
: 6-9%, C02: 2-4%, CmHn (dienes, etc.) 2-4%, Moisture: 5-10℃ saturated (trace components) C
O3: 50-80ppm.

BTX (benzene, toluene, xylene): 3-8
g/Nm'NHs: 0.05-0.41g
/Nm' Naphthalene: 0, 03~0, 26 g/Nm'NO:
5ppm (2) IA gas amount: 311/m1n (3) Catalyst filling amount: 100m1! (4) SV (space velocity): 1800h-' (5) Shape,
Dimensions: 2 balls, diameter 3-5mm (6) Temperature: 60℃ (7) Pressure: Normal pressure (8) Impregnation rate of potassium carbonate or sodium carbonate:
Figure 341 shows the experimental results of 1 to 38% alumina weight relative to alumina. For alumina alone 3, 8
Although only a little less than 0% CO8 removal performance is obtained, in the method according to the present invention, improvement in removal performance is observed with a small amount of impregnation for both potassium carbonate 1 and sodium carbonate 2. The removal performance is improved when the amount of potassium carbonate or potassium carbonate impregnated is about 0.5% by weight based on the alumina.
The removal performance is almost constant in the range of 5 to 30% by weight,
On the contrary, when the impregnation amount is 30% by weight or more, the performance deteriorates. In view of the relationship between the preparation operation of the catalyst according to the present invention, cost, and catalyst performance, the amount of impregnation is preferably in the range of 5 to 15% by weight.

(Example 2) According to the present invention, potassium carbonate was added to alumina in 12.
Figure 2 shows the relationship between the carbonyl sulfide removal performance of alumina impregnated with 11i mass % and the reaction temperature. , followed by drying at 110° C. for 1 hour.

The reaction conditions are as follows.

(1) Processing gas: Same as Example 1 (2) Processing gas amount 2 0.75-317m1n (3) Catalyst filling amount: 100mJ! (4) SV: 450-1800h-' (5)
Shape and dimensions: Same as Example 1 (6) Temperature = 20 to 80°C (7) Pressure: Normal pressure SV under 3 conditions (450 (6 in Figure 2), 900 (2nd
5) in the figure, 1aoo (4) h-' in Figure 2) were carried out, but in all three conditions, the removal performance increases rapidly when the reaction temperature is 40° C. or higher. In particular, it can be seen that sufficient carbonyl sulfide removal performance can be obtained at a low reaction temperature of 40° C. if the SV is set to about 500 h-' or less.

(Example 3 and Comparative Example) In Example 2, the change over time in the carbonyl sulfide removal performance of Catalyst 7 according to the present invention, which was demonstrated to exhibit excellent low-temperature activity, was investigated.

As a comparative example, changes over time in the carbonyl sulfide removal performance of alumina 8 impregnated with potassium hydroxide at 12.3% by weight compared to the alumina used in this example and 9 alone of this example were also investigated under the same conditions. .

When preparing the catalyst of this comparative example, the surface of the alumina carrier was partially dissolved and disintegrated in the potassium hydroxide aqueous solution. The yield of the carrier at this time was 78% by weight.

The reaction conditions are as follows.

(1) Processing gas: Same as Example 1 (2) Processing gas amount: 3.331/m1n (3) Catalyst loading amount: 100mj2 (4) SV: 2000h-' (5) Shape and dimensions: Same as Example 1 Same (6) Temperature: 50℃ (7) Pressure: Normal pressure The experimental results are shown in Figure 3. Alumina 7°8 impregnated with potassium carbonate or potassium hydroxide has better removal performance than alumina alone 9. The activity is high, and almost no decrease in activity is observed even after about 30 days. Further, the potassium carbonate-impregnated alumina 7 has higher activity than the potassium hydroxide-impregnated alumina 8.

(Example 4 and Comparative Example) Alumina 10 impregnated with sodium carbonate according to the present invention
The changes over time in the carbonyl sulfide removal performance of Alumina 11 impregnated with sodium hydroxide and as a comparative example were investigated. The impregnated amounts of sodium carbonate and sodium hydroxide are
They were 10.3 and 9.7% by weight, respectively.

In this comparative example as well, the alumina carrier collapsed during impregnation with an aqueous sodium hydroxide solution, and the yield of the carrier was 82% by weight.

The same reaction conditions as in Example 3 were used.

The experimental results are shown in Figure 4. In both cases, the decrease in activity was approximately 3
Although it was hardly seen after 0 days, the activity of alumina 10 impregnated with sodium carbonate was higher than that of alumina 11 impregnated with sodium hydroxide.

(Example 5 and Comparative Example) The influence of moisture in gas on performance was investigated using the two types of catalysts prepared in Example 3 and Comparative Example.

(1) Processing gas components: Same as Example 1 except for water content being 3 to 5% (2) Processing gas amount: 0.833 A/win (3) Catalyst filling amount: 100rnJ2 (4) sv: 5ooh -' (5) Shape and dimensions: Same as Example 1 (6) Temperature: 40°C (7) Pressure crab The results of the normal pressure experiment are shown in FIG.

As is clear from Figure 5, when the amount of water in the gas is large, the deterioration rate of alumina 13 impregnated with potassium hydroxide is much faster than that of alumina 12 impregnated with potassium carbonate, which is due to the This is thought to be due to the difference in hygroscopicity. Hydrolysis at low temperatures is different from that at high temperatures (adsorbed water and COS in the gas phase react (Reference: R9Fiedorow).
et al,, Journal of
Catalysis vol.

85 (1984), 9.339), it is thought that the CO5 adsorbed to the active sites on the catalyst reacts with the absorbed water. Therefore, it is presumed that if the water concentration in the gas is too high, the number of active sites that can adsorb CO3 will decrease, and the reaction rate will conversely decrease. Potassium hydroxide has a stronger ability to adsorb water than potassium carbonate, and therefore COS
It is thought that the amount of adsorption becomes small, leading to a significant decrease in activity as shown in FIG. Furthermore, it was difficult to desorb the adsorbed water, and the activity did not recover even after heating and drying at 200 to 300°C.

As described above, when the moisture content in the gas increases, the catalytic activity irreversibly decreases, and the degree of this decrease is remarkable for potassium hydroxide.

(Example 6 and Comparative Example) Using the two types of catalysts prepared in Example 3 and Comparative Example, the influence of moisture in gas on performance was investigated in detail.

(1) Processing gas: Same as Example 1, except that the water content is 1.2.2.4.4.6. 5.6voj! % (2) The processing gas amount, catalyst loading amount, SV, shape, dimensions, temperature, and pressure are the same as in Example 5. The experimental results are shown in Figure 346 (initial performance example).

(Performance tends to decrease as usage time increases).

As the moisture content in the gas increases, the performance of the alumina 15 impregnated with potassium hydroxide by the conventional method decreases significantly. In particular, when the moisture content is 5% or more, the decrease is severe, and it cannot be used to treat coke oven gas, etc., which is generally cooled with water, especially in the summer when the moisture content increases significantly.

The catalyst 14 according to the present invention is also applicable to gases having a moisture content of 4 to 6% or less, such as the above-mentioned coke oven gas, although the performance is also slightly lowered.

As described in Example 5, once both catalysts adsorb a large amount of water in the gas, their performance irreversibly deteriorates and they cannot be regenerated. Therefore, it is judged that it is practically difficult to apply the potassium hydroxide-impregnated alumina catalyst according to the conventional method to low-temperature desulfurization of gas containing a relatively large amount of water, such as coke oven gas.

<Effects of the Invention> According to the method for removing carbonyl sulfide in gas of the present invention,
Carbonyl sulfide can be hydrolyzed very easily using a catalyst containing potassium carbonate and/or sodium carbonate supported on alumina, which is safe to handle, does not cause the disintegration of the alumina support, and is easily available and inexpensive. It can be converted into hydrogen sulfide. In other words, it is possible to economically remove the reaction temperature at a low temperature close to room temperature and around normal pressure, and relatively large amounts of moisture and/or nitrogen oxides and/or unsaturated hydrocarbons and/or benzene and Even in the removal of carbonyl sulfide from gases containing aromatic hydrocarbons such as naphthalene derivatives, the rate of activity decline is small, and the generation of polymerized gum and clogging of the catalyst layer due to it can be suppressed, making it suitable for practical use. It is bearable.

Note that the generated hydrogen sulfide can be economically removed at room temperature and pressure by a normal method using an iron-based absorbent and will not cause any problems.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the amount of potassium carbonate or sodium carbonate impregnated and the carbonyl sulfide removal performance. FIG. 2 is a diagram showing the relationship between the carbonyl sulfide removal performance of the catalyst according to the present invention and the reaction temperature. FIG. 3 is a diagram showing changes over time in carbonyl sulfide removal performance by the method of the present invention and the conventional technology. FIG. 4 is a diagram showing changes over time in carbonyl sulfide removal performance by the method of the present invention and the conventional technology. FIG. 5 is a diagram showing changes over time in the carbonyl sulfide removal performance of the catalyst according to the present invention and the catalyst according to the prior art when the moisture content in the gas is relatively high. FIG. 6 is a diagram showing a comparison of the influence of moisture in gas on the carbonyl sulfide removal performance of the catalyst according to the present invention and the catalyst according to the prior art.

Claims (6)

[Claims] (1) Using a catalyst in which potassium carbonate and/or sodium carbonate is supported on alumina, a gas containing carbonyl sulfide is brought into contact with the catalyst to hydrolyze carbonyl sulfide and convert it into hydrogen sulfide. Method for removing carbonyl sulfide. (2) The method for removing carbonyl sulfide from a gas according to claim 1, wherein the gas contains nitrogen oxides and/or unsaturated hydrocarbons and/or aromatic hydrocarbons. (3) Claim 1, wherein the alumina is γ type or η type.
Or the method for removing carbonyl sulfide in a gas according to 2. (4) The catalyst is prepared by immersing alumina in an aqueous solution containing 0.5 to 40% by weight of potassium carbonate and/or sodium carbonate and then drying the catalyst. Removal method. (5) The method for removing carbonyl sulfide from a gas according to any one of claims 1 to 4, wherein the amount of potassium carbonate and/or sodium carbonate impregnated in the catalyst is 0.5 to 40% by weight based on alumina. (6) The catalytic reaction between the gas and the catalyst is carried out at room temperature
The method for removing carbonyl sulfide in a gas according to any one of claims 1 to 5, which is carried out at a temperature of 0°C and a pressure near normal pressure.