JPS60161317A - Method for removing oxygen from oxygen-containing gas consisting essentially of carbon monoxide - Google Patents

Abstract

PURPOSE:To remove completely the oxygen contained in an oxygen-contg. gas consisting essentially of carbon monoxide by bringing said oxygen-contg. gas into contact with a binary composition catalyst consisting of a combination of copper oxide and zinc oxide whose substrate is reduced partially. CONSTITUTION:A catalyst is constituted of a binary composition catalyst consisting of copper oxide and zinc oxide whose substrate is reduced partially and the composition rate is regulated to 10-30wt%, preferably 20-40wt% copper oxide and 90-70wt%, preferably 80-60wt% zinc oxide. When an oxygen-contg. gas consisting essentially of carbon monoxide is brought into contact with the catalyst, 100% contained oxygen is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for removing oxygen from oxygen-containing scum containing -carbon oxide as a main component.

[Prior art] As a typical gas whose main component is carbon monoxide,
There are converter gas obtained from converters in steel plants, electric furnace gas obtained from electric furnaces, etc. Most of these gases are normally consumed as fuel, but recently various methods have been proposed for separating and recovering only carbon monoxide from these gases and using it as a raw material for organic synthetic chemistry.

In order to extract highly purified carbon monoxide from a gas whose main component is carbon monoxide, coexisting carbon dioxide, oxygen, etc. must be removed. Methods for removing carbon dioxide include, for example, absorption methods and adsorption methods, but oxygen cannot be removed by these methods. However, if carbon monoxide in the presence of oxygen is used in the synthesis reaction of formic acid, for example, the oxygen will have a serious negative effect on the reaction, so it is necessary to completely separate the oxygen beforehand. .

A known method for removing oxygen from a gas containing carbon monoxide as a main component and a small amount of oxygen is to bring the gas into contact with a copper catalyst. However, this type of known catalyst not only has low activity, but also has a short catalyst life and low sulfur resistance, so it is necessary to preheat the gas, increase the size of the deoxidizing group, and frequently replace the catalyst. Furthermore, if the gas contains sulfur compounds, they must be removed in advance. Therefore, the above-mentioned known catalysts have the disadvantage that the cost required for oxygen removal is high.

[Purpose of the Invention] As a result of extensive research into a method for removing oxygen from a gas containing oxygen and containing carbon monoxide as a main component, the present inventors have found that a method for removing oxygen from a gas containing oxygen and containing carbon monoxide as a main component, which solves the above-mentioned problems. By avoiding contact with the catalyst made of a zinc-based combination, 100% of the contained oxygen can be removed.Moreover, the catalyst itself has excellent sulfur resistance and durability, and with long-term use...
The present invention was achieved based on the knowledge that there is no loss of b activity.

[Structure of the Invention] That is, the present invention includes: - bringing an oxygen-containing gas containing oxidized carbon fiber as a main component into contact with a binary composition catalyst consisting of a combination of partially reduced copper oxide and zinc oxide; The gist of this paper is a method for removing oxygen from oxygen-containing scum containing carbon monoxide as a main component.

To explain the present invention in more detail, in the method of the present invention, the substrate is a binary composition catalyst consisting of partially reduced copper oxide (Cub) and zinc oxide (,2nO), and the composition ratio is Cub' : 10-30%, preferably 20%
-40% by weight, ZnO: preferably 900-70% by weight
A material made by adding 4 to 10 weight % of a binder such as graphite to this in a range of 60 weight % and molding it into a cylindrical shape with a diameter and height of about 3 m/m is used. Ru. The above catalysts are prepared by various known methods. For example, an alkali is added to a mixed solution of inorganic acid salts such as copper and zinc nitrates to adjust P[-1, copper and zinc hydroxides are coprecipitated, and the precipitated hydroxides are thermally decomposed. A method of partially reducing copper and zinc by forming it into an oxide and contacting it with a reducing gas containing a small amount of 112 gas or Co gas in an inert gas such as N2 gas; ? A mixed solution of t IX^ is immersed in a carrier such as alumina, thermally decomposed to form an oxide, and then molded. A method of partial reduction by contact treatment with a reducing gas in the presence of a gas; an inorganic binder such as graphite is added to a mixture of organic acid salts such as copper and zinc acetate, kneaded and molded, and then heated. Disassemble it'c! 11 compound, and is prepared by contact treatment with a reducing gas in which a small amount of 1-12 gas or Co gas is present in an inert gas as described above. In preparing the above-mentioned catalyst, partial reduction treatment is essential for increasing the catalytic activity.

In the method of the present invention, this partial reduction treatment can be carried out by filling a catalyst-packed tower with a binary composition catalyst consisting of a combination of CUO and 7nO, and then directly passing a reducing gas through the tower.

The method of the present invention involves reacting a small amount of oxygen present in a gas containing CO as a main component with CO to convert it into CO2.

The CO2 thus produced may be separated and removed by applying the iron acid method or the adsorption method in the next step after the oxygen removal step.

The reaction between oxygen and CO in the method of the present invention is an exothermic reaction, which has the advantage that a constant temperature is maintained by its own heat of combustion, and that no or only a small external heat source is required. Jru. Zunawara, full of catalysts! The holding temperature in the I column is in the range of room temperature to 230°C to sufficiently complete the oxygen removal reaction. The space velocity of the gas to be treated whose main component is CO to the catalyst-packed tower is 500 to 60.
It is possible to completely remove the trace amount of oxygen present by carrying out the treatment for a range of 10,000 hours.

The catalyst used in the method of the present invention has an extremely high efficiency in removing a small amount of oxygen contained in a gas containing CO as a main component, and has a long catalyst life, as compared to conventionally known copper catalysts.

Furthermore, even if a small amount of sulfur, which acts as a catalyst poison, is present in the gas in addition to oxygen, there is an advantage that the toxicity is low.

[Effects of the Invention] As described above, the method of the present invention involves bringing a gas containing GO as a product and a small amount of oxygen into contact with a binary composition catalyst consisting of a combination of partially reduced copper oxide and zinc oxide. This method completely removes the small amount of oxygen present in this method, and its oxygen removal rate, catalyst life, and reaction conditions are all far superior to conventionally known methods, and its industrial utility value is extremely human-friendly. be. Next, the present invention will be described with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

[Example] Example 1 3Qwt% CuCuO-2t prepared by Ba precipitation θ
N2 was added to a reaction tube (10 m/mφX400 m/m) filled with a binary composition catalyst consisting of
A reducing gas (100 cc/min) consisting of Co: 99.0 vol. , 5vo1%, N
2: 15.0 VO 1%, 02: 0.5 VO 1% of raw material gas containing CO as the main component at a pressure of 11 t (1/
aAG, at a space velocity of 50,000 hr, and the temperature regulation of the catalyst phase shown in FIG. 1 was passed. The relationship between the reaction temperature of the catalytic i-layer and the 02 removal rate at this time is shown in FIG. As comparative examples, cases in which a partially reduced CuO catalyst alone is used and a case in which a partially reduced 7nO catalyst alone is used are also shown. However, since the ZnO catalyst alone has extremely low activity, the space velocity was 1000 hr.

Note that the CuO-ZnO catalyst used in this example was prepared as follows. That is, the pH of a mixed solution of copper nitrate and zinc nitrate is adjusted with aqueous ammonia, coprecipitated as copper hydroxide and zinc hydroxide, filtered, dried, and then thermally decomposed at an atmospheric width of about 400°C to obtain an oxide powder. were mixed and molded.

As is clear from the results in Figure 1, partially reduced CuO
-The method of the present invention using a ZnO binary composition catalyst has 100
It can be seen that 02. can be easily removed from the 02-containing gas, which is mainly composed of CO, at a low temperature of about °C. In both cases, the detection limit (0.5 p
pm>, it was confirmed that 02 was almost completely removed.

Example 2 A Cu0-Zno binary composition catalyst prepared in the same manner as in Example 1 was filled in the same reaction tube as in Example 1 ( ]; after partial reduction by passing a reducing gas, the catalyst layer was Furnishing 180
C. and brought into contact with a test gas containing GO as the main component similar to that in Example 1 under the space velocity and pressure conditions shown in Table 1 below to measure the 02 removal rate. The results are shown in the same table. As is clear from this result, even if the spatial velocity is increased, o2
It can be seen that the removal rate does not decrease.

Table 1 Example 3 A reaction tube similar to that in Example 1 was filled with a CuO-ZnO binary composition catalyst prepared in the same manner as in Example 1, and a reducing gas was passed through it for partial reduction. , Catalyst Temple Warm Pox 180
Maintained at °C, CO: 84.5vol 1%, N2: 1
b, 0vo1%, 02:0.5V01%, H2S:
II) Test gas consisting of pm at normal pressure and space velocity 1
The U102 removal rate was measured after 0,000 hours to see if there was any decrease in activity.

The results are shown in FIG. As a comparative example, partial reduction (
) k Regarding the results when using a single CuO catalyst (+1 J).

As is clear from the results in Figure 2, partially reduced cu
In the method of the present invention using the o -z no o binary composition catalyst, no decrease in the 02 removal rate was observed even after 3000 hours of use, and the sulfur resistance was excellent and the activity was sufficiently maintained. In contrast, the CuO single catalyst of the comparative example loses its activity at a relatively early stage, and the 02 removal rate decreases.

Example 4 The same reaction tubes as in Example 1 were filled with CuO-ZnO binary composition catalysts prepared by changing CuO and Zno in various ratios, and after partial reduction by passing a reducing gas, a catalyst layer was formed. The temperature was maintained at 100° C., and the same test gas as in Example 1 was passed through at normal pressure and space velocity of 50,000 hr to examine the relationship between the 02 removal rate and the catalyst composition. The results are shown in Figure 3. As is clear from this result, in the method of the present invention, CU
O: 20-40% by weight, ZnO: 80-60Lffi%
It can be seen that for the catalyst composition of , the 02 removal efficiency is the most significant.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the 02 removal rate and catalyst bed temperature according to the method of the present invention, Figure 2 is a diagram showing the relationship between the 02 removal rate and catalyst usage time, and Figure 3 is a diagram showing the relationship between the 02 removal rate and the catalyst usage time. FIG. 3 is a diagram showing the relationship with catalyst composition. Agent: Patent attorney Tsutomu Setatetsu and 1 other person

Claims (1)

[Claims] 1. - Monoxidation characterized by bringing an oxygen-containing gas containing carbon oxide as a main component into contact with a binary composition catalyst consisting of a combination of partially reduced copper oxide and zinc oxide. A method for removing oxygen from an oxygen-containing gas whose main component is carbon. 2. The composition of the binary composition catalyst is 20 to 40% by weight of partially reduced copper oxide and 80 to 6% of partially reduced zinc oxide.
A method for removing oxygen from an oxygen-containing gas containing carbon monoxide as a main component according to claim 1.