JPS6330310A - Production of adsorbent for separating carbon monoxide - Google Patents

Abstract

PURPOSE:To obtain the title adsorbent having excellent durability and capable of efficiently and inexpensively separating high-purity CO from blast-furnace gas, converter gas, etc., by mixing the fine powder of activated carbon with the aq. soln. of a specified resol-type phenolic resin, granulating and drying the mixture, and then heating the obtained material in an inert gaseous atmosphere. CONSTITUTION:From 10-30wt% resol-type phenolic resin soln. wherein 0.1-0.5 milliequivalent g/g activated carbon of a group IB metal ion of the periodic table (e.g., monovalent Ag and Cu ions from AgCl, CuCl, etc.) is dissolved and which is diluted by 2-3 times with water or aq. ammonia is mixed with <=100-mesh fine activated carbon powder, and sufficiently mixed. The mixture is granulated into pellets having 2-3mm diameter, for example, by an extruder, and dried. The dried pellets are heated in an inert atmosphere of gaseous N2, etc., at 150-500 deg.C in a heating furnace.

Description

[Detailed Description of the Invention] Industrial Field of Application This invention relates to an adsorbent for recovering carbon monoxide used as a raw material for synthetic chemistry, metallurgy, etc., and in particular contains multiple carbon monoxides together with nitrogen. The present invention relates to a method for producing an adsorbent that can efficiently separate and recover high-purity carbon monoxide from steelworks byproduct gases such as blast furnace gas and converter gas.

Conventional technology and its problems Steel mill gases such as blast furnace gas and converter gas contain high concentrations of carbon monoxide, and it is difficult to recover carbon monoxide from these byproduct gases industrially. Beneficial. However, these byproduct gases usually contain a large amount of nitrogen, and since the physical properties of carbon oxide and nitrogen are similar, it is possible to separate carbon oxide and nitrogen industrially at low cost. very difficult to do. Therefore, this separation from nitrogen
1 This poses a major problem when separating and recovering carbon monoxide from raw gas.

Incidentally, as conventional methods for separating carbon monoxide and nitrogen, absorption methods, deep cooling methods, adsorption methods, etc. are known. Among these methods, the absorption method and the cryogenic method are superior to the adsorption method in that they can produce high-purity carbon monoxide with a high yield of P, but they have the disadvantage of high production costs.

On the other hand, the pressure swing adsorption method (PSA method), which is based on an adsorption method, is theoretically cheaper to produce than the absorption method and deep cooling method, but the production cost is 4iir! However, there is no adsorbent that can separate the process with high yield, so it is still difficult to say that this is an established technology.

Currently known adsorbents include silica gel, activated carbon, activated alumina, and zeolite. Among these, the adsorbents that are effective for separating carbon oxide and nitrogen include zeolite, which has a molecular sieving effect, and zeolite, which has a specific surface area. An example is one in which a metal salt is supported on a large adsorbent (polymer material, activated carbon, etc.).

However, in the case of the separation method using zeolite described in (2), separation is carried out by utilizing the difference in adsorption speed between carbon monoxide and nitrogen, but because the adsorption selectivity of zeolite for carbon monoxide is insufficient, the purity of carbon monoxide is Attempts to increase the product yield result in an extremely low product yield, and conversely, attempts to increase the product yield result in a decrease in the purity of carbon monoxide, which poses many practical problems.

How to use: In the case of an adsorbent loaded with a metal salt as described in (■) above,
Polymer materials and activated carbon inherently do not have molecular sieving properties, and separation is based on chemisorption of so-called -carbon oxide onto metal sites, so it is necessary to support a large amount of metal salts, and as a result, the adsorbent This method was undesirable because it was expensive and had drawbacks such as difficulty in desorption of adsorbed gas components and reduced product yield.

On the other hand, in order to impart molecular sieving properties to activated carbon, a method of producing molecular sieve carbon by coating the surface of activated carbon with an organic substance such as phenol resin and then heat-treating it (Japanese Patent Laid-Open No. 59
-230638), a method of producing molecular sieve carbon by granulating activated carbon with a phenolic resin and then heating it (Japanese Patent Application Laid-open No. 59-230637), but these methods simply produce molecular sieve carbon. Even if only the properties are improved, the adsorption selectivity for carbon oxide is insufficient, and like the zeolite described above, it is not preferable as an adsorbent for separating carbon oxide.

Purpose of the Invention The present invention was made in order to solve the above-mentioned problems in the conventional method of separating and recovering carbon monoxide using an adsorbent. The purpose of this paper is to propose a low-cost method for producing an adsorbent for carbon monoxide separation that exhibits extremely good desorption properties.

Structure of the Invention The method for producing an adsorbent for carbon monoxide separation according to the present invention includes:
10 to 30% of a resol type phenol resin aqueous solution in which 0.1 to 0.5 milliliter of group IB metal ion (110-activated carbon is dissolved) is blended into fine powdered activated carbon, and after mixing, granulation, and drying, This invention is characterized by heating at a temperature of 150 to 500°C in an active atmosphere.In other words, the present invention aims to improve the adsorption selectivity of activated carbon to carbon monoxide and the desorption performance of adsorbed gas components. As a binder for granulation, a water-soluble resol-type phenolic resin in which group IB metal ions are dissolved in advance is used. This binder and finely powdered activated carbon are mixed, and after granulation and drying, the binder is This method heats and hardens the resin.

In this invention, a resol type phenolic resin is used as a binder because it is water-soluble and easily mixed with finely powdered activated carbon. In addition, in order to facilitate mixing with fine powder activated carbon, the phenol resin is preferably used after being diluted 2 to 3 times with water or aqueous ammonia.

The reason why the metal ions are dissolved in the phenolic resin is that the phenol resin coats the activated carbon during the mixing and granulation process, thereby effectively dispersing the metal ions and reducing the amount of metal ions used. Ingredients (-carbon oxide)
This is to improve the ease of attachment and detachment. The reason why a Group IB metal ion was used as this metal ion is that it has a suitable affinity for -carbon oxide and has both adsorption selectivity and easy desorption properties for -carbon oxide. The IB group metal ion is not particularly limited, but -valent A♂ ions or a ions are preferred because their metal salts are easily available and inexpensive.

In the case of metal salts with low solubility in water, such as silver chloride and copper(I) chloride, for example, these metal salts are dissolved in ammonia water in the form of complex ions, and this is mixed with the phenol resin. It is preferable to use a phenol resin aqueous solution in which Ai ions or a ions are dissolved.

The amount of metal ions used is limited to 0.1 to 0.5 milliequivalent duram per gram of activated carbon, because if the amount of metal ions used is less than 0.1 milliequivalent duram per gram of activated carbon, it will not be effective. On the other hand, if the amount exceeds 0.5 milliequivalent duram, it becomes difficult to desorb the adsorbed carbon monoxide at room temperature.

In this invention, the group IB metal ion dissolved in advance in the aqueous solution of the phenolic resin is used as the binder, but the amount of the binder added to the finely powdered activated carbon is limited to 10 to 30% by weight. If the content is less than 30% by weight, the strength of the granules will not be sufficient, whereas if it exceeds 30% by weight, the granules will adhere to each other and form agglomerates.

After mixing, granulating, and drying the fine powder activated carbon and the binder, this invention is characterized by heating at a temperature of 150 to 500°C in an inert atmosphere, but the heat treatment temperature is 150 to 500°C.
The reason for limiting the temperature to 00°C is that at a heating temperature of less than 150°C, the thermosetting of the phenolic resin is insufficient and an adsorbent with sufficient strength cannot be obtained, while at a temperature exceeding 500°C, the thermal decomposition of the phenolic resin occurs. This is because the strength of the adsorbent decreases as it progresses. Furthermore, the reason for the inert atmosphere is to prevent a decrease in activity due to oxidation of the added metal ions. The heat treatment time is not particularly limited, but if it is less than 1 hour, the thermosetting of the phenol resin will be insufficient, and on the other hand, if the heat treatment is performed for 4 hours or more, no improvement in the strength of the adsorbent will be observed. 1 to 4 hours is preferable.

The type of activated carbon used in this invention is not particularly limited, but activated carbon derived from coal is preferred because it is inexpensive and easily available.

FIG. 1 is a block diagram showing the method of this invention.

That is, as mentioned above, fine powder activated carbon (100 mesh or less) is mixed with IB group metal salts (AaCa, Cu(J
etc.) 10 to 30% by weight of a resol type phenolic resin diluted 2 to 3 times with water or aqueous ammonia in which 0.1 to 0.5 milliequivalent Q/Q-activated carbon is dissolved and mixed thoroughly, In the granulation process, for example, with an extruder, the particle size is 2 to 3 mm.
Pellets of φ are granulated. After drying the obtained pellets,
In the heating process, heat treatment is performed at a temperature of 150 to 500° C. using, for example, a heating furnace in an inert atmosphere such as nitrogen gas.

In the mixing and granulation process, the activated carbon is coated with a phenolic resin containing group IB metal ions, and the added metal ions are uniformly dispersed, so the amount of metal ions used is small, and - The removability is also improved. Also,
During the heating process, fine pores are generated in the phenolic resin,
Because these pores act as a kind of molecular sieve,
The adsorption selectivity of carbon monoxide to nitrogen becomes even more excellent.

Example 1 Activated carbon produced by activating 1-11-1th coal with carbonized condensate steam (specific surface area 973 m2/(J) was pulverized to 100 mesh or less, and based on 80% by weight of this fine powder activated carbon,
A 20% by weight aqueous phenolic resin solution diluted twice with ammonia water containing silver chloride dissolved therein is blended at room temperature, thoroughly mixed, and then granulated into pellets with a particle size of 2 to 3 mmφ using an extrusion molding machine. After drying at a temperature of 110° C. for 2 hours, heat treatment was performed for 3 hours at a temperature of 250° C. in a nitrogen gas atmosphere using a heating furnace.

The adsorbent thus obtained has an internal volume of 0.02.
046 i stainless steel! filled into a fill adsorption tower,
Using carbon monoxide with a purity of 99.9%, measure the amount of carbon monoxide adsorbed at a temperature of 20°C and an equilibrium pressure of 2ata, and after reaching adsorption equilibrium, leave it alone and reduce the pressure to 60 Torr to determine the amount of carbon monoxide desorbed. was measured. A similar adsorption/desorption test was also conducted for nitrogen using a gas with a purity of 99.9%.

The result of this example is A? Table 1 shows a comparison between an adsorbent prepared by the same method as described above using an aqueous phenolic resin solution to which no ions were added and an aqueous phenolic resin solution with an A ion content exceeding the range of the present invention.

As is clear from Table 1, the amount of carbon monoxide adsorbed by the adsorbent prepared by dissolving A, / ions in the aqueous phenol resin solution used as a binder was - It can be seen that the number has increased compared to 5. However, ~゛Ion amount 0.5 milliequivalent q/
In the case of Comparative Test No. 4, which exceeds g-activated carbon, although the amount of carbon monoxide adsorbed to the adsorbent was large, the carbon monoxide desorption rate began to decrease when the pressure was reduced to 60 Torr. Therefore, it can be seen that the amount of 4 to ions is preferably 0.5 millimeters g/c+-activated carbon or less as described above. On the other hand, the addition of Ag'' ions had no effect on the adsorption and desorption of nitrogen.

In addition, the hardness of all the adsorbents was in the range of 1.8 to 2.0 ki (Mizuya type hardness meter).

Table 1 Examples Example 2 In Example 1, an adsorbent was prepared using copper chloride (1) instead of silver chloride as the metal salt.

The obtained adsorbent was subjected to an adsorption/desorption test for phosphorus monoxide and nitrogen in the same manner as in Example 1. Table 2 shows a comparison with an adsorbent prepared in the same manner as in Example 1 using an aqueous phenolic resin solution of 20%.

As is clear from Table 2, the amount of carbon monoxide adsorbed by the adsorbent prepared by dissolving CIL'' ions in the phenolic resin aqueous solution used as a binder is higher than that of the comparative example Test Nα5 in which no 5 ions are added. It can be seen that the amount of G ions increases by 0.5 milliequivalent g/
(] - In the case of comparative example test Nα9 exceeding activated carbon,
Although the amount of carbon monoxide adsorbed to the adsorbent is large, 60 Tor
When the pressure was reduced to r, the carbon monoxide desorption rate began to decrease. Therefore, it can be seen that the amount of ions is preferably 0.5 milliequivalent 97 g of activated carbon or less as described above. On the other hand, the addition of ion promoters had no effect on nitrogen adsorption and desorption.

The hardness of each adsorbent was in the range of 1.8 to 2.0 (Mizuya hardness tester).

Table 2 Example 3 In Example 1, the blending amounts of the A♂ ion-added phenolic resin aqueous solution used in Test Nα2 were s and io.

Hardness of adsorbent when prepared by heating at 250°C (Mizuya hardness tester)
are shown in Table 3.

As is clear from Table 3, in the comparative example Test No. 2-1, in which the amount of the phenolic resin aqueous solution used as the binder did not reach 10% by weight, the strength of the adsorbent was insufficient; Phenol resin aqueous solution blending amount is 30% by weight
In the case of Comparative Example Test No. 2-5 exceeding the above, the granules adhere to each other during granulation and form lumps, which is not preferable. Therefore, the blending amount of the phenol resin aqueous solution is 1 as described above.
It can be seen that 0 to 30% by weight is preferable.

(The following is a blank space) Example 4 In Example 1, the heat treatment temperature of the pellets granulated in test Nα2 was set to 50.150. 250. 400°6
Table 4 shows the hardness of the adsorbent (according to a bookstore hardness tester) when the temperature was changed to 00°C.

As is clear from Table 4, in the comparative example test Nα2-6 where the heat treatment temperature of the pellets did not reach 150'C, the heat curing of the phenol resin was insufficient, so an adsorbent with sufficient strength was not obtained. On the other hand, when the heat treatment temperature was 5
In the case of Comparative Example Test No. 2-10 where the temperature exceeds 00'C, thermal decomposition of the phenol resin progresses and the strength of the adsorbent decreases. Therefore, the heat treatment temperature is 150 to 50% as described above.
It can be seen that 0°C is preferable.

As detailed in Table 4, according to the invention, an adsorbent is prepared that effectively separates m-carbon oxide and nitrogen by increasing the adsorption amount of carbon monoxide without increasing the nitrogen content. Therefore, high-purity carbon monoxide can be recovered in high yield from a raw material gas containing nitrogen and a large amount of carbon monoxide by the pressure swing adsorption method. In addition, the adsorbent prepared by the method of this invention is made by granulating fine powdered activated carbon using a phenol resin aqueous solution containing group IB metal ions as a binder, and then drying and heat-treating the mixture in an inert atmosphere. Because the amount of metal ions used can be reduced, adsorption and desorption of carbon monoxide by the pressure swing adsorption method can be easily carried out under isothermal conditions, and there is virtually no deterioration of the adsorbent. It also has the advantage of being inexpensive, such as not requiring regeneration or replacement.

[Brief explanation of drawings]

Claims (1)

[Claims] 0.1 to 0.5 of IB group metal ion to finely powdered activated carbon
Milliequivalent g/g - 10 to 30% by weight of a resol type phenolic resin aqueous solution in which activated carbon is dissolved, mixed, granulated,
A method for producing an adsorbent for separating carbon monoxide, which comprises heating at a temperature of 150 to 500°C in an inert atmosphere after drying.