JPS61263635A - Co adsorbent - Google Patents

Abstract

PURPOSE:To efficiently separate high-purity CO from a by-product gas in an iron mill by bringing sufficiently an HCl aq. soln. of CuCl into contact with a porous acidic oxide except the zeolite series such as Al2O3, thereafter removing the aq. soln. and using the obtained adsorbent. CONSTITUTION:An HCl aq. soln. of CuCl is sufficiently brought into contact with a porous acidic oxide except the zeolite series such as Al2O3 and SiO2 and thereafter the aq. soln. is removed. High-purity CO is efficiently separated and removed from a gaseous mixture contg. CO such as a by-product gas in an iron mill by using the prepared adsorbent. Since this adsorbent is a solid, the corrosion due to HCl or the like and the loss of the absorbed component are not caused and it has the high absorption performance without causing the deterioration properties due to H2O. As the porous acidic oxide except the zeolite series, 0.2-1.5cc/g narrow pore volume and 20-200Angstrom mean narrow pore diameter are desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a solid 00 adsorbent suitable for efficiently separating and recovering highly pure CO from a mixed gas containing CO.

(Prior Art) CO is a basic raw material in synthetic chemistry, and research is underway in various fields on how to effectively utilize the large amount of 00 contained in by-product gas from steel works.

Conventionally, as an absorption liquid for separating and concentrating 00 from a mixed gas, i) copper aluminum tetrachloride toluene solution 11) ammonia alkaline formic acid copper mine aqueous solution i) hydrochloric acid acidic chlorinated steel (I
) aqueous solutions were known.

(Problems to be Solved by the Invention) Although 1) above has a large absorption capacity, it irreversibly reacts with horse O to form a precipitate, and 11) causes loss of ammonia.
1ii) There are problems such as corrosivity due to corrosion.

The present invention solves these problems and proposes a solid adsorbent that has a high absorption capacity that does not deteriorate due to dust, does not cause loss of absorption components, and is not corrosive to equipment. .

(Means for solving the problem) The present invention can be achieved by using the solid adsorbent as a composite of cuprous chloride and a non-zeolitic porous acid oxide.

That is, the present invention relates to a carbon monoxide adsorbent in which a hydrogen chloride aqueous solution of cuprous chloride is sufficiently brought into contact with a non-zeolitic porous acidic oxide, and then the aqueous solution is removed.

The non-zeolite porous acidic oxide in the present invention is
A substance that does not have micropores of several A, therefore has no molecular sieving ability, and has either a Brønsted acid site that is stable at low temperatures or a Lewis acid site that is easily generated at high temperatures, such as alumina, There are silica, silica alumina, titania, etc.

In the present invention, the reason for using the above non-zeolite porous acidic oxide as a substance forming a complex with cuprous chloride is as follows. In other words, for materials with zeolitic pores such as zeolite, materials with micropores such as activated carbon, and other materials with molecular sieving ability, a Hag aqueous solution of cuprous chloride enters the inner surface of the pores. Since it is difficult to incorporate, it is not possible to fully exhibit high selective absorption of CO. On the other hand, the non-zeolitic porous acidic oxide of the present invention, which does not have micropores and therefore has no molecular sieving ability, has large pore diameters, allows the solution to enter easily, and has high selective absorption of CO. Not only can it sufficiently support copper (1), which exhibits the same properties, but it also exhibits an interaction that does not change the coordination state of the acidic oxide and the surrounding copper (1). As a result, the supported copper 11) is kept stable, a stable composite is formed, the chemical absorption ability of the steel (1) is not reduced, and its highly selective properties can be exhibited as is.

In addition, in the present invention, if the pore volume of the non-zeolitic porous acid oxide is too small, the contact efficiency between the steel (1) inside the pores and the raw material gas will decrease, the adsorption capacity will decrease, and the pore volume will decrease. As the volume increases, the amount of unabsorbed raw material gas (low concentration 00 gas) remaining in the pores increases, so if it is too large, it will cause a decrease in the purity of the recovered product gas. Therefore, the pore volume of the non-zeolite porous acidic oxide of the present invention is 02 mm/? ~1.5 CC/t, preferably α
S CC/f~1. ocr:, /l are suitable.

Furthermore, when the pore size of the non-zeolite porous acidic oxide becomes smaller, molecular sieving ability is expressed, and O
It becomes easy to adsorb O*, %O, On, etc., and moreover, the pores are crushed during the composite treatment with cuprous chloride. Therefore, it is preferable that the average pore diameter in the state before v4 production is 20 μm or more. Furthermore, as a matter of course, if the pore volume is the same, the surface area decreases as the pore diameter increases, so a high surface area is preferable in order to uniformly disperse and support the chlorinated steel. Therefore, the average pore diameter of the non-zeolitic porous acidic oxide of the present invention is 2[IA~200
A, preferably 50A to 150A is suitable.

The composite of chlorinated di-steel and non-zeolitic porous acidic oxide of the present invention is prepared by thoroughly contacting the oxide with an aqueous solution of CJaol's Hat, and then removing the aqueous solution.

At this time, the HOl concentration of the Hat aqueous solution is such that in order to obtain the desired amount of 0u(1) supported in a single contact in a short period of time, a higher K is preferable because 0uOj can be easily dissolved from a small amount to a large amount. ) can be used at any concentration depending on the supported amount, operational efficiency, etc. Similarly, any amount of Cu0l can be used.

Further, in the present invention, it is preferable that hydrogen halides exist on the surface of the non-zeolite porous acidic oxide. This is because Oust is considered to be stably maintained as monovalent by coexistence with hydrogen halides.

Furthermore, in the present invention, in order to keep ○U stable at a monovalent level, H
Salts that dissolve in water and dissociate protons and C/- have the same effect as ag, such as A / O /, 0u01
It is considered that z etc. can also be used.

In the present invention, acidic oxides are used as the non-zeolite porous material because, as is clear from the comparative examples described later, non-acidic oxides such as ZnO and ElnOl have poor CO adsorption properties. . In addition, in the present invention, the reason for using an HO/aqueous solution is that, as shown in the comparative example below, basic aqueous solutions such as ammonia cannot exhibit 00 adsorption ability, and 11fNO1 dissolves OuO/1 but has no CO adsorption ability. It is not an adsorbent with acetic acid, ZSO,
etc. do not dissolve OuO/1.

(Effects of the Invention) The adsorbent of the present invention made of a composite of Our/ and a non-zeolite porous acidic oxide exhibits high selectivity for CO, for example, CO from a steelworks converter byproduct gas. shows favorable results in the separation and recovery of At that time, a substance with small pores that has leek sieving ability in one mole,
When a complex of basic oxide and Our/ is used, 0
At the same time, it adsorbs other easily physically adsorbed gases and acidic gases. For example, zeolite (U, S, P, 4,019.+379.4.0!54,
065) or activated carbon (JP-A-59-1OSA41) can also adsorb CO, etc., and remove CO from steelworks byproduct gas.
In most cases, mixed gas containing a large amount of 00g, EIO
The purity of CO in the recovered gas is low because it simultaneously contains s, etc.
Separate removal treatment for acidic gases, etc. is required.

Further, since the adsorbent of the present invention is in a solid state, neither loss of ammonia nor corrosion due to HOI etc. occurs. Furthermore, with a solution adsorbent, the only method available was to apply heat during desorption (regeneration of the adsorbent), but by solidifying it, adsorption and desorption can also be performed by changing pressure.

(Example) Example 1 As cuprous chloride, a commercially available special grade reagent (manufactured by Wako Tsumugi Kogyo Co., Ltd.) was used as it was. Add 40 CC of Ic I N HO/aqueous solution to a 200-two-neck eggplant flask under dry nitrogen, add the above cuprous chloride αb t (6 mmo':l), and add 70
The mixture was heated and kept at ℃ for 2 hours to obtain a colorless and transparent solution. on the other hand,
3 at 550°C as a non-zeolitic porous acidic oxide.
Time-calcined alumina A carrier (catalyst chemical treatment (made by 0, average pore diameter 108 A1, B concave T surface area 250 m"/f)
11111F was prepared, and the above Ou was heated under a stream of dry nitrogen.
O/-nor @ was added to the solution. After immersion at 70° C. for 30 minutes, the inside of the eggplant flask was evacuated using an aspirator to reduce the pressure (approximately 1010 mT1) for 3 hours, and the solvent was sufficiently removed to obtain a light gray adsorbent.

This adsorbent is charged with 1 atm OO mixed gas (aO partial pressure α3
AtmS% partial pressure (17 atm) was aerated and the adsorption performance was checked, and the amount of adsorption was X Ommol in 10 minutes. Reduce the pressure in the system with a vacuum pump (15mg)
K and held for 10 minutes, aot'zammoL
Recovered.

An island gas containing H and C at saturated water vapor pressure was blown onto this adsorbent (approximately 50 mmol of contact amount). After that, when the above CO mixed gas was aerated, the adsorption amount was 2.5
mrnol, and no deterioration due to OK was observed.

Example λ A hydrochloric acid aqueous solution of cuprous chloride was prepared in exactly the same manner as in Example 1. Non-zeolitic porous acidic, 55 as oxide
Alumina fired at 0℃ for 3 hours (Sumitomo Alumina Co., Ltd.)
manufactured by, average pore diameter 68A, Bl! iT surface area 203y3
''/f, pore volume IIL 35 ■/f) was added to the above solution under a 10t1 stream of dry nitrogen. After immersing at 70°C for 30 minutes, the inside of the eggplant flask was reduced in pressure (approximately 1101HH) using an aspirator (C). The mixture was evacuated for 3 hours to thoroughly remove the solvent and obtain a light gray adsorbent.

The same 00 mixed gas used in Example 1 was passed through this adsorbent, and the amount of 00 adsorption and recovery was measured in the same manner as in Example 1, and the amount of 00 adsorbed was 2.1 mmol in 10 minutes. It was done.

This adsorbent was used in the same manner as in Example 1.
After the treatment with N and gas containing gas, the second adsorption and recovery amount of aO was measured, and the amount of 00 adsorption was confirmed to be 2.2 mmol.

Comparative Examples 1 to 2 An aqueous OuOj-Floe solution was prepared using the same reagents and amounts in the same manner as those used in Example 1. An adsorbent was prepared by using the following substance 10F as a carrier for the alumina A carrier used in Example 1.

Pore volume Average pore diameter 1, Zn0IIL10i/f 16OA2
, E? nO1α11crI? /P 200
A 1 atm of ○O mixed gas (00 partial pressure α!iatm, ) - partial pressure α7 atm) was aerated through the above adsorbent,
The amount of adsorption was measured. The results were as follows.

1. ZnOQ, 5 mmol2.8n sham
αs mmol Comparative Example Cupric pentachloride is a commercially available special grade reagent (manufactured by Wako Tsumugi Pharmaceutical Co., Ltd.)
was used as is. 20 cc of 1N ammonia aqueous solution was added to a 200-2-necked eggplant flask under dry nitrogen, and the above cuprous chloride 16f (6 mmol) was added, followed by stirring at room temperature for 50 minutes to obtain a bright-colored solution. An alumina A carrier (manufactured by Catalyst Kasei (9), average pore diameter 108 A, BIT surface area 230 m''/r) calcined at 550° C. for 3 hours was added to the above blue solution under a stream of dry nitrogen.

After immersing at room temperature for 30 minutes, the inside of the eggplant flask was reduced in pressure (approximately 10 gag) using an aspirator and evacuated for 3 hours to sufficiently remove the solvent.

1 atm CO mixed gas (aO partial pressure Q,
When 5 atm and N1 partial pressure (L 7 atm) were aerated to check the adsorption performance, the amount of adsorption was 5 mmol in 10 minutes.

Comparative age Cupric chloride is a commercially available special grade reagent (manufactured by Wako Tsumugi Pharmaceutical Co., Ltd.)
was used as is. Add 4° of IN HC1 aqueous solution to a 200-niron flask under dry nitrogen, add the above cuprous chloride [L6F, and heat and keep warm at 70'C for 2 hours.
A colorless and transparent solution was obtained. 550℃ as acidic oxide
Y-zeolite (manufactured by Linda Co., Ltd.), which had been calcined for 3 hours and cooled in a desiccator, was charged at 10F and immersed at 70'C for 50 minutes. Thereafter, the inside of the eggplant flask was evacuated for 3 hours using an aspirator to reduce the pressure (approximately 10101IIIH), and the solvent was sufficiently removed to obtain an adsorbent.
1 atm 00 mixed gas (b) partial pressure α3atmS%
When aerated at a partial pressure of 0.7 atm) and measured the amount of adsorption, the amount of adsorption was 1.2 mmol in 10 minutes.

This adsorbent was heated to 90° C., nitrogen was bubbled through it to remove aO, and then the adsorbent was cooled to room temperature. This adsorbent K 1 a
tm of CO, mixed gas (Cox partial pressure Q, 3 atm, % partial pressure (L 7 atm)) was aerated and the adsorption amount of 00m was measured, and the adsorption amount was 2.7 mmol in 10 minutes. It was revealed that the agent has a large adsorption capacity for both CO and 0.

Claims (1)

[Claims] A carbon monoxide adsorbent obtained by fully contacting a hydrogen chloride aqueous solution of cuprous chloride with a non-zeolite porous acidic oxide, and then removing the aqueous solution.