JPS62113710A - Production of adsorbent for separation and recovery of co - Google Patents

Abstract

PURPOSE:To produce the titled adsorbent having excellent adsorption and desorption performance of CO, by dissolving a Cu(I) compound in a solvent and contacting the solution with heated silica and/or alumina carrier under a specific condition. CONSTITUTION:A Cu(I) compound (e.g. cuprous chloride) is dissolved in a solvent such as water, hydrochloric acid, ammonia water, etc. The solution is optionally heated at 40-100 deg.C and sprayed to a silica and/or alumina carrier having particle diameter of 1-7mm and preliminarily heated at 50-150 deg.C. The saturated absorptivity of the solution to the carrier is adjusted to + or -10% during the above adsorption process. The adsorbed solution is dried by heating in an inert gas atmosphere and, if necessary, heated in an inert gas or reducing gas atmosphere at 100-300 deg.C to obtain an adsorbent for the separation and recovery of CO and containing 0.5-8m-mol/g of supported Cu(I) compound.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a method for separating a mixed gas containing CO by a pressure fluctuation adsorption separation method (hereinafter referred to as PSA method) or/and a temperature fluctuation adsorption separation method (hereinafter referred to as TSA method). The present invention relates to a method for producing a solid adsorbent used for the purpose of separating and recovering high-purity CO.

Conventional technology Typical gases containing CO as a main component include converter gas obtained from converters in steel plants, blast furnace gas obtained from blast furnaces, electric furnace gas obtained from electric furnaces, and gasification of coke. There is a generator gas that can be obtained. Most of these gases are normally used as fuel, but some of these gases contain CO, for example, around 70 vol 1% or more, so these gases are rejected. If CO can be separated and recovered with high purity, it can be used as a raw material for synthesizing formic acid, acetic acid, etc., and for reducing organic compounds, which is extremely useful in the chemical industry.

Conventionally, methods for separating and recovering CO from gas whose main component is CO include cryogenic separation method, copper ammonia method, and cosorb (
The COSORB method is known, but these methods have the problem of high equipment costs and high costs for thermal energy such as electricity and steam, and are not suitable for separating and recovering large amounts of co. However, these methods were not necessarily suitable for the separation and recovery of medium or small volumes of CO. Furthermore, CO obtained by separation by these methods contains o2. ,co
It has the disadvantage that it cannot be used as it is for organic synthesis because it contains gas components such as 2 that are a hindrance to organic synthesis reactions.

By the way, the PSA method and the TSA method are known as methods for selectively separating a specific gas from a medium or small volume of source gas.

The PSA method is a method for selectively separating a specific gas from a mixed gas.The adsorbent is adsorbed onto an adsorbent at high pressure, and then the adsorbed material is removed by lowering the pressure of the adsorption system. This method desorbs adsorbed substances and separates adsorbed substances and non-adsorbed substances.Industrially, multiple towers filled with adsorbent are installed, and in each adsorption tower, the steps of pressurization → adsorption → washing → deaeration are performed. By repeating a series of operations, the entire device can perform continuous separation and recovery.

Similarly to the PSA method, the TSA method is also a method for selectively separating a specific gas from a mixed gas.The TSA method is one of the methods for selectively separating a specific gas from a mixed gas. This is a method in which the adsorbed substances adsorbed to the agent are desorbed and the adsorbed substances and non-adsorbed substances are separated.

Conventionally, this PSA method was used to remove CO from a mixed gas containing CO.
A method using mordenite-based zeolite as an adsorbent has been proposed as a method for separating and recovering. (Refer to JP-A-59-22FI25 and JP-A-59-49818.) In addition, as a method for separating and recovering CO from a mixed gas containing CO by the PSA method or the TSA method, copper halide (
I), copper(I) oxide, copper(II) salt, copper(II) oxide
) and other copper compounds supported on activated carbon have been proposed. (Unexamined Japanese Patent Publication No. 58-15
8517, JP 59-89414, JP 59-105841, JP 59-13813
(Refer to Publication No. 4) Similarly, a manufacturing method for producing a co-absorbing and separating agent used for separating and recovering CO from a mixed gas containing CO by the PSA method or TSA method is used to produce copper (I) halide and aluminum halide ( III) organic solvent solution to alumina,
A method has been proposed in which the material is contacted with a porous inorganic oxide such as silica or silica/alumina, and then free organic solvent is removed. (Unexamined Japanese Patent Publication No. 80-90038, Unexamined Japanese Patent Publication No. 80-80
(Refer to Publication No. 90037) In addition, under the PSA Act or the TSA Act, criminals who have been released from the water are
As a method for separating and recovering CO from a mixed gas containing
Regarding a method using an adsorbent for CO separation and recovery that supports a compound, a copper (II) compound, or a reduced product thereof,
A patent application has already been filed. (Patent application 1980-8297
No. 8) Problems to be solved by the invention When carrying out the PSA method or the TSA method, the performance required of the adsorbent packed in the adsorption tower is: ■ selective adsorption of the component of interest relative to coexisting components; There is a large difference in the adsorption amount of the target component at low pressure or low temperature and at reduced pressure or high temperature; ■ The adsorbed target component is easily desorbed; ■ It is difficult for components other than the target component to be adsorbed and desorbed. (Glue) The long life of the adsorbent is one of the reasons. These performances are important factors in the PSA method or TSA method because they have a large impact on the purity and yield of the product gas.

However, in the method of using mordenite-based zeolite as an adsorbent, which utilizes the physical adsorption/desorption phenomenon of the adsorbent, the amount of CO adsorbed is relatively small, so the pressure swing must be changed more frequently. However, it is disadvantageous both in terms of operation and the life of the valves, and that C02 must be removed in advance before the adsorption operation.
Since co-adsorption of Z cannot be avoided, the product purity will be low.

Also, the adsorbed N2. When cleaning the inside of the tower using product CO gas to remove CO, the amount of cleaning is large, resulting in problems such as a low recovery rate of product CO.

On the other hand, in a method using an adsorbent in which the copper compound is supported on activated carbon, which utilizes the chemical adsorption/desorption phenomenon of the adsorbent, Co, N2. When attempting to separate CO from a mixed gas containing CO2, etc., it is difficult to separate and recover high-purity CO because CO2, etc., tend to co-adsorb at the same time as CO, and the amount of CO adsorbed by the adsorbent However, there are problems such as the fact that the size is not necessarily large, and it has not yet reached the point where it can be adopted on an industrial scale.

In addition, a method using an adsorbent in which copper (I) halide and aluminum halide (m) are supported on a porous inorganic oxide mainly utilizes the CO selective absorption property of CuAfLX 1,000 (X is a halogen). However, because the adsorption power for CO is too strong, the adsorbed CO is difficult to desorb during degassing, making it particularly unsuitable for the PSA method, and the adsorbent manufacturing operation must be performed in a dry inert gas atmosphere. There is still a need for improvement from an industrial standpoint, such as the fact that once the activity of an adsorbent has decreased, it is difficult to restore the activity again.

In contrast, the present applicant has previously applied for a method for co-separation in which a copper (I) compound, a copper (II) compound, or a reduced product thereof is supported on a carrier made of silica and/or alumina. The method using a recovery adsorbent is
Although it has the advantage of being able to separate and recover CO of extremely high purity, from an industrial standpoint, it is required to further increase the CO adsorption/desorption performance.

In view of these circumstances, the present invention was achieved as a result of intensive research to find an adsorbent with excellent CO adsorption/desorption performance that can efficiently separate and recover high-purity CO from a mixed gas containing CO. .

Means for Solving the Problems The method for producing an adsorbent for CO separation and recovery according to the present invention includes adding copper (I) to a carrier (X) made of silica or/and alumina.
After contacting with a solution (Y) in which the compound is dissolved in a solvent,
When removing the solvent and producing an adsorbent, the solution (Y)
The carrier (X) and the solution (Y) are mixed with each other under conditions of a saturated absorption rate of ±10% for the carrier (x) and with the carrier (X) preheated to 50 to 150°C. It is characterized by making contact.

In this case, the carrier (X) and the solution ( By contacting with Y), an adsorbent with even better CO adsorption/desorption performance can be obtained.

The present invention will be explained in detail below.

In the present invention, a carrier (X
) is used.

Silica is produced by, for example, neutralizing an aqueous sodium silicate solution with an acid such as hydrochloric acid to precipitate it, then washing it with water and drying it.
Further, if necessary, it is activated by heating under reduced pressure and obtained by making it into powder. Alumina is obtained, for example, by precipitating aluminum hydroxide from an aqueous solution of a soluble aluminum salt, filtering it, and igniting it.

When using silica and alumina together, in addition to a simple mechanical mixture of silica and alumina, methods of kneading silica gel and alumina gel in a wet state, methods of soaking aluminum salt in silica gel, and methods of mixing silica and alumina in an aqueous solution are available. A method of simultaneously gelling the silica gel, a method of depositing alumina gel on silica gel, etc. are adopted.

These silica, alumina and silica-alumina are
All of these are commercially available.In the present invention, we select granular particles with a particle size of, for example, about 1 to 7 mm, taking into account the pressure loss when filling the column, and dry them as necessary before using them. do.

In the present invention, the carrier (X) is brought into contact with a solution (Y) in which a copper (I) compound is dissolved in a solvent, and then the solvent is removed to produce an adsorbent.

Here, m(I) compounds include copper halides (1) such as m(I) chloride, 4(I) fluoride, and #1(I) bromide.
: Copper (I) oxide; Copper cyanide (1); Copper (I) such as copper (I) formate, copper acetate (1), copper oxalate (1), copper sulfate (1), copper sulfite (I), etc. oxyacid or organic acid salt; copper sulfide (1); dichlorocuprate (I), tetrachlorocopper (I)
) acid salt, dicyanocopper(I) acidate, tetracyanocopper(I)
Examples include complex salts such as acid salts. In particular, tli4(I chloride)
) is preferred.

Examples of the solvent include water, hydrochloric acid, acetic acid, formic acid, ammoniacal formic acid aqueous solution, aqueous ammonia, halogen-containing solvents,
Hydrocarbons, alcohols, ketones, esters, ethers, cellosolves, carpitols, etc. are used, but hydrochloric acid is particularly suitable from an industrial standpoint.

The contact between the carrier (x) and the solution (Y) is carried out so that the following two conditions are satisfied.

First of all, the solution (Y) should be added in an amount within the range of saturated absorption rate of the carrier (X) ±10%, in other words, the solution (Y) should be added in an amount that is approximately in excess or deficiency of the saturated amount absorbed by the carrier (X). Use for circumstances that are not present. Although the saturated absorption rate varies depending on the temperature, it refers to the saturated absorption rate at the temperature during actual absorption operation. In this case, if the amount of solution (Y) used is insufficient, g
The amount of A(I) compound supported decreases accordingly, and the C of the adsorbent decreases accordingly.
The amount of OO deposited decreases. On the other hand, even if the amount of solution (Y) used is greater than the above range, the carrier (X) made of silica and/or alumina has a smaller adsorption capacity for copper (I) compounds than other porous carriers such as activated carbon. Therefore, carrier (X)
The amount of the copper(I) compound supported by the copper(I) compound is not large, but rather the solvent is consumed more than necessary, which is industrially disadvantageous.

If the amount of solvent is too large, the copper CI) compound impregnated into the carrier (X) will be eluted into the solvent again during the solvent removal process, and the adsorbent's ability to absorb and adsorb CO will become worse. become. Therefore, it is preferable to measure the saturated absorption amount of the solution (Y) with respect to the carrier (X) in advance, and bring the solution (Y) into contact with the carrier (X) in proportion to the saturated absorption rate.

Second, the carrier (X) is heated in advance to 50-150°C, preferably 80-120°C, before being brought into contact with the solution (Y). By heating the carrier (X) in advance in this manner, the amount of the m (I) compound supported on the carrier (X) increases, and an adsorbent with a large amount of COO deposited can be obtained.

When it is desired to further increase the amount of the gA(I) compound supported on the carrier (X), the carrier (X) and the solution (Y)
If not only the carrier (X) but also the solution (Y) is heated to 40 to 100°C, preferably 50 to 90°C, before contact with agent is obtained.

Contact between the carrier (X) and the solution (Y) is usually carried out by impregnation or spraying. In this case, in order to completely exchange the gas present in the pores of the carrier with the solution (Y), the carrier is vacuum degassed. (X) may be brought into contact with the solution (Y), or the carrier (X) may be brought into contact with the solution (Y) and then degassed under reduced pressure conditions.

After the carrier (X) and the solution (Y) are brought into contact, the solvent is removed by distillation by heating and drying in an inert gas atmosphere such as nitrogen, argon, helium, etc., preferably without lowering the system temperature. do. The solvent can be removed not only by simple heat drying but also by vacuum drying. By such a method, the copper (I) compound can be efficiently supported on the carrier (X).

The amount of copper (I) compound supported on the carrier (X) is usually 0.5 to 8 m-mol/g, preferably 1 to 5 layers-m
Select from the range of ol/g. If the amount of copper (I) compound supported is too small, the co adsorption capacity will be insufficient;
If there are too many special grade compound phases, the separation efficiency will actually decrease.

Although an adsorbent exhibiting sufficient COO adsorption ability is obtained by the above-mentioned drying, N2 and argon are added after drying.

Inert gas such as helium or Co, N2. If heat treatment is performed in an atmosphere of an invertible gas such as, an adsorbent exhibiting even better COO adsorption ability can be obtained. The heat treatment temperature is
When using either an inert gas or a reducing gas, it is appropriate to select it from the range of 100 to 300°C, preferably 150 to 250°C.

The adsorbent ti obtained as described above is packed into an adsorption tower, and CO is separated and recovered from a mixed gas containing CO by a PSA method or a TSA method.

When separating and recovering CO using the PSA method, the adsorption pressure in the adsorption process must be above atmospheric pressure, even if CO is
It is desirable to set it to Kg/cmZG, and the degree of vacuum in vacuum desorption 7 and one step is below atmospheric pressure, for example, 200 to 1
It is desirable to set it to 0 Tarr.

When separating and recovering CO by the TSA method, it is desirable that the adsorption temperature in the adsorption step is, for example, about 0 to 40°C, and the degassing temperature in the degassing step is, for example, about 60 to 180°C.

It is also possible to use the PSA method and the TSA method in combination, performing adsorption at atmospheric pressure or higher under low temperature conditions and degassing at atmospheric pressure or lower under high temperature conditions.

In addition, since the TSA method is disadvantageous compared to the PSA method in terms of energy consumption, it is desirable to adopt the PSA method or a combined PSA-TSA method from an industrial perspective.

As the applicable mixed gas containing CO, for example, converter gas generated from a converter in a steel mill is used. Converter gas usually contains CO as a main component, as well as 02, methane and other hydrocarbons, water, and small amounts of HzS, NH3, and the like. In addition to converter gas, blast furnace gas, electric furnace gas,
Generator gas and the like can also be used as raw material gas.

In this case, prior to the CO fraction collection step, a step of adsorption and removal of impurities such as sulfur compounds and NH>, a moisture removal step and an 02 removal step are carried out which may poison the adsorbent or shorten its lifespan. However, it is desirable to provide CO1O removal process and N2. There is no need to provide a removal process.

Function In the present invention, when producing an adsorbent, a solution (
Y) is used in a manner that is approximately commensurate with the saturation absorption rate for the carrier (x), and the carrier (X) or a solution thereof (Y) is used.
The carrier (X) and the solution (Y) are heated in advance.
), the absorption of the solution (Y) into the carrier (x) is increased, and as a result, the compound 8(I) is supported even inside the pores of the carrier (X), and the CO Adsorption and desorption will be carried out most efficiently.

The COO desorption phenomenon by the solid adsorbent obtained by the method of the present invention is mainly due to the reversible chemical reaction (complex formation reaction and dissociation reaction) between the copper (I) compound supported on the carrier (X) and CO. (8%, no chemical reaction occurs with CO2,) and secondary to the physical adsorption of CO onto the pore surface of the carrier (X) and desorption from it. It is thought that.

Example Next, the present invention will be further explained by giving examples.

Example 1 Copper (I) chloride 8.9 in a 200 cc Erlenmeyer flask
A copper(I) chloride solution (Y) was prepared by dissolving g in 18 cc of hydrochloric acid at room temperature.

Into this solution (Y) at room temperature, 1 20 g of alumina (Al-5it' manufactured by Fujimi Abrasives Industry Co., Ltd.) (X) with an average particle size of 3 mm that had been previously dried at 110°C for about 4 hours was added.
After adding the mixture under heating at 10°C and stirring for 1 hour, the solvent was distilled off in a N2 stream while heating to 200°C with a mantle heater. Thereafter, it was cooled to room temperature to obtain a solid adsorbent for co separation and recovery.

Note that the mixing ratio of the carrier (X) and the solution (Y) in the above is the same as the saturated absorption rate of the solution (Y) to the carrier (X).

CO separation and recovery The adsorbent obtained above was transferred to an adsorption tower (15 φ x 300 mmH)
A mixed gas of 1 atm with a composition of Co: 71.4 vat% Nλ: 12.7701% CO2,: 15.9 vol% was supplied to this adsorption tower, and carbon was heated at 20°C.
O was adsorbed. The amount of COO deposited at this time was 17.3 c
It was c/cc.

After the adsorption operation, deaeration was performed using a vacuum pump at a pressure of 25 Torr for 5 minutes to release the adsorbed gas. The amount of Co released at this time was 13.8 cc/cc, and the released gas composition was as follows: C'O: 95.8 vo1% Nλ: 1.6 mao1% COl: 2. Etvo1%.

When adsorption was performed again under the same conditions as above, the same amount of co as released was adsorbed.

Even if the same operation was repeated, the amount of adsorption and desorption of CO did not change.

After the first adsorption operation, the inside of the column is cleaned with 90 cc of CO and then vacuum degassed, resulting in a released gas composition of Co: 99.9 vol% Nz: trace CO2,: 0.1 vat%.

Example 2 Alumina carrier (X) was heated at 110°C for 70 g.
Copper(I) chloride solution (Y) warmed to °C was added to the system.
The same operation as in Example 1 was performed except that the mixture was stirred for 15 minutes while maintaining the temperature at 0°C.

The amount of CO adsorption at this time was 18.41jc/cc, Co
The release amount was 10.9 cc/cc, which was an even better result than in Example 1.

Example 3 Alumina used in Example 1 and Example 2 (AH-Sll manufactured by Fujimi Abrasives Industry Co., Ltd.) was used as the carrier (X).
) instead of alumina ACBM manufactured by Catalysts & Chemicals Co., Ltd.
The same operation as in Example 2 was performed except that -1 was used.

The results were as follows.

CO adsorption amount 19.7 cc/cc CO release amount 9J cc/cc Example 4 Example except that 18.3 g of silica-alumina (N831L manufactured by JGC Chemical Co., Ltd.) with a particle size of 3.1 m was used instead of alumina. The same operation as in 2 was performed. However, the amount of hydrochloric acid was 13 cc, and the amount of copper (I) chloride was 5 g. In this case, the mixing ratio of carrier (X) and solution (Y) is
is the same as the saturated absorption rate for carrier (X).

The results were as follows.

CO @ Arrival - 16.3 cc/cc CO release amount 4.1 cc/cc Comparative Example 1 Example 1 was added to a copper chloride (I) solution (Y) at room temperature in which 9 g of copper chloride (I) L was dissolved in 30 cc of hydrochloric acid. The same operation as in Example 1 was performed except that 20 g of the alumina carrier (X) used in Example 1 was added at room temperature.

The results were as follows, and were inferior to Examples 1 and 2.

CO adsorption amount 13.9 cc/cc CO release-needle f3. o cc/cc Comparative Example 2 The silica-alumina extrusion (X) 18 used in Example 4 was added to a copper chloride (I) solution (Y) at room temperature in which 8.9 g of copper chloride (I) was dissolved in 30 cc of hydrochloric acid. The same operation as in Example 1 was performed except that .3 g was added at room temperature.

The results were as follows, and were inferior to Example 4.

CO adsorption! 5.8 cc/cc CO emission amount 3.8 cc/cc Effects of the invention A carrier made of silica and/or alumina generally has a higher ability to adsorb copper (I) compounds than activated carbon or other porous carriers. However, according to the present invention, this weakness is overcome and the copper (I) compound is efficiently supported even inside the pores of the carrier (X), and as a result, the CO adsorption and desorption capacity is improved. An excellent adsorbent can be obtained, and the amount of solvent required for producing the adsorbent can be small.

Therefore, the present invention is useful in the chemical industry as a method for producing an adsorbent for separating and recovering high-purity CO from converter gas and other CO-containing gases on an industrial scale.

Claims (1)

[Claims] 1. Support (X) made of silica or/and alumina
After contacting a solution (Y) in which a copper (I) compound is dissolved in a solvent, the solvent is removed to produce an adsorbent.
Use an amount in the range of 10% and carrier (X) in advance from 50% to
While heating to 150°C, carrier (X) and solution (
A method for producing an adsorbent for CO separation and recovery, characterized by contacting with Y). 2. The saturated absorption rate of the solution (Y) to its carrier (X) ±
Use an amount in the range of 10% and carrier (X) in advance from 50% to
While heating to 150℃, the solution (Y) is heated to 40~1
While heating to 00°C, carrier (X) and solution (Y
) Claim 1 characterized in that contact is made with
Manufacturing method described in section. 3. The manufacturing method according to claim 1, further comprising heat treatment under an inert gas or reducing gas atmosphere after removing the solvent. 4. The manufacturing method according to claim 1, wherein the solvent is hydrochloric acid.