JPH0335975B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is applicable to nitrogen, methane, carbon dioxide, hydrogen,
The present invention relates to a method for activating a solid adsorbent composed of copper salt and activated carbon for adsorbing and separating carbon monoxide from a mixed gas containing carbon monoxide along with water and the like.

(Prior art) Conventionally, as a solid adsorbent for separating carbon monoxide, which is mainly composed of copper and activated carbon, copper halide ()-activated carbon system (Japanese Patent Application Laid-open No. 156517/1982), copper ()
A salt-activated carbon system (JP-A-59-69414) is known.

The method for preparing a copper halide ()-activated carbon adsorbent is to mix copper halide () with activated carbon in a solvent, stir it, and then remove the solvent by depressurizing or distilling it off. Methods that use hydrochloric acid as a solvent have the disadvantage of severe corrosion of preparation equipment, etc., and adsorbents that use acetonitrile or the like as a solvent have the disadvantage of a small amount of carbon monoxide adsorption.

In copper() salt-activated carbon based adsorbents, copper()
An activation step was necessary because the salt does not inherently have the property of adsorbing carbon monoxide. This activation process is a heat treatment under an inert gas or reducing gas atmosphere, but it is not sufficiently effective due to the low heating temperature, and the amount of carbon monoxide adsorbed is also lower than that of halogen when hydrochloric acid is used as a solvent. The amount of copper oxide was lower than that of the activated carbon adsorbent. Furthermore, this method is not intended for activating degraded adsorbent.

These copper halide ()-activated carbon type, copper ()
Tests have shown that the adsorption performance of salt-activated carbon adsorbents deteriorates in the presence of oxygen.

Conventionally, in gas separation and purification equipment using the PSA (Pressure Swing Adsorption) method, the adsorbent used has been required to have a long life because it is difficult to replace the adsorbent.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems and provides an efficient, simple, and economical adsorbent for carbon monoxide separation made of copper salt-activated carbon that has lost its carbon monoxide adsorption ability. The purpose of the present invention is to provide a method for restoring the carbon monoxide adsorption capacity of a carbon monoxide adsorbent.

(Means for Solving the Problems) The gist of the present invention to achieve the above object is to restore the carbon monoxide adsorption ability to a carbon monoxide adsorbent made of copper salt-activated carbon that has lost its carbon monoxide adsorption ability. Under non-oxidizing atmosphere or under reduced pressure to recover
This is a method for activating an adsorbent for carbon monoxide separation, which is characterized by heating to a temperature exceeding 250°C.

As a result of extensive studies, the present inventors have determined that by heat-treating an adsorbent for carbon monoxide separation made of copper salt-activated carbon, which has lost its carbon monoxide adsorption ability due to oxidation, etc., at a higher temperature than previously known. discovered a method of activating the adsorbent to fully utilize its inherent carbon monoxide adsorption ability, and completed the present invention.

The present invention is a method of activating an adsorbent for carbon monoxide separation by heat treating an adsorbent for carbon monoxide separation made of copper salt and activated carbon in a non-oxidizing atmosphere or under reduced pressure.

Copper salt-activated carbon adsorbents applicable to the present invention include, for example, copper salt-activated carbon adsorbents, copper salt-activated carbon adsorbents, copper complex-activated carbon adsorbents, etc., which have copper salts and activated carbon as their main components. This is an adsorbent for separating carbon monoxide.

Copper () salt-activated carbon adsorbent is activated carbon with 1
It is an adsorbent that supports divalent copper, and after supporting divalent copper on activated carbon, it absorbs divalent copper in the liquid phase or gas phase.
It also includes activated carbon in which monovalent copper is reduced to monovalent copper and monovalent copper is supported.

Copper() salt-activated carbon adsorbent is activated carbon with 2
This is an adsorbent that carries valent copper.

The copper complex-activated carbon adsorbent is an adsorbent in which a copper complex, such as a copper ammonia complex, is supported on activated carbon.

The heating temperature in the present invention is a temperature exceeding 250°C. If the heating temperature is below 250°C, the activation treatment will not fully utilize the ability of the adsorbent. The maximum temperature varies depending on various factors such as the type of adsorbent and the degree of pressure reduction, and can be up to 500℃.
The following are preferred. The heating atmosphere is a non-oxidizing atmosphere or under reduced pressure. It has been confirmed that copper salt-activated carbon-based adsorbents for carbon monoxide separation deteriorate in the presence of oxygen, and therefore activation must be performed in a non-oxidizing atmosphere or under reduced pressure. The non-oxidizing atmosphere is a reducing atmosphere such as carbon monoxide, hydrogen, etc., or an inert atmosphere such as nitrogen, argon, etc. Further, the reduced pressure is preferably 1 mmHg or less.

The carbon monoxide separation adsorbent activated by the method of the present invention selectively and rapidly adsorbs carbon monoxide. Further, the adsorbed carbon monoxide can be easily desorbed and released by heating or reduced pressure.

The adsorbent for carbon monoxide separation activated by the method of the present invention is PSA (Pressure Swing)
Adsorption) and TSA (Thermal Swing)
In addition to being used to separate and purify carbon monoxide using the adsorption method, it can also be used to remove carbon monoxide from a mixed gas containing carbon monoxide.

The present invention will be explained below with reference to Examples.

Example 1 Copper chloride () dihydrate special grade reagent manufactured by Showa Kagaku Co., Ltd. was used as copper chloride (), and anhydrous sodium sulfite special grade reagent manufactured by Showa Kagaku Co., Ltd. was used as sodium sulfite. The activated carbon used was 4GV manufactured by Tsurumicol Co., Ltd., and the hydrochloric acid used was a special grade reagent manufactured by Wako Pure Chemical Industries, Ltd.

25.6g (150.0mmol) in a 500ml round bottom flask
200 ml of water was added, and the mixture was left at 25°C for about 10 minutes while stirring using a magnetic stirrer. 100 g of activated carbon was added to the round bottom flask and stirring was continued for 24 hours, after which water was removed under reduced pressure using a rotary evaporator. Furthermore, an aqueous sodium sulfite solution (20.0 g of anhydrous sodium sulfite, 200 g of water) was added to this, and stirring was continued at 38°C for 24 hours.
) and then heat-treated at 260° C. for 2 hours in a nitrogen gas atmosphere to obtain a black particulate adsorbent for separating carbon monoxide.

As a result of measuring the equilibrium adsorption amount of this adsorbent for carbon monoxide and nitrogen at 1 atm, it was found that carbon monoxide
The nitrogen content was 21.2 ml/g, and the nitrogen content was 3.62 ml/g.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed under reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

After leaving this adsorbent in the air for 3 days to lose its carbon monoxide adsorption ability, it was
Heat treatment was performed at ℃ for 2 hours.

As a result of measuring the equilibrium adsorption amount of carbon monoxide and nitrogen at 1 atm of this adsorbent, it was 6.47 ml/g of carbon monoxide/g and 3.61 ml/g of nitrogen before heat treatment, but after heat treatment, it was monoxide. Carbon 22.7ml/g,
Nitrogen was 3.20ml/g.

Example 2 The same reagents as described in Example 1 were used.

25.6g (150.0mmol) in a 500ml round bottom flask
200 ml of water was added, and the mixture was left at 25°C for about 10 minutes while stirring using a magnetic stirrer. 100 g of activated carbon was added to the round bottom flask and stirring was continued for 24 hours, after which water was removed under reduced pressure using a rotary evaporator. Furthermore, after adding a sodium sulfite aqueous solution (anhydrous sodium sulfite 20.0 g, water 200 g) and continuing stirring at 38°C for 24 hours, a hydrochloric acid acidic sodium sulfite aqueous solution (hydrochloric acid 5 ml, anhydrous sodium sulfite 2.5 g, water 2.5
) and then under argon gas atmosphere for 300 min.
A heat treatment was performed at ℃ for 2 hours to obtain a black granular adsorbent for separating carbon monoxide.

The equilibrium adsorption amount of carbon monoxide of this adsorbent at 1 atm was measured and found to be 19.3 ml/g.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed against reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

After leaving this adsorbent in the air for 3 days to lose its carbon monoxide adsorption ability, it was
Heat treatment was performed at ℃ for 2 hours.

As a result of measuring the equilibrium adsorption amount of carbon monoxide on this adsorbent at 1 atm, it was 6.47 before heat treatment.
ml/g, but carbon monoxide after heat treatment
It was 21.1ml/g.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed under reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

Example 3 Copper chloride () special grade reagent manufactured by Showa Kagaku Co., Ltd. was used as copper chloride (). Activated carbon is made by Tsurumicol Co., Ltd.
4GV and acetonitrile are from Wako Pure Chemical Industries.
A liquid chromatograph manufactured by Co., Ltd. was used.

1.5g (15.0mmol) in a 300ml round bottom flask
of copper chloride (), add 40 ml of acetonitrile, and stir at 25℃ using a magnetic stirrer.
It was left for 10 minutes. Activated carbon 10 in this round bottom flask
After stirring was continued for 24 hours, the solvent was removed under reduced pressure using a rotary evaporator, and further heat-treated at 120°C for 2 hours under reduced pressure (0.5 mmHg) to obtain a black granular carbon monoxide adsorbent. .

The equilibrium adsorption amount of carbon monoxide on this adsorbent at 1 atm was measured and found to be 11.9 ml/g.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed by applying reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

This adsorbent was left in the air for 24 hours to make it inactive, and then heated under reduced pressure (0.1 mmHg) at 300° C. for 2 hours to activate the adsorbent for carbon monoxide separation.

As a result of measuring the equilibrium adsorption amount of carbon monoxide of this adsorbent at 1 atm, it was found that before activation, it was 7.16ml/
g, but after activation it became 23.1 ml/g.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed by applying reduced pressure (0.1 mmHg) at 24°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

Example 4 Copper chloride () special grade reagent manufactured by Showa Kagaku Co., Ltd. was used as copper chloride (). Activated carbon is made by Tsurumicol Co., Ltd.
4GV and ammonium hydrogen carbonate from Kanto Chemical
A special grade reagent manufactured by Co., Ltd. was used.

Add 10 g of ammonium hydrogen carbonate and 40 ml of purified water to a 300 ml round bottom flask and stir using a magnetic stirrer. After the ammonium hydrogen carbonate has completely dissolved, add 1.5 g (15 mmol) of copper chloride and stir. This was continued and left at 25°C for about 20 minutes. After adding 10 g of activated carbon into this round bottom flask and continuing stirring for 24 hours, the solvent was removed under reduced pressure using a rotary evaporator, and further under reduced pressure (0.5 mmHg) at 120 g.
A black granular carbon monoxide adsorbent was obtained by heat treatment at ℃ for 2 hours.

The equilibrium adsorption amount of carbon monoxide of this adsorbent at 1 atm was measured and found to be 12.7 ml/g.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed by applying reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

This adsorbent was left in the air for 24 hours to make it inactive, and then heated under reduced pressure (0.1 mmHg) at 300° C. for 2 hours to activate the adsorbent for carbon monoxide separation.

As a result of measuring the equilibrium adsorption amount of carbon monoxide on this adsorbent at 1 atm, it was found to be 7.97ml/
The amount was 27.2 ml/g after activation.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed by applying reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

Example 5 Copper chloride () dihydrate special grade reagent manufactured by Showa Kagaku Co., Ltd. was used as copper chloride (). Activated carbon is Tsurumicol
4GV manufactured by Co., Ltd. was used.

In a 300 ml round bottom flask, add 2.56 g of copper chloride ()
Dihydrate and 40 ml of purified water were added and stirred using a magnetic stirrer to completely dissolve the copper chloride (). Add 10g of activated carbon to this round bottom flask and add 24
After continuing to stir for an hour, the solvent was removed under reduced pressure using a rotary evaporator, and the mixture was further heat-treated at 300° C. for 2 hours under reduced pressure (0.5 mmHg) to obtain a black granular carbon monoxide adsorbent.

The equilibrium adsorption amount of carbon monoxide on this adsorbent at 1 atm was measured and found to be 24.2 ml/g.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed by applying reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

This adsorbent was left in the air for 24 hours to make it inactive, and then heated under reduced pressure (0.1 mmHg) at 300° C. for 2 hours to activate the adsorbent for carbon monoxide separation.

As a result of measuring the equilibrium adsorption amount of carbon monoxide on this adsorbent at 1 atm, it was found to be 8.30ml/
The amount was 24.4 ml/g after activation.

This adsorbent was then pumped for 20 minutes using a vacuum pump.
The adsorbed carbon monoxide was desorbed by applying reduced pressure (0.1 mmHg) at 25°C.

Thereafter, even if this adsorption and desorption operation was repeated, no change was observed in the carbon monoxide adsorption rate and adsorption amount.

Comparative Example 1 Example 1 except that instead of heating the adsorbent after being left for 3 days as described in Example 1 at 260°C for 2 hours under a nitrogen gas atmosphere, it was heat-treated at 150°C for 2 hours under a nitrogen gas atmosphere. The adsorbent was activated in the same manner.

As a result of measuring the equilibrium adsorption amount of this adsorbent for carbon monoxide and nitrogen at 1 atm, it was found that carbon monoxide
The amount of carbon monoxide adsorbed was 14.9 ml/g and nitrogen 3.30 ml/g, which was considerably smaller than that of the activated adsorbent described in Example 1.

Comparative Example 2 The same procedure as in Example 2 was carried out, except that the adsorbent left for 3 days as described in Example 2 was heat-treated at 150°C in a nitrogen gas atmosphere instead of being heat-treated at 300°C in a nitrogen gas atmosphere. The adsorbent was activated.

As a result of measuring the equilibrium adsorption amount of this adsorbent for carbon monoxide and nitrogen at 1 atm, it was found that carbon monoxide
The amount of carbon monoxide adsorbed was 13.8 ml/g and nitrogen 3.58 ml/g, which was considerably smaller than that of the activated adsorbent described in Example 2.

(Effects of the Invention) The adsorbent activated by the method of the present invention, which once loses its activity, stably becomes capable of adsorbing a large amount of CO. Therefore, the carbon monoxide separation and purification equipment or carbon monoxide removal equipment using this adsorbent can be made quite small-scale, and there is an advantage that the equipment cost can be kept low.

In addition, by incorporating simple heating equipment into carbon monoxide separation and purification equipment or carbon monoxide removal equipment that uses this adsorbent, the carbon monoxide adsorption capacity can be restored without removing the adsorbent that has deteriorated due to oxidation etc. from the equipment. It is efficient and can be recovered.

Claims (1)

[Claims] 1. To restore carbon monoxide adsorption capacity to a carbon monoxide adsorbent made of copper salt-activated carbon that has lost its carbon monoxide adsorption capacity, heat it to a temperature exceeding 250°C in a non-oxidizing atmosphere or under reduced pressure. A method for activating an adsorbent for carbon monoxide separation, characterized by: