KR102254172B1 - Dry ice production method using calcium carbonate generated from waste gas - Google Patents

Abstract

The present invention relates to a method for producing dry ice using calcium carbonate generated from waste gas which is environment-friendly and cost-effective by recycling waste gas generated and discharged during a combustion process in an industrial boiler. The method for producing dry ice using calcium carbonate generated from waste gas according to the inventions comprises the steps of: calcining calcium carbonate produced by mixing calcium hydroxide with carbon dioxide, separating calcium oxide and carbon dioxide, and compressing the separated carbon dioxide; and producing an absorbent by mixing sodium hydroxide and magnesium oxide in a state in which calcium hydroxide is mixed with carbon dioxide in the calcium carbonate, and separating a product by mixing an amine-based enhancer with the absorbent.

Description

Dry ice production method using calcium carbonate generated from waste gas}

The present invention relates to a method of generating dry ice used for various purposes, and more particularly, carbon dioxide (CO ₂ ) contained in combustion gases generated and discharged during combustion in industrial boilers such as heat engines, especially thermal power plants. Calcium hydroxide (Ca(OH) ₂ ) is added to the reactor to remove carbon dioxide, and the resulting reaction product, calcium carbonate, is separated into calcium oxide and carbon dioxide, and then the carbon dioxide is solidified to generate dry ice. The present invention relates to a method for generating dry ice using calcium carbonate generated from waste gas that is environmentally friendly and cost-saving by recycling waste gas generated during combustion in a boiler.

In general, dry ice is used to freshly preserve fruits, vegetables, dairy products, frozen meats, frozen fruits and fish.

The official name of the dry ice is'solid carbonic acid', that is, carbon dioxide produced by burning oil or coal, so-called ice of carbon dioxide gas.

The manufacturing method has remained almost unchanged since industrial production began in 1925, except that part of it was mechanized.

In other words, carbon dioxide gas, carbon dioxide, which is a raw material for dry ice, is obtained by burning petroleum or coal, but in actual production, it is compressed and cooled.

However, in order to generate or manufacture dry ice, there is a problem of waste of resources and environmental pollution because it is generated by separately burning oil or coal as described above.

In order to solve such a problem, there is no way to use _{carbon dioxide (CO 2} ) contained in combustion gases generated and discharged during combustion in industrial boilers such as heat engines, especially thermal power plants.

Korean Patent Registration No. 10-2195969 Korea Utility Model Registration No. 20-0353286 Korean Patent Registration No. 10-2195970 Korean Patent Registration No. 10-1458769

In order to solve the above problems, the present invention generates dry ice by using calcium carbonate generated from waste gases that are environmentally friendly and cost-saving, including industrial waste, thereby recycling waste gas, which is a major cause of environmental pollution. At the same time, its purpose is to provide a method of generating dry ice using calcium carbonate generated from wasted resources and environmentally friendly waste gas.

In addition, calcium hydroxide (Ca(OH) _{2 ) is added to carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during the combustion process in industrial boilers such as heat engines, especially thermal power plants, and carbon dioxide, which is the remaining residue after removing carbon dioxide. Dry ice production method using calcium carbonate generated from waste gas that is eco-friendly and cost-saving by recycling calcium carbonate, which is a residue of waste gas, by separating calcium into calcium oxide and carbon dioxide and then compressing and cooling the carbon dioxide to generate dry ice. Its purpose is to provide

_{In addition, in the carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged from the combustion process in industrial boilers such as heat engines, especially thermal power plants, an absorbent mixture of sodium hydroxide as a reaction sustaining agent and magnesium oxide as a reaction retardant in an aqueous calcium hydroxide solution. After removing carbon dioxide by adding a reaction agent mixed with an amine-based promoter to remove carbon dioxide, the remaining calcium carbonate is separated into calcium oxide and carbon dioxide, and the carbon dioxide is compressed and cooled to generate dry ice to recycle calcium carbonate, a residue of waste gas. Its purpose is to provide a method of generating dry ice using calcium carbonate generated from waste gas that is environmentally friendly and capable of reducing costs.

In addition, calcium hydroxide (Ca(OH) ₂ ), magnesium oxide (MgO), sodium hydroxide (NaOH _{) in carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during combustion in industrial boilers such as heat engines, especially thermal power plants. ) Is added to remove carbon dioxide and the remaining calcium carbonate is separated into calcium oxide and carbon dioxide, and then the carbon dioxide is compressed and cooled to generate dry ice. Its purpose is to provide a method for producing dry ice using calcium carbonate generated from waste gas capable of reducing costs.

Specific solution means to achieve the above object,

_{"Calcium carbonate (CaCO 3} ), a reaction product produced by mixing calcium hydroxide (Ca(OH) _{2 ) with carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during combustion in an industrial boiler, is fired and oxidized. said carbon dioxide separation after separation of calcium (CaO) and carbon dioxide (CO _2), including those that are produced by compressing (CO _2), and
The calcium carbonate (CaCO ₃ ) is a mixture of carbon dioxide (CO ₂ ) with calcium hydroxide (Ca(OH) ₂ ), by mixing sodium hydroxide as a reaction sustaining agent and magnesium oxide as a reaction retarding agent to create an absorbent, and an amine series in the absorbent. Dry ice production method using calcium carbonate generated from waste gas comprising mixing and separating the promoter of

The calcium carbonate is a dry ice production method using calcium carbonate generated from waste gas including those limited to light calcium carbonate,

A composition obtained by mixing calcium hydroxide (Ca(OH) ₂ ), magnesium oxide (MgO), and sodium hydroxide (NaOH) into _{carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during combustion in an industrial boiler is added. Dry ice production method using calcium carbonate generated from waste gas comprising generating calcium carbonate as a reaction product,

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When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 50 mm, 14 hours 53 minutes at 925°C or 7 hours 30 minutes at 950°C, 1000°C Dry ice production method using calcium carbonate generated from waste gas comprising firing at 3 hours and 55 minutes at 1100°C for 1 hour 50 minutes or at 1200°C for 1 hour and 13 minutes,

When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 30 mm, 7 hours 52 minutes at 925°C or 3 hours 30 minutes at 950°C, 1000°C Dry ice production method using calcium carbonate generated from waste gas comprising firing at 1 hour 55 minutes or 1100°C for 1 hour or 1200°C for 38 minutes,

When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 20 mm, 4 hours 53 minutes at 925°C or 2 hours 05 minutes at 950°C, 1000°C Dry ice production method using calcium carbonate generated from waste gas comprising firing at 1 hour 10 minutes or 1100°C for 40 minutes or 1200°C for 24 minutes,

The calcium carbonate (CaCO ₃ ) is calcined and separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), and the separated carbon dioxide (CO ₂ ) is produced by compressing it at an absolute pressure of 1 atm below -78°C. Dry ice production method using calcium carbonate generated from waste gas,

Dry ice production method using calcium carbonate generated from waste gas including 1.5 to 2.3 parts by weight of an amine-based promoter based on 100 parts by weight of the absorbent, and

Dry ice production method using calcium carbonate generated from waste gas comprising a mixture of 95 to 99.5% by weight of the absorbent and 0.5 to 5% of an amine-based promoter, and

Dry ice production method using calcium carbonate generated from waste gas containing any one of ethanolamine, triethanolamine, piperazine, and triethylamine as the amine-based promoter The above object can be achieved by making "as its constitutive feature.

The present invention manufactured by the above manufacturing method is eco-friendly in that it uses calcium carbonate generated from waste gas, has an effect in terms of resource recycling, and thus has a cost-saving effect,

In addition, in the present invention, by adding and mixing an amine-based promoter to the absorbent, the absorption rate of carbon dioxide is improved by up to 74% compared to the previous one according to the addition ratio. It is a compound that is more expensive than calcium and does not generate VOCs (volatile organic compounds), and can be used in various eco-friendly fields through recycling.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in the present specification are exemplified only for the purpose of describing the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention are Since various changes can be added and may have various forms, all changes, equivalents, or substitutes included in the spirit and scope of the present invention are included, and terms or words used in the specification and claims are conventional or dictionary. The meaning and concept corresponding to the technical idea of the present invention are not limited to the meaning, and based on the fact that the inventor can appropriately define the concept of terms in order to describe his own invention in the best way. Should be interpreted as. Accordingly, the embodiments described in the specification of the present invention and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention, but are replaced at the time of filing of the present invention. It will be appreciated that various equivalents and variations that may be made are possible or exist.

In addition, unless otherwise defined in the specification of the present invention, all terms including technical or scientific terms used herein have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention belongs. Have. Terms as defined in a commonly used dictionary should be construed as having a meaning consistent with the meaning of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present specification. Does not.

Hereinafter, a specific configuration for the present invention will be described in detail.

First of all, before describing the present invention,

Referring to calcium carbonate, calcium carbonate is referred to as chalk, limestone, and the like, and has been applied not only to traditional fields such as cement, iron making, steel making, etc., but also to various fields.

Calcium carbonate as described above is generally two types of ground limestone manufactured by directly crushing and classifying limestone by a physical method (dry or wet), and precipitated calcium carbonate manufactured by chemical treatment. It is divided into.

The heavy calcium carbonate is industrially obtained by pulverizing limestone to form powder, sieving it, or peeling (an operation of dividing particles according to size or specific gravity using the difference in speed when solid particles freely settle in air). Heavy calcium carbonate is manufactured by physically and mechanically pulverizing and classifying high-purity limestone with high whiteness. Their quality and dignity are evaluated according to their characteristics and the like.

On the other hand, light calcium carbonate is obtained through carbonation reaction and has a particle diameter of about 0.8 to 3 microns, which is disadvantageous because it has a larger particle size than heavy calcium carbonate as a reinforcing agent. Is losing. In addition, hard calcium carbonate is also used for food additives, and is widely used from food additives to industrial applications (rubber, PVC, PE, HDPE, LDPE paint, toothpaste, etc.).

The calcium carbonate applied in the present invention is light calcium carbonate.

Hereinafter, a description will be given of a method for producing dry ice using calcium carbonate generated from waste gas according to the present invention,

Calcium carbonate, a reaction product produced by mixing calcium hydroxide (Ca(OH) _{2 ) with carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during the combustion process in industrial boilers such as heat engines, especially thermal power plants, is calcined. After separating into calcium oxide and carbon dioxide, the separated carbon dioxide is compressed to generate dry ice,

The calcium carbonate is limited to light calcium carbonate,

Preferably, a composition obtained by mixing calcium hydroxide, magnesium oxide, and sodium hydroxide into _{carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during the combustion process in an industrial boiler is added to generate calcium carbonate as a reaction product. Will,

The calcium carbonate is produced by mixing sodium hydroxide (a reaction sustaining agent) and magnesium oxide (a reaction retarding agent) in a state in which calcium hydroxide (Ca(OH) _{2) is mixed with carbon dioxide to produce an absorbent, and by mixing an amine-based enhancer with the absorbent to be separated.} And

1.5 to 2.3 parts by weight of an amine-based promoter are combined based on 100 parts by weight of the absorbent,

Specifically, 95 to 99.5% by weight of the absorbent and 0.5 to 5% of an amine-based promoter are mixed.

When explaining in detail the absorbent that is a component of the present invention,

In order to remove carbon dioxide after various tests, 0.5% of sodium hydroxide as a reaction sustaining agent and 2.25% of magnesium oxide as a reaction delaying agent were included in 97.50% of calcium hydroxide aqueous solution and 2.25% of magnesium oxide as a reaction retarding agent in order to solve the problem of the reaction occurring too quickly. In order to demonstrate, the absorbent was prepared by containing 20PPM of red dye.

In other words, the calcium hydroxide aqueous solution reacts quickly with carbon dioxide and removes carbon dioxide while controlling the speed of the reaction by adding magnesium oxide, a reaction retardant, in order to solve the economic inefficiency caused by the rapid progress of the sodium hydroxide transient reaction. There is an advantage that can improve the purification effect.

The calcium hydroxide and sodium hydroxide undergo a chemical reaction with carbon dioxide to generate insoluble calcium carbonate particles, and carbon dioxide can be removed by removing them. The chemical reaction is shown in Scheme 1 below.

Scheme 1

Ca(OH) ₂ + CO ₂ → CaCO ₃ + H ₂ O

In other words, calcium ions react with carbon dioxide to produce insoluble calcium carbonate, and a constant rate is generated by simultaneously generating a reaction continuation phenomenon by sodium hydroxide (NaOH), a reaction sustaining agent, and a reaction delay phenomenon by magnesium oxide (MgO), a reaction retarding agent. It is to react while maintaining.

As described above, after preparing an absorbent, which is a component of the present invention, an amine-based promoter is added and mixed to the absorbent to complete,

The amine-based promoter will be described in detail as follows.

Looking at the specific reaction equation for this,

Looking at the reaction formula with triethylamine, especially among the amines,

_{R 3 N + CO 2 ------>} R 3 N + CO 2 - --- (fast) ---> H 2 CO 3 -------------> CaCO 3

As the triethylamine reacts with carbon dioxide, when H ₂ 0 is added, carbonic acid is produced, and when calcium hydroxide is added to the carbonic acid, hard calcium carbonate is finally produced.

Looking at the performance evaluation of the present invention configured as described above,

Carbon dioxide absorption performance of absorbent and performance evaluation of amine-based promoter

Experimental method: After putting the absorbent in a pick-up bottle and adding carbon dioxide for a predetermined rate and time, the actual absorbed amount was accurately measured by the difference in weight.

Experimental conditions: ① Use 220g of absorbent in 250mL container

② Use of pure carbon dioxide

③ Carbon dioxide input rate: 5.0L/10 minutes

Experimental results of measuring the absorption capacity of carbon dioxide under the above conditions:

1. When using absorbent (220g) + amine-based promoter (3.3g, 1.5%)

Average absorption rate: 16.4% (0.82L absorbed CO ₂ /5.0L injected CO ₂₎

When compared with the case of adding only the absorbent, the result of an increase in absorption rate of 37% (based on 1 hour) was derived as shown in Table 1.

Time (minutes)
Weight (g)/volume (L) _{of CO 2} absorbed by absorbent + amine-based enhancer 10 2.40/1.22 20 1.47/0.75 30 1.43/0.73 40 1.53/0.78 50 1.40/0.71 60 1.42/0.72 1 hours
Average 10 minutes 9.65/4.91
1.61/0.82

2. When using absorbent (220g) + amine-based promoter (4.0g, 1.8%)

Average absorption rate: 19.4% (0.82L absorbed CO ₂ /5.0L injected CO ₂₎

When compared with the case of adding only the absorbent, the result of an increase in the absorption rate of 55% (based on 1 hour) was derived as shown in Table 2.

Time (minutes)
Weight (g)/volume (L) _{of CO 2} absorbed by absorbent + amine-based enhancer 10 3.01/1.53 20 1.80/0.92 30 1.65/0.84 40 1.62/0.82 50 1.70/0.87 60 1.65/0.84 1 hours
Average 10 minutes 11.43/5.82
1.91/0.97

3. When using absorbent (220g) + amine-based promoter (5.0g, 2.3%)

Average absorption rate: 21.6% (0.82L absorbed CO ₂ /5.0L injected CO ₂₎

When compared to the case of adding only the absorbent, the results of the 74% absorption rate increase (based on 1 hour) were derived as shown in Table 3.

Time (minutes)
Weight (g)/volume (L) _{of CO 2} absorbed by absorbent + amine-based enhancer 10 3.69/1.88 20 1.89/0.96 30 1.77/0.90 40 1.87/0.95 50 1.81/0.92 60 1.74/0.86 1 hours
Average 10 minutes 12.77/6.47
2.13/1.08

As described above, unlike when only the absorbent is added, it can be seen that the removal and absorption rate of carbon dioxide is very high when the amine-based promoter is added and mixed.

In other words, by adding and mixing an amine-based promoter to the absorbent under certain experimental conditions, the absorption rate of carbon dioxide was improved by up to 74% compared to the previous one depending on the addition ratio. It is a compound that is more expensive than calcium carbonate and does not generate VOCs (volatile organic compounds), and can be used in various fields through recycling.

The amine-based promoter may be any one of ethanolamine, triethanolamine, piperazine, and triethylamine, but most preferably, the amine-based promoter is triethylamine. This is optimal.

Preferably,

When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 50 mm, 14 hours 53 minutes at 925°C or 7 hours 30 minutes at 950°C, 1000°C At 3 hours 55 minutes or 1 hour 50 minutes at 1100°C or 1 hour 13 minutes at 1200°C,

Further, when the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 30 mm, it is 7 hours 52 minutes at 925°C or 3 hours 30 minutes at 950°C. , It is to be sintered at 1000°C for 1 hour 55 minutes or 1100°C for 1 hour or 1200°C for 38 minutes,

When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 20 mm, 4 hours 53 minutes at 925°C or 2 hours 05 minutes at 950°C, 1000°C At 1 hour 10 minutes, 1100 ℃ 40 minutes, or 1200 ℃ 24 minutes in any one of firing.

Next, the calcium carbonate (CaCO ₃ ) is calcined and separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), and then the separated carbon dioxide (CO ₂ ) is compressed with an absolute pressure of 1 atm below -78°C to dry ice. To create.

The present invention manufactured by the above manufacturing method is eco-friendly in that it uses calcium carbonate generated from waste gas, has an effect in terms of resource recycling, and thus has a cost-saving effect,

In addition, in the present invention, by adding and mixing an amine-based promoter to the absorbent, the absorption rate of carbon dioxide is improved by up to 74% compared to the previous one according to the addition ratio. It is a compound that is more expensive than calcium and does not generate VOCs (volatile organic compounds), and can be used in various eco-friendly fields through recycling.

As described above, although the present invention has been described by a limited embodiment, the present invention is not limited to the above embodiment, as well as various modifications from the above description by those of ordinary skill in the field to which the present invention pertains. And, of course, variations may be possible.

Therefore, the technical idea in the present invention should be grasped by the claims described below, but it will be apparent that all of the equivalent or equivalent modifications thereof belong to the scope of the technical idea of the present invention.

Claims (11)

Calcium oxide by burning _{calcium carbonate (CaCO 3} ), a reaction product produced by mixing calcium hydroxide (Ca(OH) _{2 ) with carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during combustion in an industrial boiler. including those that are produced by compressing (CaO) and carbon dioxide (CO ₂₎ of the carbon dioxide (CO ₂₎ was separated by separation, and
The calcium carbonate (CaCO ₃ ) is a mixture of carbon dioxide (CO ₂ ) with calcium hydroxide (Ca(OH) ₂ ), by mixing sodium hydroxide as a reaction sustaining agent and magnesium oxide as a reaction retarding agent to create an absorbent, and an amine series in the absorbent. Dry ice production method using calcium carbonate generated from waste gas comprising mixing and separating the promoter.
The method of claim 1,
The method for producing dry ice using calcium carbonate generated from waste gas, wherein the calcium carbonate is limited to light calcium carbonate.
The method of claim 1,
A composition obtained by mixing calcium hydroxide (Ca(OH) ₂ ), magnesium oxide (MgO), and sodium hydroxide (NaOH) into _{carbon dioxide (CO 2} ) contained in the combustion gas generated and discharged during combustion in an industrial boiler is added. Dry ice production method using calcium carbonate generated from waste gas comprising generating calcium carbonate as a reaction product.
delete The method of claim 1,
When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 50 mm, 14 hours 53 minutes at 925°C or 7 hours 30 minutes at 950°C, 1000°C Dry ice production method using calcium carbonate generated from waste gas comprising firing in any one of 3 hours 55 minutes or 1100°C for 1 hour 50 minutes or 1200°C for 1 hour 13 minutes.
The method of claim 1,
When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 30 mm, 7 hours 52 minutes at 925°C or 3 hours 30 minutes at 950°C, 1000°C Dry ice production method using calcium carbonate generated from waste gas comprising firing at 1 hour and 55 minutes or at 1100° C. for 1 hour or at 1200° C. for 38 minutes.
The method of claim 1,
When the calcium carbonate (CaCO ₃ ) is separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), when the size of the calcium carbonate is 20 mm, 4 hours 53 minutes at 925°C or 2 hours 05 minutes at 950°C, 1000°C Dry ice production method using calcium carbonate generated from waste gas comprising firing at 1 hour and 10 minutes or at 1100°C for 40 minutes or at 1200°C for 24 minutes.
The method of claim 1,
The calcium carbonate (CaCO ₃ ) is calcined and separated into calcium oxide (CaO) and carbon dioxide (CO ₂ ), and the separated carbon dioxide (CO ₂ ) is produced by compressing it at an absolute pressure of 1 atm below -78°C. Dry ice production method using calcium carbonate generated from waste gas.
The method of claim 1,
Dry ice production method using calcium carbonate generated from waste gas comprising a combination of 1.5 to 2.3 parts by weight of an amine-based promoter based on 100 parts by weight of the absorbent.
The method of claim 1,
Dry ice production method using calcium carbonate generated from waste gas comprising a mixture of 95 to 99.5% by weight of the absorbent and 0.5 to 5% of an amine-based promoter.
The method of claim 1,
Dry ice production method using calcium carbonate generated from waste gas containing any one of ethanolamine, triethanolamine, piperazine, and triethylamine as the amine-based promoter .