WO2024019448A1

WO2024019448A1 - Resource recycling system

Info

Publication number: WO2024019448A1
Application number: PCT/KR2023/010174
Authority: WO
Inventors: 홍원방; 박무신; 홍정환; 장인영; 박성수
Original assignee: 홍원방
Priority date: 2022-07-19
Filing date: 2023-07-17
Publication date: 2024-01-25
Also published as: KR102556854B1

Abstract

The present invention relates to a resource recycling system comprising: a pretreatment section that receives exhaust gas from an exhaust gas source and removes pollutants from the exhaust gas; a desulfurization section that receives the exhaust gas from the pretreatment section and removes sulfur oxides from the exhaust gas before discharging same; a carbon dioxide absorption tank that receives the exhaust gas from either before or after the desulfurization section, removes carbon dioxide and sulfur oxides from the exhaust gas through a reaction with a carbon dioxide absorbent, and discharges the treated gas; a primary settling tank that receives the reaction liquid from the carbon dioxide absorption tank and precipitates impurities through a coagulation reaction with a coagulant; a secondary settling tank that receives the reaction liquid from the primary settling tank and produce calcium carbonate through a react with calcium oxide with the concomitant regeneration of the carbon dioxide absorbent by removing the carbon dioxide collected from the reaction liquid; an acquisition tank that receives and stores calcium carbonate from the secondary settling tank; and a regenerated carbon dioxide absorbent storage tank that receives the regenerated carbon dioxide absorbent from the secondary settling tank and circulates same back to the carbon dioxide absorption tank.

Description

resource circulation system

The present invention relates to a system for recycling resources such as carbon dioxide absorbents in the process of purifying exhaust gas emitted from power plants, etc.

In power plants using fossil fuels, the exhaust gas after combustion contains a large amount of carbon dioxide. At this time, nitrogen oxides (NOx) generated due to the high-temperature combustion process are removed using a denitrification facility (SCR or SNCR). Also, excluding the case of relatively expensive LNG power generation, first of all, depending on the type of fossil fuel used as fuel, Sulfur oxides (SOx) are generated after combustion due to the sulfur content in the fuel, and dust containing ash and heavy metals is removed with an electrostatic precipitator (EP).

To suppress the emission of SOx into the atmosphere, a large-scale desulfurization facility (FGD) is operated, and sulfur components are removed in the form of CaSO ₄ using limestone as an absorbent from a huge absorption tower. Among these exhaust gases, _CO2 (366 tons/hr, based on one 500 MWH power plant) is more than 100 times more than the SOx generated and removed, and is currently being emitted into the atmosphere (2.6 million tons/year, 366 tons/hr*24 hours). *Based on 300 days).

In order to remove or reduce such a huge amount of CO ₂ , it is expected that the facility and operation will be impossible using absorbent methods such as limestone, and wastewater generation will also be enormous.

Therefore, there is a need to develop an adsorbent that has excellent adsorption capacity for carbon dioxide and is capable of low-cost _CO2 degassing or easy resource conversion from a facility that is economically feasible and feasible on a scale, and also enables a circulation system for the adsorbent to minimize additional chemical costs and reduce wastewater It is desirable to suppress its occurrence.

The technology behind the present invention is disclosed in patent document Republic of Korea Patent Registration No. 10-1938424.

The present invention was devised to solve the above problems, and aims to provide a system that allows efficient reuse of resources such as carbon dioxide absorbents in the process of treating pollutants containing carbon dioxide in exhaust gas.

The resource circulation system according to the present invention (hereinafter referred to as “the system of the present invention”) to achieve the above object includes a preprocessing unit that receives exhaust gas discharged from an exhaust gas source and removes pollutants from the exhaust gas. ; A desulfurization unit that receives exhaust gas from the pretreatment unit, removes sulfur oxides from the exhaust gas, and discharges the exhaust gas; a carbon dioxide absorption tank that receives exhaust gas from the front or rear end of the desulfurization unit, removes carbon dioxide and sulfur oxides from the exhaust gas by reacting with a carbon dioxide absorbent, and discharges treated gas; a primary sedimentation tank that receives the reaction solution from the carbon dioxide absorption tank and precipitates foreign substances through a coagulation reaction with a coagulant; a secondary precipitation tank in which the reaction liquid is introduced from the primary precipitation tank and reacts with calcium oxide to produce calcium carbonate, and at the same time, the carbon dioxide collected from the reaction liquid is removed to regenerate the carbon dioxide absorbent; a yield tank that receives calcium carbonate from the secondary precipitation tank and stores it; and a regenerated carbon dioxide absorbent storage tank that receives the regenerated carbon dioxide absorbent from the secondary precipitation tank and circulates it to the carbon dioxide absorbent tank.

As an example, the process gas discharged from the desulfurization unit or the process gas discharged through the carbon dioxide absorption tank is discharged to the outside through a heat exchanger.

As an example, a carbon dioxide absorbent is manufactured by mixing an aqueous solution of sodium hydroxide, illite extract, sodium tetraborate, and water glass, and a manufacturing unit that supplies the manufactured carbon dioxide absorbent to the carbon dioxide absorption tank is further included.

As an example, the carbon dioxide absorbent further contains hydrogen peroxide.

As an example, the front end of the emission source further includes a coal crushing unit that crushes fossil fuel supplied as a fuel source of the emission source, and in the production unit, the sediment generated during the carbon dioxide absorbent manufacturing process is used as a pre-combustion desulfurization catalyst in the coal crushing unit. It is characterized by supply.

As an example, the calcium carbonate stored in the obtaining tank is delivered to the desulfurization unit to remove sulfur oxides from the exhaust gas.

As described above, the present invention uses a carbon dioxide absorbent that can simultaneously treat carbon dioxide and sulfur oxides in the treatment of pollutants containing carbon dioxide in exhaust gas, and operates the system efficiently without desulfurization equipment or without load on the desulfurization equipment. It has the advantage of being environmentally friendly because it allows the carbon dioxide captured in the carbon dioxide absorbent to be recovered as high-purity precipitated calcium carbonate without impurities, and at the same time, the carbon dioxide absorbent can be regenerated and circulated.

In addition, the system of the present invention can be used as a pre-combustion desulfurization catalyst for fossil fuels used at the emission source in the case of not only the manufacturing liquid but also the sediment generated during the manufacturing process of the carbon dioxide absorbent, thereby controlling the generation of waste and circulating resources. There is an advantage.

In addition, the system of the present invention has the advantage of recycling resources because part of the obtained calcium carbonate can be used to remove sulfur oxides in the desulfurization unit.

1 is a block diagram showing the system of the present invention,

Figure 2 is a diagram showing the carbon dioxide absorption mechanism of the carbon dioxide absorbent applied to the present invention,

Figure 3 is a graph showing the results of an experiment on the removal of sulfur oxides,

Figure 4 is a graph showing experimental results regarding the removal of carbon dioxide.

Below, preferred embodiments according to the present invention will be described in detail.

As shown in FIG. 1, the system 1 of the present invention includes a preprocessing unit 5 that receives exhaust gas discharged from an exhaust gas source 4 and removes pollutants from the exhaust gas; a desulfurization unit (6) that receives exhaust gas from the pretreatment unit (5), removes sulfur oxides from the exhaust gas, and discharges the sulfur oxides; a carbon dioxide absorption tank (8) that receives exhaust gas from the front or rear end of the desulfurization unit (6), removes carbon dioxide and sulfur oxides from the exhaust gas by reacting with a carbon dioxide absorbent, and discharges treated gas; a primary sedimentation tank (9) that receives the reaction solution from the carbon dioxide absorption tank (8) and precipitates foreign substances through a coagulation reaction with a coagulant; a secondary precipitation tank (10) that receives the reaction solution from the primary precipitation tank (9) and reacts it with calcium oxide to produce calcium carbonate, and at the same time, carbon dioxide collected from the reaction liquid is removed to regenerate the carbon dioxide absorbent; an acquisition tank (11) that receives calcium carbonate from the secondary precipitation tank (10) and stores it; and a regenerated carbon dioxide absorbent storage tank (12) that receives the regenerated carbon dioxide absorbent from the secondary settling tank (10) and circulates it to the carbon dioxide absorbent tank (8).

The pre-processing unit 4 receives the exhaust gas discharged from the emission source 4 and removes pollutants from the exhaust gas. The pollutants may be nitrogen oxides, dust, etc., and the pre-processing unit 4 contains nitrogen. An oxide removal device, a dust collection device, etc. may be configured.

The emission source 4 is a concept that refers to places and facilities that emit exhaust gas mixed with various pollutants such as power plants, nitrogen oxides, sulfur oxides, and carbon dioxide.

The desulfurization unit (6) is configured to remove sulfur oxides from the exhaust gas, and in the system (1) of the present invention, a carbon dioxide absorbent capable of simultaneously removing sulfur oxides and carbon dioxide in the carbon dioxide absorption tank (8) described below is used. As it is used, the desulfurization unit 6 can be selectively bypassed, thereby simplifying the system and controlling the load on the desulfurization unit 6.

Various known technologies can be applied to the removal of sulfur oxides in this desulfurization unit 5. For example, a mechanism that allows sulfur oxides to be removed by contacting calcium carbonate slurry with exhaust gas can be applied, which is described below. A part of the calcium carbonate obtained in the yield tank 11 can be supplied to the desulfurization unit 5 to enable desulfurization from the exhaust gas.

In other words, the calcium carbonate generated within the system can be reused as a catalyst for desulfurization within the system. Here, the operating mechanism that causes desulfurization by calcium carbonate is a known operating mechanism, so detailed description thereof will be omitted.

The heat exchanger (7) allows heat exchange while passing the processed gas through the desulfurization unit (6) or the carbon dioxide absorption tank (8). In the case of the heat exchanger (7), various known technologies exist. , the detailed description is omitted.

The carbon dioxide absorption tank 8 receives exhaust gas from the front end of the desulfurization unit 6 or from the rear end, although not shown in the drawing, and removes carbon dioxide and sulfur oxides from the exhaust gas by reacting with a carbon dioxide absorbent containing an aqueous sodium hydroxide solution. This corresponds to a configuration in which the process gas is removed and discharged to the heat exchanger (7).

As mentioned above, the carbon dioxide absorption tank 8 is capable of allowing exhaust gas that does not pass through the desulfurization unit 6 to flow in as shown in the drawing by applying a carbon dioxide absorbent that simultaneously removes carbon dioxide and sulfur oxides. Although this has not been done, the reaction can be achieved by introducing exhaust gas that has passed through the desulfurization unit (6).

This carbon dioxide absorbent is manufactured in the manufacturing unit 2 as shown in FIG. 1, and the carbon dioxide absorbent contains an aqueous sodium hydroxide solution, illite extract, sodium tetraborate, and water glass.

In the production unit 2, sediment is produced as a carbon dioxide absorbent and a desulfurization catalyst by the method described below.

The manufacturing method includes the step of adding illite powder to a reaction tank storing water heated to 40 to 100° C. and stirring it (S10); Adding sodium hydroxide to the reaction tank and stirring it (S20); Separating and filtering the supernatant from the reaction tank (S30); Characterized in that it includes a step (S40) of separating the precipitate from the reaction tank.

First, step S10 includes adding illite powder to a reaction tank storing water heated to 40 to 100° C. and stirring it.

An illite extract is obtained through this step (S10), and the illite is expressed as {K _0.75 [Al _1.75 (Mg·Fe ₂₊ ) _0.25 ](Si _3.50 Al _0.50 )O ₁₀ (OH) ₂ } This mineral was found to be buried in large quantities in the Yeongdong region of Korea. The layer charge is lower than that of muscovite, and the charge is due to the reduction of isomorphic substitution of Al ³⁺ and Si ⁴⁺ of the tetrahedral plate. Some isomorphic substitutions occur in the octahedral plate.

Illite is non-expandable due to the strong bonding force caused by K+ that exists between layers, and the layer spacing is 10Å. Therefore, it is a mineral that is extracted from the liquid phase, has a full cationic charge, and is easily converted into a chelation compound. In the present invention, it is appropriate to use micronized illite to facilitate extraction of these metal foreign substances.

The extract extracted from illite is an extract containing several types of metal oxides such as potassium oxide, and provides minerals that are easily converted into chelation compounds in the liquid phase, and is used in the carbon dioxide and sulfur oxide absorption reaction of the aqueous sodium hydroxide solution described below. It acts as a reaction enhancer.

That is, in the absorption of carbon dioxide including SOx in the sodium hydroxide aqueous solution, more illite extract is added to increase the absorption efficiency.

Next, there is a step (S20) of adding sodium hydroxide to the reaction tank and stirring it.

In this way, the illite extract is mixed with an aqueous sodium hydroxide solution, which is characterized in that a mixed gas containing high temperature and high concentration of carbon dioxide and COS (hydrocarbon, O ₂ , SOx) can be removed at the same time. there is. In other words, it absorbs not only sulfur oxides (SOx) but also carbon dioxide from power plant exhaust gases.

The principle by which the sodium hydroxide aqueous solution removes sulfur oxide and carbon dioxide is shown in the following reaction equation. That is, sulfur trioxide (sulfurous acid) and sulfur dioxide are removed by reacting with sodium hydroxide and extracting them into anhydrous sodium sulfate and sodium sulfite, respectively, as shown below.

And carbon dioxide is removed by reacting with sodium hydroxide to produce sodium carbonate as shown in the reaction equation below. Additionally, the produced sodium carbonate reacts with excess sulfur oxide to further increase the sulfur oxide removal effect, and the produced carbon dioxide is removed by sodium hydroxide.

1) 2NaOH + SO ₃ = Na ₂ SO ₄ + H ₂ O

2) 2NaOH + SO ₂ = Na ₂ SO ₃ + H ₂ O

3) 2NaOH + CO ₂ = Na ₂ CO ₃ + H ₂ O

4) NaOH + CO ₂ = NaHCO ₃

In addition, as mentioned above, the reaction equation for sodium hydroxide of illite extract as a reaction enhancer is as shown below. Only the main components of illite are described, and oxides of other minor components such as Ca, Fe, Mg, Mn, Ti, and P ₂ O ₅ also contribute greatly to forming a stable metal chelation compound in the liquid phase.

1) 2NaOH + SiO ₂ = Na ₂ O.SiO ₂ + H ₂ O

2) 2NaOH + K ₂ O = Na ₂ O + 2KOH

3) Na ₂ O + Al ₂ O ₃ + H ₂ O = 2NaAlO ₂ + H ₂ O

In addition, the present invention provides an example in which a step (S10-1) of adding sodium tetraborate to the reaction tank and stirring is provided before step S20. In addition, after step S20, an example is presented in which a step (S20-1) of adding water glass to the reaction tank and stirring it is further included.

That is, an example is presented in which sodium tetraborate (Na ₂ B ₄ O ₇ ·10H ₂ O) and water glass (Na ₂ SiO ₃ ) are further included in the illite extract and aqueous sodium hydroxide solution.

The aqueous sodium hydroxide solution contains sodium tetraborate and water glass in addition to the illite extract. As more sodium tetraborate and water glass are added, the carbon dioxide and the absorbent component react directly, so the reaction rate is much faster and the mass transfer coefficient increases.

Moreover, because sodium tetraborate and water glass have high viscosity, the absorbed gaseous carbon dioxide cannot escape, but quickly dissolves in the liquid state and reacts with carbonic acid, thereby doubling the carbon dioxide absorption rate.

In addition, the present invention provides an example in which, after step S20-1, a step (S20-2) of adding hydrogen peroxide to the reaction tank and stirring is further included. That is, an example is presented in which hydrogen peroxide (H ₂ O ₂ ) is further added as a reaction-promoting additive.

The reaction equation of sodium tetraborate and hydrogen peroxide in aqueous sodium hydroxide solution is as follows.

1) Na ₂ B ₄ O ₇ + H ₂ O = Na ₂ O + 2B ₂ O ₃

2) 2NaOH + H ₂ O ₂ = Na ₂ O + H ₂ O + 0.5O ₂

Therefore, the carbon dioxide absorption mechanism is as shown in Figure 2 and the reaction equation below.

1) CO ₂ (g) + CO ₂ (aq) + Na ₂ O + 2OH- = CO ₂ (g) + CO ₃ -- + 2NaOH = CO ₂ (aq) + CO ₃ --

2) CO ₃ -- + H ₂ O + CO ₂ (aq) = 2HCO ₃ -

3) CO ₂ (aq) + OH- = HCO ₃ -

4) HCO ₃ - + OH- = CO ₃ -- + H ₂ O

When the reaction is completed in this way, the next step is to separate and filter the supernatant from the reaction tank (S30). The supernatant is separated from the reaction tank, and foreign substances contained in the supernatant are removed to produce a carbon dioxide absorbent.

Next, there is a step (S40) of separating the precipitate from the reaction tank. By separating these sediments, a desulfurization catalyst, a fuel additive, is manufactured.

The precipitate in the reaction tank contains components extracted from illite, etc. and various types of metal salts such as Ca, Fe, Mg, Mn, and Ti.

Therefore, these active ingredients enable a pre-combustion desulfurization catalyst, which is another use of the prepared liquid, and the remaining active ingredients of the separated sediment as described above can be used as a desulfurization catalyst.

In addition, at the end of S40, a step (S40-1) of mixing an additive including a surfactant and an oxy acid with the separated precipitate may be further included.

The precipitate separated as described above, that is, the metal salt aqueous solution, contains additives including a surfactant and an oxy acid.

The surfactant acts as a dispersant so that the desulfurization catalyst has a large surface area, and it is preferable to use a nonionic surfactant. The nonionic surfactant is a surfactant that does not have a group that dissociates into ions in an aqueous solution and has an -OH group. Although it is relatively hydrophilic, it has ester, acid amide, and ether bonds within the molecule. The nonionic surfactant includes ether type, ester ether type, ester type, and nitrogen-containing type.

The ether-type surfactants include alkyl and alkylaryl polyoxyethylene ethers, alkylaryl formaldehyde condensed polyoxyethylene ethers, block polymers with polyoxypropylene as the lipophilic group, and polyoxyethylene-polyoxypropylene copolymers. .

The oxyacid is used to increase the dissolution stability of the metal compound in an aqueous metal salt solution.

The oxy acid is a hydroxy carboxylic acid, and specific examples thereof include citric acid, malic acid, tartaric acid, tartronic acid, glyceric acid, hydroxy butyric acid, hydroxy acrylic acid, lactic acid, and glycolic acid.

On the other hand, in order to improve the desulfurization activity, it is necessary to control the cohesion between the metal components and increase the degree of dispersion. To this end, the stability of the aqueous metal salt solution can be improved to some extent by adding oxy acid to the above additive, but the cohesion between the metal components must not be sufficient. The problem of deteriorating catalytic activity due to uncontrollability still exists.

Accordingly, in step S40-1, an example is presented in which precipitated carbonate is further included in the additive.

By adding the precipitated carbonate, a fine coating film is formed on the metal salt, thereby increasing the repulsive force between the metal salts and controlling the agglomeration phenomenon. Preferably, the metal salt and the precipitated carbonate are stored as a mixture and added to the mixture to form an aqueous solution, thereby preventing agglomeration between particles during the storage process.

The precipitated carbonate includes crystalline and/or amorphous carbonate compounds precipitated as metastable carbonate compounds precipitated from water, such as alkaline earth metal-containing water such as brine.

This desulfurization catalyst is stabilized by mixing the compositions and allowing them to precipitate for a certain period of time without separating and drying the precipitate. Although not shown in the drawing, the desulfurization catalyst is a solid type added during combustion at the emission source 4. It can be used as a desulfurization catalyst, and the liquid composition remaining after separating the sediment is input into the coal crushing unit 3, which crushes fossil fuel used as fuel from the discharge source 4, as shown in FIG. 1, and carries out the crushing process. It is intended to be used as a liquid desulfurization catalyst applied to the surface of coal.

The primary sedimentation tank (9) receives the reaction solution from the carbon dioxide absorption tank (8) and precipitates foreign substances through a coagulation reaction with a coagulant, thereby removing foreign substances such as heavy metals, ash, and SS from the reaction solution by coagulation. This is to increase the purity of calcium carbonate obtained in the secondary precipitation tank 10 at the rear stage, and to ensure that a regenerated carbon dioxide absorbent without impurities is regenerated when regenerating the reaction solution.

The type of coagulant is not limited, and for example, calcium hydroxide (Ca(OH) ₂ ) may be applied.

The secondary settling tank 10 receives the reaction liquid from the primary settling tank 9 and reacts it with calcium oxide to produce calcium carbonate, and at the same time, the carbon dioxide captured from the reaction liquid is removed to regenerate the carbon dioxide absorbent. corresponds to

Here, the reaction solution is a carbon dioxide absorbent in which carbon dioxide is captured, and in the secondary precipitation tank 10, the carbon dioxide captured in the reaction solution is converted to calcium carbonate by dropping calcium oxide, thereby simultaneously regenerating the carbon dioxide absorbent.

That is, by adding CaO to the secondary precipitation tank 10 in accordance with the equivalent number of carbon dioxide present as carbonic acid in the reaction solution, high-purity, high-value precipitated calcium carbonate, which is a useful resource, is produced.

In addition, the reaction solution from which foreign substances as well as captured carbon dioxide are removed while passing through the first sedimentation tank 9 and the second sedimentation tank 10 can be reused as a regenerated carbon dioxide absorbent.

In order to achieve the goal of reducing carbon dioxide, costs such as the size of additional facilities, absorbents, and convenience of operation must be considered, and the cost of input energy is also one of the important items.

Therefore, according to the present invention, the cost of the provided carbon dioxide absorbent is that it has a mechanism for recovering the absorption power by precipitating it again as calcium carbonate after the chemical absorption reaction of carbon dioxide, and there is no loss other than a slight loss in the pipe and absorption tower through the circulation system, After calcium carbonate precipitation, the temperature of the filtrate is maintained above 60°C due to the dilution heat generated when CaO is added in the secondary precipitation tank 10, and an exothermic reaction occurs with little heat energy loss. Of course, calcium carbonate has almost no solubility in alkaline water even at high temperatures above 60℃, but it only affects the size and crystal form of the precipitate depending on the temperature.

Calcium carbonate obtained in the secondary precipitation tank 10 is stored in the harvest tank 11, and some of the calcium carbonate stored in the harvest tank 11 is used as a catalyst in the desulfurization unit 6 as mentioned above. It is to be reused.

Since the calcium carbonate obtained in this way has a very high purity without impurities, it can be used without restrictions across industries such as papermaking, construction, and steelmaking. High-purity carbon dioxide and slaked lime are manufactured through the sintering process, making it a natural resource. It can be recycled. In addition, pure calcium carbonate like this is a pollution-free resource that is not affected by the natural world and can at least be used for reclaiming abandoned mines.

In addition, the system (1) of the present invention does not directly collect carbon dioxide and then store or recycle it. It does not require large-scale facilities, generates little or no wastewater, and quickly produces calcium carbonate of very low solubility through a 1:1 reaction with carbonic acid. As the entire amount is deposited at a rapid rate, heat energy is obtained through the exothermic reaction of calcium carbonate, rather than reducing conversion energy costs in a small-scale sedimentation tank. Although not shown in the drawing, operating costs such as additional chemical costs are expected to be minimized through the circulation of carbon dioxide absorbents with restored performance. It is done.

As a conversion product, high purity precipitated calcium carbonate can be expected to have high added value in terms of market size and price.

Below, a preferred embodiment of the carbon dioxide absorbent will be described based on an experimental example.

[Example 1]

1,350 g of yellow illite ground to 1,000 mesh was added to 15 L of RO water heated to 60°C and stirred for 30 minutes. Next, add 150g of sodium tetraborate and stir for 10 minutes to dissolve it well (temperature drop of about 10℃), then slowly add 300g of sodium hydroxide and stir. When the temperature of the reaction solution reaches 70℃ due to the heat of dilution, add 300g of water glass and stir for 1 hour. It was stirred. The temperature of the reaction solution naturally decreased and was stirred until it reached room temperature. Stirring was stopped at room temperature, left to stand overnight, and the supernatant was filtered to prepare an adsorbent.

[Example 2]

540 g of yellow illite ground to 325 mesh was added to 6 L of RO water heated to 60°C and stirred for 30 minutes. Add 300g of sodium tetraborate and stir for 30 minutes (temperature drop of reaction solution about 20℃). When the temperature of the reaction solution under natural conditions falls below 40℃, slowly add 900g of sodium hydroxide and stir. The temperature of the reaction solution drops to 80℃ due to the heat of dilution. Once added, 300 g of water glass was added and stirred for 1 hour.

After the temperature of the reaction solution naturally decreased to below 60°C, 90 g of hydrogen peroxide was added and the reaction solution was stirred until it reached room temperature. Stirring was stopped at room temperature, left to stand overnight, and the supernatant was filtered to prepare an adsorbent.

NOVA 9K (MRU Emission Monitoring System, Germany) was used, and the sensor, measurement range, and resolution for each measurement target are as shown below.

- O ₂ (EC): 0 ~ 21 Vol% / 0.2%

- CO ₂ (NDIR): 0 ~ 40 Vol% / 0.3%

- SO ₂ (EC): 0 ~ 2,000 ppm / 5ppm

* E.C: Electrochemical sensor, NDIR: Non-dispersive infrared sensor

-. _SO2 analysis

Ignition coal was put into the Meseta Harry wood stove and ignited, and after 5 minutes, 1kg of lignite was added to start combustion. After about 15 minutes, 100 g of the liquid desulfurization catalyst prepared in Example 1 was evenly sprayed with 3 kg of lignite, and combustion began in earnest.

In order to suck in some of the exhaust gases exhausted through the flue, a hole was drilled in the middle of the flue, a silicone hose was connected, the gap was completely sealed with silicone, and the exhaust gas was sucked in through a diaphragm pump. The flowmeter was adjusted to 35L/min and the experiment was conducted. Blow was blown into the reaction tank of the device through the In-Let pipe of the gas trap adapter. The exhaust gas discharged through the out-let pipe of the gas trap adapter was connected to NOVA 9K and the amount of SO ₂ was measured.

-. _CO2 analysis

After preparing an N ₂ bomb and a CO ₂ bomb with a heating device, adjust the flow meter to N ₂ 30L/min and CO ₂ 5L/min, respectively, and mix the gases through the Y-shaped adapter through the in-let pipe of the gas trap adapter. It was blown into the reaction tank through . The CO ₂ concentration was measured at the Out-Let of the gas trap adapter, and 1L of the CO ₂ chemical adsorbent prepared in Example 2 was added to the reaction tank through the dropping funnel and the CO ₂ concentration was measured.

<Experimental Example 1> Measurement of SOx removal ability

After burning lignite in a wood-burning stove, the amount of SOx generated in exhaust gas was measured using the above experimental device, and the amount of SOx reduction was measured.

The experimental results are shown in FIG. 3. As can be seen from the graph, it can be seen that the SOx reduction ability was developed by the action of the absorbent of Example 1 from approximately 37 minutes to 91 minutes.

<Experimental Example 2> Measurement of CO ₂ removal capacity

In the above experimental device, 14% CO ₂ Gas is adjusted to be injected into the main reactor through the N ₂ Bombe and CO ₂ Bombe, then 1L of the CO ₂ chemical absorbent prepared in Example 2 is added and the injected gas is passed through, and the CO ₂ reduction amount is calculated. was measured.

The experimental results are shown in FIG. 3. The first downward curve on the graph indicates that CO ₂ is being reduced due to the injection of Example 2, and the rising curve while CO ₂ is being reduced is when the lid of the reactor is opened to allow outside air. It can be seen that CO ₂ is reduced again as a result of introducing a regenerated absorbent obtained by regenerating the previously used absorbent of Example 2 after allowing CO ₂ to rise.

<Experimental Example 3> CaCO ₃ production and regeneration of CO ₂ absorbent

In Experimental Example 2, 1L of the absorbent (solution temperature 32℃) that absorbed CO ₂ was transferred to a 2L Beaker and stirred while adding 62.16g of CaO (assay 90%). (Solution temperature rose to 62℃) As soon as it was added, a white solid formed. As precipitated, the gray-brown CaO particles quickly dissolved, and then the solid was filtered and dried with hot air to obtain 100.1 g of white CaCO ₃ . The filtrate was again used as the CO ₂ absorption regeneration liquid in Experimental Example 2.

As described above, although the present invention has been described with reference to limited examples and drawings, the present invention is of course not limited to the above-mentioned examples, and those skilled in the art in the field to which the present invention pertains can easily understand the above-described content. Of course, various modifications and variations may be possible.

Claims

A pre-processing unit that receives exhaust gas discharged from an exhaust gas source and removes pollutants from the exhaust gas;

A desulfurization unit that receives exhaust gas from the pretreatment unit, removes sulfur oxides from the exhaust gas, and discharges the exhaust gas;

a carbon dioxide absorption tank that receives exhaust gas from the front or rear end of the desulfurization unit, removes carbon dioxide and sulfur oxides from the exhaust gas by reacting with a carbon dioxide absorbent, and discharges treated gas;

a primary sedimentation tank that receives the reaction solution from the carbon dioxide absorption tank and precipitates foreign substances through a coagulation reaction with a coagulant;

a secondary precipitation tank in which the reaction liquid is introduced from the primary precipitation tank and reacts with calcium oxide to produce calcium carbonate, and at the same time, the carbon dioxide collected from the reaction liquid is removed to regenerate the carbon dioxide absorbent;

a yield tank that receives calcium carbonate from the secondary precipitation tank and stores it;

a regenerated carbon dioxide absorbent storage tank that receives the regenerated carbon dioxide absorbent from the secondary sedimentation tank and circulates it to the carbon dioxide absorbent tank;

A resource circulation system comprising:
According to clause 1,

A resource circulation system, characterized in that the process gas discharged from the desulfurization unit or the process gas discharged through the carbon dioxide absorption tank is discharged to the outside through a heat exchanger.
According to clause 1,

A resource circulation system in which a carbon dioxide absorbent is manufactured by mixing an aqueous solution of sodium hydroxide, illite extract, sodium tetraborate, and water glass, and further comprising a manufacturing unit that supplies the manufactured carbon dioxide absorbent to the carbon dioxide absorption tank.
According to clause 3,

A resource circulation system, characterized in that the carbon dioxide absorbent further contains hydrogen peroxide.
According to clause 4,

The front end of the emission source further includes a coal crushing unit that crushes fossil fuel supplied as a fuel source of the emission source, and the manufacturing unit supplies sediment generated during the carbon dioxide absorbent manufacturing process to the coal crusher as a desulfurization catalyst. resource circulation system.
According to clause 1,

A resource circulation system characterized in that the calcium carbonate stored in the yield tank is delivered to the desulfurization unit to remove sulfur oxides from the exhaust gas.