JPH0620555B2 - Exhaust gas treatment agent activation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for activating an exhaust gas treating agent, more specifically, the combustion of wastes such as coal, heavy oil, and municipal waste, and other substances,
The present invention relates to an activation method for dramatically improving the performance of silicic acid, alumina, and lime-based exhaust gas treating agents used in the treatment of exhaust gas associated with drying, roasting, and the like.

[Conventional technology]

Sulfur oxides and nitrogen oxides, chlorides, fluorides, etc., contained in the exhaust gas generated by the combustion of coal, heavy oil, etc., not only harm buildings, structures, etc., but also extremely harmful to animals and plants and human bodies. It has been found that it has a significant effect, and a method for removing the above substances in exhaust gas, that is, desulfurization and deHC1
Such methods have been studied and various methods have been developed.

Methods such as desulfurization and deHC1 are roughly classified into a dry method and a wet method.

The exhaust gas treating method utilizing the activated exhaust gas treating agent or the treating agent to be activated of the present invention is a dry method, and the method shown in Table 1 is already known. In the absorption method in Table 1, (1) expensive NH3 is required for the regeneration of the reactant (sulfur or recovery of sulfur compounds) (active manganese oxide method), and a valuable reducing gas is required (alkaline). (Raised alumina method), or raising the reaction temperature (alkalized alumina method) (lime blowing method), etc. are required. In the adsorption method, activated carbon used is expensive and deterioration is likely to occur. There are drawbacks. In the catalytic oxidation method, there are various problems in the conventional dry desulfurization method such that the vanadium-based catalyst used is expensive, easily deteriorates, and the reaction temperature needs to be relatively high.

Other harmful gas removal treatment methods are roughly divided into a wet method and a dry method.The wet method involves contacting the harmful gas with an alkaline aqueous solution or an alkaline slurry in a gas-liquid contact device such as a packed tower or a spray tower. It has the advantage that it has a high effect of removing harmful components, but it produces a large amount of wastewater containing harmful components such as sulfite ions, sulfate ions, and chlorine ions, and requires advanced wastewater treatment. Further, since the exhaust gas after treatment contains a large amount of water vapor and produces white smoke when released into the atmosphere, there is a problem that a white smoke prevention device must be installed.

In the dry method, an alkaline powder such as calcium hydroxide or calcium carbonate or these are made into an absorbent, and a harmful gas is reacted and absorbed through exhaust gas, and a reaction product is collected, or the absorbent powder is sprayed on the exhaust gas passage. Generally, it is contacted with harmful gas and collected by a dust collector.

Since the dry method is a direct contact reaction between gas and solid absorbent, there is almost no decrease in temperature, almost no waste water is generated, and no white smoke is generated.

The method of treating the exhaust gas in a moving bed system using the above-mentioned absorbent using calcium hydroxide or the like is to form pellets of calcium oxide, calcium carbonate, calcium hydroxide adsorbed in a lump or on a carrier. It is a method of contacting with a gas while moving as an alkaline absorbent. Generally, a cross flow is the flow direction of the gas to the moving bed, but a parallel flow or a counter flow is also possible. Since the surface of the discharged absorbent is coated with the reaction product and unreacted alkali may remain inside the particles, the reaction product is usually peeled off by a dry separation method using a sieve or the like. After the separation, the alkali absorbent is repeatedly used to try to improve the alkali utilization rate. However, since the conventional alkaline absorbent has insufficient mechanical strength and buffer structure, it tends to be pulverized by swelling when moving in the moving bed and when it is vibrated by the sieve or by expansion by taking in the substance to be absorbed, The disadvantage is that the pressure loss of the bed is increased. As one of the measures, as in JP-A-56-67524, granular (or spherical)
There is also a method of using a porous body of as a carrier and using an alkaline aqueous solution of sodium hydroxide, potassium hydroxide or the like or a slurry of calcium hydroxide, calcium carbonate, magnesium hydroxide or the like adhered and supported thereon. There are problems such as a small amount of adhesion and difficulty in completely separating the reaction product.

[Problems to be Solved by the Invention]

An object of the present invention is to provide a method for activating an exhaust gas treating agent that increases the reaction rate between lime contained in silicic acid, alumina, and a lime-based exhaust gas treating agent and a reaction target, and further improves the utilization rate of lime. is there.

[Means for Solving the Problems] In the present invention, a substance capable of supplying a sulfuric acid compound is added to a substance capable of supplying calcium oxide, silicon dioxide, and aluminum oxide, and non-consolidated hydration or hydration hardening is performed in the presence of water. An exhaust gas treating agent comprising: a method for activating an exhaust gas treating agent, which comprises contacting HC1, as described below,
Specifically, the contact includes not only gas-solid contact but also liquid-solid contact with an aqueous solution.

First, the raw material of the exhaust gas treating agent which is the target of the method for activating the exhaust gas treating agent of the present invention will be described.

Examples of substances that can supply the calcium oxide of the present invention include quick lime, slaked lime, lime carbonate, cement, slag,
Examples include by-products such as dolomite plaster (containing lime) and acetylene slag.

Substances that can supply silicon dioxide are, for example, silicic acid, hydrous silicic acid, metasilicic acid, aluminum silicate, calcium silicate and cristobalite, tridymite, kaolin, bentonite, talc, perlite, shirasu, diatomaceous earth, glass, etc. Examples thereof include compounds containing silicon dioxide.

As the substance capable of supplying aluminum oxide, for example,
Alumina, calcium aluminate, aluminum hydroxide, aluminum silicate, alum sulfate, alum, aluminum sulfide, aluminum sulfate, aluminum chloride, bentonite, kaolin, diatomaceous earth, zeolite, perlite, bauxite, sodium aluminate, cryolite A compound containing isoreactive aluminum may be mentioned.

The substance capable of supplying a sulfuric acid compound is, for example, a substance produced by combining an alkaline earth metal such as calcium and magnesium, an alkali metal such as sodium and sulfuric acid, and calcium sulfate, magnesium sulfate, sodium sulfate and calcium sulfite. , Calcium hydrogen sulfate,
Examples include sodium thiosulfate and black liquor combustion ash.

Furthermore, in the case where the required materials described so far, for example, by adding elemental sulfur, mutual reaction between the materials proceeds, and as a result, calcium sulfate is produced and supplied, silicic acid and caustic acid are further added. It also includes water glass produced by the reaction of alkali.

In addition, examples of other substances that can simultaneously supply two or more of the above-mentioned four types of compounds include coal ash and volcanic ash, coal fluidized bed combustion ash (calcium oxide, silicon dioxide, aluminum oxide, calcium sulfate, sodium sulfate). Source, one example is shown in Table 2), cement and cement clinker (calcium oxide, calcium sulfate, silicon dioxide, aluminum oxide source), slag and silas, andesite, bauxite, chert, quartz trachyte, opal, zeolite,
Reacting silicon dioxide such as feldspar, clay minerals, ettringite (silicon dioxide, aluminum oxide, calcium oxide source), minerals containing chlorides such as sodium, aluminum and calcium, sulfates, etc., and furnace for fluidized bed combustion ash etc. Internal desulfurization ash and waste desulfurization agent after flue gas desulfurization, sludge incineration ash,
Examples include the case where waste materials such as municipal waste incineration ash, cement waste, acetylene slag and the like and simple substances such as calcium oxide, silicon dioxide and aluminum oxide are used in combination.

Further, wastes of the treatment agent discharged in the process of producing the exhaust gas treatment agent which is the subject of the present invention, splashes, pulverized unused exhaust gas treatment agent, exhaust gas treatment agent in which unreacted substances remain, etc. It can be used as a raw material.

Table 2 shows an example of the chemical composition of these typical substances.

The exhaust gas treating agent used when activating the exhaust gas treating agent of the present invention can be obtained by combining various substances capable of supplying calcium oxide, a sulfuric acid compound, silicon dioxide, aluminum oxide and the like.

The present inventor, depending on the conditions at the time of manufacturing the exhaust gas treating agent,
In the process of studying the problem of producing agents with extremely low exhaust gas treatment performance, we found that exhaust gas treatment agents with low performance show an unexpected performance by undergoing an activation process,
The present invention has been completed.

The basic substances that control the exhaust gas of the exhaust gas treatment agent are CaO and Ai ₂ O.
₃ , SiO ₂ , and Me *. Here, Me * changes depending on the type of gas to be removed when the exhaust gas to be treated is exhaust gas of the furnace. For example, in the case of burning coal, SOx and NOx are the main gases to be removed, but in the case of municipal waste gas, HCl is the main. If SO ₂ is the main constituent, Me * is mainly CaSO ₄ , but if HCl is the main constituent, CaCl ₂
Is the main.

The basic substance that controls the exhaust gas treatment of the exhaust gas treatment agent is not simply composed of a mixture of pure substances, and when Me * is CaSO ₂ , unexplained XCaO ・ Al ₂ O ₃・ ZSiO ₂
- YSO ₃ - nH consisting ₂ O would be material very close to the sulfuric acid and calcium aluminate composite compound suggests.

In this formula, X = 4 to 7 and Y = 2 to 4,
X is larger than Y and Z = 0.1> 3, preferably 0.3> 1, and a composition in which n is 5 to 22 is reported as a synthetic pigment (UK Patent 1115482). There is no.

Also, the ettringite approximation used in the form of a paper coating aqueous paste is composed of a SiO ₂ free material.

3CaO · Al ₂ O ₃ / 3CaSO ₄ · 31 to 32H ₂ O However, this ettringite has a low ability to purify the exhaust gas, and since the strength of the compound is low, its value as an exhaust gas treatment agent is small. However, the CaO, Al ₂ O ₃ , SiO ₂ , and Me * -based compound of the present invention, in which SiO ₂ is incorporated, is hard and the performance of desulfurization and the like is dramatically increased. At this time, in the exhaust gas treating agent, Ca (O
H) ₂ crystals cannot be detected by X-ray diffraction. That is, since Ca (OH) ₂ does not exhibit the property as a single crystal, it supports that it is a compound form.

Although CaO is an oxide display that absorbs and fixes acidic substances such as SO _2, the effect of each pure substance on the performance of the desulfurization agent built up is that SiO ₂ contributes to the sustainability of performance, and Al ₂ O ₃ helps to increase the reaction rate with SO _2, etc., so that SiO ₂ , CaO, Al ₂
A hard material is obtained by O ₃ and Me *. At this time, Me * is considered to have a role of promoting the synthetic hydration reaction of the mixture.

The synthetic hydration reaction means that the material constituting the exhaust gas treating agent used in the present invention reacts with water to grow CaO, Me *, SiO ₂ , and Al ₂ O ₃ -based crystals and bond between the material particles. The treatment necessary for proceeding this reaction includes, for example, normal temperature water or wet air curing, atmospheric pressure or high pressure curing, steam curing, hot water slurry curing and the like.

Non-consolidated hydration means that material particles are dispersed in a liquid so that they do not become bound and coarsen due to the progress of the hydration reaction, and the hydration reaction proceeds. ≦ A liquid slurry is aged in an excess amount of 1: 1 to 1:20 in warm water, hot water or boiling water.
It is suitable for the production of slurry type exhaust gas treatment agents and powder type exhaust gas treatment agents.

The hydration hardening means that the solid-liquid ratio at the time of kneading is less than 1: 1 so that the existence interval between the material particles can be remarkably reduced and the bonding between the particles due to crystal growth can easily occur. It is suitable for producing granules of several millimeters to several tens of millimeters or large cured products.

The basic substances of the exhaust gas treating agent used in the present invention are CaO and Al ₂ O.
₃ , consisting of a substance capable of supplying SiO ₂ and an exhaust gas treating agent forming reaction accelerator capable of supplying a sulfuric acid compound such as CaSO ₄ .
What is more important is that it can be obtained by carrying out curing with wet air, water, hot water, steam or the like for promoting the hydration reaction of these basic substances at normal pressure or high pressure.

When K compounds and Na compounds in a form that can be easily eluted are present in the material used for the exhaust gas treatment agent, and when the Me * form of the exhaust gas treatment agent is CaSO ₄ , it negatively affects the exhaust gas treatment performance. . That is, in the case of the SiO ₂ · Al ₂ O ₃ · CaO · CaSO ₄ system exhaust gas treatment agent, the addition of a few percent of KOH and NaOH may adversely affect the desulfurization performance. This phenomenon becomes a problem when the CaSO ₄ form is abundant. On the contrary, when a large amount of NaOH is present, it does not cause much problem.

A material capable of simultaneously supplying two or more kinds out of four kinds of compounds, which are the basic substances of the present invention, to a material for producing an exhaust gas treating agent,
For example, when coal ash is used, it generally contains Na and K compounds, but depending on this content and the form of Ca * in the exhaust gas treatment agent, it negatively affects the exhaust gas treatment performance. There are cases. This phenomenon causes Na and K compounds to concentrate on the surface layer of the particles during the manufacturing process due to rolling during granulation, forming voids and impairing the reaction with acidic substances in the exhaust gas. Of course, during the granulation process, the substances that concentrate on the surface layer of the particles are not only Na and K compounds, but also non-reactants, that is, "particles of coal ash that have not reacted to form an exhaust gas treatment agent," and these form color. It will be.

However, this is not the case when a molding method that does not employ rolling granulation, such as an extrusion method, or when granulating agent particles after completion of the synthesis reaction, that is, after hydration curing. K compound means K ₂ SO ₄ , KCl, KNO ₃ , KOH, etc., which can usually be used in the range of 0.1 to 70%, but when Me * is in the form of Ca, addition of 1% or more, 5% or more The performance of the rolling granulated product tends to decrease when a material that causes the elution of is used.

Na compounds are NaCl and NaOH, and when using a material that causes addition or elution of 1% or more, it is necessary to pay sufficient attention to concentration on the surface layer of the particles during granulation.

However, CaO, SiO ₂ , Al ₂ O ₃ can be supplied as a basic form, to which NaOH, NaCl, water glass, etc. are added,
When a material that elutes NaOH or NaCl is used, it does not cause a problem because it does not take the form of CaSO ₄ -NaOH or the like as described above. Therefore, the CaSO
The SiO ₂ · Al ₂ O ₃ · CaO · NaOH exhaust gas treatment agent, which is different from the 4 type agent, is hydrated and synthesized.

Next, basic manufacturing conditions of the exhaust gas treating agent will be described.
If necessary, the above raw materials are ground and mixed, and then water is added and mixed. The water-soluble salt in the raw material is used by dissolving it in water to be added. The water content of the raw material mixture after addition of water is dry matter.
10 to 2000 parts by weight per 100 parts by weight, preferably about 20 to about 100
It is 0 copy. Since this water naturally contains water derived from the raw materials, the use of dilute sulfuric acid may occur even when water is not required to be added.

Next, the mixture is cured at room temperature by wet air or steam. The curing process is hot water curing for high water content products. Slurry or mud mixture, by going through this step,
It completes the important initial stage of active compound formation required for gas purification, during which most of the water is consumed in the compound formation reaction.

That is, the mixture is cured at room temperature in a moist air or in water or steam or hot water by steam heating. The same is done under high pressure.

Hot water curing disperses the raw material in water, and at 40 ℃ ~ 180 ℃, so that the raw material does not settle and harden at the bottom, non-consolidated hydration (particles do not solidify each other and become coarse particles It is preferable to carry out stirring, bubbling, circulation, shaking, etc. for several minutes to 72 hours so that the hydration reaction proceeds.

Humid air curing, temperature 10 ℃ ~ 40 ℃, relative humidity 50% ~ 100%
It is preferably several minutes or several tens of days, and steam curing is performed at a temperature of 40 ° C to 180 ° C and a relative humidity of 100% for about several minutes to 72 ° C.
Time is preferred.

The cured product after curing is, for example, crushed to obtain coarse particles (several mm to several tens of mm) and pulverized to obtain fine particles (1 mm or less and several tens of microns or more) by a conventional method. Crush and crush the hydrated cured product at a convenient time before and after drying. The slurry-like substance (ultrafine particles of several microns or less) is used as it is, or is used as it is in a state where the water content is adjusted, or is used after being molded (granulated). The molded product is used as it is or after drying. In this way, the flue gas treatment agent used in the flue gas treatment of the present invention can be obtained.

Curing for obtaining coarse particles and fine particles can also be performed in the following two stages.

The conditions of the first stage wet air curing are preferably a temperature of 10 ° C. to 40 ° C. and a relative humidity of 50% to 100% for several minutes to several days. The steam curing is preferably carried out at a temperature of 40 ° C to 180 ° C and a relative humidity of 100% for about several minutes to several days.

This first-stage curing is an appropriate water content for easily molding and granulating the mixture in which a partial hydration reaction is progressing from a fine particle size to a coarse particle size or crushing a cured product after the completion of the curing. It is performed under the condition that the state and the cured state are obtained.

That is, the first stage curing is to accelerate the hydration reaction for forming the active compound in the initial stage necessary for molding and granulating the raw material mixture, but the used desulfurizing agent and the fluidized bed are used as raw materials. activity Ca * such as a combustion ash, when using a material containing such SiO _2, Al ₂ O ₃ or, in the case of using materials such as heat during hydration as CaO, of course the temperature of the mixture during kneading And the hydration reaction proceeds remarkably even while the raw materials are kneaded. For this reason, it is possible to obtain an appropriate water state for forming and granulating, which is the object of the first stage curing proposed by the present invention.

Thus, when the hydration reaction significantly progresses during kneading, the first stage curing can be omitted.

The conditions of the first stage wet air curing are preferably a temperature of 10 ° C. to 40 ° C. and a relative humidity of 50% to 100% for several minutes to several days. The steam curing is preferably carried out at a temperature of 40 ° C to 180 ° C and a relative humidity of 100% for about several minutes to several days.

This first stage curing is a water state suitable for easily molding, granulating and pulverizing the mixture into a fine particle size after the curing,
It is performed under the condition that the cured state is obtained.

Next, the substance that has undergone the first-stage curing is molded (granulated) by a marmelizer, a disk pelleter, a briquette machine, a pelletizer or the like. Since the molding is carried out through the above-mentioned steps, the particle size can be easily dispersed in the flue gas or brought into contact with the flue gas, and the molding can be performed with good yield. The molded product can be subjected to the second stage curing and sized to obtain the flue gas treatment agent used for activation of the present invention.

The second stage of curing is 10 ℃ to 40 ℃, relative humidity in wet air curing.
50% to 100%, preferably several minutes to several tens of days,
In steam curing, the temperature is 40 ℃ -180 ℃, relative humidity is 100%,
A few minutes to 72 hours is preferred.

When producing a flue gas treatment agent in the form of coarse particles or fine particles by one-time curing, it is carried out in the same manner as in the second step.

In the compression molding of the cured product after curing, the cured product is crushed or crushed, and if the cured product is in the form of a slurry, it is dehydrated, and then part or all of the water content is removed if necessary, or conversely water is added. The water content can be adjusted by using a briquette machine, a tablet molding machine, an extrusion molding machine, a disk pelleter, another pressure molding machine, or a device capable of granulating while applying pressure.

The molding pressure varies depending on the use of the agent and the shape of the molded product (rod shape, tablet shape, plate shape, honeycomb shape, Raschig ring, etc.),
10 kg / cm ₂ for relatively large particles such as layered packing
~10t / cm ^2, the number the case of producing the particles of 0.01 to several mm are kg / cm
² to several tons / cm ² .

For compression molding, ultrafine particles, fine particles, and particles of several millimeters such as coarse particles, particles with a diameter of around 10 mm are also used to remove some or all of the water content or conversely add water to remove water. By adjusting, the same molding can be performed without adding a binder. However, if necessary, a binder such as clay, CMC or PVA may be added. If the steam curing and drying of the coarse and fine particulate flue gas treatment agent is performed by dielectric heating, the treatment can be performed from the inside.For example, the drying time can be completed several times faster than the hot air treatment. Is. Further, in the case of a coarse, fine particulate flue gas treatment agent used for a method of suspending flue gas in a dry state, the molded product after curing is 30 ° C. or higher, preferably in the range of 30 ° C. to 500 ° C., 0.1 The performance of the treating agent can be further improved by drying for 10 hours, but the water content changes depending on the object to be treated. For example, the desulfurization is preferably 10% or less, de-CHl, HF elimination 27% or less, de H ₂ S is 20% or less and the like.

The activation method of the present invention is performed by contacting HCl with the above exhaust gas treating agent. This contact includes a method of contacting HCl in a gaseous state and a method of contacting in a liquid state.

Exhaust gas treatment agent 1 in the case of gaseous or gas-solid contact
A desired activating ability can be imparted by contacting 0.1 to 10% of HCl per g with 0.1 to 10% of HCl for 1 second to 24 hours. At this time, the diluent gas for HCl is H such as nitrogen gas.
Any substance that does not react with Cl and the exhaust gas treating agent to be activated may be used. The temperature at the time of contact is 10 to 100 ° C, preferably 2
It is 0 to 60 ° C.

Further, the gas-solid contact can be carried out by mixing HCl in the exhaust gas to be removed. In this case, the concentration range in the air is 1/100 to 1/2 of the substance to be removed, preferably 1/10 to 1/1. Mixing amount is 100% HCl and 3.5c per kg of exhaust gas treatment agent
c / H or more, preferably 35 to 350 cc / H. The temperature at the time of contact may be the same as that at the time of treating the exhaust gas.

When the flue gas treatment agent directly absorbs the activating substance, the temperature is 10 to 100 ° C, preferably 20 to 60 ° C.

An aqueous solution of HCl can be used for activation with HCl. In this case, a 0.01-10% aqueous solution of HCl, preferably
Soak the flue gas treatment agent in 0.05 to 5% aqueous solution for 10 seconds to 24 hours, preferably 5 minutes to 2 hours, remove it, and remove it at 50 to 500 ° C.
And preferably at 70 to 200 ° C. The temperature of the aqueous HCl solution is 1 to 100 ° C, preferably 10 to 40 ° C.

The activation of the flue gas treatment agent of the present invention has many unclear points, but it has the effect of significantly increasing the inherent or low performance of the flue gas treatment agent.

The treatment temperature of the exhaust gas of the activated flue gas treatment agent can be carried out in a wider temperature range than the conventional method, that is, 10 ° C to 1200 ° C, preferably desulfurization is 30 ° C to 1000 ° C, and denitration is 50 ° C to 40 ° C.
0 ° C., de HCl is 30 ° C. to 1000 ° C., de HF and de H ₂ S is 30 ° C. to 1
For example, 000 ℃. The pressure may be normal pressure, but the performance can be further improved by pressurizing the area where the smoke and the smoke treatment agent contact.

Flue gas treatment using coarse, ultrafine or fine particulate flue gas treatment agents (high water content slurry, water content agent, dried agent) is, for example, coarse particulate matter obtained by crushing or compression-molding a cured product. As a method of contacting the exhaust gas with the exhaust gas, a method of filling a layer of a particulate smoke treatment agent of several mm to several tens of mm that is wet or dried and allowing the gas to pass, or suspending the agent by the force of the exhaust gas flow By doing so, the contact area is increased, and the collision between the agent and the particles induces the exposure of a new surface of the agent and improves the performance. At this time, the agent should be dispersed in the exhaust gas as widely as possible.

In the case of non-consolidated hydrated ultrafine particles, the contact area with the exhaust gas is increased by spraying the high water content slurry as it is into the exhaust gas by a general method to make it into the finest droplets. The exhaust gas can be treated by the synergistic effect of SO ₂ uptake by.

In the subsequent collection of the used agent, in the case of particles that are still wet or dried at the exhaust gas temperature, they can be collected by a cyclone, an electrostatic precipitator, a filtration type precipitator, and other general methods.

The collected exhaust gas treating agent, until there is no unreacted matter,
Used repeatedly.

Examples will be described below.

〔Example〕

Example 1 Various materials having the chemical compositions shown in Table 2 are mixed with water according to the formulation shown in Table 3. Next, as the first stage of curing, steam curing at atmospheric pressure of 100 ° C is performed for 120 minutes, and the obtained soft cured product is passed through a 5 mm sieve to form seeds for granulation. Buffer granulation for a few minutes to prevent moisture, K, Na compounds, and non-reactants from concentrating on the surface layer.
Perform steam curing at 0 ° C and atmospheric pressure for 4 hours. Here, the buffer granulation refers to a method in which granulation is performed not by contact between the surface of the granulator and the granulation object but by mutual contact of the granulation material. The obtained granulated product is sized to 1.7 to 2.5 m / m, and as it is (hereinafter referred to as treating agent A), heat-treated for 2 hours at 130 ° C. in a hot air dryer (hereinafter referred to as treating agent B), and 500 W By using the above dielectric dryer, heat treatment was performed for 8 minutes (hereinafter referred to as treatment agent C) to obtain treatment agents A, B and C.

With respect to each of the treating agents A, B and C, 100% of 2% HCl gas diluted with nitrogen gas per 1 kg was contacted with each other at room temperature for 10 minutes to activate the exhaust gas treating agent of the present invention (Examples 1-1, 1-2). , 1-3) was obtained.

In the performance test, a removal test of SO ₂ , NOx, H ₂ S, HCl, HF, etc. was performed for each component under the conditions shown in Table 4 (space velocity of 6000 h-1 and gas temperature of 130 ° C.). In order to clarify the effect of the activated exhaust gas treating agent of the present invention, the removal rate was calculated as an integrated value for 4 hours after passing gas. (Performance test conditions of each example were also similarly performed below.) The specific surface area was also measured. To measure the specific surface area,
After degassing at 0 ° C., the BET method was used.

These values are collectively shown in Table 5.

Example 2 Various materials shown in Table 2 are mixed with water according to the formulation shown in Table 3. Next, water is added externally so that the total amount becomes 300%, and non-consolidated hydration is performed at 95 to 100 ° C. for 9 hours.
The slurry thus obtained is subjected to solid-liquid separation, and the solid portion is dried at 250 ° C. for 1 hour. The white fine particles obtained are molded as it is under a pressure of 640 kg / cm ² (particle size 1.7 to
2.5 m / m) to obtain a treating agent D.

100% of 2% HCl gas diluted with nitrogen gas per 1 kg of treating agent D
Was contacted at room temperature for 10 minutes to obtain an activated exhaust gas treating agent of the present invention (Example 2).

The performance test was conducted in the same manner as in Example 1, and the results are shown in Table 5.

Example 3 1 kg of the treating agent C described in Example 1 was immersed in a 0.5% aqueous solution of HCl (room temperature) for 10 minutes each and then heat-treated for 8 minutes by a 500 W dielectric dryer to obtain an activated desulfurizing agent. .

The performance test of the test exhaust gas treating agent was conducted not for NOx and HCl among the gases shown in Table 4, but for SO ₃ .

Others were the same as in Example 1.

The results are shown in Table 5.

Comparative Examples 1 to 5 Performance tests were conducted under the test conditions corresponding to each Example without performing the activation treatment on the treating agents A, B, C and D, and the results are shown in Table 5 as Comparative Examples 1 to 5. showed that.

Example 4, Comparative Example 6 Various materials having the chemical compositions shown in Table 2 are mixed with water according to the formulation shown in Table 3. Next, as the first stage curing, steam curing at atmospheric pressure of 100 ° C. is performed for 120 minutes, and the obtained soft cured product is molded by a disc pelleter using a 5 mm die, and 100% is used as the second stage curing.
℃ normal pressure, steam curing for 4 hours. The obtained granulated product was 1.
It was crushed to 7 to 2.5 m / m, sized, and heat treated for 2 hours in a hot air dryer at 130 ° C. to obtain a treating agent E.

Treatment agent E was diluted with nitrogen gas per kg of 2
100 liters of% HCl gas was contacted for 10 minutes at room temperature to obtain the activated exhaust gas treating agent of the present invention.

The performance test results and the like of the activated exhaust gas treating agent and the exhaust gas treating agent before the activation treatment (Treatment agent E) performed in the same manner as in Example 1 are shown in Table 5 as Example 4 and Comparative Example 6, respectively. It was shown to.

[Advantages of the Invention] Since the exhaust gas treating agent used in the method of the present invention is different from the conventional adsorbents, it is mainly composed of a substance capable of supplying CaO, SiO ₂ , and Al ₂ O ₃ , so that the raw material is coal ash , Cement, volcanic ash, slag, shirasu, fluidized bed combustion ash, used exhaust gas treatment agent (containing unused exhaust gas treatment agent), silicates such as clay and calcium compounds can be used. is there.

The present invention relates to SiO ₂ , Al obtained by these materials.
₂ O ₃ , increase the reaction rate of the lime containing CaO-based exhaust gas treatment agent and the reaction target, and provide an activation method of the exhaust gas treatment agent that further improves the utilization rate of lime, SiO ₂ , Al ₂ O ₃ , It is intended to further improve the performance of CaO-based exhaust gas treating agents and solve various problems in exhaust gas processing that have been difficult to date.

Furthermore, not only is it useful as a resource recycling technology such as the utilization of waste materials such as coal ash, slag, used desulfurization agents, waste glass, fluidized bed combustion ash, SO ₂ , NOx, SO ₃ , H
Since it is possible to remove harmful components such as F, Hcl, and Cl ₂ contained in flue gas with high efficiency and at low cost, it greatly contributes to pollution prevention.

Claims (3)

[Claims] 1. An exhaust gas treating agent obtained by adding a substance capable of supplying a sulfate compound to a substance capable of supplying calcium oxide, silicon dioxide, and aluminum oxide, and subjecting the substance to non-consolidation hydration or hydration hardening in the presence of water to obtain HC1. A method for activating an exhaust gas treating agent, comprising: 2. The activation method according to claim 1, wherein the contact is a gas-solid contact. 3. The activation method according to claim 1, wherein the contact is a liquid-solid contact.