JPH01297144A - Activation of exhaust gas treatment agent - Google Patents

Abstract

PURPOSE:To activate an exhaust gas treatment agent by adding a material which supplies calcium sulfate to a material which supplies calcium oxide and allowing HCl to come in contact with the exhaust gas treatment agent obtained through non-solidification, hydration and curing in the presence of water. CONSTITUTION:At least, one kind of material selected from a group of materials which supply sulphate compounds, halogen element compounds, hydrosulphide and hydroxides of alkali metals, is added to materials which supply calcium oxide, silicon dioxide and aluminum oxide. Next, an exhaust gas treatment agent is produced by hydrating by non-solidification or curing by hydration the blended materials in the presence of water. This exhaust gas treatment agent is activated by allowing HCl to come in contact with said agent. The preferable contact methods of the exhaust gas treatment agent with HCl are gas/solid contact method, and a liquid/solid contact method using an aqueous nitrite solution.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for activating an exhaust gas treatment agent, and more specifically, a method for activating an exhaust gas treatment agent, and more specifically, a method for activating an exhaust gas treatment agent,
This invention relates to an activation method that dramatically improves the performance of silicic acid, alumina, and lime-based exhaust gas treatment agents used in the treatment of exhaust gas associated with drying, roasting, etc.

(Prior art) Sulfur oxides, nitrogen oxides, chlorides, fluorides, etc. contained in the exhaust gas generated from the combustion of coal, heavy oil, etc. not only harm buildings and structures, but also harm animals, plants, and more. It has been found that these substances have an extremely large impact on the human body, and methods for removing the above substances from exhaust gas, such as desulfurization and desulfurization, have been developed.
Methods such as c1 have been studied, and a wide variety of methods have been developed.

These desulfurization, HCI removal, etc. methods are broadly classified into dry methods and wet methods.

The exhaust gas treatment method using the activated exhaust gas treatment agent of the present invention or the treatment agent to be activated is a dry method, and the methods shown in Table 1 are already known. The absorption methods in Table 1 require expensive NH3 (activated manganese oxide method) to regenerate the reactants (recovery of sulfur or sulfur compounds), require noble reducing gases, and require alkali In the adsorption method, the activated carbon used is expensive and easily deteriorates, etc. There are drawbacks. In the catalytic oxidation method, the conventional dry desulfurization method has various problems, such as the vanadium-based catalyst used is expensive and easily deteriorates, and the reaction temperature needs to be relatively high.

Other harmful gas removal treatment methods are generally divided into wet methods and dry methods. The wet method involves contacting the harmful gas with an aqueous alkaline solution or an alkaline slurry in a gas-liquid contact device such as a packed tower or a spray tower. Although it has the advantage of being highly effective in removing harmful components, it generates a large amount of wastewater containing harmful components such as sulfite ions, sulfate ions, and chloride ions, and requires sophisticated wastewater treatment. Furthermore, the exhaust gas after treatment contains a large amount of water vapor, and when released into the atmosphere, it produces white smoke, so there are some problems such as the need to install a white smoke prevention device.

The dry method uses alkaline powders such as calcium hydroxide and calcium carbonate. Generally, the agent powder is sprayed, brought into contact with harmful gases, and collected with a dust collector.

Since the dry method relies on a direct contact reaction between the gas and the solid absorbent, there is no drop in temperature, almost no waste water is generated, and no white smoke is generated, so it has major advantages over the wet method.

The method of treating exhaust gas using a moving bed method using an absorbent using calcium hydroxide, etc., is to form pellets of calcium oxide, calcium carbonate, or calcium hydroxide that are either lump-like or adhered to and adsorbed on a carrier. This is a method in which the gas is brought into contact with the gas while moving it as an alkaline absorbent. The direction of gas passage through the moving bed is generally a cross flow, but parallel flow, countercurrent flow, etc. are also possible.

The surface of the discharged absorbent is coated with reaction products, and unreacted alkali may remain inside the particles, so the reaction products are usually removed by a dry separation method using a sieve, etc. After separation, attempts have been made to repeatedly use the alkali absorbent to improve the alkali utilization rate. However, conventional alkaline absorbents have insufficient mechanical strength and buffer structure, and are easily powdered due to expansion when moving in a moving bed, when subjected to vibration in a sieve, or when absorbing substances are incorporated. However, the disadvantage is that the pressure loss in the moving bed increases. As one of the countermeasures, as in JP-A No. 56-67524, a granular (or spherical) porous material is used as a carrier, and an alkaline aqueous solution such as sodium hydroxide, potassium hydroxide, calcium hydroxide, carbonate, etc. There is also a method using a slurry of calcium, magnesium hydroxide, etc., which is deposited and supported, but there are problems such as a small amount of alkali deposited and difficulty in completely separating the reaction products.

[Problem to be solved by the invention]

The purpose of the present invention is to increase the reaction rate between lime and reactants containing silicic acid, alumina, and lime-based exhaust gas treatment agents;
Another object of the present invention is to provide a method for activating an exhaust gas treatment agent that improves the utilization rate of lime.

[Means to solve the problem]

In the present invention, one or more substances selected from the group of substances capable of supplying sulfuric compounds, halogen element compounds, sulfides, and alkali metal hydroxides are added to substances capable of supplying calcium oxide, silicon dioxide, and aluminum oxide. An exhaust gas treatment agent obtained by non-consolidating hydration or hydration curing in the presence of
A method for activating an exhaust gas treatment agent, which is characterized by contacting with 11Cl, and as described later, the contact is specifically a gas-solid contact, and more specifically a liquid-solid contact using an aqueous solution. Cases are included.

First, the raw materials for the exhaust gas treatment agent to be used in the method for activating the exhaust gas treatment agent of the present invention will be explained.

Examples of substances that can supply calcium oxide of the present invention include quicklime, slaked lime, carbonated lime, cement, slag,
By-products include dolomite plaster (containing lime) and acetylene slag.

``Substances that supply silicon dioxide include, for example, silicic acid,
Hydrous silicic acid, metasilicic acid, aluminum silicate, calcium silicate and cristobalite, tridymite, kaolin, bentonite, talc, pearlite, shirasu,
Examples include compounds containing reactive silicon dioxide such as diatomaceous earth and glass.

Examples of substances that supply aluminum oxide include:
Alumina, calcium aluminate, aluminum hydroxide, aluminum silicate, sulfuric acid, alum, aluminum sulfide, aluminum sulfate, aluminum chloride, bentonite, kaolin, diatomaceous earth, zeolite, perlite, bauxite, sodium aluminate, cryolite Examples include compounds containing equireactive aluminum.

Substances that can supply sulfuric acid compounds and monohalogen compounds are, for example, substances produced by combining alkaline earth metals such as calcium and magnesium, alkali metals such as sodium, and sulfuric acid and hydrogen halides. Calcium, magnesium sulfate, calcium chloride, magnesium chloride, sodium sulfate, calcium sulfite,
Examples include calcium hydrogen sulfate, sodium chloride, strontium chloride, calcium bromide, calcium iodide, sulfur and lithium thiosulfate, sodium hydrogen carbonate, calcium hydrogen carbonate, and black liquor combustion ash.

Examples of substances that can supply sulfide include calcium sulfide, iron sulfide, and zinc sulfide.

Examples of substances capable of supplying alkali metal hydroxide include sodium hydroxide.

Furthermore, when the necessary materials described so far are used alone, for example, by adding sulfur, mutual reactions between the materials proceed, and as a result, calcium sulfide, calcium sulfate, etc. are produced and supplied. The first category also includes filtered water glass produced by the reaction of silicic acid and caustic alkali.

In addition, examples of other substances that can simultaneously supply two or more of the seven types of compounds described in Moejo include coal ash and volcanic ash, coal fluidized bed combustion ash (calcium oxide, silicon dioxide, aluminum oxide, calcium sulfate, Sodium sulfate source, 2nd
An example is shown in the table), cement and cement talin force -
(calcium oxide, calcium sulfate, silicon dioxide, aluminum oxide sources), slag and shirasu, andesite, bauxite, chert, quartz trachyte, opal, zeolite,
Minerals containing reactive silicon dioxide such as feldspar, clay minerals, ettringite (sodium oxide, silicon dioxide, aluminum oxide, calcium oxide), chlorides and sulfates of sodium, aluminum, calcium, etc., as well as fluidized bed combustion ash, etc. A combination of in-furnace desulfurization ash, waste desulfurization agent after flue desulfurization, sludge incineration ash, municipal waste incineration ash, cement scraps, acetylene slag, and other single substances such as calcium oxide, silicon dioxide, and aluminum oxide are used in combination. There are cases where this is done.

In addition, waste gas treatment agents that are discharged in the process of manufacturing the exhaust gas treatment agents that are the subject of the present invention, splatters, pulverized unused exhaust gas treatment agents, and exhaust gas treatment agents with unreacted substances remaining are also included. Can be used as a raw material.

Table 2 shows an example of the chemical composition of typical substances found in Kowara.

The exhaust gas treatment agent used when activating the exhaust gas treatment agent of the present invention is a combination of various substances capable of supplying calcium oxide, sulfuric compounds, halogen element compounds, silicon dioxide, aluminum oxide, sulfides, alkali metal hydroxides, etc. It can be obtained by

The present inventor has discovered that depending on the conditions at the time of manufacturing the exhaust gas treatment agent,
In the process of researching the problem of producing a gas treatment agent with extremely low exhaust gas treatment performance, we discovered that a gas treatment agent with low performance exhibited unexpected performance when subjected to an activation process, and thus completed the present invention.

The basic substances that control the exhaust gas treatment of the exhaust gas treatment agent are GaO,
Ai, 03, Sin□, Me*. Here, Me*
varies depending on the type of gas to be removed when the exhaust gas to be treated is combustion gas from a furnace. For example, in the case of coal combustion, the gases to be removed are SOx, N
Ox is the main ingredient, but in the case of city garbage furnace gas, 11C
! or the subject. If SO□ is the main component, Me* is mainly CaSO4, but if l [l is the main component, then CaCl
2 is the main one.

The basic substance that controls the exhaust gas treatment of the exhaust gas treatment agent is not simply a mixture of pure substances, but in the case of Me* being CaSO4, the unidentified) l:aO・
Al□0. , ・ZSi02-YSO3・nl(2
It is suggested that this substance is very similar to a sulfuric acid/calcium aluminate complex compound consisting of 0.

In this formula, X=4 to 7, Y=2 to 4,
X is thicker than Y, Z=0.1>3 preferably O, :]>
1, and a composition in which n is 5 to 22 has been reported as a synthetic pigment (British Patent No. 1.115482), but there is no description of its exhaust gas purification properties.

Also, the approximate formula for ettringite used in the form of a paper coating aqueous paste is composed of 5in2-free material.

3 CaO+ 8I2O3' 3 GaSO4" 3
1 to 32t (20) However, the ability of this ettringite to purify exhaust gas is low, and the strength of the composite is also low, so its value as a gas treatment agent is small.
02. Me*-based composites are hard and have dramatically improved desulfurization performance. At this time, the exhaust gas treatment agent contains Ga(OH)z
The crystals cannot be detected even by X-ray diffraction. That is, since Ca(01()2) does not exhibit properties as a single crystal, it is supported that it is in the form of a compound.

Absorbs and fixes acidic substances such as 502, which is represented by oxide C.
aO, but the effects of each pure substance on the performance of the desulfurization agent created are: ■ 5 in 2 contributes to the sustainability of performance, ■ A
12O3 helps to increase the reaction rate with SO□, etc., and hard materials are obtained by ■5in2, Can, Al2O3, Me*. (2) At this time, Me* is considered to play a role in promoting the synthetic hydration reaction of the mixture.

Synthetic hydration reaction refers to the reaction of water with the materials constituting the exhaust gas treatment agent used in the present invention to form CaO1Me*, 5i02, Δ
This refers to the growth of 1□03 crystals and bonding between material particles, and the treatments necessary to advance this reaction include, for example, curing in room temperature water or humid air, curing at normal pressure or high pressure,
Includes steam curing, hot water slurry curing, etc.

Non-consolidation hydration refers to a process in which the hydration reaction proceeds while the material particles are dispersed in the liquid to prevent them from bonding and becoming coarse due to the progress of the hydration reaction, and the solid-liquid ratio is ≦ A slurry with an excess water content of about 1:1 to 1:20 is cured in warm water, hot water, or boiling water.
Suitable for producing slurry-like exhaust gas treatment agents and powder-like exhaust gas treatment agents.

Hydration hardening is a process in which the solid-liquid ratio during kneading is set to between 1 and less than 1 to significantly reduce the gap between material particles and facilitate bonding between particles through crystal growth. It is suitable for producing granular materials of several millimeters to tens of millimeters or large cured products.

The basic substance of the exhaust gas treatment agent used in the present invention is (:aO
, a substance capable of supplying Al2O3,5i02 and CaSO4
, GaCl2, etc., and more importantly, humid air, water, hot water, steam, etc., to promote the hydration reaction between these basic substances. This can be achieved by curing under normal pressure or high pressure.

If a compound or Na compound exists in the material used for the exhaust gas treatment agent in a form that easily dissolves, Me in the exhaust gas treatment agent
*If the form is CaSO4, it will have a negative impact on the exhaust gas treatment performance. i.e. 5in2-A1
203- In the case of CaO-Ca504-based exhaust gas treatment agent,
Addition of several percent of KOtl or Na0tl may adversely affect desulfurization performance. This phenomenon becomes a problem when large amounts of CaSO4 forms are present. On the other hand, if there are a large amount of Na leaves, this will not be much of a problem.

A material that can simultaneously supply two or more of the seven types of compounds that are the basic substances of the present invention to the material for producing the exhaust gas treatment agent,
For example, when coal ash is used, it often contains compounds such as Na and Na, but depending on this content and the form of the exhaust gas treatment agent, this can have a negative impact on the exhaust gas treatment performance. There are cases. This phenomenon is caused by Na,
During the rolling manufacturing process such as during granulation, the compound concentrates on the surface layer of the particles, forming empty particles and impairing the reaction with acidic substances in the exhaust gas. Of course, during the granulation process, the substances that concentrate on the particle surface are not only Na and compounds, but also non-reactants, ie "coal ash particles that have not reacted to become an exhaust gas treatment agent", and these form the waste. I will do it.

However, this does not apply in the case of a molding method that does not employ rolling granulation, such as extrusion, or in the case of granulating agent particles after the completion of the synthesis reaction, that is, after completion of hydration and curing. K compounds are K2SO4, KCI, KNO3
, KOH etc. usually 0. It can be used in the range of i to 70%, but when Me* is in the form of Ca, the performance of rolling granules when using a material that causes addition of 1% or more and elution of 5% or more is as follows. It is on a declining trend.

The Na compound refers to Na1L, and when using a material that causes addition or elution of 1% or more, care must be taken to ensure that it is concentrated on the surface layer of the particles during granulation.

However, the basic form is a substance that supplies CaO, Sin□, and Al2O3, and Na011. If NaCl, water glass, etc. are added, or if a material that elutes Na011 or Na1l is used, this does not pose a problem because the shape of Ca5O4-Na leaves does not occur as described above. Therefore, the Ca5O'4-based agent is 5i02.A I20.・CaO・Nal
This is because the system exhaust gas treatment agent is synthesized by hydration.

Next, the basic manufacturing conditions of the exhaust gas treatment agent will be described.

The various raw materials are mixed after being pulverized if necessary, and water is further added and mixed. The water-soluble salts in the raw materials are used after being dissolved in the water to be added. The water content of the raw material mixture after water addition is 10 to 2000 parts by weight, preferably about 20 to about 1000 parts per 100 parts by weight of dry matter.

Naturally, this moisture also includes moisture derived from the raw materials, so by using dilute sulfuric acid, hydrochloric acid, etc., it is possible to eliminate the need to add water.

The mixture is then cured in humid air or steam at room temperature. The curing process involves curing in hot water in the case of high water content materials. By going through this process, the slurry-like or mud-like mixture becomes
The important initial stage of active compound formation necessary for gas purification is completed, during which most of the water is consumed in the compound-forming reaction.

That is, the mixture is cured in humid air or water at room temperature, or cured in hot water using steam or steam heating. The same procedure is also carried out under high pressure.

Hot water curing involves dispersing the raw materials in water and performing non-consolidation hydration (preventing particles from solidifying each other and becoming coarse particles) at 40°C to 180°C to prevent the raw materials from settling and hardening at the bottom. ,
Allow the hydration reaction to proceed. ) stirring, bubbling,
It is preferable to perform circulation, shaking, etc. for several minutes to 72 hours.

Humid air curing is performed at a temperature of 10°C to 40°C and a relative humidity of 50% to 1
00% for several minutes or several tens of days, and steam curing is preferably for several minutes to 72 hours at a temperature of 40° C. to 180° C. and a relative humidity of 100%.

After curing, the cured product can be crushed into coarse particles (several mm to several +n+m) or fine particles (from several mm to several + n+m) by a conventional method.
1 mm or less to several tens of microns or more). Crushing and crushing of the hydrated cured product is carried out at a good time after drying. The slurry-like material (ultrafine particles of several microns or less) is dried as it is, or used as it is after adding 2 g of moisture, or after being molded (granulated). The molded product is used as it is or after drying. In this way, a flue gas treatment agent for use in the flue gas treatment of the present invention can be obtained.

Curing to obtain coarse particles or fine particles can also be carried out in the following two steps. 1 The conditions for the first stage of moist air curing are a temperature of 10° C. to 40° C., a relative humidity of 50% to 100%, and preferably a period of several minutes to several seconds. Further, steam curing is preferably performed 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 of curing is carried out to maintain an appropriate moisture state after the curing is completed, in order to easily shape and granulate the mixture in which the permanent reaction has partially progressed from a fine particle size to a coarse particle size, and to crush the cured product. , under conditions that result in a hardened state.

That is, the curing in the first stage is to advance the hydration reaction to form the initial stage active compound necessary for molding and granulating the raw material mixture. Active Ca*, 5in2, Al2O3 such as combustion ash
When using a substance that contains substances such as CaO, or when using a substance that generates heat during hydration, such as CaO, the temperature of the mixture during kneading naturally rises, and the hydration occurs even while the raw materials are being kneaded. The reaction progresses significantly. Therefore, it is possible to bring the material into a suitable moisture state for forming and granulating it, which is the purpose of the first stage curing proposed by the present invention.

In this way, if the hydration reaction progresses significantly during kneading, the first stage of curing can be omitted.

The conditions for the first step, “humid air curing,” are a temperature of 10°C to 40°C,
Preferably, the period is from several minutes to several days at a relative humidity of 50% to 100%. Further, steam curing is preferably performed 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 of curing is carried out in such a way that the mixture can be easily molded into fine particles, granulated, and pulverized after the curing is completed.
This is done under conditions that will result in a hardened state.

Next, the material that has undergone the first stage of curing is processed into quince, isar,
Molding (granulation) using a disc beretter, briquette machine, pelletizer, etc.

Since the molding process is performed through the above-mentioned steps, the particle size can be made such that the particles can be easily dispersed in or come into contact with the flue gas, and can be carried out with a high yield. This molded product is subjected to a second stage of curing and sized to obtain the flue gas treatment agent used for activation of the present invention.

The second stage of curing is preferably carried out at a temperature of 10°C to 40°C and a relative humidity of 50% to 1.00% for several minutes to several tens of days for moist air curing, and for steam curing at a temperature of 40°C to 180°C and a relative humidity of 50% to 1.00%. Preferably, the humidity is 100% for several minutes to 72 hours.

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

Compression molding of the cured product involves crushing or pulverizing the cured product, dehydrating the cured product if it is in the form of a slurry, and then removing some or all of the water if necessary, or conversely adding water. The water content can be adjusted using a briquette machine, tablet machine, extruder, disc beretter, other 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-shaped, tablet-shaped, plate-shaped, honeycomb-shaped, rasp and ring, etc.).
10kg for relatively large particles packed in layers
/crn' ~IOt /crn'', 0.01 ~ number a+
When manufacturing particles of m, several kg/cyn' to several t/
crn'.

Compression molding can be used to process particles of several millimeters such as ultrafine particles, fine particles, and coarse particles, as well as particles as large as 10 mm @'71, by removing part or all of the moisture contained therein or conversely by adding water. By adjusting the moisture content, molding can be carried out in the same way without adding a binder. However, a binder such as clay, CMC, PVA, etc. may be added if necessary. By steam curing and drying coarse and fine particulate flue gas treatment agents using dielectric heating, it is possible to treat them from the inside, so for example, the drying time can be completed several times faster than with hot air treatment. It is. Furthermore, in the case of a coarse or fine particulate flue gas treatment agent used in a method in which it is suspended in flue gas in a dry state, the molded product after curing is heated to 30°C or higher, preferably 30°C.
The performance of the treating agent can be further improved by drying at a temperature of 0° C. to 500° C. for 0.1 to 10 hours, but the ice content varies depending on the object to be treated. For example, desulfurization is preferably 10% or less, theory 11 (:l, de-HF
is 27% or less, de-1 (2S is 20% or less, etc.).

The activation method of the present invention is carried out by bringing HCl into contact with the above exhaust gas treatment agent. This contact includes a method of contacting HCI in a gaseous state and a method of contacting HCI in a liquid state.

In the case of gaseous state, that is, gas-solid contact, exhaust gas treatment agent 1
Concentration per g 1-100%] tlCI O, 1-1of
A desired activation ability can be imparted by contacting fi for 1 second to 24 hours. At this time, the diluent gas of H(:1) may be any substance that does not react with IIcI and the exhaust gas treatment agent to be activated, such as nitrogen gas.The temperature during contact is 10 to 100°C, preferably 20 to 60°C. be.

Furthermore, the gas-solid contact can be carried out by mixing HCI into the exhaust gas to be removed. In this case, % IIcI is 3.5 cc/It or more, preferably 35 to 350 cc/H per Ikg of exhaust gas treatment agent. The temperature at the time of contact may be the same as the temperature at the time of exhaust gas treatment.

The temperature when the activated substance is directly absorbed into the flue gas treatment agent is 10 to 100°C, preferably 20 to 60°C.

An aqueous solution of HCl can be used for activation with 11C1. In this case, the flue gas treatment agent is immersed in a 0.01 to 10% aqueous solution of HCI, preferably a 0.05 to 5% aqueous solution, for 10 seconds to 24 hours, preferably 5 minutes to 2 hours, taken out, and then at a temperature of ~500°C, preferably 7
Dry at 0-200°C. The temperature of the HCI aqueous solution is 1 to 1
00°C, preferably 10-40°C.

The activation of the flue gas treatment agent of the present invention has the effect of significantly improving the inherent performance or poor performance of the flue gas treatment agent, although there are still many unknown points.

The flue gas treatment temperature of the activated flue gas treatment agent can be carried out in a wider temperature range than in conventional methods, that is, from 10°C to 1200°C, and desulfurization is preferably 30°C to 1000°C, and denitration is preferably 50°C to 400°C. ℃, HCI removal from 30℃ to 1000℃
, de-11F and de-112S are at 30°C to 1000°C, etc. The pressure may be normal pressure, but the performance can be further improved by pressurizing the area where the flue gas and flue gas treatment agent come into contact.

Flue gas treatment using coarse, ultrafine, and fine particulate flue gas treatment agents (highly water-containing slurry, water-containing agents, dried agents) is, for example, coarse particulate material obtained by crushing or compression molding a cured product. The method of bringing the gas into contact with the exhaust gas is to fill it with wet or dried particulate 11 smoke treatment agent of several mm to several-1-mm in size and allow the gas to pass through it, or to make it come into contact with the flue gas by the force of the flow of the exhaust gas. By floating the
Increasing the contact area, agent-particle collisions induce the exposure of new surfaces of the agent, improving performance. At this time, the agent must be dispersed as widely as possible in the exhaust gas.

In the case of non-consolidated hydrated ultrafine particles, the contact area with the exhaust gas can be increased by spraying the highly water-containing slurry directly into the exhaust gas using a general method to form as fine droplets as possible. The effect of S02 uptake by the liquid is synergistic, and the exhaust gas can be treated.

The spent agent can be subsequently collected using a cyclone, an electrostatic precipitator, a filtration type precipitator, or other numerical methods in the case of particles that are wet or dried at the exhaust gas temperature.

The collected exhaust gas treatment agent is kept until there are no unreacted substances left.
Used repeatedly.

Examples will be given and explained below.

〔Example〕

Example 1 Various materials whose chemical compositions are shown in Table 2 are mixed with water according to the formulations shown in Table 3. Next, as the first stage of curing, steam curing at normal pressure of 100°C is carried out for 120 minutes, and the obtained soft cured product is passed through a 511III+ mesh sieve to prepare seeds for granulation. Buffer granulation is performed for several minutes to prevent moisture, K, Na compounds, and non-reactants from concentrating on the surface layer, and as a second stage of curing, steam curing is performed at 100° C. and normal pressure for 4 hours. Here, buffer granulation refers to a method in which granulation is performed not by contact between the surface of the granulator and the object to be granulated, but by mutual contact between the objects to be granulated. The obtained granules were spread at 1.7 to 2.5 m/m.
The particles were sized and left as is (hereinafter referred to as processing agent A), 130
℃ hot air dryer for 2 hours (hereinafter referred to as treatment agent B) and a 500W dielectric dryer for 8 minutes (hereinafter referred to as treatment agent C) to obtain treatment agents A, B, and C. Ta.

For treating agents A, B, and C, each 1 kg was brought into contact with 100 ml of 2% 11C1 gas diluted with nitrogen gas at room temperature for 10 minutes, and the activated exhaust gas treating agent of the present invention (actual jJl!
i Example 1-1. l-2,! -3) was obtained.

The performance test was conducted under the conditions shown in Table 4 (space velocity 6000h-
1 and gas temperature 130°C), SO2, NOx,
Removal tests for H2S, HCI, HF, etc. were conducted for each component. In order to clarify the effect of the activated exhaust gas treatment agent of the present invention, the removal rate was calculated using an integral value for 4 hours after gas passage. (Performance test conditions for each example were performed in the same manner below.) The specific surface area was also measured. To measure the specific surface area, the sample is
After degassing at 00°C, the BET method was used.

These values are listed in Table 5.

Example 2 The various materials shown in Table 2 are mixed with water according to the formulation shown in Table 3. Next, add water to the outside so that the total amount is 300%, and hydrate without solidification 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 obtained white microparticles were molded as they were at a pressure of 640 kg/cm' (particle size: 1.7 to 2.5 m/m) to obtain a processing agent.

An activated exhaust gas treatment agent of the present invention (Example 2) was obtained by contacting 100 J2 of 2% 11C1 gas diluted with nitrogen gas per 1 kg of treatment agent D at room temperature for 10 minutes.

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 treatment agent C described in Example 1 was mixed with 0.5 of IIcI.
% aqueous solution (room temperature) for 10 minutes each.
A heat treatment was performed for 8 minutes using a 00W dielectric dryer to obtain an activated desulfurization agent.

The performance test of the sample exhaust gas treatment agent was not performed on NOx and HCI among the gases shown in Table 4, but instead on 50%
I followed 3.

The rest was carried out in the same manner as in Example 1.

The results are shown in Table 5.

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

Table 4 Performance test conditions (fixed bed method) * The simulated gases used are all of the gas compositions listed above.
It was adjusted by adding one of the gases marked * to the gas marked with an asterisk.

(Effects of the invention!!!,) Unlike conventional adsorbents, the exhaust gas treatment agent used in the method of the present invention is mainly composed of substances that can supply CaO, 5in2, and Al2O3, so the raw material is coal ash. , cement, volcanic ash, slag, shirasu, fluidized bed combustion ash, used exhaust gas treatment agents (including unused exhaust gas treatment agents), clay, and other silicates and calcides can be used, and there is a wide range of usable raw materials. be.

The present invention provides a 5in2,
Provides a method for activating an exhaust gas treatment agent that increases the reaction rate between the lime contained in the Al2O3, CaO-based exhaust gas treatment agent and reactants, and further improves the utilization rate of lime, 5in2, ^120
3. The purpose is to further improve the performance of CaO-based exhaust gas treatment agents and solve various problems in exhaust gas treatment that have been considered difficult up to now.

Furthermore, it is not only useful as a resource recycling technology, as it can utilize waste materials such as coal ash, slag, used desulfurization agents, waste glass, and fluidized bed combustion ash, but also for S02, NO.
x, 503, HF, Hcl, Gl. etc.υ
Since harmful components contained in F smoke can be removed with high efficiency and at low cost, it greatly contributes to pollution prevention.

Patent applicant: Hokkaido Electric Power Co., Inc.

Claims (3)

[Claims] (1) One or more substances selected from the group of substances capable of supplying sulfuric compounds, halogen element compounds, sulfides, and alkali metal hydroxides are added to substances capable of supplying calcium oxide, silicon dioxide, and aluminum oxide, and water H
A method for activating an exhaust gas treatment agent, the method comprising contacting with Cl. (2) Claim (1) wherein the contact is gas-solid contact.
Activation method described. (3) The activation method according to claim 1, wherein the contact is a liquid-solid contact using an aqueous solution of nitrite.