JPH04190820A - Preparation of exhaust gas treatment agent and treatment of exhaust gas - Google Patents

Abstract

PURPOSE:To activate and reuse a used exhaust gas reacting substance by a method wherein the exhaust gas reacting substance is treated with gas containing SO2, NOx or the like and subsequently washed with water or the like and, subsequently, the treated substance is separated from the washing solution to be used as it is or dried before use. CONSTITUTION:One or more kind of a substance (e.g. CaSO4) selected from the group consisting of substances capable of supplying a sulfur compound, a hologen element compound, sulfide and alkali metal hydroxide is added to a substance capable of supplying CaO, Al2O3 and SiO2 and the resulting composition is mixed with water to be subjected to hydration treatment to obtain an exhaust gas reacting substance which is, in turn, washed with gas containing SO2, NOx, HCl and/or HF. Thereafter, the treated substance is washed with water or an aqueous alkali solution and/or an aqueous alkali suspension and subsequently separated from the washing solution and used as an exhaust gas treatment agent as it is or dried to prepare the exhaust gas treatment agent. As a result, the used exhaust gas reacting substance can be activated and reused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the treatment of various exhaust gases, and particularly to a method for producing an exhaust gas treatment agent containing No. 1, and a method for treating exhaust gas.

[Prior art and problems to be solved by the invention] When various fuels are burned in the air, nitrogen, etc. in the air is oxidized and various nitrogen compounds, so-called NO, are formed.

Because of the large impact it has on the environment,
Various studies have been conducted on the removal of NOx from combustion exhaust gas, that is, denitrification methods.

As the dry denitrification method to which the present invention pertains, a novel denitrification method using a cured composition obtained by a relatively simple manufacturing method from inexpensive raw materials has been disclosed (Japanese Patent Laid-Open No. 63-69523).

However, improvements were still desired in terms of the lifespan of the denitrification agent. The object of the present invention is to provide a method for producing an exhaust gas treatment agent having improved denitrification performance, desulfurization performance, etc. in the same system, and an exhaust gas treatment method using the same.

[Means to solve the problem]

This invention provides calcium oxide, aluminum oxide, and silicon dioxide, and one or more substances selected from the group of substances capable of supplying g, acid compounds, halogen element compounds, sulfides, and alkali metal hydroxides to calcium oxide, aluminum oxide, and silicon dioxide. The exhaust gas reactants obtained by adding and mixing with water and hydration treatment are
treated with a gas containing S02, HCI, HF and/or NO, followed by washing treatment with water or an alkaline aqueous solution and/or a water suspension thereof, and separated from the washing liquid,
A method for producing an exhaust gas treatment agent, which is characterized in that it is produced as is or by drying, and the exhaust gas treatment agent obtained by this method is used to produce S02, HCl, HF and/or NO.
, , is characterized in that the gas treatment of the exhaust gas reactant in the production of the exhaust gas treatment agent is performed using the exhaust gas to be treated or the exhaust gas to be treated after being treated with the exhaust gas treatment agent. This is an exhaust gas treatment method.

In the present invention, substances capable of supplying calcium oxide include by-products such as quicklime, slaked lime, charcoal lime, cement, slag, dolomite plaster (containing lime), and acetylene slag.

Substances that supply aluminum oxide include, for example, alumina, aluminum hydroxide, aluminum silicate, sulfuric acid, alum, aluminum sulfide, aluminum sulfate,
Aluminum chloride, calcium aluminate, hentonite, kaolin, diatomaceous earth, zeolite, perlite,
These include compounds containing reactive aluminum such as phooxide, sodium aluminate, cryolite, and aluminum cleaning residue (alcite).

Substances that can supply silicon dioxide include, for example, silicic acid, hydrous silicic acid, metasilicic acid, aluminum silicate, water glass, calcium silicate, cristobalite, tridymite, kaolin, hentonite, talc, perlite,
These include compounds containing reactive silicon dioxide, such as whitebait, diatomaceous earth, glass, rice husk ash, incineration ash such as wood ash, etc.

In addition, examples of substances that simultaneously supply at least two or more of the three types of compounds mentioned above include - coal ash and volcanic ash, coal fluidized bed combustion ash (source of calcium oxide, silicon dioxide, and aluminum oxide), cement, and cement. Clinker (
Calcium oxide, silicon dioxide, aluminum oxide sources)
, slag and shirasu, andesite, chert, quartz trachyte,
Minerals containing reactive silicon dioxide such as opal, zeolite, feldspar, clay minerals, ettringite (silicon dioxide, aluminum oxide, calcium oxide source), and oxides such as aluminum, calcium, chlorides, sulfates, etc., fluidized bed Used desulfurization agents for in-furnace desulfurization and flue desulfurization of combustion ash, sludge incineration ash, municipal waste incineration ash, cement waste,
Examples include acetylene slag and used wastewater treatment agents. Here, the used desulfurization agent is CaO1Ca (0)1)
2. Used calcium-based desulfurization agents such as CaCO3 and JP-A No. 61-209038.
It refers to used desulfurization agents made of O1Aha3.5in2, Ca5Oa-based compositions, etc.

Table 1 shows examples of chemical compositions of these typical raw materials.

The group of substances that can supply sulfuric compounds, halogen element compounds, sulfides and alkali metal hydroxides are gypsum, magnesium sulfate, calcium chloride, magnesium chloride,
Sodium sulfate, calcium sulfite, calcium hydrogen sulfate, sodium chloride, strontium chloride, calcium bromide, calcium iodide, potassium chloride, sodium thiosulfate, sodium hydrogen carbonate, calcium hydrogen carbonate, calcium sulfide, iron sulfide, zinc sulfide, hydroxide Among sodium and potassium hydroxide, gypsum and sodium hydroxide are particularly preferred.

The proportion of the above components in the cured product (when CaSO4 is included) is 1 to 90% for CaO (and Ga50<) as CaO, 2 to 70% for 81203, and 2 to 70% for 5i02.
2-90%, preferably 2-80% as CaO, (0.1-70% as CaSO4,) as Al2O2
5~70%, as 5in2 5~
80%.

When one or more substances selected from the group of substances other than gypsum that can supply sulfuric compounds, halogen element compounds, sulfides, and alkali metal hydroxides are added, one or more of Na25o, CaCl2, NaCl1 or The sulfide is preferably 0.1 to 50% calcium sulfide, and the alkali metal hydroxide is preferably Na11 (and/or K1-10) 0.1 to %.

In this invention, hydration treatment refers to, for example, JP-A-64-381:
] As disclosed in 0, it refers to the treatments necessary to advance the hydration reaction between the various substances (raw materials) mentioned above, such as normal pressure or high pressure room temperature water or hot water curing, humid air curing, steam It includes curing, etc., and is classified into hardening hydration treatment and non-caking hydration treatment.

Curing hydration treatment refers to the ratio of the above raw materials and water during treatment (
(solid-liquid ratio) to be small, e.g. 1:0.2 to 1:0.8
By setting it to 0, the bond between material particles is promoted,
A hydration process to obtain a hardened product.

Non-caking hydration treatment refers to treatment that prevents material particles from bonding together and growing into coarse particles during hydration treatment, and the solid-liquid ratio at the start of treatment is increased, for example, 1:1. In hot water curing, the raw materials are dispersed in water at 40°C to 180°C, and stirred to prevent the raw materials from settling and hardening at the bottom.
This process involves bubbling, circulation, and shaking for several minutes to several days.

In the hydration treatment process, after providing sufficient moisture necessary for the production of active substances in the treatment agent, the important stage for the formation of active compounds necessary for exhaust gas purification is completed, and during this period, some of the moisture is Alternatively, most of it is consumed in the compound formation reaction.

Humid air curing in hardening hydration treatment is performed at a temperature of 10°C to 4°C.
A period of several minutes or several tens of days is preferable at 0°C and a relative humidity of 50% to 100%, and steam curing is performed at a temperature of 40°C to 18°C.
Preferably, the temperature is 0°C and 100% relative humidity for several minutes to several days.

Treatment with a gas containing SO□, HCl, HF, and/or N2 is performed with a gas containing 10 ppm to 90% of these gases at a temperature of 20°C to 500°C, with an SV of 5 to 50.000.
It is only necessary to treat the exhaust gas at h-1 for a time sufficient to contact with at least 1 mole of these gases alone or in a mixture per 1 kg of the exhaust gas reactant, and the exhaust gas to be normally treated (exhaust gas to be treated) can be used.

The shape of the exhaust gas reactant is O,1, such as powder produced by evaporation of slurry or powder obtained by powder spraying.
These include fine particles with a diameter of 1 mm or less, and particles with a diameter of 0.1 mm or more up to several tens of meters.

The cleaning process uses water or an alkaline aqueous solution or aqueous suspension. The alkali is a hydroxide or carbonate of an alkali metal and/or an alkaline earth metal, and an aqueous solution and/or suspension thereof is used. Although there are no particular restrictions on the concentration of the liquid during the cleaning treatment, the treatment time, the specific method of treatment, etc., the temperature of the treatment liquid is within a wide range from 5°C to 180°C, preferably from 50°C to 150°C. Through this cleaning process, Ca5o4 and CaC in the exhaust gas reactants are removed.
12, NaC1, NaNO3, Ca(N(1+)2, etc.), "generated substances" are eluted by the reaction between the exhaust gas reactants and the processing gas, and voids increase especially in the part near the surface of the particles, causing the inside of the particles to This makes it easier for gas to diffuse into the air.

Therefore, it is preferable to elute as many "produced substances" as possible, and furthermore, it is a feature of the technology of the present invention that exhaust gas reactants are separated from the cleaning liquid containing these eluted substances.

In the case of cleaning fluids or alkaline aqueous solutions and/or aqueous suspensions thereof, the alkaline substances or exhaust gas reactants may be retained, either by physical adsorption or by chemical reaction with components of the exhaust gas reactants. It is not clear whether they are connected. However, from the fact that the curing strength of the particulate exhaust gas reactants increases after treatment, it is clear that some kind of reaction is progressing. Furthermore, it is unclear whether this treatment promotes the reaction of NO with the constituent components of the exhaust gas treatment agent or the adsorption of N08 to the exhaust gas treatment agent, or whether the retained alkaline substances promote the NOx in the exhaust gas or the exhaust gas that has been treated with the exhaust gas. There is no certainty as to whether NO in the reactant (released into the air from the exhaust gas reactant under specific conditions) or its compounds reacts, but in any case, the Thus, it is clear that it is effective in removing NO, 1, is effective in increasing the strength of particulate exhaust gas reactants after treatment, and also has a significant effect on the ability to remove S02 and HF.

For gas treatment of the exhaust gas reactant, the obtained exhaust gas treatment agent, the gas to be treated, or the gas treated with the exhaust gas treatment agent may be used. The exhaust gas reactants before cleaning treatment have already been disclosed by the applicant in Japanese Patent Application Laid-Open No. 61-209038.
82-97640.52-213842.62-254
824.63-69523.64-38130.64-
As disclosed in No. 80425, it has the ability to treat exhaust gas such as desulfurization and denitrification, so it can be assembled into the exhaust gas treatment system shown in FIGS. 1 to 3.

That is, in FIG. 1, the exhaust gas reactant S is first subjected to the abatement of the to-be-treated exhaust gas G containing NOx, SO2, MCI, and/or HF in the first abatement device 1;
itself is treated with this to-be-treated exhaust gas, and then treated with water or an aqueous alkali solution and/or its water suspension (cleaning liquid) A in the cleaning treatment device 3 to become the exhaust gas treatment agent R of the present invention, Furthermore, it is filled into the second abatement device 2 and is effective in removing residual gas remaining in the exhaust gas to be treated, mainly in denitrification.

In FIG. 2, the exhaust gas reactant S is first filled into the second abatement device 2, passed through the first abatement device 1, and then converted to SO.
□, HCI and/or) IF performs a detoxification treatment on the remaining treated exhaust gas, and is itself treated with this treated exhaust gas, and then treated with cleaning liquid A in the cleaning treatment device 3 to obtain the exhaust gas treatment agent of the present invention. R, and then filled into the first abatement device 1 to perform primary abatement of the exhaust gas to be treated as a treatment agent with enhanced denitrification ability.

In FIG. 3, the exhaust gas to be treated passes through the abatement devices in the order of the first, second, and third abatement devices. The exhaust gas reactant S is first filled into the second abatement device 2, and passed through the first abatement device No.
A secondary abatement treatment is performed on the treated exhaust gas in which X, S02, HCl and/or HF remain, and the waste gas itself is treated with this treated gas, and then treated with the cleaning liquid A in the cleaning treatment device 3. The exhaust gas treatment agent R is then filled into the first abatement device 1 to perform primary abatement of the exhaust gas to be treated as a treatment agent with enhanced denitrification ability. Furthermore, the processing agent whose denitrification ability has decreased is cleaned with cleaning liquid A in the cleaning treatment device 3, and the denitration ability is restored and the process is filled into the third abatement device 4 to perform tertiary abatement of the gas to be treated. .

The exhaust gas treatment agent will be described in detail below using Examples.

〔Example〕

Example 1 Coal ash (produced overseas) (AlO322%, 5in26
4%) 51 parts by weight, Ca (Of() 230 parts by weight, Ca
45 parts by weight of water was added to a powder containing 19 parts by weight of SO4, kneaded, steam-cured at 95-100°C for 12 hours, dried at 130°C for 2 hours, and then crushed to give a particle size of 3.36-4.76 mm.
of particulate exhaust gas reactants were obtained.

This exhaust gas reactant is the gas shown in Table 2, and 5vio
oh-', treated at a temperature of 130°C for 200 hours, and then
After cooling to room temperature, 40 g of the suspension was added to the supernatant liquid (1 tate) that had been prepared by suspending 22 g of Ca (leaf leaves) in 2 fl of pure water and left for 5 minutes.The temperature of the liquid was kept at 20°C, and the suspension was stirred occasionally. After washing for 30 minutes, the particulate exhaust gas reactants were separated by filtration through a stainless steel screen with 3 openings, and the exhaust gas treatment agent (Example 1-1) was dried at 100°C for 1 hour. An exploded exhaust gas treatment agent (Example 1-2) was obtained. Furthermore, supernatant liquid (
Cleaning liquid> Exhaust gas treatment agent (Example!-3) which was heated to 95℃ and treated in the same manner, after which particulate exhaust gas reactants were taken out and dried on the surface (Example!-3), and exhaust gas treatment agent that was dried at 100℃ for 1 hour. (Example 1-4) was obtained. A test device was filled with 30mj2 of these exhaust gas treatment agents (bulk specific gravity 0.9), and the gases shown in Table 2 were passed through at 5V2000 (h-1) and a temperature of 130°C, and the nitrogen content in the inlet and outlet gases was evaluated. The concentrations of S02 and S02 were measured to determine the denitrification and desulfurization rates. Furthermore, the concentrations of NOx and SO□ in the treatment liquid were measured to determine the denitrification and desulfurization rates. Furthermore, NO3-1SO in the cleaning solution
4" concentration was also measured and the results are shown in Table 3.

The agents of Comparative Examples were not subjected to the washing treatment in each Example (the same applies to Tables 4 to 11).

Table 2 502 (ppm) 90 ONO, (p
pm) 450 0□ (*)6 co2 (*) 13 H20 (96) 1O N2 (!l;) Remainder Table 3 Book 1 After treating the exhaust gas reactants with the gases shown in Table 2, SV 2000 h- The test was conducted for 5 hours and the average value.

Ne2 Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after gas passage Ne3 There is no denitrification ability in this case. Conversely, NOX compounds in the exhaust gas reactants are decomposed to release NO.
NOx in the exhaust gas that has passed through the exhaust gas reactant layer becomes higher than the population concentration. Below, when such a phenomenon occurs, it will be indicated as "vomiting". The number indicated by "all" is the amount of N gas released in 5 hours.

Example 2 The particulate exhaust gas reactant obtained in Example 1 was heated at 5 V 1000 h-' and a temperature of 130° C. for 200 min with the gas shown in Table 2.
After processing for an hour and then cooling to room temperature, 40 g of (
: Pour 220 g of a(OH) into a solution suspended in 22% pure water, stir occasionally and wash by varying the treatment temperature and treatment time, then filter through a stainless steel mesh with a 3 mm opening to separate. A surface-dried particulate exhaust gas treatment agent was obtained. 2
Example 2-1 was a treatment at a liquid temperature of 0° C. for 30 minutes, and Example 2-2 was a treatment at a liquid temperature of 95° C. for 30 minutes. Example 2-3
The solution was heated to 95°C for 60 minutes.

Further 1 of each of the agents of Example 2-1.2-2.2-3
Examples 2-4 and 2-4 were dried at 00°C for 1 hour, respectively.
This was referred to as Example 2-5 and Example 2-6.

Performance tests of these exhaust gas treatment agents and No.
3~, SO4'' concentration was measured in the same manner as in Example 1.

The test results are shown in Table 4.

Table 4 - 1 After treatment of the exhaust gas reactants with the gases shown in Table 2, a test was conducted at SV 2000 h-' for 5 hours, and the average value.

Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after passing the gas Book 3 Third Display 3 Reference Example 3 The particulate exhaust gas reactant obtained in Example 1 was subjected to the gas test shown in Table 2. , 5V 1000h'' and a temperature of 130°C for 200 hours, then cooled to room temperature, and 40g of it was poured into water IJ.
2, keep the liquid temperature at 20°C or 95°C, stir occasionally and wash for 30 minutes, then filter the particulate exhaust gas reactants through a 3-ounce stainless steel mesh to separate them and leave them to dry on the surface. Example 3: 20°C liquid temperature treatment using an exhaust gas treatment agent
-1, and 95°C liquid temperature treatment was set as Example 3-2.

An additional 1o of the agents of Examples 3-1 and 3-2 was added.

Exhaust gas treatment agents dried at ℃ for 1 hour were prepared in Example 3.
-3 and Example 3-4.

Performance tests of these exhaust gas treatment agents and No.
The measurement of the 3-5o4'' concentration was carried out in the same manner as in Example 1.

The test results are shown in Table 5.

Table 5 - 1 After treatment of the exhaust gas reactants with the gases shown in Table 2, a test was conducted at SV 2000 h-' for 5 hours, and the average value.

*2 Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after gas passage Umbrella 3 Table 3 *3 Reference Example 4 The particulate reactants obtained in Example 1 are shown in Table 2. Treated with gas for 200 hours at 5vtoooh-' and a temperature of 130°C, then cooled to room temperature, and 40g thereof was treated with (:a(
:O,, 2g was suspended in pure water iIL and left to stand for 5 minutes, then added to the supernatant liquid IJ:t, kept the liquid temperature at 95°C, and after washing for 30 minutes with occasional stirring, the particulate reactant was removed. distance of 3m
An exhaust gas treatment agent (Example 4-1) which was separated by filtration through an In stainless steel net and dried on the surface, and an exhaust gas treatment agent (Example 4-2) which was dried at 100° C. for 1 hour were obtained.

Performance tests of these exhaust gas treatment agents and NO in cleaning solutions
3-5S04" The concentration was measured in the same manner as in Example 1.

Umbrella 1 After treating the exhaust gas reactants with the gases shown in Table 2, a test was conducted at 5V2000h-' for 5 hours, and the average value.

Book 2 Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after passing gas -', treated at a temperature of 13-0"C for 200 hours, then cooled to room temperature, and added 40g of it (7) to an aqueous solution of 0.2g of Na01+ dissolved in pure water of step 21, and the temperature of the solution was lowered. After washing for 30 minutes while maintaining the temperature at 95°C and stirring occasionally, the particulate reactants were separated by filtration through a stainless steel mesh with a mesh size of 31 nlIl, and the exhaust gas treatment agent (Example 5-1) was dried on the surface. , an exhaust gas treatment agent (Example 5-2) was obtained by drying at 100° C. for 1 hour.

Performance tests of these exhaust gas treatment agents and NO in cleaning solutions
, -1S04" concentration was measured in the same manner as in Example 1.

The test results are shown in Table 7.

After treating the exhaust gas reactants with the gases shown in Table 2, a (7) test was conducted at 5V2000h-' for 5 hours, and the average value.

Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after passing the gas *3 Table 3 *3 Reference Example 6 37.8 parts by weight of Ca (Ca (OR)
) 2 equivalent fi 50 parts by weight) was added and sufficiently digested,
Add 30 parts by weight of coal ash (overseas coal) shown in Table 1 and 20 parts by weight of the spent exhaust gas reactant in that order and heat at 95°C to 100°C.
After hydration and curing in hot water for 2 hours, solid-liquid separation was carried out using a vacuum dehydrator, pulverized using an attritor, and dried to 0.1+n.
A powdery exhaust gas reactant of less than m was obtained.

This powdered exhaust gas reactant was sprayed into the gas shown in Table 2, and the powdered exhaust gas reactant was collected using a bag filter. The collected powdered exhaust gas reactant was used repeatedly and taken out when the desulfurization rate after passing through the bald filter became 10% or less. This used powdered exhaust gas reactant is used as a comparative example.
Perform the performance test shown below. The results are shown in Table 8.

Then, the spent powdered exhaust gas reactant is cooled to room temperature,
40g of the suspension was added to a solution containing 22g of Ca(OH) suspended in 2k of pure water, the temperature of the solution was maintained at 95°C, and after washing for 30 minutes with occasional stirring, solid-liquid separation was performed using a vacuum dehydrator. 10
After drying at 0'C for 1 hour, fixed particles were separated using a centrifugal pulverizer to obtain an exhaust gas treatment agent.

The performance of the agent was determined by dispersing and adhering 10 g of this exhaust gas treatment agent to 5 g of absorbent cotton and filling a Pyrex glass reaction tube with a diameter of 32 mm and a height of 180 am.
NO8 and 50 in the inlet and outlet gases passed through at
．． The denitrification and desulfurization rates were determined by measuring the concentration of Furthermore, we measured the concentration of NO3-1Soj'' in the cleaning solution and reported the test results in the 8th test.
Shown in the table.

*1 After treating the exhaust gas reactants with the gases shown in Table 2, a test was conducted at 5V2000h-' for 5 hours, and the average value.

*2 Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after gas passage *3 Third Table Comparison Reference Example 7 Exhaust gas treatment agent obtained in Example 1, 1-1.1-2. 1-3
．． 1-4, the 502 concentration in the processing gas and test gas (gas shown in Table 2) before cleaning was adjusted to 800 ppc,
An exhaust gas treatment test was conducted under the same test conditions as in Example 1 except that the NOx concentration was changed to 100 ppm, and the results were designated as Example 7-1.7-2.7-3.7-4 and No. 9.
Shown in the table.

Table 9 *1 After treating the exhaust gas reactants with the gases shown in Table 2, a 17) test was conducted at 5V2000h-' for 5 hours, and the average value.

Ne2 Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after gas passage An exhaust gas treatment agent of the present invention was obtained in the same manner as in Example 1, except that the time was changed to 150 hours.

That is, the agents corresponding to Examples 1-1.1-2.1-3.1-4 were used as agents 8-1.8-2.8-3.8-4, respectively. Exhaust gas treatment tests were conducted on these under the same test conditions as in Example 1, and the results shown in Table 10 were obtained.

Table 6 HCI 910ppID NOw aopp Mark 5Q260 ppm 0026% 02 14% N2 Balance Table 10 *l After treating the exhaust gas reactants with the gases shown in Table 2, a test at SV 2000 h-' was carried out for 5 hours. its average value.

2 Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after gas passage Table 3 *3 Reference Example 9 Coal ash (overseas coal) (A1□0322%, Si0□64
%), 68 parts by weight, C,1(Of()) After adding 25 parts by weight of water to 230 parts by weight of powder and kneading, N a (l
A solution obtained by adding 10 parts by weight of water to 2 parts by weight of ft was added, kneaded again, and pressed using a die with a hole diameter of 4 Ua+n.

After molding with a molding machine, it is cured at room temperature and in a humid air for 30 minutes.

After that, it was steam-cured at 95-100℃ for 12 hours, and then heated to 130℃.
After drying for 2 hours, a particulate exhaust gas reactant with a diameter of 4 vn and a length of about 4 mm was obtained.

The exhaust gas reactants are the gases shown in Table 2.svi,oo
oh-', treated at a temperature of 130°C for 200 hours, then cooled to room temperature, suspended 22 g of Ca (leaf leaves) in Pure 22, left for 5 minutes, and then added to the extraction treatment liquid of supernatant 12. After washing for 30 minutes while keeping the liquid temperature at 20°C and stirring occasionally, the particulate exhaust gas reactants were washed with aperture 311101.
An exhaust gas treatment agent (Example 9-1) which was dried on the surface by filtration through a stainless steel net and an exhaust gas treatment agent (Example 9-2) which was dried at 100° C. for 1 hour were obtained. Furthermore, the temperature of the extraction treatment liquid was set to 95°C, and after the same treatment, the particulate exhaust gas reactants were taken out and dried on the surface. (Example 9-4) was obtained.

The test equipment was filled with 30 mu of these exhaust gas treatment agents (bulk specific gravity 0.95), and the gases shown in Table 2 were heated to SV2.00.
0 (h-'), passed at a temperature of 130 °C, No. in the main and outlet gases. The denitrification and desulfurization rates were determined by measuring the concentrations of SO, and N03-1504' in the cleaning solution.
The concentration was also measured and the results were reported in the 11th *1. The exhaust gas reactants were reported in the 2nd.
After treatment with the gas shown in the table, 5V2000SV-”'j
The test was conducted for 5 hours and the average value.

Book 2 Average desulfurization rate (%) and average denitrification rate (%) for 5 hours after gas passage *3 See Table 3, page 3 [Effect of the invention] The denitrification rate by the flue gas treatment agent of this invention is 50% or less. Although not expensive, it is possible to activate and reuse used exhaust gas reactants that had to be disposed of due to extremely low performance despite remaining exhaust gas treatment capacity with simple equipment and operation. Something will happen. In other words, it is possible to effectively bring out already degraded abilities such as denitrification, and the temperature during denitration may be low, so its practical value is extremely great.

[Brief explanation of drawings]

1 to 3 are basic conceptual diagrams of an exhaust gas treatment system incorporating the method of the present invention. 1.--First abatement device, 2...Second abatement device, 3.3'...Cleaning treatment device, 4.-Third abatement device, G...Exhaust gas to be treated, S. ...Exhaust gas reactant, R--Exhaust gas treatment agent, A--Cleaning liquid.

Claims (1)

[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 to substances capable of supplying calcium oxide, aluminum oxide, and silicon dioxide. The exhaust gas reactants obtained by adding the substances, mixing with water, and performing hydration treatment are SO_2,
After treatment with a gas containing NO_x, HCl and/or HF, cleaning treatment with water or an aqueous alkali solution and/or aqueous suspension of an alkali, and then separation from the cleaning liquid,
A method for producing an exhaust gas treatment agent, characterized in that it is produced as is or dried. 2. The manufacturing method according to claim 1, wherein the one or more substances selected from the group of substances capable of supplying sulfuric compounds, halogen element compounds, sulfides, and alkali metal hydroxides is calcium sulfate. 3. In an exhaust gas treatment method in which exhaust gas containing SO_2, NO_x, HCl and/or HF is treated with an exhaust gas treatment agent obtained by the production method according to claim 1, the exhaust gas reaction substance is gas treated in the production of the exhaust gas treatment agent. An exhaust gas treatment method, characterized in that the treatment is carried out using the exhaust gas to be treated or the exhaust gas to be treated after being treated with the exhaust gas treatment agent.