JPH07115871B2 - Method for producing hydrogen-type zeolite - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a hydrogen-type zeolite, and more particularly to a method for producing a hydrogen-type zeolite useful for applications of a solid acid catalyst and a catalyst carrier. .

(Prior Art and Technical Problem of Invention) Hydrogen-type zeolite has an activity as a solid acid, and by utilizing this activity, an alkylation reaction of an aromatic hydrocarbon (for example, Japanese Patent Publication No. 42-3298). ), Alkyl aromatic hydrocarbon isomerization reaction, n-paraffin or n-olefin isomerization reaction, petroleum catalytic cracking, and petroleum heavy oil fraction hydrocracking. It is also known that the above-mentioned hydrogen-type zeolite is used as a carrier and a metal such as Ni, Pd, or Pt supported on the carrier is used for hydrogenation of unsaturated hydrocarbons.

Among the hydrogen-type zeolites, those using zeolite Y as a precursor have a high SiO ₂ / Al ₂ O ₃ ratio, are excellent in heat resistance, acid resistance, hydrothermal resistance, etc., and have a pore size in a range suitable for the reaction. In addition, since it is excellent in caulking resistance, it is particularly suitable for the above field.

A known method for producing hydrogen-type zeolite Y is that the silicic acid content, the alumina content, the sodium content and the water content are zeolite Y.
A step of preparing a composition within a production range and, if necessary, producing zeolite Y in the presence of a mineralizer, and the zeolite Y
Is contacted with an ammonium salt to produce an ammonium-type zeolite, and a step of firing the ammonium-type zeolite to convert it into a hydrogen-type zeolite. Hydrogen-type zeolite Y produced by a known method
Is still unsatisfactory in terms of reaction selectivity and conversion.

For example, the alkylation reaction of an aromatic hydrocarbon will be described as an example. In the case of the known hydrogen-type zeolite Y, when the relationship between the reaction time and the conversion rate is plotted, even if the conversion rate is relatively high in the initial stage of the reaction, However, even if the reaction time is extended, the conversion rate is small and the overall conversion rate tends to be saturated at a relatively low level. In addition to monoalkyl aromatic hydrocarbons, polyalkyl aromatic hydrocarbons and olefin oligomers, as well as by-products such as condensates of aromatic hydrocarbons such as binaphthyl, are generated, and the selectivity of the target product is still low. There is also.

(Summary and Purpose of the Invention) The present inventors have succeeded in synthesizing a hydrogen-type zeolite having a certain acidity by using an acid-treated product of a clay mineral having a layered structure as a silicic acid raw material. Found that the above-mentioned drawbacks found in conventional hydrogen-type zeolites are eliminated.

That is, an object of the present invention is to provide a method for producing a hydrogen-type zeolite in which the above-mentioned drawbacks of the conventional hydrogen-type zeolite are eliminated.

Another object of the present invention is to provide a method for producing a hydrogen-type zeolite having novel properties which is useful as a solid acid catalyst or a catalyst carrier.

Still another object of the present invention is to provide a method capable of advantageously constructing a hydrogen-type zeolite from a clay mineral which is easily obtained as a raw material.

(Structure of the Invention) According to the present invention, a step of preparing a composition having a silicic acid content, an alumina content, a sodium content and a water content in a zeolite Y production range, and producing zeolite Y in the presence of a mineralizer, if necessary. And a step of producing an ammonium-type zeolite by bringing the zeolite Y into contact with an ammonium salt, and a step of calcining the ammonium-type zeolite to convert it into a hydrogen-type zeolite. As active silicic acid or active aluminosilicic acid obtained by acid treatment of a clay mineral having a layered structure is used, the acidity of hydrogen-type zeolite is 0.5 to 1.0 meq / as an acidity of −5.6 or less in Hammett's acid strength function. Provided is a method for producing a hydrogen-type zeolite, which comprises contacting with an ammonium salt and calcining so that the amount falls within the range of g.

(Characteristics and Effects of the Invention) As described above, the present invention uses, as a silicic acid raw material for producing zeolite Y, active silicic acid or active aluminosilicic acid obtained by acid treatment of a clay mineral having a layered structure. Use; The acidity of the hydrogen-type zeolite has a remarkable feature in the combination of the acid strength function of Hammett being controlled to be in the range of 0.5 to 1.0 meq / g as −5.6 or less.

Conventionally, it has already been known to synthesize various zeolites including zeolite Y by using a clay mineral acid-treated product having a layered structure as a silica raw material (for example, British Patent No.
1,062,064, U.S. Pat. No. 3,393,045, and JP-A-52-62314). However, as far as the inventors of the present invention know, no example has been known in which a hydrogen-type zeolite is produced from zeolite Y using a clay acid-treated product as a raw material.

However, according to the present invention, a zeolite Y produced by using the above-mentioned clay acid treated product as a silica raw material is used as a precursor, and this precursor has an acidity of −5.6 or less in the Hammett acid strength function of 0.5 to 1.0 meq / g. The hydrogen-type zeolite obtained by ammonium exchange and calcination exhibits novel characteristics which are not found in the conventional hydrogen-type zeolite using synthetic silicic acid as a raw material, and the hydrogen-type zeolite is The inventors have found that the solid acid catalyst has extremely excellent reaction selectivity and conversion.

Table A below shows a typical example of a hydrogen-type zeolite Y (hereinafter referred to as HY zeolite) that has been conventionally used for alkylation of aromatic hydrocarbons, and a material using an acid-treated product of a smectite group clay as a raw material. Regarding the HY zeolite according to the method of the invention, the relationship between various characteristics, that is, the specific surface area, the pore area, the acidity, and the selectivity and conversion obtained during the alkylation of naphthalene with α-olefin (20 carbon atoms). Indicates.

According to the results in Table A, the hydrogen-type zeolite according to the present invention has a specific surface area,
It is inferior in terms of pore volume and acidity in all respects, and thus is expected to be inferior in performance as a solid acid catalyst. However, according to the present invention, contrary to such prediction, far superior selectivity and conversion ratio can be obtained as compared with the conventional one, which is an unexpected effect of the present invention. Is.

The exact reason for this is unknown, but it is presumed as follows. That is, while the conventional hydrogen-type zeolite causes a side reaction because the acidity is too large, in the hydrogen-type zeolite according to the present invention, the acidity is suppressed to an appropriate range, and this is a suppression of the side reaction. It is estimated that this has a positive effect on the improvement of the conversion rate.

(Description of preferred embodiments of the invention) Raw material clay mineral In the present invention, a clay mineral having a layered structure is used as a silica raw material. As a layered structure of clay minerals, a three-layer structure (smectite) represented by montmorillonite and a two-layer structure represented by kaolin and halloysite are known.

Smectite-type clay minerals are generally based on a three-layer structure in which two tetrahedral layers of SiO ₄ are sandwiched with an AlO ₆ octahedral layer sandwiched therebetween, and this basic three-layer structure is further laminated in the C-axis direction. It has a multi-layered crystal structure. As the smectite group clay mineral, for example, so-called montmorillonite group clay minerals such as acid clay, bentonite, subbentonite, and frass earth, and one kind or a combination of two or more kinds of beidellite, saponite, nontronite and the like are used. These clay minerals may be in the form of a mixture of, for example, a smectite group clay mineral and another clay mineral, and a clay mineral in which the smectite group clay mineral is slightly modified in nature, for example, a crystal in which the multilayer structure of smectite is slightly destroyed. Sanko clay from Shibata City, Niigata Prefecture, which exhibits a structure, can be used for the purpose of the present invention.

On the other hand, the clay mineral having a two-layer structure is basically a two-layer structure composed of the tetrahedral layer of SiO ₄ and the AlO ₆ octahedral layer, and has a layered structure in which the basic structure is laminated in the C-axis direction. ing.
Suitable examples thereof are halloysite and kaolin, the former being capable of being directly acid-treated to produce active silicic acid or active alumino-silicic acid, and the latter being difficult to be directly acid-treated, however, milling and If the crystal structure is destroyed by calcination treatment, activated silicic acid or activated aluminosilicic acid can be produced by acid treatment.

Other examples of clay minerals having a layered structure include attapulgite, palygorskite, and sepiolite, and these clay minerals are composed of octahedral layers of AlO ₆ or MgO ₆ between layers of SiO ₄ tetrahedral layers. Have a structure in which they are intermittently and alternately inserted.

All of these clay minerals have a tetrahedral layer of SiO ₄ ,
It is common in that acid treatment gives active silicic acid or active aluminosilicic acid having a layered silica as a skeleton.

Acid Treatment First, the clay mineral is subjected to an acid treatment under the condition that the X-ray diffraction peak of the surface index [001] disappears, that is, under the condition that at least the multilayer laminated structure of clay is destroyed.

The acid treatment of the smectite group clay mineral can be performed under conditions known per se except that the above-mentioned requirements are satisfied. For example, as the acid, any of mineral acids such as sulfuric acid, hydrochloric acid and nitric acid, and organic acids such as benzenesulfonic acid, toluenesulfonic acid and acetic acid can be used, but mineral acids such as sulfuric acid are generally used. The method of contacting the clay mineral and the acid may be any method, including Japanese Patent Publications No. 28-5666 and 29-
112, 29-2169, 32-2960, 45-11208, 45-11209, 47
Acid treatment of clay minerals disclosed in -44154 and the like is particularly suitable for the present invention. For example, so-called slurry activation method of contacting clay and acid in a slurry state, solid-liquid of granulated clay and acid. A so-called granular activation method of contacting, a so-called dry activation method of reacting a mixture of clay and an acid by a dry method (granular material), and then extracting a basic salt can be applied to the acid treatment of the present invention.

The concentration of acid used for acid treatment, treatment temperature and treatment time are
It varies depending on the type of clay mineral and the acid treatment method, and it is difficult to specify unconditionally, but for example, when acid treatment is performed by a dry method, the basic components in the smectite group clay mineral and clay mineral are 0.3 to 1.5 equivalents, especially 0.4 to 0.9
5 equivalents of an acid or an aqueous solution thereof are uniformly contacted at a ratio of 0.3 to 2.5 parts by weight of the acid or an aqueous solution thereof with respect to 1 part by weight of the clay based on the dry matter of the clay, to obtain plasticity or To form a solid reaction product directly,
Then, the reaction product is treated in an aqueous medium at a pH of 1 or less to extract and remove the basic metal component in the product. The basic metal component to be removed in the clay means the amount of all the basic components such as the alkali metal component, the alkaline earth metal component, the iron component and the aluminum component contained in the clay. By maintaining the liquid ratio of the clay and the acid or the aqueous solution thereof within the above range, the mixture becomes solid or creamy, and the mixture is heated at a temperature in the range of 60 to 300 ° C. for 10 to 600 minutes. Among them, the reaction is completed by maintaining the conditions under which the X-ray diffraction peak of the plane index [001] substantially disappears. Then, the soluble base component in the reaction product was adjusted to pH.
It is extracted and removed by treatment in an aqueous medium having a pH of 1 or less, preferably 0.5 or less. At this time, it is important to extract and remove the soluble base component in the reaction product under the above-mentioned pH conditions in order to prevent the hydrolysis of the base component, and the colloid generated by the hydrolysis in the aluminosilicate component. When iron-like iron is contained, the yield or crystallinity of the synthetic zeolite seems to be considerably lowered.

In order to produce the acid-treated alumino-silicic acid raw material by bringing the granulated clay into solid-liquid contact with a mineral acid, 10
~ 98% concentration of mineral acids, 1: 0.01 to
A non-disintegrating granule is prepared under the conditions of the subsequent acid treatment, which is added in an amount of 1: 0.1 by weight. Then, the non-disintegrating clay granules are immersed in a 5 to 72%, particularly 10 to 50%, aqueous solution of a mineral acid, at room temperature to the boiling point of the solution and 0.5 to 100 hours in the clay. The treatment is performed under the condition that the X-ray diffraction peak of the [001] plane of (1) disappears substantially.

The acid treatment of the clay mineral can be carried out by wet-dispersing the clay in a slurry in a mineral acid such as 5 to 98% sulfuric acid,
The acid treatment conditions in this case can be based on the above-mentioned granular acid treatment.

Thus, activated silicic acid or activated alumino-silicic acid can be obtained by acid treatment of the clay used in the present invention. The smectite group clay mineral or acid-treated product thereof has a particle size of 5 μm or less in an amount of 20% by weight or more, particularly It is possible to adjust the particle size so that the content of 30% by weight or more and the particle size larger than 20μ is smaller than 30% by weight of the whole, particularly smaller than 10% by weight.
It is desirable for facilitating the synthesis of zeolite Y.

Synthesis of Zeolite Y The above-mentioned activated silicic acid or activated alumino-silicic acid, an additional amount of alumina component, sodium content and water are mixed and aged to form a homogeneous composition in which each component is in the zeolite Y forming range.

Examples of the alumina component include amorphous alumina such as aluminum hydroxide hydrogel and xerogel; alumina monohydrate such as boehmite and pseudoboehmite: alumina trihydrate such as vialite, gibbsite and nordstrandite: eg γ, η , Fine powder of activated alumina such as δ, k, θ, χ and ρ type alumina can be used.
Further, sodium hydroxide is particularly preferably used as the sodium content. The alumina component and sodium component are
They may be used in combination in the form of compounds or mixtures, and are preferably used in the form of sodium aluminate. Of course, at this time, if an alumina component or sodium component in excess of sodium aluminate is required, these components can be mixed with sodium aluminate and supplied to the reaction system.

In the present invention, the active aluminosilicic acid content, the additional amount of alumina component, the sodium component and water are mixed in a component ratio known per se. Conventionally, according to a known method, the zeolite Y forming component is used in the following component ratio (on the basis of oxide).

Na ₂ O / SiO ₂ = 0.2 to 1.4 Si ₂ O / Al ₂ O ₃ = 6 to 40 H ₂ O / Na ₂ O = 12 to 90 Generally, an aqueous slurry of activated silicic acid or activated aluminosilicic acid and aluminate are used. It is desirable to mix sodium and an aqueous solution containing sodium to form a slurry having the above composition ratio.

In the present invention, when these samples are mixed, the components in the mixture are gelated to form a heterogeneous slurry. The gelled slurry is thoroughly stirred to obtain a homogenized slurry and then aged. The temperature and time of aging are not particularly limited, but generally 0 to 50 ° C, particularly 10 to
Aging is preferably carried out at a temperature of 30 ° C. for 0.1 to 100 hours, particularly 1 to 50 hours.

Crystallization of zeolite is carried out by maintaining the above-mentioned homogeneous composition at the zeolite crystallization temperature. Generally, when the temperature is low, it takes a long time to crystallize, while when the temperature is high, the primary particle size becomes large, and atmospheric pressure treatment becomes difficult. Therefore, at a temperature of 50 to 100 ° C., A crystallization treatment of 1 to 100 hours is advantageous.

Although not always necessary, in order to improve the yield of zeolite Y and develop its crystal structure, it is preferable to coexist a mineralizer known per se in the crystallization system. As the mineralizer, chlorides, sulfates, nitrates and phosphates of alkali metals, especially sodium are used. The mineralizer may be added at the time of preparing the homogenized composition, or may be added at a stage after aging and before crystallization. The amount of the mineralizer to be added is 0.1 to 2 mole times with respect to the alumina content. The amount should be

The produced zeolite Y is separated from the mother liquor by filtration or the like, washed with water, and then subjected to the next ammonium exchange.

Ammonium exchange treatment The produced zeolite Y was brought into contact with an aqueous solution of ammonium salt, and the final hydrogen type zeolite had a Na ₂ O / Al ₂ O ₃ molar ratio of 0.10.
Ammonium exchange is carried out so that the ratio becomes to 0.40, especially 0.15 to 0.35. When the Na ₂ O / Al ₂ O ₃ molar ratio is out of the above range, effective acid sites are not formed, and the activity as a solid acid catalyst tends to decrease, which is not preferable.

The ammonium exchange treatment is advantageously carried out using an aqueous solution of ammonium chloride, but it can also be carried out using other ammonium salts such as ammonium sulfate. The concentration of ammonium chloride used is generally desired to be in the range of 5 to 150 g /, and the contact between the zeolite and the ammonium chloride solution can be carried out in a single stage or in multiple stages, or continuous contact of both in a countercurrent manner. Alternatively, the ammonium chloride solution may be passed through a column packed with zeolite or a column packed with zeolite.

This exchange treatment is sufficient at room temperature, but it can also be carried out by heating to a temperature up to the boiling point of the liquid.

The zeolite after ammonium exchange is washed with water to remove by-produced salts to obtain ammonium type zeolite.

Firing Treatment According to the present invention, ammonium-type zeolite is fired to be converted into hydrogen-type zeolite.

Incidentally, in order to produce a hydrogen-type zeolite having an acidity in the range according to the present invention, it is essential to use active silicic acid or active aluminosilicic acid by acid treatment of clay mineral, but it is essential to use the above raw materials. It is not possible to obtain the acidity in the desired range, and it is necessary to select certain conditions for the ammonium exchange treatment and the calcination treatment.

Although the conditions for ammonium exchange have already been described, the baking treatment is preferably carried out at a temperature of 380 to 580 ° C., particularly 400 to 550 ° C., for 0.5 to 20 hours, particularly 1 to 10 hours. That is, if the temperature and time are within the above ranges, the ammonium groups are almost completely decomposed and converted into hydrogen-type zeolite. However, when the temperature is higher than the above range and / or the time is longer than the above range, the activity of the solid acid catalyst is likely to decrease. On the other hand, when the temperature is lower than the above range and / or when the time is shorter than the above range, the ammonium group tends to remain without being decomposed into hydrogen form, and an effective acid point may not be formed. .

Application The hydrogen-type zeolite according to the present invention can be used for all solid acid catalysts and catalyst carriers for which hydrogen-type zeolite has been conventionally used, by utilizing the above-mentioned unique properties.

For example, this hydrogen-type zeolite is an alkylation reaction of aromatic hydrocarbons, an isomerization reaction of alkylaromatic hydrocarbons,
It can be used for isomerization reaction of n-paraffin or n-olefin, catalytic cracking of petroleum, and hydrocracking of heavy oil fraction of petroleum. Also, platinum, palladium, iron, cobalt,
It can also be used as a carrier for supporting a hydrogenation catalyst or the like such as nickel or a rare earth element.

This hydrogen-type zeolite can be used in the form of powder having an average particle size of 0.1 to 100 μm, or can be used in the form of granules such as pellets, tablets and extruded granules using various clay binders. . In the latter case, granulation may be carried out in the form of hydrogen-type zeolite, or after granulation is carried out in advance, ammonium exchange and calcination may be carried out.

The invention is illustrated by the following example.

Test Method The test method for each item in this specification was as follows.

(1) Na ₂ O / Al ₂ O ₃ molar ratio and SiO ₂ / Al ₂ O molar ratio Determined by chemical composition analysis. However, the quantification of Al ₂ O ₃ and SiO ₂ is performed by the gravimetric method, and the quantification of Na ₂ O is performed by the atomic absorption method.

(2) Specific surface area and pore volume BET surface area measuring device (P
-600 type) is used for nitrogen gas adsorption measurement. The specific surface area is obtained by the BET one-point method, and the pore volume is obtained from the adsorption amount at saturated vapor pressure.

However, the sample is heated and degassed at 10 ^-2 to 10 ^-3 mmHg and 200 ° C for 2 hours, and then adsorption measurement is performed.

(3) Acidity The acidity of -5.6 or less is measured by the Benesi method with Hammett's acid strength function. All reagents used for the measurement are manufactured by Wako Pure Chemical Industries, Ltd.

(B) Grind in 7 aerial flasks with 50 ml stoppers, which were weighed beforehand, in an agate mortar and crush them with 200 mesh (open eyes 7
4 micron) through a sieve, take about 0.1g each, and
After drying in a thermostatic oven at 00 ° C for 2 hours, the sample is allowed to stand for 15 minutes in a desiccator and weighed. The dry sample weight W (g) is determined from the difference with the weight of the empty Erlenmeyer flask.

(B) Reagent n-butylamine and reagent special grade benzene
A 0.1N n-butylamine benzene solution is prepared and standardized with a 0.1N oxalic acid solution for volumetric analysis to determine the factor f.

(C) The amount V (ml) of the 0.1 Nn-butylamine benzene solution to be added is calculated by the following formula.

Here, A is the amount of n-butylamine per 1 g of dried sample (meq /
g) and A = 0.5n (n = 0,1,2,3,4,5,6).

(D) Special grade benzene reagent is added to the Erlenmeyer flask so that the total amount with V (ml) calculated in (c) is 10 ml, and after stoppering, the sample is dispersed using an ultrasonic cleaner.

(V) Add 0.1N n-butylamine solution of V (ml) calculated in (c) to Erlenmeyer flask, hold down with vinyl tape so that the stopper does not come off, and shake with figure 8 (Tokyo Rika Kikai Co., Ltd.) Fix it to SS-80) and shake at room temperature for 24 hours.

(F) Using a 0.1% benzalacetophenone benzene solution prepared with reagent benzene acetophenone and reagent grade benzene as an indicator of pKa-5.6, add 3 drops to the Erlenmeyer flask after shaking. After plugging and shaking gently, observe the color of the sample surface.

(G) The largest A (meq / g) value among those whose surface is yellow, which is the acidic color of the indicator, is A ₁ (m
eq / g).

(H) Set the number of Erlenmeyer flasks in (a) to 10,
A in (c) is A = A ₁ + 0.05n (n = 0,1,2,3,4,5,
Repeat steps (a) to (f) with exactly the same contents, except for 6,7,8,9).

(I) The largest value of A (meq / g) among the samples whose surface is colored yellow is A ₂ (meq / g), and the acidity of the sample is below 5.6 (meq / g). ) To A ₂ ~ A ₂ +0.05 (me
q / g).

(4) Catalytic activity The catalytic activity was defined as the conversion of olefins and the selectivity to monoalkylnaphthalene in the reaction of alkylating purified naphthalene with 1-icosene.

A 1-four-necked flask equipped with a thermometer, a stirring blade, and an air-cooled tube was charged with 224 g (0.8 mol) of 1-icosene, 205 g (1.6 mol) of purified naphthalene (melting point 79.8 ° C.), and 11.2 g of HY zeolite. Set on the heater. While stirring, the temperature is raised from room temperature to 210 ° C in about 30 minutes. At this point, the reaction temperature is set to 21
Keep the temperature at 0 to 215 ° C and continue the reaction for 6 hours. The obtained reaction mixture is centrifuged at 80 ° C. or higher, and the supernatant is used as a sample for analysis. The unreacted naphthalene content, unreacted olefin content, and monoalkylnaphthalene content in the sample are quantified by gas chromatography, and the olefin conversion rate and the monoalkylnaphthalene selectivity are calculated based on the results.

Example 1 In this example, a case where an HY zeolite is produced by using acid clay from Nakajo Town, Niigata Prefecture as a clay mineral having a layered structure will be described.

The acid clay produced in Nakajo Town, Niigata Prefecture used in this example contains 45% by weight of water in a natural state, and its main components are SiO ₂ 72.1 and Al _{2 in} dry matter reference weight% (110 ° C. dry). O ₃ 14.2, Fe ₂ O
₃ 3.87, MgO 3.25, CaO 1.06, and loss on ignition of 3.15.
This raw material acid clay was molded into a cylindrical shape with a diameter of 5 mm and a length of 5 to 20 mm, and an amount equivalent to 76.5 g in terms of dry matter was sampled in a 500 ml conical beaker, and a 50 wt% concentration sulfuric acid solution was added to it.
After adding 200 ml and heating at 90 ° C. for 20 hours for acid treatment, the mother liquor was separated by decantation and then washed with water until the sulfate radicals disappeared to obtain a granular acid-treated product of activated aluminosilicate. Next, the obtained granules are wet-milled in an aqueous medium using a ball mill, and the coarse particles are removed through a 200 mesh (mesh opening = 74 micron) sieve to remove the coarse particles. An aluminosilicate slurry was obtained. (First Step) Table B shows the chemical composition of the obtained activated aluminosilicate based on a 110 ° C. dried product, and Table C shows the particle size distribution by the sedimentation method.

In 378 g of the above activated aluminosilicate slurry, 96.5 g of sodium aluminate solution (containing 23.2 wt% of Al ₂ O _{3 and} 18.7 wt% of Na ₂ O), 90.8 g of sodium hydroxide solution (containing 37.0 wt% of Na ₂ O) and 140 g of water. Mix the diluted solution and mix at room temperature for 48 hours.
After stirring for an hour, the reaction vessel was sealed and left standing in a water bath at 95 ° C for 48 hours for crystallization. Subsequently, the solid was separated by suction filtration and washed with water until the pH of the washing liquid became 10.5.
The product obtained was analyzed by X-ray diffraction and chemical composition analysis.
It was confirmed to be sodium type zeolite Y (hereinafter referred to as Na—Y zeolite) having a SiO ₂ / Al ₂ O ₃ molar ratio of 3.79.
(Second step) 50 g of the above Na-Y zeolite (converted at 110 ° C dry matter) to 53.5 g /
Disperse in 1000 ml of concentrated ammonium chloride solution at 80 ℃
After stirring for 3 hours, the mixture was filtered with suction and washed with 1000 ml of water. After repeating the ion exchange operation with a 53.5 g / concentration ammonium chloride solution three times, water washing was performed until chlorine ions were no longer detected in the washing solution, and the obtained ammonium-type zeolite Y (hereinafter referred to as NH ₄ -Y zeolite)
Was dried at 110 ° C. for 20 hours. (Third Step) Finally, 30 g of the above NH ₄ —Y zeolite was placed in an alumina dish and calcined in an electric furnace at 450 ° C. for 5 hours to be converted into HY zeolite. (Fourth Step) The physical properties of the obtained HY zeolite are shown in Table G, and the results of the catalytic activity test are shown in Table H.

Example 2 In this example, acid white clay from Odo, Shibata City, Niigata Prefecture was used to produce H
The case where -Y zeolite is manufactured will be described.

The main components of the acid clay from Odo, Shibata City, Niigata Prefecture used in this example are SiO ₂ 74.6 and Al ₂ O in terms of dry matter reference weight% (110 ° C. dry).
₃ 14.1, Fe ₂ O ₃ 2.99, MgO 1.84, CaO 1.77, ignition loss 4.
It was 65. This raw acid clay was treated by the method described in the first step of Example 1 to obtain an active aluminosilicate slurry having an average particle size of 5.9 microns and a concentration of 27.4% by weight. (First Step) Table D shows the chemical composition of the obtained activated aluminosilicate based on a 110 ° C dried product, and Table E shows the particle size distribution by the sedimentation method.

To the active aluminosilicate slurry 390 g, sodium aluminate solution (Al ₂ O ₃ 23.2 wt%, Na ₂ O 18.7 wt% content) 79.4 g sodium hydroxide solution (Na ₂ O 37.0 wt% content) in 113g water 210g The diluted solutions were mixed and stirred at room temperature for 5 hours, 12.2 g of sodium chloride was added, and the mixture was stirred for 20 hours in a water bath at 95 ° C for crystallization. After suction filtration, washing with water was carried out until the pH of the washing solution reached 10.5. The obtained product was analyzed by X-ray diffraction and chemical composition analysis to obtain SiO ₂ / Al ₂ O ₃
It was confirmed to be Na-Y zeolite with a molar ratio of 3.90. (Second step) 50 g of the above Na-Y zeolite (converted at 110 ° C dry matter) to 53.5 g /
The mixture was dispersed in 1000 ml of a concentrated ammonium chloride solution, stirred at room temperature for 20 hours, suction-filtered, and washed with 1000 ml of water. After repeating the ion exchange operation with a 53.5 g / concentration ammonium chloride solution three times, water washing was performed until chlorine ions were not detected in the washing solution, and the obtained NH ₄ -Y
The zeolite was dried at 110 ° C for 20 hours. (Third Step) Finally, 30 g of the above NH ₄ —Y zeolite was placed in an alumina dish and calcined in an electric furnace at 450 ° C. for 5 hours to be converted into HY zeolite. (Fourth step) Physical properties of the obtained HY zeolite are shown in Table F, and catalytic activity test results are shown in Table G.

As a comparative example, a case where the ion exchange conditions are changed (Comparative Example 1) and a case where the firing conditions are changed (Comparative Example 2) will be described.

Comparative Example 1 In this comparative example, the Na-Y zeolite obtained in the second step of Example 2 was used. In Comparative Example 1-1, Na-Y zeolite 50
g (110 ° C. dry matter conversion) was dispersed in 1000 ml of a 26.8 g / concentration ammonium chloride solution, and the ion exchange operations of stirring, suction filtration, and washing with water at room temperature for 20 hours were performed only once, and Comparative Example 1-
In 2, Na-Y zeolite 50g (110 ℃ dry matter conversion) 53.5
Disperse in 1000 ml of g / concentration ammonium chloride solution,
Ion exchange operations such as stirring at ℃ for 3 hours, suction filtration, and washing with water
I repeated it. Finally, in each case, washing with water was performed until chlorine ions were no longer detected in the washing solution, the resulting NH ₄ -Y zeolite was dried at 110 ° C for 20 hours, and then 30 g was calcined in an electric furnace at 450 ° C for 5 hours to produce HY. Converted to zeolite.

Comparative Example 2 In this Comparative Example, the NH ₄ —Y zeolite obtained in the third step of Example 2 was used. 30 g of NH ₄ -Y zeolite was placed in an alumina dish and fired in an electric furnace at 350 ° C. for Comparative Example 2-1 and 600 ° C. for Comparative Example 2-2 for 5 hours to convert it into HY zeolite.

Physical properties of the HY zeolites obtained in Comparative Example 1 and Comparative Example 2 are shown in Table F, and catalytic activity test results are shown in Table G.

From the above results, it is understood that the acidity is low and the conversion rate in the catalytic reaction is low when the ion exchange conditions and the firing conditions are not properly selected.

Example 3 A case will be described in which the activated aluminosilicate slurry obtained in the first step of Example 2 is used as a raw material to produce HY zeolite by another method.

To 390 g of the activated aluminosilicate slurry obtained by the method shown in the first step of Example 2, 61.3 g of sodium aluminate solution (containing 23.2% by weight of Al ₂ O _{3 and} 18.7% by weight of Na ₂ O) and sodium hydroxide solution. A solution obtained by diluting 136 g (containing 37.0% by weight of Na ₂ O) in 154 g of water was mixed and stirred until uniform. The reaction mixture was allowed to stand at room temperature for 20 hours, 11.6 g of sodium chloride was added, and the mixture was stirred in a water bath at 95 ° C for 20 hours for crystallization. After suction filtration, washing with water was carried out until the pH of the washing solution reached 10.5. The resulting product is to be a Na-Y zeolite of SiO ₂ / Al ₂ O ₃ molar ratio 4.20 was confirmed by X-ray diffraction and chemical composition analysis.

The Na-Y zeolite was converted to an HY zeolite using the method shown in the third and fourth steps of Example 2.

The physical properties of the obtained HY zeolite are shown in Table F, and the catalytic activity test results are shown in Table G.

Next, for comparison, a case of using sodium silicate as a silicic acid content raw material (Comparative Example 3) and a case of using an aqueous colloidal silica sol (Comparative Examples 4 and 5) will be described.

Comparative Example 3 No. 3 sodium silicate solution (SiO ₂ 21.5 wt% Na ₂ O 0.70
51.2 g of sodium aluminate solution (Al ₂ O ₃ 22.9 wt%, Na ₂ O 18.4 wt% contained) and sodium hydroxide solution (Na ₂ O 37.0 wt% contained) in a solution obtained by diluting 512 g of water into 1060 g of water. ) Mix a solution of 236 g diluted with 1093 g of water,
After standing still at room temperature for 24 hours, the reaction vessel was sealed and left standing in a water bath at 95 ° C for 40 hours for crystallization. After suction filtration, washing was carried out with water until the pH of the washing solution became 10.5. The resulting product is to be a Na-Y zeolite of SiO ₂ / Al ₂ O ₃ molar ratio 3.65 was confirmed by X-ray diffraction and chemical composition analysis. This Na-Y zeolite was used in the third step of Example 2 and the fourth step.
It was converted to an HY zeolite using the method shown in step.

The physical properties of the obtained HY zeolite are shown in Table F, and the catalytic activity test results are shown in Table G.

Comparative Example 4 667 g of commercially available aqueous colloidal silica sol (containing Snowtex 30, SiO ₂ 30.0% by weight of Nissan Chemical Industries, Ltd.) and sodium aluminate solution (Al ₂ O ₃ 22.9% by weight, Na ₂ O 18.4% by weight).
52.4 g (containing wt%) and sodium hydroxide solution (Na ₂ O 37.0
(Containing wt.%) 250 g and a solution diluted with 346 g of water are mixed,
After stirring at room temperature for 48 hours, the reaction vessel was sealed and left standing in a water bath at 95 ° C for 24 hours for crystallization. After suction filtration, washing with water was carried out until the pH of the washing solution reached 10.5. The resulting product is to be a Na-Y zeolite of SiO ₂ / Al ₂ O ₃ molar ratio 3.97 was confirmed by X-ray diffraction and chemical composition analysis.
This Na-Y zeolite was converted to an H-Y zeolite using the method shown in the third and fourth steps of Example 2.

The physical properties of the obtained HY zeolite are shown in Table F, and the catalytic activity test results are shown in Table G.

Comparative Example 5 667 g of a commercially available aqueous colloidal silica sol (containing Snowtex 30, SiO ₂ 30.0 wt% manufactured by Nissan Chemical Industries, Ltd.) was added to a sodium aluminate solution (Al ₂ O ₃ 22.9 wt%, Na ₂ O 18.
45.0% by weight) and 55.0 g of sodium hydroxide solution (Na ₂ O 37.
A solution obtained by diluting 200 g (containing 0% by weight) with 188 g of water was mixed, stirred at room temperature for 48 hours, sealed with a reaction vessel, and allowed to stand in a water bath at 95 ° C for 24 hours for crystallization. After suction filtration, washing with water was carried out until the pH of the washing solution reached 10.5. The obtained product is SiO ₂ / Al ₂ by X-ray diffraction and chemical composition analysis.
It was confirmed O ₃ is Na-Y zeolite in a molar ratio 4.76. 50 g of this Na-Y zeolite (converted to 110 ° C dry matter)
Dispersed in 1000 ml of 3.5 g / concentration ammonium chloride solution, in Comparative Example 5-1, ion exchange operations of stirring, suction filtration and washing with water at room temperature for 20 hours were performed only once, and in Comparative Example 5-2.
The ion exchange operations of stirring at 80 ° C. for 3 hours, suction filtration, and washing with water were repeated 5 times. In each case, the product was finally washed with water until no chlorine ions were detected in the washing solution, and the obtained NH ₄ -Y
After drying the zeolite at 110 ℃ for 20 hours, 30 g of 550 ℃
In an electric furnace for 3 hours for conversion into HY zeolite.

The physical properties of the obtained HY zeolite are shown in Table F, and the catalytic activity test results are shown in Table G.

From the results of Comparative Example 3 and Comparative Example 4, Na- having an apparently similar SiO ₂ / Al ₂ O ₃ molar ratio in that the silicic acid raw materials were different.
It is understood that, even though Y zeolite is used as a precursor, the physical properties of the H-Y zeolite produced are greatly changed and the desired catalytic activity is not exhibited. Further, it is said that the SiO ₂ / Al ₂ O ₃ molar ratio of HY zeolite generally used as a catalyst is preferably as large as possible in view of high hydrothermal stability and acid resistance. However, from the results of Comparative Example 5, SiO ₂ / Al ₂ using silica gel as the silicic acid raw material was used.
Even in HY zeolite having a relatively large O ₃ molar ratio,
Catalytic activity compared to HY zeolite by the method of the present invention,
It is understood that it is inferior in terms of selectivity.

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Claims (1)

[Claims] 1. A step of preparing a composition in which a silicic acid content, an alumina content, a sodium content and a water content are in a zeolite Y production range and, if necessary, producing zeolite Y in the presence of a mineralizer, and the zeolite Y A method for producing a hydrogen-type zeolite comprising a step of producing an ammonium-type zeolite by contacting with an ammonium salt and a step of calcining the ammonium-type zeolite to convert it into a hydrogen-type zeolite, wherein a clay having a layered structure as a silicic acid content raw material. Using activated silicic acid or activated alumino-silicic acid obtained by acid treatment of minerals, the acidity of hydrogen-type zeolite is in the range of 0.5 to 1.0 meq / g as the acidity of -5.6 or less in Hammett's acid strength function. As described above, a method for producing a hydrogen-type zeolite, which comprises contacting with an ammonium salt and calcining.