JP5399658B2 - Method for producing artificial zeolite - Google Patents

Description

  The present invention relates to a zeolite and a method for producing a zeolite used as a solid acid catalyst.

  Zeolites have been used for the adsorption and separation of various substances. Furthermore, the catalytic function as a solid acid is also known. Recently, a specific zeolite is used for decomposing nitrogen oxides (NOx) into nitrogen and oxygen. For example, nitrogen oxides formed in an internal combustion engine are decomposed and processed by a catalyst before a gas containing such nitrogen oxides is released to the atmosphere.

  Furthermore, the zeolite known as ZSM-5 is well-known as a highly functional solid acid catalyst and has a catalytic function that effectively promotes chemical reactions such as hydrocarbon isomerization, alkylation and catalytic cracking of hydrocarbons. Is known.

  However, since these zeolites are relatively expensive, an inexpensive method for obtaining them has been demanded. In response to such problems, the present inventors have also proposed a method for producing artificial zeolite using slag as a raw material in Japanese Patent Application Laid-Open No. 2000-335916 (Patent Document 1).

At present, there is a demand for effective use of waste palms. At present, it is reused as a raw material for products such as blocks, tiles, and building materials. It is used. For this reason, there has been a demand for an effective utilization method unique to such an abandoned lion.
JP 2000-335916 A

  An object of the present invention is to provide a method for obtaining a high-value zeolite by effectively using an insulator as a raw material.

  In order to solve the above-mentioned problems, the method for producing an artificial zeolite of the present invention is characterized in that, as described in claim 1, the waste sawdust is melted at a high temperature, then rapidly cooled and pulverized, and then heat-treated in an alkaline aqueous solution. And an artificial zeolite production method.

  Further, the method for producing an artificial zeolite of the present invention is the method for producing an artificial zeolite according to claim 1, wherein the silicon in the raw material is heated before the heat treatment in the alkaline aqueous solution. It has the process of adjusting the ratio of atomic abundance and aluminum atom abundance.

  Moreover, the manufacturing method of the artificial zeolite of this invention is the manufacturing method of the artificial zeolite of Claim 1 or Claim 2 as described in Claim 3, and the said heat processing is the temperature over 100 degreeC under pressure. It is performed.

  Moreover, the manufacturing method of the artificial zeolite of this invention is the manufacturing method of the artificial zeolite of any one of Claim 1 thru | or 3 as described in Claim 4, The melting of the said insulator waste material is a plasma furnace. Is performed.

  Moreover, the manufacturing method of the artificial zeolite of this invention is the manufacturing method of the artificial zeolite of any one of Claim 1 thru | or 4 as described in Claim 5. It is characterized by being introduced in water.

  According to the method for producing an artificial zeolite of the present invention, a useful zeolite can be efficiently obtained by effectively utilizing the waste insulator by making full use of its characteristics.

  According to the method for producing artificial zeolite described in claim 2, various types of zeolite can be obtained.

  According to the method for producing artificial zeolite according to claim 3, the zeolite can be efficiently obtained in a short time.

  According to the method for producing an artificial zeolite described in claim 4, the zeolite can be obtained more easily.

  According to the method for producing an artificial zeolite according to claim 5, it is possible to simply, easily and surely perform quenching to make vitreous, and to obtain zeolite with higher yield. .

  In the present invention, the waste insulator may be a general one containing silicon such as for high-voltage power transmission or general power transmission. In these cases, metal fittings or the like are bonded with cement or the like as an adhesive, or sulfur or the like may be applied, but those other than such insulators are removed in advance, and dirt and the like are removed in advance. It is preferable. However, since organic substances and the like are removed by high-temperature treatment, it is possible not to remove these deposits depending on the type of deposits.

  The insulator waste material may be used as it is when it is melted in a large furnace at the time of melting, but is usually pulverized to about 0.01 m to 5 m.

  Basically, these waste insulators are sufficient as a silicon source, but the waste insulator contains aluminum, and depending on the composition of the zeolite to be produced, there may be too little or too much aluminum. For this reason, waste optical fiber or fine silicon dioxide powder waste (white soot) generated in the optical fiber manufacturing process by the soot method, etc. Used) as a silicon feedstock (silicon-containing inorganic compound) or used as an aluminum feedstock such as coal ash, waste porcelain pulverized product, ceramic pulverized product, porcelain pulverized product, aluminum dross, waste metal aluminum, etc. It can mix | blend and use as (aluminum-containing inorganic compound). When a silicon-containing inorganic compound and an aluminum-containing inorganic compound described later are added at the time of melting, the size is approximately the same as that of the insulator waste material.

  In the case of raw materials other than these insulators, those that are not crystallized or those that are small in size may be finely divided as necessary, and added and blended after melting and cooling the insulator waste material. . That is, there may be a step of adjusting the ratio of the silicon atom existing amount and the aluminum atom existing amount in the raw material before the heat treatment in the alkaline aqueous solution.

  Here, in addition to adjusting the ratio of the silicon atom abundance and the aluminum atom abundance in the raw material by adding other materials to the insulator waste material as described above, the insulator waste material or the insulator waste material was melted and rapidly cooled. For example, it is possible to adjust the components of the silicon atom abundance and the aluminum atom abundance using an acid such as hydrochloric acid, and both of them can be used in combination.

  In this way, a silicon-containing inorganic compound and / or an aluminum-containing inorganic compound (these are also referred to as auxiliary materials) are added to the above-mentioned insulator waste material or to a material obtained by melting and rapidly cooling insulator waste material, By adjusting the number of aluminum atoms in the raw material to 1 or more and 5 or less when the number of aluminum atoms in the material is 1, the efficiency of general zeolite can be improved. It is desirable to obtain it. In addition, in order to obtain a zeolite which is a highly functional solid acid catalyst such as ZSM-5, the caivan ratio is 7.5 or more, preferably 5000 or more.

  Although the insulator waste material can be melted by a general heating means, it is desirable to use a plasma furnace in consideration of the heating efficiency and the time required for melting. Examples of the plasma furnace include an oxygen plasma furnace, an air plasma furnace, an argon plasma furnace, and the like, but it is desirable that the air plasma furnace be low in operating cost and remove the influence of organic substances attached to the raw material.

  The heating temperature and the heating time at the time of melting need to be a temperature at which the insulator waste material and the auxiliary material are completely melted. If the melting is not complete, crystals of these raw materials remain, and the yield and yield in the next step (heat treatment in an alkaline aqueous solution) are significantly reduced. Usually, it is 1300-1500 degreeC or more and 2000 degrees C or less although it depends also on the insulator waste material to be used.

  In the present invention, it is necessary to quench the melt after melting. By this rapid cooling, a glassy crushed material is obtained. As the rapid cooling, it is preferable to introduce a melt into water in view of cost, safety, ease of process and device design, and the like. Here, when the rapid cooling is not sufficient, that is, when the cooling is slow, crystals are formed, and as a result, the yield and yield in the next step (heat treatment in an alkaline aqueous solution) are significantly reduced.

  Due to the rapid cooling, the melt becomes a glassy solid and at the same time becomes finer. However, in order to increase the reaction rate in the heat treatment in the alkaline aqueous solution, further miniaturization is performed as necessary. It is desirable that the particle size be 0.1 μm or more and 0.1 mm or less.

  From the glassy raw material thus obtained, the silicon component and the aluminum component are eluted in the solution by the heat treatment with the alkaline aqueous solution as the next step, and zeolite is formed from these two components.

  The alkali metal component used in the alkaline aqueous solution and its ionic radius (which may involve the radius of the hydrated ion) affect the pore size of the resulting zeolite. Sodium and / or potassium hydroxide is used. At this time, high reactivity and low cost can be achieved.

  Alkali metals in aqueous alkali solutions can also react to extract silicon and aluminum components from the raw material in the reaction in the solution to form a three-dimensional skeleton consisting of a silicon / oxygen tetrahedral structure and an aluminum / oxygen tetrahedral structure. And

  The reaction temperature is preferably 60 ° C. or higher, more preferably 100 ° C. or higher and 250 ° C. or lower in order to increase the reaction rate. If it is lower than 100 ° C., the heat treatment time becomes longer and it becomes impractical. On the other hand, if it is 250 ° C. or higher, the cost for the apparatus becomes too large. Further preferable treatment temperature is 140 ° C. or higher and 180 ° C. or lower. Generally, as the processing temperature increases, the particle size of the resulting zeolite increases.

  In the heat treatment in an alkaline aqueous solution in the present invention, in order to obtain a general zeolite, the type of zeolite to be obtained can be selected by controlling the Keiban ratio, but a high-functionality such as ZSM-5 can be selected. To obtain a zeolite that can be used as a solid acid catalyst, a template agent is used in combination. Here, when the template agent is used together in this way, the optimal concentration of alkali metal in the aqueous alkali solution may differ from the case where the template agent is not used. Determine the alkali concentration.

  The template agent plays an important role in determining the shape and size of the pores of the solid acid catalyst. That is, the solid skeleton of the solid acid catalyst mainly composed of a silicon / oxygen tetrahedral structure and an aluminum / oxygen tetrahedral structure is formed so as to surround the template agent. Therefore, selection of the shape and size of the template agent is important.

Here, in the present invention, a quaternary ammonium salt or a combination of compounds forming a quaternary ammonium salt-like steric structure is used as the template agent. As such, a compound represented by the following chemical formula 1,
A compound represented by the following chemical formula 2, a compound represented by the chemical formula R ₈ X (wherein R ₈ is an alkyl group, X is a halide ion or a hydroxide ion), and a compound represented by the chemical formula R ₁₄ COR ₁₅ (formula Wherein R ₁₄ and R ₁₅ are alkyl groups)
In the formula, R _{5 to} R ₇ are compounds represented by an alkyl group chemical formula R ₉ NHR ₁₀ (wherein R ₉ and R ₁₀ are alkyl groups), chemical formula R ₁₁ X (wherein R ₁₁ is an alkyl group, X is a halide ion) Or a hydroxide ion) and a compound B represented by the chemical formula R ₁₄ COR ₁₅ (wherein R ₁₄ and R ₁₅ are alkyl groups), or a compound represented by the chemical formula NH ₂ R ₁₂ (Wherein R ₁₃ is an alkyl group) and a compound represented by the chemical formula R ₁₄ COR ₁₅ (wherein R ₁₄ and R ₁₅ are alkyl groups), chemical formula R ₁₃ X (wherein R ₁₃ is an alkyl group, X is a halogen) And a combination C with a compound represented by the chemical formula R ₁₄ COR ₁₅ (wherein R ₁₄ and R ₁₅ are alkyl groups).

Here, quaternary ammonium salt or quaternary ammonium salt-like structure is used so that the solid acid catalyst obtained is free from defects in the three-dimensional skeleton mainly composed of silicon / oxygen tetrahedral structure and aluminum / oxygen tetrahedral structure. It is desirable that the combination of compounds forming a three-dimensional structure forms a regular tetrahedral structure. Therefore, when the above combination A is used as the template agent, R _{5 to} R ₈ are all the same alkyl groups. In addition, since the catalytic function of the resulting solid acid catalyst is improved, the number of carbon atoms of such an alkyl group is preferably 2 or more and 5 or less.

Similarly, when the above combination B is used as the template agent, R _{9 to} R ₁₁ are preferably the same alkyl group, and the carbon number of these alkyl groups is preferably 2 or more and 5 or less. The compounding ratio of the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula R ₈ X is preferably 1: 2 or the vicinity thereof.

Further, when the above combination C is used as the template agent, R ₁₂ and R ₁₃ are preferably the same alkyl group, and the carbon number of these alkyl groups is preferably 2 or more and 5 or less. The compounding ratio of the compound represented by the chemical formula NH ₂ R ₁₂ and the compound represented by the chemical formula R ₁₃ X is preferably 1: 3 or the vicinity thereof.

In the method for producing an artificial zeolite of the present invention, in the combinations A to C, a compound represented by the chemical formula R ₁₄ COR ₁₅ (wherein R ₁₄ and R ₁₅ are alkyl groups), so-called ketones, is blended.

Here, R ₁₄ and R ₁₅ are preferably the same, and more preferably the same as the alkyl group of the amine used in combination AC.

  These ketones are usually blended so that the weight of silicon in the raw material in the blend is 1 to 0.01 or more and 5 or less. If the amount is less than 0.01, the reaction is delayed and the yield tends to be low, and if it exceeds 5, a reaction between organic compounds, that is, a side reaction occurs, the raw material is wasted, or a solid acid catalyst is generated. There is also the possibility of inhibiting the reaction.

  In the present invention, any one of the above-mentioned template agents (one combination) is usually used, but two or more of these may be used in combination.

  These template agents are usually blended so as to be 0.1 or more and 0.5 or less with respect to the silicon weight of the raw material in the blend being 1. If the blending amount is less than 0.1, the reaction is delayed and the yield tends to be low, and if it exceeds 0.5, a reaction between organic compounds, that is, a side reaction occurs, and the template agent is not used effectively. There is a possibility that it will be wasted or the solid acid catalyst formation reaction may be hindered. A preferable range is 0.15 or more and 0.45 or less.

In order to obtain a zeolite that can be used as a highly functional solid acid catalyst such as ZSM-5, together with the above template agent, a compound represented by the chemical formula R ₁₄ COR ₁₅ (wherein R ₁₄ and R ₁₅ are alkyl groups), You may mix | blend what is called ketones.
Here, R ₁₄ and R ₁₅ may be the same, and the number of carbon atoms is preferably 2 or more and 10 or less. Examples of such ketones include diethyl ketone.

  These ketones are usually blended so that the weight of silicon in the raw material in the blend is 1 to 0.01 or more and 5 or less. If the amount is less than 0.01, the reaction is delayed and the yield tends to be low, and if it exceeds 5, a reaction between organic compounds, that is, a side reaction occurs, the raw material is wasted, or a solid acid catalyst is generated. There is also the possibility of inhibiting the reaction.

  In the method for producing an artificial zeolite of the present invention, the template and the ketones are added as necessary depending on the raw materials (melted and quenched pulverized product, auxiliary raw materials as required) and the target zeolite, React with.

  The water in the aqueous solution is sufficient so that the reaction solution can be stirred well. If the water is too large, the reaction rate will be slow, and if it is small, the stirring will not be sufficient and the reaction will be uneven.

  A solid skeleton composed mainly of silicon / oxygen tetrahedral structure and aluminum / oxygen tetrahedral structure of the solid acid catalyst can be formed by putting these raw materials in a closed container (reaction container) and reacting them by heating. it can.

  This heating reaction time is determined in advance by examination. For example, in the treatment at 140 ° C., it is usually about 30 minutes or more and several hours, generally longer when the temperature is low, and shorter when the temperature is high.

  After the heat treatment is completed, usually after cooling, the reaction product is taken out from the reaction vessel, and if necessary, washed with water, alcohol or the like as appropriate and then dried.

  When the reaction is carried out in combination with the template agent, the template agent is incorporated in the crystal lattice of the zeolite, and this template agent can be removed or carbonized depending on the application.

  In order to remove the template agent, heat treatment is performed in an oxygen-containing atmosphere to oxidize and remove.

  At this time, a template agent in a three-dimensional skeleton mainly composed of a silicon / oxygen tetrahedral structure and an aluminum / oxygen tetrahedral structure formed by heat treatment in an alkaline aqueous solution is used as oxygen in the atmosphere (for example, oxygen gas in the air). ) Is removed by oxidation. For example, it is performed at 500 ° C. or higher. Although the skeleton has high heat resistance, it is usually performed at 600 ° C. or lower due to cost factors.

  In addition, in the case of zeolite with low heat resistance, such as when the Keiban ratio is low, the template can be removed by wet oxidation using an oxidizing agent such as 30% hydrogen peroxide.

  Depending on the application, the template agent can be carbonized by heating in a non-oxidizing atmosphere.

  Examples of the present invention will be specifically described below.

<Example 1>
As insulator waste material, insulators for high-voltage power transmission (metal fittings, cement, dirt and other deposits removed) were used. It grind | pulverized so that a particle size might be about 2-4 mm. The cayban ratio of this product was 2.9.

Subsequently, 10 kg of the pulverized insulator waste was heated to 1600 ° C. in an air plasma type plasma furnace and sufficiently melted. This melt was dropped into water at room temperature (about 1 m ³ ) from the furnace bottom opening provided at the bottom of the plasma furnace and quenched.

  The obtained melt-quenched material is pulverized by quenching, and the particle size is 2 mm to 5 mm. This is a pulverizer manufactured by Hosokawa Powder Research Laboratory so that the particle size is about 1 μm and the average particle size is 40 μm. And a rapidly pulverized product A was obtained.

  The quenched pulverized product A was added to 4 kg and a 2.5 mol / L sodium hydroxide aqueous solution was made into a slurry and added to such an extent that it could be sufficiently stirred, followed by heat treatment.

  Specifically, it was kept at 160 ° C. using a pressure vessel and reacted for 2 hours while stirring.

  The obtained reaction product α was sufficiently washed with water and dried to find 3.8 kg.

  Further, the obtained reaction product α was subjected to X-ray diffraction analysis. The result is shown in FIG. It was confirmed from FIG. 1 that the reaction product α obtained was Na-P1 type zeolite. A scanning electron micrograph of the reactant α is shown in FIG.

<Example 2>
To 100 g of the rapidly pulverized product A, 50 g of waste optical fiber (quartz glass) was added to make the cayban ratio 5.2. This mixture was reacted in an aqueous sodium hydroxide solution in the same manner as in Example 1 to obtain 140 g of the reaction product β.

  Further, X-ray diffraction analysis was performed on the obtained reaction product β. The results are shown in FIG. The reaction product obtained from FIG. 2 was confirmed to be a faujasite type zeolite. A scanning electron micrograph of the reactant β is shown in FIG.

<Example 3>
40 g of the rapidly pulverized product A in Example 1 and 4 kg of the pulverized optical fiber as a silicon-containing inorganic compound were mixed to obtain a mixed raw material having a Keiban ratio of 103.

  As the template agent, tetrapropylammonium bromide was used and heat treatment was performed with an alkaline aqueous solution.

  An alkaline solution in which 3 kg of tetrapropylammonium bromide and 400 g of sodium hydroxide were dissolved in 75 kg of water was added to the above mixed raw material, charged in a pressure vessel, and kept at 160 ° C. for 2 hours with stirring.

  The sample obtained after 2 hours was filtered and dried to give 4 kg of reaction product γ. X-ray diffraction analysis of the obtained reaction product γ was performed. The results are shown in FIG. The result of FIG. 5 agreed with the analysis result in ZSM-5, and it was confirmed that the obtained reaction product γ was a ZSM-5 type zeolite. A scanning electron micrograph of the reaction product γ is shown in FIG.

<Example 4>
200 g of the rapidly pulverized product A in Example 1 was sufficiently washed with 6 mol / L hydrochloric acid and then washed with water to obtain an acid-washed product B. This acid washed product B had a Keiban ratio of 100.

  After adding 37 g of tetrapropylammonium bromide and 5 g of sodium hydroxide in 1 g of water to 50 g of this acid-washed product B, the mixture was charged into a pressure vessel and then stirred at 160 ° C. for 2 hours. Kept.

  The sample obtained after 2 hours was filtered and dried to yield 50 g of reaction product δ. X-ray diffraction analysis of the obtained reaction product δ was performed. The result was the same as FIG. 5, and it was confirmed that the obtained reaction product δ was a ZSM-5 type zeolite.

FIG. 3 is a diagram showing a diffraction analysis result of the zeolite obtained in Example 1. 2 is a scanning electron micrograph showing the zeolite obtained in Example 1. FIG. FIG. 4 is a diagram showing a diffraction analysis result of the zeolite obtained in Example 2. 3 is a scanning electron micrograph showing the zeolite obtained in Example 2. FIG. FIG. 4 is a diagram showing a diffraction analysis result of the zeolite obtained in Example 3. 3 is a scanning electron micrograph showing the zeolite obtained in Example 3. FIG.

Claims (5)

  A method for producing an artificial zeolite, comprising melting an insulator waste material at a high temperature, rapidly cooling and pulverizing, and then heat-treating in an alkaline aqueous solution.   The method for producing an artificial zeolite according to claim 1, further comprising a step of adjusting a ratio of a silicon atom existing amount and an aluminum atom existing amount in the raw material before the heat treatment in the alkaline aqueous solution. .   The method for producing an artificial zeolite according to claim 1 or 2, wherein the heat treatment is performed at a temperature exceeding 100 ° C under pressure.   The method for producing an artificial zeolite according to any one of claims 1 to 3, wherein the insulator waste material is melted in a plasma furnace.   The method for producing an artificial zeolite according to any one of claims 1 to 4, wherein the rapid cooling is performed by introducing molten insulator waste into water.