WO2022196043A1

WO2022196043A1 - Method for producing zeolite

Info

Publication number: WO2022196043A1
Application number: PCT/JP2022/000346
Authority: WO
Inventors: 悠哉池原; 啓介田中; 昌義村上; 航平関
Original assignee: 住友化学株式会社
Priority date: 2021-03-17
Filing date: 2022-01-07
Publication date: 2022-09-22
Also published as: TW202244003A; JP2022142840A

Abstract

The present invention further improves the selectivity of ε-caprolactam.　This method is for producing zeolite and comprises steps (1)-(5).　Step (1): A step for mixing tetraalkyl orthosilicate, water, and a hydroxylated quaternary ammonium to obtain a mixture. Step (2): A step for, while causing the mixture obtained in step (1) to undergo a hydrothermal synthesis reaction, supplying, to the mixture, at least one compound (A) selected from the group consisting of boron compounds, germanium compounds, magnesium compounds, aluminum compounds, tin compounds, and iron compounds to obtain a reaction mixture containing zeolite crystals. Step (3): A step for performing solid-liquid separation on the reaction mixture containing zeolite crystals obtained in step (2), to obtain zeolite crystals. Step (4): A step for sintering the zeolite crystals obtained in step (3). Step (5): A step for bringing the zeolite crystals sintered in step (4) into contact with an aqueous solution containing at least one acid selected from the group consisting of inorganic acids and organic acids to obtain zeolite.

Description

Method for producing zeolite

The present invention relates to a method for producing zeolite. The present invention also relates to a method for producing ε-caprolactam using the zeolite as a catalyst.

Nylon 6 is used as a fiber material for clothing, as well as a resin material for automobile parts and electronic parts. As a method for producing ε-caprolactam, which is particularly useful as a raw material for nylon 6, a method is known in which zeolite is used as a catalyst and cyclohexanone oxime undergoes a Beckmann rearrangement reaction in the gas phase to produce ε-caprolactam. .

Regarding the zeolite used as a catalyst in such a method for producing ε-caprolactam, the activity as a catalyst is further increased, and as a result, the conversion rate of cyclohexanone oxime is improved, and further the selectivity of ε-caprolactam is improved. , various studies have been made.

Specifically, for example, for the purpose of reacting cyclohexanone oxime at a high conversion rate and obtaining it at a high selectivity, the zeolite crystals obtained by the hydrothermal synthesis reaction are contact-treated with an aqueous solution containing a predetermined acid. A method for producing zeolite is known (see Patent Document 1).

JP 2017-30986 A

However, even with the zeolite produced by the technique according to Patent Document 1, it is difficult to say that the catalytic activity such as ε-caprolactam selectivity is sufficient.

Therefore, an object of the present invention is to provide a method for producing zeolite that can further improve the selectivity of ε-caprolactam in the production of ε-caprolactam using the Beckmann rearrangement reaction.

The present inventors have made intensive studies to achieve the above object, and found that the above object can be achieved by supplying predetermined components while hydrothermally synthesizing raw materials in a method for producing zeolite. and completed the present invention.

That is, the present invention provides the following [1] to [8].
[1] A method for producing zeolite, comprising the following steps (1) to (5).
Step (1):
A step of mixing a tetraalkyl orthosilicate, water, and a quaternary ammonium hydroxide to obtain a mixture Step (2):
At least one compound (A) selected from the group consisting of a boron compound, a germanium compound, a magnesium compound, an aluminum compound, a tin compound and an iron compound is added while the mixture obtained in the step (1) is subjected to a hydrothermal synthesis reaction. supplying to the mixture to obtain a reaction mixture containing zeolite crystals Step (3):
A step of solid-liquid separation of the reaction mixture containing the zeolite crystals obtained in the step (2) to obtain zeolite crystals Step (4):
Step (5) of calcining the zeolite crystals obtained in step (3):
Step [2] of obtaining zeolite by contact-treating the zeolite crystals calcined in step (4) with an aqueous solution containing at least one acid selected from the group consisting of inorganic acids and organic acids; In the above, the method for producing a zeolite according to [1], wherein an inorganic acid is further supplied to obtain a reaction mixture.
[3] The method for producing zeolite according to [2], wherein in the step (2), the compound (A) and the inorganic acid are supplied simultaneously to obtain a reaction mixture.
[4] Any one of [1] to [3], wherein in the step (2), the compound (A) is supplied to the mixture 1 to 6 hours after the start of the hydrothermal synthesis reaction. of the zeolite.
[5] The zeolite according to any one of [1] to [4], wherein in step (1), the molar ratio of the amount of water to the amount of tetraalkyl orthosilicate is 18 to 36. manufacturing method.
[6] Production of zeolite according to any one of [1] to [5], wherein in the step (2), the reaction temperature when hydrothermally synthesizing the mixture is 105° C. to 170° C. Method.
[7] In the step (2), the reaction temperature after supplying the compound (A) to the mixture is further increased from the reaction temperature before supplying the compound (A) to perform a hydrothermal synthesis reaction. The method for producing zeolite according to [6], which is allowed to proceed.
[8] A method for producing ε-caprolactam, comprising the following steps (1) to (6).
Step (1):
A step of mixing a tetraalkyl orthosilicate, water, and a quaternary ammonium hydroxide to obtain a mixture Step (2):
At least one compound (A) selected from the group consisting of a boron compound, a germanium compound, a magnesium compound, an aluminum compound, a tin compound and an iron compound is added to the mixture while hydrothermally reacting the mixture obtained in step (1). to obtain a reaction mixture containing zeolite crystals Step (3):
A step of solid-liquid separation of the reaction mixture containing the zeolite crystals obtained in the step (2) to obtain zeolite crystals Step (4):
Step (5) of calcining the zeolite crystals obtained in step (3):
A step of contact-treating the zeolite crystals calcined in step (4) with an aqueous solution containing at least one acid selected from the group consisting of inorganic acids and organic acids to obtain zeolite; step (6):
A step of obtaining ε-caprolactam by Beckmann rearrangement reaction of cyclohexanone oxime in a gas phase using the zeolite obtained in step (5) as a catalyst.

According to the method for producing zeolite according to the present invention, it is possible to efficiently produce zeolite from which ε-caprolactam can be obtained with high selectivity.

The embodiments according to the present invention will be specifically described below. The present invention is not limited to the specific embodiments shown below, and can be modified as appropriate without departing from the scope of the present invention.

1. Zeolite The zeolite according to the present embodiment can function as a catalyst in the production of ε-caprolactam.

First, the zeolite produced by the method for producing zeolite according to the embodiment of the present invention will be described.

In this embodiment, the zeolite contains elemental silicon and elemental oxygen as elements constituting its skeleton.

In the present embodiment, the zeolite may be crystalline silica whose framework is substantially composed of only silicon and oxygen elements, and may be a crystalline metallosilicate containing other elements as elements constituting the framework. good too.

　Crystalline metallosilicates include, for example, aluminosilicates and titanosilicates. In this embodiment, the zeolite may contain two or more of these.

The zeolite that can be produced by the zeolite production method of the present embodiment is preferably zeolite having a pentasil structure.

Examples of pentasil-type structures indicated by the structural codes of zeolite structures include ABW, ACO, AEI, AEL, AEN, AET, AFG, AFI, AFN, AFO, AFR, AFS, AFT, AFX, AFY, AHT, ANA, APC, APD, AST, ATN, ATO, ATS, ATT, ATV, AWO, AWW, BEA, BIK, BOG, BPH, BRE, CAN, CAS, CFI, CGF, CGS, CHA, CHI, CLO, CON, CZP, DAC, DDR, DFO, DFT, DOH, DON, EAB, EDI, EMT, EPI, ERI, ESV, EUO, FAU, FER, GIS, GME, GOO, HEU, IFR, ISV, ITE, JBW, KFI, LAU, LEV, LIO, LOS, LOV, LTA, LTL, LTN, MAZ, MEI, MEL, MEP, MER, MFI, MFS, MON, MOR, MSO, MTF, MTN, MTT, MTW, MWW, NAT, NES, NON, OFF, OSI, PAR, PAU, PHI, RHO, RON, RSN, RTE, RTH, RUT, SAO, SAT, SBE, SBS, SBT, SFF, SGT, SOD, STF, STI, STT, TER, THO, TON, TSC, VET, VFI, VNI, VSV, WEI, WEN, YUG, ZON. Also, the pentasil-type structure may include a structure consisting of a combination of two or more of these.

The zeolite produced by the production method of the present embodiment is preferably zeolite having an MFI structure. The zeolite structure can be analyzed, for example, using an X-ray diffractometer.

2. Method for producing zeolite The method for producing zeolite according to the present embodiment includes the following steps (1) to (5).
Step (1):
A step of mixing a tetraalkyl orthosilicate, water, and a quaternary ammonium hydroxide to obtain a mixture Step (2):
At least one compound (A) selected from the group consisting of a boron compound, a germanium compound, a magnesium compound, an aluminum compound, a tin compound and an iron compound is added while the mixture obtained in the step (1) is subjected to a hydrothermal synthesis reaction. supplying to the mixture to obtain a reaction mixture containing zeolite crystals Step (3):
A step of solid-liquid separation of the reaction mixture containing the zeolite crystals obtained in the step (2) to obtain zeolite crystals Step (4):
Step (5) of calcining the zeolite crystals obtained in step (3):
A step of contact-treating the zeolite crystals calcined in the step (4) with an aqueous solution containing at least one acid selected from the group consisting of inorganic acids and organic acids to obtain zeolite.

Each of steps (1) to (5) will be specifically described below.

(i) step (1)
Step (1) is a step of mixing tetraalkyl orthosilicate, water, and quaternary ammonium hydroxide to obtain a mixture.

Examples of tetraalkyl orthosilicate in step (1) include tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate.

In step (1), the tetraalkyl orthosilicate is preferably tetraethyl orthosilicate. In the present embodiment, as the tetraalkyl orthosilicate, the above examples may be used alone, or two or more thereof may be used.

From the viewpoint of improving the activity of the catalyst, the "water" used in the present embodiment is preferably water whose purity has been increased by, for example, removing impurities through a predetermined treatment. Examples of "water" in the present embodiment include distilled water, ion-exchanged water, and ultrapure water. In the present embodiment, it is preferable to use ion-exchanged water as "water".

The quaternary ammonium hydroxide used in step (1) can function as a structure directing agent. Here, the structure-directing agent is a component that contributes to the formation of the zeolite structure.

In this embodiment, the structure-directing agent can form a precursor of the zeolite structure by organizing polysilicate ions and polymetallosilicate ions around it (Science and Engineering of Zeolite, Kodansha Scientific, 2000). , p.33-34.). Examples of the quaternary ammonium hydroxide used in step (1) include compounds represented by the following formula (I).
R ¹ R ² R ³ R ⁴ N ⁺ OH ⁻ (I)

In formula (I), R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group, alkenyl group, aralkyl group or aryl group.
R ¹ , R ² , R ³ and R ⁴ may be the same or different.

Examples of alkyl groups represented by R ¹ , R ² , R ³ or R ⁴ in formula (I) include methyl, ethyl, propyl and butyl groups. The alkyl group represented by R ¹ , R ² , R ³ or R ⁴ is preferably a propyl group.

In formula (I), the alkenyl group represented by R ¹ , R ² , R ³ or R ⁴ includes vinyl group, allyl group, 1-propenyl group and isopropenyl group. Examples of the aralkyl group represented by R ¹ , R ² , R ³ or R ⁴ include benzyl group and tolylmethyl group. Examples of the aryl group represented by R ¹ , R ² , R ³ or R ⁴ include phenyl group and tolyl group.

Tetraalkylammonium hydroxide is preferable as the quaternary ammonium hydroxide represented by formula (I). Tetraalkylammonium hydroxides include, for example, tetramethylammonium hydroxide, tetraethyl hydroxide, tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, triethylmethylammonium hydroxide, tri-n-hydroxide Examples include propylmethylammonium and tri-n-butylmethylammonium hydroxide. The quaternary ammonium hydroxide is preferably tetra-n-propylammonium hydroxide.

The mixture obtained in step (1) may be mixed with components other than tetraalkyl orthosilicate, water and quaternary ammonium hydroxide.

Such other components include, for example, basic compounds such as sodium hydroxide and potassium hydroxide, and silicon compounds other than tetraalkyl orthosilicate such as silica, in order to adjust the hydroxide ion concentration in the mixture. It may be added, and it is preferable to add a basic compound.

When adding a tetraalkylammonium hydroxide as the quaternary ammonium hydroxide, a tetraalkylammonium salt such as a tetraalkylammonium bromide may be added to adjust the tetraalkylammonium ion concentration in the mixture. good.

The amount of water contained in the mixture obtained in step (1) is preferably 5 mol or more and 100 mol or less, more preferably 10 mol or more and 60 mol or less, per 1 mol of silicon element contained in the mixture.

The amount of the quaternary ammonium ion contained in the mixture is preferably 0.1 mol or more and 0.6 mol or less, more preferably 0.2 mol or more and 0.5 mol or less per 1 mol of silicon element contained in the mixture. is.

The amount of hydroxide ions contained in the mixture is preferably 0.01 mol or more and 0.6 mol or less, more preferably 0.05 mol or more and 0.5 mol or less per 1 mol of silicon element contained in the mixture. is.

In step (1), the amount of tetraalkyl orthosilicate contained in the mixture is the ratio of the amount of water to the amount of tetraalkyl orthosilicate (water/tetraalkyl orthosilicate (molar ratio)) from the viewpoint of catalyst particle size. is preferably 10 to 40, more preferably 18 to 36.

If the amount of each component contained in the mixture is within the above range, a zeolite having excellent catalytic activity can be obtained, and by using the zeolite as a catalyst, cyclohexanone oxime can be reacted at a high conversion rate. Thus, ε-caprolactam can be obtained with higher selectivity, and ε-caprolactam can be produced with higher productivity.

(ii) step (2)
In the step (2), while the mixture obtained in the step (1) is hydrothermally synthesized, at least one selected from the group consisting of a boron compound, a germanium compound, a magnesium compound, an aluminum compound, a tin compound and an iron compound. This is a step of supplying compound (A) to a mixture to obtain a reaction mixture containing zeolite crystals.

Specifically, the hydrothermal synthesis reaction in step (2) is a reaction in which a compound is synthesized (crystals are grown) under heating and pressure to form a reaction mixture containing zeolite crystals.

In the step (2), the reaction temperature for hydrothermally synthesizing the mixture obtained in the already explained step (1) is preferably 100° C. to 200° C., more preferably 100° C. to 200° C., from the viewpoint of catalyst crystallinity. 105°C to 170°C.

In the hydrothermal synthesis reaction of step (2), the reaction temperature after supplying the compound (A) to the mixture is further increased from the reaction temperature before supplying the compound (A) to a higher temperature to hydrothermally It is preferable to allow the synthesis reaction to proceed. In this case, the range of temperature rise is preferably 20°C to 80°C, more preferably 35°C to 65°C.

If the reaction temperature after supplying the compound (A) to the mixture is further raised from the reaction temperature before supplying the compound (A) as described above to proceed with the hydrothermal synthesis reaction, hydrothermal synthesis The reaction rate of the reaction can be further improved, and as a result, the zeolite of the present embodiment can be produced more efficiently. In addition, by using the zeolite produced in this manner as a catalyst, cyclohexanone oxime can be reacted at a higher conversion rate, and the yield of ε-caprolactam can be improved.

In step (2), the time for subjecting the mixture to the hydrothermal synthesis reaction, ie, the reaction time, is preferably 1 to 200 hours, more preferably 1 to 100 hours, from the viewpoint of catalyst crystallinity.

In step (2), the time for hydrothermal synthesis reaction after supplying compound (A) to the mixture is preferably 1 to 200 hours, more preferably 10 to 100 hours, from the viewpoint of catalyst crystallinity. .

In the hydrothermal synthesis reaction of step (2), the hydrothermal synthesis reaction is preferably performed under pressure, and the pressure is preferably 0.1 MPa or more and 5 MPa or less from the viewpoint of hydrothermal reactivity. More preferably, the pressure is 2 MPa or more and 3 MPa or less.

In step (2), if the reaction temperature, reaction time and pressure are within the above ranges, a zeolite having excellent catalytic activity can be produced, and by using the zeolite as a catalyst, cyclohexanone oxime can be converted to a higher degree ε-caprolactam can be obtained with high selectivity.

In the step (2), the hydrothermal synthesis reaction method is not particularly limited. In the hydrothermal synthesis reaction, for example, the mixture obtained in step (1) is placed in a reaction vessel such as an autoclave to be airtight, and the reaction temperature, reaction time and pressure are set to the conditions described above and stirred. can be implemented by

In the present embodiment, in step (2), the mixture obtained in step (1) is hydrothermally synthesized, and selected from the group consisting of a boron compound, a germanium compound, a magnesium compound, an aluminum compound, a tin compound and an iron compound. At least one compound (A) is supplied to the mixture to further advance the hydrothermal synthesis reaction.

In step (2), the timing of adding compound (A) is not particularly limited as long as the hydrothermal synthesis reaction is in progress. The timing of adding the compound (A) is preferably 1 to 10 hours after the start of the hydrothermal synthesis reaction from the viewpoint of catalyst crystallinity, and 1 to 6 hours after the start of the hydrothermal synthesis reaction. It is more preferable to have

In the step (2), the amount of the metal element contained in the compound (A) is, from the viewpoint of catalyst crystallinity, the amount of the compound (A) relative to the amount of the orthosilicic acid contained in the mixture obtained in the step (1). The amount of tetraalkyl (tetraalkyl orthosilicate/compound (A) (molar ratio)) is preferably 10 to 100,000, more preferably 15 to 50,000, and more preferably 20 to 10,000. It is even more preferable to

In the step (2), examples of the boron compound that is the compound (A) include boric acid, ammonium borate, ammonium tetrafluoroborate, lithium metaborate, lithium tetraborate, lithium tetrafluoroborate, and sodium metaborate. , sodium tetraborate, sodium perborate, sodium tetrahydroborate, sodium tetraethylborate, sodium tetraphenylborate, sodium tetrafluoroborate, potassium metaborate, potassium tetraborate, potassium pentaborate, tetrafluoroborate potassium borate, calcium borate, magnesium borate, zinc borate, trimethyl borate, trimethylene borate, triethyl borate, tetrafluoroboric acid, tri-n-butyl borate, triisopropyl borate, triethanolamine borate, Nitrosyl tetrafluoroborate can be mentioned. As the boron compound that is the compound (A), boric acid, trimethyl borate, or triethyl borate is preferably used, and boric acid is more preferably used.

In step (2), the germanium compound that is the compound (A) includes, for example, germanium oxide, germanium chloride, germanium bromide, germanium iodide, tetraethylgermanium, tetramethylgermanium, and tetraisopropoxygermanium. Germanium oxide is preferably used as the germanium compound that is the compound (A).

Examples of the magnesium compound that is the compound (A) in step (2) include magnesium nitrate, magnesium sulfite, magnesium benzoate, magnesium chloride, magnesium perchlorate, magnesium peroxide, magnesium glutamate, magnesium silicide, and silicic acid. magnesium, magnesium acetate, magnesium oxide, magnesium bromide, magnesium hydroxide, magnesium carbonate, magnesium nitride, magnesium diboride, magnesium tetraborate, magnesium fluoride, magnesium iodide, magnesium sulfide, magnesium sulfate, magnesium hydrogen sulfate, Magnesium thiosulfate, magnesium phosphate, magnesium arsenate, magnesium bicarbonate and magnesium metasilicate. As the magnesium compound that is the compound (A), magnesium nitrate, magnesium sulfate or magnesium chloride is preferably used, and magnesium nitrate or magnesium sulfate is more preferably used.

In the step (2), examples of the aluminum compound that is the compound (A) include aluminum nitrate, aluminosilicate, sodium aluminate, strontium aluminate, aluminum antimonide, aluminum monochloride, aluminum monofluoride, aluminum chloride, Aluminum permanganate, aluminum formate, aluminum silicate, aluminum oxide, aluminum hydroxide, aluminum bromide, aluminum dodecaboride, aluminum hydride, lithium aluminum hydride, aluminum borohydride, aluminum carbonate, aluminum nitride, tetra Sodium hydridoaluminate, aluminum diboride, aluminum arsenide, aluminum fluoride, aluminum monostearate, aluminum iodide, aluminum sulfide, aluminum sulfate, aluminum phosphide and aluminum phosphate. As the aluminum compound which is the compound (A), aluminum nitrate, aluminum chloride or aluminum phosphate is preferably used, and aluminum nitrate or aluminum chloride is more preferably used.

In the step (2), the tin compound that is the compound (A) includes, for example, tin (II) chloride, tin (IV) chloride, triphenyltin chloride, triphenyltin acetate, indium tin oxide, and tin (II) oxide. , tin(IV) oxide, tributyltin oxide, stanines, stanols, tetramethyltin, tributyltin, tin(IV) fluoride, tin iodide and tin sulfide. As the tin compound that is the compound (A), tin (IV) chloride, tin iodide or tin oxide is preferably used, and tin (IV) chloride or tin iodide is more preferably used.

In the step (2), the iron compound as the compound (A) includes, for example, iron nitrate, iron (II) chloride, iron (III) chloride, iron ammonium citrate, chromite, iron (II) acetate, iron oxide (II), iron (III) oxide, iron (II) cyanide, iron oxalate, triiron tetroxide, iron tetraboride, iron (III) bromide, iron (II) nitrate, iron (III) nitrate, iron (II) hydroxide, sucroferric oxyhydroxide, iron (II) carbonate, iron nitride, iron (II) lactate, iron (II) iodide, iron iodate, iron (II) sulfide, iron (III) sulfide, Ammonium iron(II) sulfate, iron(II) sulfate, iron(III) sulfate, iron(III) ammonium sulfate, iron(II) phosphate and iron(III) phosphate. As the iron compound which is the compound (A), iron (II) nitrate, iron (III) nitrate or iron (II) sulfate is preferably used, and iron (II) nitrate or iron (III) nitrate is more preferably used. preferable.

In step (2), as the compound (A) of boron compound, germanium compound, magnesium compound, aluminum compound, and tin compound iron compound, the above examples may be used alone, or two or more of them may be used. good.

In step (2), hydrates such as magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, and iron nitrate nonahydrate may be used as compound (A).

In step (2), boric acid, magnesium nitrate, aluminum nitrate, and iron nitrate are preferably used as compound (A) because ε-caprolactam can be obtained with high selectivity. It is more preferable to use boric acid, magnesium nitrate, and iron nitrate because they can improve the conversion rate, the selectivity of ε-caprolactam, and thus the yield.

In step (2), examples of the combination of the compounds (A) described above include a combination of boric acid and magnesium nitrate, a combination of ammonium borate and magnesium phosphate, sodium tetraborate and magnesium chloride. , sodium perborate and magnesium sulfate, and potassium pentaborate and magnesium thiosulfate. As the combination of the above exemplified compound (A), a combination of boric acid and magnesium nitrate, a combination of ammonium borate and magnesium phosphate, or a combination of sodium tetraborate and magnesium chloride is preferable. A combination of acid and magnesium nitrate is more preferred.

In step (2), from the viewpoint of increasing the metal content in the catalyst, it is preferable to further supply an inorganic acid to obtain a reaction mixture.

In this case, step (2) is preferably a step of simultaneously supplying compound (A) and an inorganic acid to obtain a reaction mixture.

(iii) step (3)
Step (3) is a step of subjecting the reaction mixture containing zeolite crystals obtained in step (2) to solid-liquid separation to obtain zeolite crystals.

In step (3), methods for solid-liquid separation of the reaction mixture containing the zeolite crystals obtained in step (2) include, for example, concentration, filtration, and decantation. In step (3), the solid-liquid separation method is preferably filtration.

As a filtration method, it is preferable to apply a membrane separation method using a microfiltration membrane (MF membrane) or an ultrafiltration membrane (UF membrane) as a filtration membrane. As the MF membrane or UF membrane, an MF membrane or UF membrane having an appropriate pore size made of any conventionally known suitable material can be used.

The filtration method may be a cross-flow method or a dead end filtration method. The method of filtration is preferably a cross-flow method from the viewpoint of performing filtration (washing) simply and efficiently.

In addition, the filtration method may be an external pressure filtration method or an internal pressure filtration method. Filtration may be either pressure filtration or suction filtration, and pressure filtration is preferred.

The pressure in filtration can be set as appropriate, and it may be either constant flow rate filtration in which the flow rate of the filtrate is kept constant or constant pressure filtration in which the transmembrane differential pressure is kept constant.

In the cross-flow method, the reaction mixture (slurry liquid to be treated) flows parallel to the surface of the filtration membrane (filtration membrane surface) to prevent contamination of the filtration membrane due to deposition of filter cake on the filtration membrane surface. A part of the reaction mixture is filtered laterally in the direction of flow of the reaction mixture.

The temperature of the reaction mixture during solid-liquid separation is preferably 0°C or higher and 160°C or lower, and the pressure applied to the reaction mixture during solid-liquid separation is preferably 0.1 MPa or higher and 5 MPa or lower.

In addition, in the solid-liquid separation in step (3), it is not necessary to remove all the dissolved components and solvent in the reaction mixture.

In step (3), the liquid obtained by solid-liquid separation usually contains silicic acid and its oligomers, which are active ingredients. It may also contain unreacted quaternary ammonium hydroxide and the like. Therefore, the liquid material obtained by solid-liquid separation in step (3) can be fed back to step (1) already explained in another reaction system and recycled. That is, the liquid material obtained by solid-liquid separation in step (3) can be mixed and used as a further raw material (active ingredient) in step (1) in another reaction system.

After the solid-liquid separation, residual components other than the zeolite crystals remaining in the obtained zeolite crystals may be removed by further washing with an organic solvent such as methanol or ethanol or water.

Examples of the washing treatment method include (a) a method of adding water to the obtained zeolite crystals and washing and filtering by a cross-flow method, and (b) adding water to the obtained zeolite crystals and performing a dead end filtration method. and (c) a method of mixing the obtained zeolite crystals with water, stirring the mixture, allowing the mixture to stand, and separating and removing the supernatant liquid by decantation. Among these methods (a) to (c), the method (a) is preferably adopted because the washing can be performed simply and efficiently.

As a method of washing and filtering when performing washing and filtration, it is preferable to adopt the membrane separation method using the MF membrane or UF membrane already explained. The washing filtration method may be an external pressure filtration method or an internal pressure filtration method. Washing filtration may be either pressure filtration or suction filtration, but pressure filtration is preferred. The pressure in the washing filtration can be set as appropriate, and may be constant flow filtration in which filtration is performed while maintaining a constant flow rate of the filtrate or constant pressure filtration in which filtration is performed while maintaining a constant transmembrane pressure.

Since the cleaning solution obtained by the cleaning treatment, particularly the cleaning solution in the initial stage of cleaning, may contain silicic acid, its oligomers, quaternary ammonium hydroxide, etc. as active ingredients, the resulting cleaning solution is treated in another reaction system. It may be recycled by feeding back to step (1) and mixed for use as a further component.

The temperature of the cleaning liquid during cleaning is preferably 0°C or higher and 100°C or lower, and the pressure applied during cleaning is preferably 0.1 MPa or higher and 5 MPa or lower. In the washing treatment, the zeolite crystals and the washing solution do not necessarily need to be completely separated. For example, after the washing treatment is performed using a cross-flow filtration facility, they may be concentrated and recovered as a slurry. The washing treatment is preferably carried out so that the pH of the washing liquid obtained after washing the zeolite crystals by adding water is 7 or more and 9 or less at 25°C.

The obtained zeolite crystals may be dried by a drying treatment. A drying method in the drying treatment is not particularly limited. As a drying method, any suitable conventional drying method commonly used in this technical field can be employed. Such drying methods include, for example, evaporation to dryness, spray drying, drum drying, and flash drying. Drying conditions in these drying methods can be appropriately set according to a conventional method.

(iv) step (4)
Step (4) is a step of firing the zeolite crystals obtained in step (3).

In step (4), the zeolite crystals obtained by performing step (3) already described are fired.

Firing in step (4) is usually performed in an oxygen-containing gas atmosphere. Examples of the oxygen-containing gas that can be used include air and a mixed gas of air and nitrogen. Also, before or after firing in an oxygen-containing gas atmosphere, firing in an inert gas atmosphere such as nitrogen gas may be further performed.

Specifically, the firing in step (4) can be, for example, a step of first firing in a nitrogen gas atmosphere (under circulation) and then further firing in an air atmosphere (under circulation). .

In step (4), the firing temperature is preferably 400°C or higher and 600°C or lower, more preferably 500°C or higher and 600°C or lower. The firing time is preferably 0.5 hours or more and 12 hours or less, more preferably 1 hour or more and 6 hours or less.

(v) step (5)
Step (5) is a step of contact-treating the zeolite crystals fired in step (4) with an aqueous solution containing at least one acid selected from the group consisting of inorganic acids and organic acids to obtain zeolite.

Step (5) is a step for removing unnecessary elements derived from the compound (A), such as boron, germanium, magnesium, aluminum, tin, and iron elements incorporated in the zeolite crystals. is.

In step (5), "contact-treating the zeolite crystals with an aqueous solution" means bringing the zeolite crystals into contact with an acid-containing aqueous solution by any conventionally known contact treatment method.

Examples of contact treatment include a mode in which the zeolite crystals are immersed in an aqueous solution, and a mode in which the zeolite crystals are sprayed with a misty aqueous solution. Since the contact treatment is simple, it is preferable to immerse the zeolite crystals in an aqueous solution.

Examples of inorganic acids that can be contained in the aqueous solution used in step (5) include nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid.

Examples of organic acids that can be contained in the aqueous solution used in step (5) include formic acid, acetic acid, propionic acid, benzoic acid, citric acid, oxalic acid, terephthalic acid, and p-toluenesulfonic acid.

In step (5), the inorganic acid and the organic acid may be used singly or in combination of two or more.

Also, in step (5), the inorganic acid and the organic acid can be used as an aqueous solution containing only one of them, or can be used as an aqueous solution containing both.

In step (5), the at least one acid selected from the group consisting of inorganic acids and organic acids is preferably an inorganic acid, more preferably nitric acid, phosphoric acid, hydrochloric acid, sulfuric acid, or carbonic acid. More preferably, nitric acid or phosphoric acid is used.

The hydrogen ion concentration in at least one acid selected from the group consisting of inorganic acids and organic acids that can be contained in the aqueous solution is preferably 0.001 mol/L or more and 20 mol/L or less, more preferably 0.01 mol/L. It is more than 10 mol/L or less.

In step (5), per equivalent of at least one compound (A) selected from the group consisting of boron compounds, germanium compounds, magnesium compounds, aluminum compounds, tin compounds and iron compounds in the fired zeolite crystals, It is preferable to carry out the contact treatment by adding an aqueous solution containing 1 equivalent or more and 100 equivalents or less of at least one acid selected from the group consisting of inorganic acids and organic acids.

In addition, the aqueous solution used in step (5) may contain at least one acid selected from the group consisting of inorganic acids and organic acids, as well as salts such as ammonium nitrate, ammonium chloride, ammonium sulfate and ammonium carbonate. .

In the contact treatment in step (5), the temperature of the zeolite crystals is preferably 0°C or higher and 100°C or lower, more preferably 45°C or higher and 95°C or lower.

In the contact treatment in step (5), by setting the temperature of the zeolite crystals within the above range, a zeolite with excellent catalytic activity can be obtained, and by using the zeolite as a catalyst, a higher conversion rate of cyclohexanone oxime can be obtained. can be reacted to obtain ε-caprolactam with higher selectivity, and ε-caprolactam can be produced with higher productivity.

In the contact treatment in step (5), the zeolite crystals may be subjected to contact treatment under pressurized conditions, and the pressure when pressurized is preferably 0.1 MPa or more and 5 MPa or less.

The treatment time for the contact treatment in step (5) is preferably 0.1 hours or more and 100 hours or less, more preferably 0.1 hours or more and 10 hours or less.

Here, the contact treatment in step (5) may be performed batchwise or continuously. The contact treatment in step (5) may be carried out, for example, by immersing the calcined zeolite crystals in an aqueous solution in a stirring tank and stirring the aqueous solution in a tubular container filled with the calcined zeolite crystals. You can let me go.

When the contact treatment in step (5) is performed batchwise, the same contact treatment may be repeated one or more times after solid-liquid separation. When the contact treatment is further repeated one or more times, the number of contact treatments is preferably 1 or more and 10 or less.

In the contact treatment in step (5), the amount of the aqueous solution used is preferably 80 parts by mass or more and 5000 parts by mass or less with respect to 100 parts by mass of the fired zeolite crystals.

The treated material subjected to the contact treatment in step (5) can be obtained as zeolite by, for example, concentration, filtration, and solid-liquid separation by decantation (drying step 1).

It is preferable that the temperature of the treated material be 0°C or higher and 160°C or lower when performing solid-liquid separation after the contact treatment in step (5).

When performing solid-liquid separation after the contact treatment in step (5), the solid-liquid separation may be performed under pressurized conditions. It is preferable that the pressure applied to the material to be treated in the solid-liquid separation is 0.1 MPa or more and 5 MPa or less. Solid-liquid separation may not completely remove unnecessary components such as an aqueous solution contained in the processed material.

After the contact treatment and solid-liquid separation in step (5), in order to remove as much as possible residual components other than zeolite remaining in the obtained zeolite, an organic solvent such as methanol or ethanol or water is used. Additional cleaning treatments may be performed.

The temperature of the zeolite in the further washing treatment is preferably 0°C or higher and 100°C or lower.

In addition, the zeolite may be washed under pressurized conditions for further washing treatment. It is preferable that the pressure under the pressurization condition is 0.1 MPa or more and 5 MPa or less. In further washing treatments, the zeolite-containing washing liquid may not be completely removed.

The zeolite obtained by performing step (5) may be further dried (drying step 2). A drying method in this drying treatment is not particularly limited. Examples of the drying method include conventionally known arbitrary and suitable methods such as an evaporation drying method, a spray drying method, a drum drying method, and a flash drying method. Moreover, the drying conditions in this drying treatment can be appropriately set according to a conventional method.
By carrying out the steps (1) to (5) as described above, the zeolite of the present embodiment can be produced.

According to the method for producing zeolite of the present embodiment, particularly in step (2), the compound (A) is supplied while the hydrothermal synthesis reaction is in progress, and the hydrothermal synthesis reaction is further advanced to obtain ε-caprolactam. can be produced with a very high selectivity.

3. Method for producing ε-caprolactam In the method for producing ε-caprolactam of the present embodiment, the steps (1) to (5) already described are performed, and the zeolite obtained in step (5) is used as a catalyst to produce cyclohexanone oxime. is subjected to a Beckmann rearrangement reaction in the gas phase to obtain ε-caprolactam (6).

Further, in the method for producing ε-caprolactam of the present embodiment, zeolite produced by the method for producing zeolite including the steps (1) to (5) already described is prepared, and the zeolite is used as a catalyst to produce cyclohexanone oxime. may be a method for producing ε-caprolactam, in which ε-caprolactam is obtained by Beckmann rearrangement reaction in the gas phase.

That is, in the step (6), the zeolite produced by the zeolite production method including the steps (1) to (5) is used as a catalyst to cause the Beckmann rearrangement reaction of the raw material cyclohexanone oxime in the gas phase. and as a result, ε-caprolactam can be produced.

The zeolite of the present embodiment can be used as a compact molded into a predetermined size and shape according to the size and shape of the reaction vessel used for producing ε-caprolactam.

The zeolite of the present embodiment (hereinafter, when referred to as zeolite, may also include zeolite crystals in the middle of production) can be formed by any conventionally known suitable method such as extrusion, compression, tableting, flow, tumbling, or spraying. It can be performed by a suitable molding method.

The zeolite can be formed into any desired and suitable shape, such as spherical, cylindrical, plate-like, ring-like, clover-like, and granular shapes, by the forming method exemplified above.

The zeolite molding may be performed after the step (3) already explained, may be performed after the step (4), or may be performed after the step (5).

Further, when cleaning treatment is performed in step (3), molding may be performed after cleaning treatment. The molded body may be further subjected to a contact treatment with, for example, water vapor in order to improve the mechanical strength of the molded body.

The compact may consist essentially of zeolite alone, or may contain other components in addition to zeolite. That is, the molded body may be, for example, a molded body obtained by substantially molding only zeolite, or may be a molded body obtained by mixing zeolite with other components such as a predetermined binder and reinforcing material. may be a shaped body in which zeolite is supported on a predetermined carrier.

The reaction temperature in the Beckmann rearrangement reaction in step (6) is preferably 250°C or higher and 500°C or lower, more preferably 300°C or higher and 450°C or lower.

The reaction pressure in the Beckmann rearrangement reaction in step (6) is preferably 0.005 MPa or more and 0.5 MPa or less, more preferably 0.005 MPa or more and 0.2 MPa or less.

Step (6) may be carried out in a fixed bed format or in a fluidized bed format. In the step (6), the supply rate of the vaporized cyclohexanone oxime is 0.1 h ^-1 or more for 20 h at the supply rate (unit: g/h) per 1 g of the catalyst, that is, the space velocity WHSV (unit: h ^-1 ). ⁻¹ or less, and more preferably 0.2 h ⁻¹ or more and 10 h ⁻¹ or less.

Cyclohexanone oxime, for example, may be introduced into the reaction system alone in a gas phase, or may be introduced together with an inert gas such as nitrogen gas, argon gas, or carbon dioxide gas. Further, as disclosed in JP-A-2-250866, a method of introducing cyclohexanone oxime in the gas phase in the presence of ether, and as disclosed in JP-A-2-275850, cyclohexanone oxime is introduced in the gas phase in the presence of a lower alcohol, as disclosed in JP-A-5-201965, cyclohexanone oxime in the gas phase in the presence of an alcohol and/or ether, and further water. A method of introducing cyclohexanone oxime in the presence of ammonia as disclosed in JP-A-5-201966, a method of introducing cyclohexanone oxime in the presence of ammonia as disclosed in JP-A-6-107627. A method of coexisting with methylamine in a phase and introducing it may also be used.

The cyclohexanone oxime used in step (6) may be prepared, for example, by oximating cyclohexanone with hydroxylamine or a salt thereof, by reacting cyclohexanone with ammonia and hydrogen peroxide in the presence of a catalyst such as a titanosilicate. It may be prepared by ammoximation, or may be prepared by oxidation of cyclohexylamine.

Step (6) may be carried out in combination with a process of calcining the zeolite catalyst in an oxygen-containing gas atmosphere such as air. By this calcination treatment, the carbonaceous substances deposited on the surface of the zeolite can be removed by burning, so that the conversion rate of cyclohexanone oxime and the selectivity of ε-caprolactam can be sustained.

For example, when step (6) is performed in a fixed bed system, cyclohexanone oxime is supplied in a gas phase together with other components as necessary to a fixed bed reactor filled with zeolite as a catalyst. After performing the Beckmann rearrangement reaction by , the supply of cyclohexanone oxime is stopped, and then the oxygen-containing gas is supplied into the reaction vessel to calcine the zeolite, and then the same Beckmann rearrangement reaction and calcination are repeated. It is preferable to set it as a method.

Further, when the step (6) is carried out, for example, in a fluidized bed system, cyclohexanone oxime is added in a gas phase to a fluidized bed reaction vessel in which the zeolite catalyst is fluidized, and other components are added as necessary. It is preferable that the zeolite is continuously or intermittently withdrawn from the reaction vessel while the Beckmann rearrangement reaction is performed by supplying the zeolite together with the Beckmann rearrangement reaction, and the extracted zeolite is calcined in a calciner and then returned to the reaction vessel.

The product containing ε-caprolactam obtained in step (6) can be treated by any suitable conventionally known post-treatment step. In the post-treatment step, for example, after cooling and condensing the reaction product gas, which is the product of step (6), conventionally known arbitrary and suitable extraction treatment, distillation treatment, crystallization treatment, etc. are performed to obtain ε- It can be a step of separating caprolactam.

4. Applications The zeolite of the present embodiment can be applied to various applications such as molecular sieves and adsorbents. The zeolite of the present embodiment can be suitably applied to various uses, particularly as a catalyst, in organic synthesis reactions. Among them, the zeolite of the present embodiment can be suitably used as a catalyst for producing ε-caprolactam by Beckmann rearrangement reaction of cyclohexanone oxime in the gas phase.

Examples of the present invention are shown below. The present invention is not limited to the examples shown below.

The space velocity WHSV (unit: h-1) of cyclohexanone oxime was calculated by dividing the feed rate (unit: g/h) of cyclohexanone oxime by the catalyst weight (unit: g).

Analysis of cyclohexanone oxime and ε-caprolactam was performed by gas chromatography. The conversion rate of cyclohexanone oxime and the selectivity of ε-caprolactam are obtained by setting the number of moles of supplied cyclohexanone oxime as X, the number of moles of unreacted cyclohexanone oxime as Y, and the number of moles of ε-caprolactam produced as Z, respectively. It was calculated by the following formula.

Conversion rate of cyclohexanone oxime (%) = [(XY) / X] × 100
Selectivity of ε-caprolactam (%) = [Z/(XY)] × 100

<Example 1>
(a) Production of zeolite [step (1)]
115.00 g of tetraethylorthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight aqueous tetra-n-propylammonium hydroxide (0.9% by weight of potassium, 1.0% by weight of 68.00 g of hydrogen bromide, and 58.4% by weight of water; 0.72 g of 85% by weight of potassium hydroxide (containing 15% by weight of water); 00 g and stirred at room temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. to proceed with the hydrothermal synthesis reaction. 0.32 g of magnesium nitrate hexahydrate (a magnesium compound), 14.20 g of 60% by weight nitric acid (containing 40% by weight of water) and 6.60 g of water were added and the temperature was raised to 150°C. A reaction mixture containing zeolite crystals was obtained by heating and stirring for 42 hours to further advance the hydrothermal synthesis reaction. The amount of silicon element contained in the obtained mixture was 50.0 mol per 1 mol of boron element. The amount of silicon element contained in the obtained mixture was 890.0 mol per 1 mol of magnesium element.

[Step (3)]
The reaction mixture containing the zeolite crystals obtained in step (2) was subjected to solid-liquid separation by filtration to obtain zeolite crystals.

[Washing step 1 and drying step 1]
The zeolite crystals obtained in step (3) were washed with ion-exchanged water and filtered. After washing and filtering was repeated several times until the pH of the filtrate reached 6 or more and 9 or less, the washed zeolite crystals were dried at 100° C. or more.

[Step (4)]
The dried zeolite crystals are calcined at 530° C. for 1 hour under nitrogen gas flow, and then further calcined at 530° C. for 1 hour under air flow to obtain zeolite crystals that are powdery white crystals. Obtained.

[Step (5)]
Add 4.0 g of powdered white zeolite crystals obtained in step (4) to an eggplant flask, then add 280 g of a 6 mol/L nitric acid aqueous solution, stir at 90° C. for 1 hour, and filter. Zeolite crystals were subjected to solid-liquid separation. The obtained zeolite crystals were treated with the same aqueous nitric acid solution and solid-liquid separation was repeated twice to obtain a treated product as zeolite.

[Washing step 2 and drying step 2]
The zeolite obtained in step (5) was washed several times with ion-exchanged water until the pH of the filtrate reached 5 or higher, and then dried at 100° C. or higher. The dried zeolite was then classified into particles with a particle size of 0.50-0.85 mm. The zeolite thus obtained was used as a catalyst in step (6) of (b) below.

(b) Production of ε-caprolactam [Step (6)]
0.375 g of the zeolite obtained in (a) above was filled in a quartz glass reaction tube with an inner diameter of 1 cm to form a catalyst layer, and was preliminarily heated at 350° C. for 1 hour under a stream of nitrogen gas of 4.2 L/h. heat treated. After that, the temperature of the catalyst layer was lowered to 316° C. under the flow of 4.2 L/h of nitrogen gas. Thereafter, the vaporized mixture of cyclohexanone oxime/methanol = 1/1.8 (mass ratio) was supplied to the reaction tube at a rate of 8.4 g/h (WHSV of cyclohexanone oxime = 8h ^-1 ), and the Beckmann rearrangement reaction was carried out. did After 5.5 to 5.75 hours from the start of the reaction, the reaction gas was collected and analyzed by gas chromatography.

As a result, the conversion of cyclohexanone oxime was 99.8% and the selectivity of ε-caprolactam was 97.4%. The results are also shown in Table 1 below.

<Example 2>
(a) Production of zeolite [step (1)]
In a glass beaker, 115.00 g of tetraethyl orthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight of tetra-n-propylammonium hydroxide aqueous solution (0.9% by weight of potassium, 1.0% by weight of % hydrogen bromide, 58.4% water by weight), 0.72 g 85% by weight potassium hydroxide (containing 15% by weight water) and 308.0 g 20 g was added and stirred at room temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. to proceed with the hydrothermal synthesis reaction. 1.41 g of magnesium hexahydrate, 9.20 g of 60% by mass nitric acid (containing 40% by mass of water) and 1.06 g of water are added, heated to 140° C. and stirred for 42 hours to give water A reaction mixture containing zeolite crystals was obtained by allowing the thermal synthesis reaction to proceed further. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of boron element. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of magnesium element.

[Other processes]
The steps other than the steps (1) and (2) were carried out in the same manner as in Example 1 to obtain the zeolite of Example 2.

(b) Production of ε-caprolactam [Step (6)]
Step (6) was carried out in the same manner as in Example 1, except that the zeolite obtained in (a) above was used. After 5.5 to 5.75 hours from the start of the reaction, the reaction gas was collected and analyzed by gas chromatography.

As a result, the conversion of cyclohexanone oxime was 99.6%, and the selectivity of ε-caprolactam was 97.1%. The results are also shown in Table 1 below.

<Example 3>
(a) Production of zeolite [step (1)]
In a glass beaker, 115.00 g of tetraethyl orthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight of tetra-n-propylammonium hydroxide aqueous solution (0.9% by weight of potassium, 1.0% by weight of % hydrogen bromide, 58.4% water by weight) 67.20 g, 0.72 g 85% by weight potassium hydroxide (containing 15% by weight water) and 308% water .20 g was added and stirred at ambient temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. for a hydrothermal synthesis reaction. 1.41 g of the hydrate, 7.50 g of 85% by mass phosphoric acid (containing 15% by mass of water) and 8.77 g of water were added, heated to 140° C. and stirred for 42 hours. A reaction mixture containing zeolite crystals was obtained by allowing the thermal synthesis reaction to proceed further. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of boron element. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of magnesium element.

[Other processes]
The steps other than the steps (1) and (2) were carried out in the same manner as in Example 1 to obtain the zeolite of Example 3.

As a result, the conversion of cyclohexanone oxime was 99.4% and the selectivity of ε-caprolactam was 97.2%. The results are also shown in Table 1 below.

<Example 4>
(a) Production of zeolite [step (1)]
In a glass beaker, 115.00 g of tetraethyl orthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight of tetra-n-propylammonium hydroxide aqueous solution (0.9% by weight of potassium, 1.0% by weight of % hydrogen bromide, 58.4% water by weight), 0.72 g 85% by weight potassium hydroxide (containing 15% by weight water) and 129% water. .20 g was added and stirred at ambient temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. to proceed with the hydrothermal synthesis reaction. 1.41 g of magnesium hexahydrate and 10.8 g of water were added, the temperature was raised to 140° C., and the mixture was stirred for 42 hours to further advance the hydrothermal synthesis reaction, thereby obtaining a reaction mixture containing zeolite crystals. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of boron element. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of magnesium element.

[Other processes]
The steps other than the steps (1) and (2) were carried out in the same manner as in Example 1 to obtain the zeolite of Example 4.

As a result, the conversion of cyclohexanone oxime was 98.8% and the selectivity of ε-caprolactam was 97.5%. The results are also shown in Table 1 below.

<Example 5>
(a) Production of zeolite [step (1)]
In a glass beaker, 115.00 g of tetraethyl orthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight of tetra-n-propylammonium hydroxide aqueous solution (0.9% by weight of potassium, 1.0% by weight of % hydrogen bromide, 58.4% water by weight) 67.20 g, 0.72 g 85% by weight potassium hydroxide (containing 15% by weight water) and 308% water .20 g was added and stirred at ambient temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. to proceed with the hydrothermal synthesis reaction. After 6 hours, 0.34 g of boric acid, 1.41 g of magnesium nitrate hexahydrate and 10.8 g of water were added and stirred at 140° C. for 42 hours for further hydrothermal synthesis reaction to obtain a reaction mixture containing zeolite crystals. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of boron element. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of magnesium element.

[Other processes]
The steps other than the steps (1) and (2) were carried out in the same manner as in Example 1 to obtain the zeolite of Example 5.

As a result, the conversion of cyclohexanone oxime was 99.1% and the selectivity of ε-caprolactam was 97.6%. The results are also shown in Table 1 below.

<Example 6>
(a) Production of zeolite [step (1)]
In a glass beaker, 115.00 g of tetraethyl orthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight of tetra-n-propylammonium hydroxide aqueous solution (0.9% by weight of potassium, 1.0% by weight of % hydrogen bromide, 58.4% water by weight) 67.20 g, 0.72 g 85% by weight potassium hydroxide (containing 15% by weight water) and 308% water .20 g was added and stirred at ambient temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. for a hydrothermal synthesis reaction. After 6 hours, 1.70 g of boric acid and 9.8 g of water are added to the mixture obtained. was added, the temperature was raised to 170° C., and the mixture was stirred for 42 hours to further advance the hydrothermal synthesis reaction, thereby obtaining a reaction mixture containing zeolite crystals. The amount of silicon element contained in the obtained mixture was 20.0 mol per 1 mol of boron element.

[Other processes]
The steps other than the steps (1) and (2) were carried out in the same manner as in Example 1 to obtain the zeolite of Example 6.

As a result, the conversion of cyclohexanone oxime was 99.0% and the selectivity of ε-caprolactam was 97.3%. The results are also shown in Table 1 below.

<Example 7>
(a) Production of zeolite In step (2), the procedure was carried out in the same manner as in Example 6, except that the temperature was raised to 140 ° C. when boric acid and water were added 6 hours after the start of the hydrothermal synthesis reaction. Thus, a zeolite according to Example 7 was obtained. The amount of silicon element contained in the obtained mixture was 20.0 mol per 1 mol of boron element.

As a result, the conversion of cyclohexanone oxime was 98.5%, and the selectivity of ε-caprolactam was 97.8%. The results are also shown in Table 1 below.

<Example 8>
(a) Production of zeolite In step (2), when boric acid and water were added 6 hours after the start of the hydrothermal synthesis reaction, the procedure was carried out in the same manner as in Example 6, except that the temperature was maintained at 105 ° C. , a zeolite according to Example 8 was obtained. The amount of silicon element contained in the obtained mixture was 20.0 mol per 1 mol of boron element.

As a result, the conversion of cyclohexanone oxime was 97.4%, and the selectivity of ε-caprolactam was 97.6%. The results are also shown in Table 1 below.

<Example 9>
(a) Production of zeolite [step (1)]
115.00 g of tetraethylorthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight aqueous tetra-n-propylammonium hydroxide (0.9% by weight of potassium, 1.0% by weight of 67.20 g of hydrogen bromide, containing 58.4% by weight of water, 0.72 g of 85% by weight of potassium hydroxide (containing 15% by weight of water) and 308.20 g of water was added and stirred at room temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. to proceed with the hydrothermal synthesis reaction, and magnesium nitrate hexahydrate 1 is added to the reaction mixture obtained after 6 hours. 0.41 g and 9.80 g of water were added, the temperature was raised to 140° C., and the mixture was stirred for 42 hours to further advance the hydrothermal synthesis reaction, thereby obtaining a reaction mixture containing zeolite crystals. The amount of silicon element contained in the obtained mixture was 100.0 mol per 1 mol of magnesium element.

[Other processes]
A zeolite according to Example 9 was obtained in the same manner as in Example 1 except for the above steps (1) and (2).

As a result, the conversion of cyclohexanone oxime was 97.7%, and the selectivity of ε-caprolactam was 97.4%. The results are also shown in Table 1 below.

<Example 10>
(a) Production of zeolite In step (2), when magnesium nitrate hexahydrate and water were added 6 hours after the start of the hydrothermal synthesis reaction, the temperature was maintained at 105 ° C., except that the temperature was maintained at 105 ° C. A zeolite according to Example 10 was obtained in the same manner. The amount of silicon element contained in the obtained mixture was 20.0 mol per 1 mol of magnesium element.

As a result, the conversion of cyclohexanone oxime was 97.6%, and the selectivity of ε-caprolactam was 97.4%. The results are also shown in Table 1 below.

<Example 11>
(a) Production of zeolite [step (1)]
115.00 g of tetraethyl orthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight aqueous tetra-n-propylammonium hydroxide (0.9% by weight potassium, 1.0% by weight of hydrogen bromide, containing 58.4 wt. 20 g was added and stirred at room temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. to advance the hydrothermal synthesis reaction, and aluminum nitrate nonahydrate (aluminum Compound) 4.15 g and water 8.00 g were added, and the mixture was stirred for 42 hours while maintaining the temperature at 105° C. to further advance the hydrothermal synthesis reaction, thereby obtaining a reaction mixture containing zeolite crystals. The amount of silicon element contained in the obtained mixture was 50.0 mol per 1 mol of aluminum element.

[Step (3)]
The reaction mixture obtained in step (2) was filtered to obtain zeolite crystals.

[Washing step 1 and drying step 1]
The zeolite crystals obtained in step (3) were washed with ion-exchanged water and filtered. After washing and filtering was repeated several times until the pH of the filtrate reached 6 or more and 9 or less, the obtained zeolite crystals were dried by heating to 100° C. or more.

[Step (4)]
The obtained zeolite crystals were calcined at 530°C for 1 hour under nitrogen gas flow, and then further calcined at 530°C for 1 hour under air flow to obtain powdery white crystals. .

[Step (5)]
Add 4.0 g of the powdered white crystals obtained in step (4) to an eggplant flask, then add 280 g of a 13 mol/L nitric acid aqueous solution, stir at 115° C. (reflux conditions) for 1 hour, and then filter to obtain crystals. was separated to obtain zeolite crystals. The treatment with the aqueous nitric acid solution was repeated two more times on the obtained zeolite crystals.

[Washing step 2 and drying step 2]
The zeolite crystals obtained in step (5) were washed with ion-exchanged water and filtered. After washing and filtering was repeated several times until the pH of the filtrate reached 5 or higher, the resulting zeolite crystals were dried by heating to 100° C. or higher to obtain zeolite. The obtained zeolite was classified into particles with a particle size of 0.50-0.85 mm. The zeolite thus obtained was used as a catalyst in (b) below.

As a result, the conversion of cyclohexanone oxime was 86.3%, and the selectivity of ε-caprolactam was 97.1%. The results are also shown in Table 1 below.

<Example 12>
(a) Production of zeolite [step (1)]
In a glass beaker, 115.00 g of tetraethyl orthosilicate [Si(OC ₂ H ₅ ) ₄ ], 39.7% by weight of tetra-n-propylammonium hydroxide aqueous solution (0.9% by weight of potassium, 1.0% by weight of % hydrogen bromide, 58.4% water by weight) 67.20 g, 0.72 g 85% by weight potassium hydroxide (containing 15% by weight water) and 308% water .20 g was added and stirred at ambient temperature for 150 minutes to obtain a mixture.

[Step (2)]
The mixture obtained in step (1) is added to a stainless steel autoclave and stirred at 105 ° C. to proceed with the hydrothermal synthesis reaction. After 6 hours, iron nitrate nonahydrate ( Iron compound) (4.50 g) and water (8.00 g) were added, and the mixture was stirred for 42 hours while maintaining the temperature at 105° C. to further advance the hydrothermal synthesis reaction, thereby obtaining a reaction mixture containing zeolite crystals. The amount of silicon element contained in the obtained mixture was 50.0 mol per 1 mol of iron element.

[Other processes]
The steps other than the steps (1) and (2) were carried out in the same manner as in Example 1 to obtain the zeolite of Example 12.

As a result, the conversion of cyclohexanone oxime was 98.2% and the selectivity of ε-caprolactam was 97.2%. The results are also shown in Table 1 below.

<Comparative Example 1>
(a) Production of zeolite [step (1)]
In a glass beaker, 115.00 g of tetraethyl orthosilicate [Si(OC2H5)4], 39.7% by weight of tetra-n-propylammonium hydroxide aqueous solution (0.9% by weight of potassium, 1.0% by weight of odor 153.00 g of hydrogen chloride, containing 58.4% by mass of water, 3.40 g of boric acid and 269.00 g of water were added and stirred at room temperature for 120 minutes to obtain a mixture. The amount of silicon element contained in the obtained mixture was 10.0 mol per 1 mol of boron element.

[Step (2)]
The mixture obtained in step (1) was added to a stainless steel autoclave and stirred at 120° C. for 24 hours to carry out a hydrothermal synthesis reaction.

[Washing step 1 and drying step 1]
The zeolite crystals obtained in step (3) were washed with ion-exchanged water and filtered. After washing and filtering was repeated several times until the pH of the filtrate became 9 or less, the obtained zeolite crystals were dried by heating to 100° C. or more.

[Step (5)]
Add 5.0 g of the powdery white crystals obtained in step (4) to an autoclave, then add 150 g of a 0.2 mol/L nitric acid aqueous solution, stir at 90° C. for 1 hour, and then filter to separate the zeolite crystals. did. The treatment with the aqueous nitric acid solution was repeated two more times on the obtained zeolite crystals.

[Washing step 2 and drying step 2]
The zeolite crystals obtained in step (5) were washed with ion-exchanged water and filtered. After washing and filtering was repeated several times until the pH of the filtrate reached 5 or higher, the resulting zeolite crystals were dried by heating to 100° C. or higher to obtain zeolite. The dried powdered zeolite was classified into particles with a particle size of 0.50-0.85 mm. The zeolite thus obtained was used as a catalyst in (b) below.

As a result, the conversion of cyclohexanone oxime was 95.5%, and the selectivity of ε-caprolactam was 95.1%. The results are also shown in Table 1 below.

Claims

A method for producing zeolite, comprising the following steps (1) to (5).
Step (1):
A step of mixing a tetraalkyl orthosilicate, water, and a quaternary ammonium hydroxide to obtain a mixture Step (2):
At least one compound (A) selected from the group consisting of a boron compound, a germanium compound, a magnesium compound, an aluminum compound, a tin compound and an iron compound is added while the mixture obtained in the step (1) is subjected to a hydrothermal synthesis reaction. supplying to the mixture to obtain a reaction mixture containing zeolite crystals Step (3):
A step of solid-liquid separation of the reaction mixture containing the zeolite crystals obtained in the step (2) to obtain zeolite crystals Step (4):
Step (5) of calcining the zeolite crystals obtained in step (3):
A step of contact-treating the zeolite crystals calcined in the step (4) with an aqueous solution containing at least one acid selected from the group consisting of inorganic acids and organic acids to obtain zeolite.
The method for producing zeolite according to claim 1, wherein in the step (2), an inorganic acid is further supplied to obtain a reaction mixture.
The method for producing zeolite according to claim 2, wherein in the step (2), the compound (A) and the inorganic acid are supplied simultaneously to obtain a reaction mixture.
The method for producing a zeolite according to any one of claims 1 to 3, wherein in the step (2), the compound (A) is supplied to the mixture 1 to 6 hours after the start of the hydrothermal synthesis reaction. .
The method for producing a zeolite according to any one of claims 1 to 4, wherein in the step (1), the molar ratio of the amount of water to the amount of the tetraalkyl orthosilicate is 18-36.
The method for producing zeolite according to any one of claims 1 to 5, wherein in the step (2), the reaction temperature when hydrothermally synthesizing the mixture is 105°C to 170°C.
In the step (2), the reaction temperature after supplying the compound (A) to the mixture is further increased from the reaction temperature before supplying the compound (A) to proceed with the hydrothermal synthesis reaction; A method for producing a zeolite according to claim 6.
A method for producing ε-caprolactam, comprising the following steps (1) to (6).
Step (1):
A step of mixing a tetraalkyl orthosilicate, water, and a quaternary ammonium hydroxide to obtain a mixture Step (2):
At least one compound (A) selected from the group consisting of a boron compound, a germanium compound, a magnesium compound, an aluminum compound, a tin compound and an iron compound is added to the mixture while hydrothermally reacting the mixture obtained in step (1). to obtain a reaction mixture containing zeolite crystals Step (3):
A step of solid-liquid separation of the reaction mixture containing the zeolite crystals obtained in the step (2) to obtain zeolite crystals Step (4):
Step (5) of calcining the zeolite crystals obtained in step (3):
A step of contact-treating the zeolite crystals calcined in step (4) with an aqueous solution containing at least one acid selected from the group consisting of inorganic acids and organic acids to obtain zeolite; step (6):
A step of obtaining ε-caprolactam by Beckmann rearrangement reaction of cyclohexanone oxime in a gas phase using the zeolite obtained in step (5) as a catalyst.