JP2000239210A - Method for producing cycloalkanone - Google Patents

Abstract

(57) [Problem] To provide a method for producing cycloalkanone with high efficiency. SOLUTION: (A) A cycloalkane is brought into contact with molecular oxygen in the presence of an oxidation catalyst (oxidation reaction apparatus 2), and (B)
From the reaction mixture, a catalyst, an acid component produced as a by-product, or a derivative thereof are separated, and then filtered (filtration device 3, extraction column 4, hydrolysis device 7,
Saponification device 8), (C) By separating cycloalkane, cycloalkanol and cycloalkanone from the reaction mixture (distillation columns 5, 6, 9 and 10) and recycling the cycloalkanol to the reaction system And cycloalkanone can be produced efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an oxidized catalyst,
The present invention relates to a method for producing a cycloalkanone from a cycloalkane and molecular oxygen, wherein the by-product cycloalkanol is efficiently converted to a cycloalkanone.

[0002]

2. Description of the Related Art Among cycloalkanones, cyclohexanone is a compound useful for producing ε-aminocaprolactam which is a raw material of nylon. In the production of cyclohexanone, in a liquid phase, in the presence of a soluble cobalt salt (for example, 0.1 to 100 ppm of cobalt) as a catalyst,
Using molecular oxygen or a gas containing molecular oxygen,
It is known that cyclohexane is oxidized to produce cyclohexanone and cyclohexanol, and that by-produced cyclohexanol is converted to cyclohexanone by subjecting it to a dehydrogenation reaction using a dehydrogenation reactor ( "Chemical Handbook Applied Chemistry" p. 536,
61.15.1986, edited by The Chemical Society of Japan, Maruzen). However, in the conventional method, the amount of by-products generated is large, the production ratio of cyclohexanone is low, and the by-produced cyclohexanol must be further dehydrogenated. Therefore, not only does the process become complicated, but cyclohexanone cannot be obtained with high efficiency.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing cycloalkanone at a high production rate.

Another object of the present invention is to provide a method for efficiently producing cycloalkanone with high selectivity in an oxidation reaction system without subjecting a by-product cycloalkanol to a dehydrogenation step.

It is still another object of the present invention to provide a method capable of converting cycloalkanone with high efficiency by a simple structure of separating and recycling cycloalkanol using a distillation column.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, in the oxidation reaction of cycloalkane, by recycling by-product cycloalkanol to the oxidation reaction system, the present invention has been made efficient. They have found that they can be converted to cycloalkanone, and have completed the present invention.

That is, the present invention provides a method for producing
In a reaction system for reacting cycloalkane with molecular oxygen, by-product cycloalkanol is recycled to the reaction system to produce cycloalkanone with high efficiency.

As the cycloalkane, cyclohexane or the like can be used, and as the oxidation catalyst, a compound having an imide unit represented by the following formula (I) (particularly, N-hydroxyphthalimide) can be used. Further, the oxidation catalyst may be used in combination with a co-oxidizing agent.

[0009]

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(In the formula, X represents an oxygen atom or a hydroxyl group.) In the present invention, cycloalkanol by-produced in a reaction system for reacting cycloalkane and molecular oxygen in the presence of an oxidation catalyst. Is separated using a still and the method for producing cycloalkanone is recycled to the reaction system.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings as necessary. The method of the present invention may include a step of separating cycloalkanone and cycloalkanol from the reaction mixture, and a step of recycling the separated cycloalkanol to the oxidation reaction system.

FIG. 1 is a flow chart for explaining the manufacturing method of the present invention. In this example, a step of preparing a catalyst solution containing an oxidation catalyst in a mixing tank 1 and (A) in an oxidation reactor 2, a cycloalkane is contacted with molecular oxygen using the catalyst solution to form a cycloalkanone. (B1) a step for separating a catalyst from the obtained reaction mixture, (B2) a step for separating an acid component from the reaction mixture, and (C1) a reaction in which the catalyst and the acid component are separated. Separating a low boiling component from the mixture;
3) a step of separating impurities such as carboxylate from the reaction mixture from which low-boiling components such as cycloalkane and water are separated; and (C2) a step of separating high-boiling points from the reaction mixture from which low-boiling components and impurities are separated. And a step of separating the high-boiling-point component (C2), wherein the cycloalkanone and the cycloalkanol are separated. Then, the cycloalkanol is produced by recycling the separated and recovered cycloalkanol to the reactor 2. The oxidation reaction may be performed by reactive distillation.For example, water and cycloalkane are distilled off by azeotropic distillation, and the cycloalkane phase is completely refluxed.
The reaction may be carried out by reactive distillation for extracting the aqueous phase. Further, the catalyst separated from the reaction mixture may be recycled to the mixing tank 1 or the reaction device 2 through a catalyst regeneration step if necessary.

The step (B) of separating a catalyst, an acid component or a derivative thereof includes a step (B1) of separating the catalyst from the reaction mixture, a step (B2) of separating an acid component, and impurities such as a carboxylic acid ester. (B3)
Wherein the step (C) of separating cycloalkane, cycloalkanol and cycloalkanone comprises the step of separating low-boiling components from the reaction mixture (C1) and the step of separating high-boiling components (C2) It is composed of

(Oxidation catalyst) As the oxidation catalyst for catalyzing the oxidation reaction between cycloalkane and molecular oxygen, a compound having an imide unit represented by the formula (I) (hereinafter sometimes simply referred to as an imide compound) is used. No.

[0015]

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(In the formula, X represents an oxygen atom or a hydroxyl group.) A preferred oxidation catalyst is represented by the following formula (II).

[0017]

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(Wherein R ¹ and R ² are the same or different and are each a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group R ¹ and R ² are bonded to each other to form a double bond,
Or may form an aromatic or non-aromatic ring,
The aromatic or non-aromatic ring formed by R ¹ and R ² may have at least one imide unit represented by the above formula (I). X is the same as defined above.) In the compound of the formula (II), the substituents R ¹ and R ²
Among them, the halogen atom includes iodine, bromine, chlorine and fluorine. Alkyl groups include, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s
A linear or branched alkyl group having about 1 to 10 carbon atoms such as ec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, and decyl group (preferably a C _1-6 alkyl group, particularly C _{1 -4} alkyl group).

The aryl group includes a phenyl group, a naphthyl group and the like, and the cycloalkyl group includes a C _3-10 cycloalkyl group such as a cyclopentyl, cyclohexyl and cyclooctyl group. Examples of the alkoxy group include an alkoxy group having about 1 to 10 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, t-butoxy, pentyloxy, and hexyloxy, preferably a C _1-6 alkoxy group. , Especially C
_1-4 alkoxy groups are included.

The alkoxycarbonyl group includes, for example,
Toxoxycarbonyl, ethoxycarbonyl, propoxyca
Rubonyl, isopropoxycarbonyl, butoxycarbo
Nil, isobutoxycarbonyl, t-butoxycarbonyl
, Pentyloxycarbonyl, hexyloxycarbo
Carbon number of an alkoxy moiety such as a nyl group is about 1 to 10
An alkoxycarbonyl group (preferably C_1-6Alkoki
C-carbonyl group, C _1-4Alkoxy-carbonyl group)
Is included.

Examples of the acyl group include those having 1 to 6 carbon atoms such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl and pivaloyl groups.
A certain number of acyl groups can be exemplified.

The substituents R ¹ and R ² may be the same or different. In the above formula (II), R ¹
And R ² may combine with each other to form a double bond or an aromatic or non-aromatic ring. The preferred aromatic or non-aromatic ring is a 5- to 12-membered ring, particularly a 6- to 10-membered ring, and may be a heterocyclic ring or a fused heterocyclic ring, but is often a hydrocarbon ring. The aromatic or non-aromatic ring may have at least one (usually 1 or 2) imide units represented by the formula (I). Such a ring includes, for example, a non-aromatic alicyclic ring (a cycloalkene ring which may have a substituent such as a cyclohexane ring and a cycloalkene which may have a substituent such as a cyclohexene ring) Ring), a non-aromatic bridged ring (eg, a bridged hydrocarbon ring which may have a substituent such as a 5-norbornene ring), a benzene ring, a naphthalene ring, etc. And aromatic rings. The ring is often composed of an aromatic ring.

Preferred imide compounds include those represented by the following formula:

[0024]

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(Wherein, R ^{3 to} R ⁶ are the same or different and are each a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an acyl group, a nitro group, a cyano group, an amino group, Represents a halogen atom, and R ¹ , R ² and X are the same as described above).

In the substituents R ^{3 to} R ⁶ , an alkyl group,
Examples of the alkoxy group, alkoxycarbonyl group, acyl group, and halogen atom include the same groups and atoms as described above. The substituents R ^{3 to} R ⁶ are usually a hydrogen atom,
It is often about 4 to about 4 lower alkyl groups, carboxyl groups, nitro groups, and halogen atoms.

One or more imide compounds can be used as an oxidation catalyst in the oxidation reaction. Formula (I)
Examples of the acid anhydride corresponding to the imide compound represented by the formula include saturated or unsaturated aliphatic dicarboxylic anhydrides such as succinic anhydride and maleic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride (1,2). -Cyclohexanedicarboxylic anhydride), 1,2,3,4-cyclohexanetetracarboxylic acid 1,2-anhydride and other saturated or unsaturated non-aromatic cyclic polycarboxylic anhydrides (alicyclic polycarboxylic acids) Acid anhydrides), cross-linked cyclic polycarboxylic anhydrides such as hetic anhydride and hymic anhydride (alicyclic polycarboxylic anhydride), phthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride Nitrophthalic anhydride, trimellitic anhydride, methylcyclohexentricarboxylic anhydride, pyromellitic anhydride, mellitic anhydride, 1,8; 4,5- Aromatic polycarboxylic anhydrides such as naphthalenetetracarboxylic dianhydride are included.

Preferred imide compounds include, for example,
N-hydroxysuccinimide, N-hydroxymaleimide, N-hydroxyhexahydrophthalimide, N, N'-dihydroxycyclohexanetetracarboxylic imide, N-hydroxyphthalimide, N-hydroxytetrabromophthalimide , N-hydroxytetrachlorophthalimide, N-hydroxyhettimide, N-hydroxyhymic imide, N-hydroxytrimellitic imide, N, N'-dihydroxypyromellitic imide, N, N'-dihydroxy And naphthalenetetracarboxylic imide. Particularly preferred compounds include N-hydroxyimide compounds derived from alicyclic polycarboxylic anhydrides, especially aromatic polycarboxylic anhydrides, such as N-hydroxyphthalimide.

[Step of Producing Oxidation Catalyst] The imide compound is subjected to a conventional imidization reaction, for example, by reacting a corresponding acid anhydride with hydroxylamine NH ₂ OH to open the acid anhydride group and then close the ring. And then imidized. More specifically, when the oxidation catalyst is N-hydroxyphthalimide, the oxidation catalyst may be produced by reactive distillation while using phthalic anhydride and hydroxylamine as catalyst raw materials and removing water generated in the reaction. . The oxidation catalyst can be produced by a conventional method such as a batch system, a semi-batch system, and a continuous system.

The obtained oxidation catalyst can be directly used as a catalyst in a catalyst solution preparation step described below. In addition,
As described below, the oxidation catalyst and the co-oxidant may be separated from the reaction mixture, regenerated if necessary, and recycled to the reaction system.

[Manufacturing process of hydroxylamine]
Hydroxylamine as an oxidation catalyst raw material can be produced, for example, as follows.

Ammonia (which may be by-produced in the catalyst regeneration step described below) is oxidized by molecular oxygen to produce nitrogen oxides. As a catalyst for this oxidation reaction, a platinum-based catalyst is generally used. This nitrogen oxide may be extracted with an extraction solvent (for example, water). When water is used for the extraction, water separated in a low-boiling-point component separation step described later may be used. The extracted nitrogen oxides are subjected to a hydrogenation reaction with hydrogen to produce hydroxylamine. The reactor for oxidizing ammonia is not particularly limited, but a tube reactor is often used. A conventional apparatus can be used as an apparatus for extracting nitrogen oxides. As the hydrogenation reaction device, a conventional device, for example, a stirring tank type device can be used. The reaction can be carried out by a conventional method such as a continuous system, a batch system or a semi-batch system. The obtained hydroxylamine may be reused as it is in the oxidation catalyst production step and the catalyst regeneration step.

(Co-Oxidizing Agent) By using the imide compound, the oxidizing activity can be increased without using a co-oxidizing agent such as copper chloride, and even under mild conditions, the oxidation reaction can be carried out catalytically. Can be promoted. Therefore, the cycloalkane can be efficiently oxidized at a high selectivity, and cycloalkanone can be generated. Further, when the cycloalkane is oxidized in the presence of the imide compound having the unit represented by the general formula (I) and the co-oxidizing agent, the conversion and / or the selectivity can be further improved.

The co-oxidizing agent as a co-catalyst includes a metal compound, for example, a compound containing a Group 13 element of the periodic table (boron B, aluminum Al, etc.) such as a transition metal compound and a boron compound. Co-oxidants can be used alone or in combination of two or more.

Examples of the element of the transition metal include elements of Group 3 of the periodic table (eg, scandium Sc, yttrium Y, lanthanum La, cerium Ce, samarium S).
lanthanoid elements such as m, actinoid elements such as actinium Ac), Group 4 elements of the periodic table (such as titanium Ti, zirconium Zr, and hafnium Hf); Group 5 elements (such as vanadium V, niobium Nb, and tantalum Ta); Chromium Cr, molybdenum Mo, tungsten W, etc.), Group 7 elements (manganese Mn, etc.), Group 8 elements (iron F
e, ruthenium Ru, osmium Os, etc.), group 9 elements (cobalt Co, rhodium Rh, iridium Ir, etc.), group 10 elements (nickel Ni, palladium Pd, platinum Pt, etc.), group 11 elements (copper Cu, silver Ag, Au, etc.).

Particularly, when combined with the imide compound represented by the above formula (I), a lanthanoid element such as Ce, Ti
Group 4 element such as V, group 5 element such as V, 6 such as Mo and W
A compound containing a Group 7 element, a Group 7 element such as Mn, a Group 8 element such as Fe or Ru, a Group 9 element such as Co or Rh, a Group 10 element such as Ni, or a Group 11 element such as Cu has high oxidation activity. Show.

The co-oxidizing agent (co-catalyst) contains the above elements,
It is not particularly limited as long as it has oxidizing ability, and may be a hydroxide or the like, but is usually a metal oxide containing the element,
It is often an organic acid salt, an inorganic acid salt, a halide, a coordination compound (complex) containing the metal element, a heteropoly acid or a salt thereof. Examples of the boron compound include, for example, borohydride (eg, borane, diborane, tetraborane, pentaborane, decaborane), boric acid (eg, orthoboric acid, metaboric acid, tetraboric acid), borate (eg, boric acid) Nickel, magnesium borate, manganese borate, etc.), boron oxides such as B ₂ O ₃ , nitrogen compounds such as borazane, borazene, borazine, boron amide, boron imide, BF ₃ , BCl ₃ , tetrafluoroborate, etc. And borate esters (for example, methyl borate, phenyl borate, etc.).

Examples of the organic acid salt include acetate, propionate, naphthenate, stearate and the like, and examples of the inorganic acid salt include nitrate, sulfate and phosphate. . Examples of the halide include chloride and bromide.

Examples of the ligand forming a complex include alkoxy groups such as OH (hydroxo), methoxy, ethoxy, propoxy and butoxy groups, acyl groups such as acetyl and propionyl, and alkoxy groups such as methoxycarbonyl (acetato) and ethoxycarbonyl. Phosphorus such as carbonyl group, acetylacetonate, cyclopentadienyl group, halogen atom such as chlorine and bromine, CO, CN, oxygen atom, H ₂ O (aquo), phosphine (for example, triarylphosphine such as triphenylphosphine) Compound, NH
₃ (ammine), NO, NO ₂ (nitro), NO ₃ (nitrat), ethylenediamine, diethylenetriamine,
And nitrogen-containing compounds such as pyridine and phenanthroline. In the complex or complex salt, the same or different ligands may be coordinated by one kind or two or more kinds.

Preferred complexes include those containing the aforementioned transition metal elements. The transition metal element and the ligand can be appropriately combined to form a complex, for example, cerium acetylacetonate, cobalt acetylacetonate,
Ruthenium acetylacetonate, copper acetylacetonate and the like may be used.

The polyacid forming the heteropolyacid is, for example, an element belonging to Group 5 or 6 of the periodic table, for example, V (vanadic acid), Mo (molybdic acid) and W (tungstic acid).
In many cases, and the central atom is not particularly limited. Specific examples of the heteropolyacid include, for example,
Cobalt molybdate, cobalt tungstate,
Molybdenum tungstate, vanadium molybdate, vanadomolybdophosphate and the like can be mentioned.

In the oxidation catalyst, the heteropolyacid is predicted to take part in the hydrogen abstraction reaction, and the cobalt compound and the boron compound are predicted to take part in peroxide decomposition. The imide compound represented by the formula (I) or the catalyst system composed of the imide compound (I) and the co-oxidizing agent may be a homogeneous system or a heterogeneous system.
Further, the catalyst system may be a solid catalyst in which a catalyst component is supported on a carrier. Activated carbon, zeolite,
In many cases, a porous carrier such as silica, silica-alumina and bentonite is used. The supported amount of the catalyst component in the solid catalyst is about 0.1 to 50 parts by weight with respect to 100 parts by weight of the carrier. The amount of the co-oxidizing agent to be supported is 0.1% with respect to 100 parts by weight of the carrier.
About 30 parts by weight.

[Step of preparing catalyst solution] In the catalyst solution preparation process
Is to adjust the oxidation catalyst to a predetermined catalyst concentration,
Other components (eg, cycloalkane, co-oxidant, solvent
To prepare a catalyst solution.
are doing.

The ratio of the imide compound of the formula (I) and the co-oxidizing agent is, for example, imide compound / co-oxidizing agent = 95 /
5/5/95 (molar ratio), preferably 90 / 10-20
/ 80 (molar ratio), more preferably 85/15 to 50
/ 50 (molar ratio). Further, the catalyst concentration is adjusted according to the supply amount of the catalyst solution so as to be the catalyst concentration in an oxidation step described later.

The catalyst solution thus adjusted is supplied to the oxidation reactor 2. [Oxidation Step (A)] In the oxidation reactor 2, cycloalkane is produced by reacting cycloalkane with molecular oxygen in the presence of an oxidation catalyst or a co-oxidant.

(Cycloalkane) As cycloalkane
Is, for example, cyclobutane, cyclopentane,
Xane, cycloheptane, cyclooctane, methylcycl
Hexane, ethylcyclohexane, dimethylcyclohexane
Xane, chlorocyclohexane, methoxycyclohexa
, Cyclooctane, cyclononane, cyclododecane,
C such as cyclopentadecane and cyclooctadecane_4-20
And cycloalkane. These cycloal
The cans may be used alone or in combination of two or more.

[0047] Preferred cycloalkanes include cyclohex
C such as sun, methylcyclohexane, cyclooctane
_6-12Cycloalkanes. Usually cyclohexa
Is used.

If the conversion of the cycloalkane such as cyclohexane in the oxidation reaction is 10% or more, it is considered to be a considerably excellent oxidation method. However, if such an oxidation catalyst is used, for example, Cyclohexanone can be obtained with high selectivity and yield (about 20-60% or more) simply by stirring with cyclohexane under an atmosphere. Therefore, the oxidation method is useful for oxidizing cycloalkane.

(Oxygen source) Used for oxidation of cycloalkane
The molecular oxygen is not particularly limited, and pure oxygen is used.
Or nitrogen, helium, argon, carbon dioxide, etc.
Oxygen diluted with an inert gas may be used. Operability
Air is used for safety and economy as well as safety.
Is preferred.

The amount of molecular oxygen to be used is generally 0.5 mol or more (for example, 1 mol or more), preferably 1 to 100 mol, more preferably about 2 to 50 mol, per 1 mol of cycloalkane. is there. Often an excess of molecular oxygen is used relative to the cycloalkane.

When supplying molecular oxygen into the reaction vessel,
After supplying sufficient molecular oxygen in advance, the reaction may be performed in a closed system, or the reaction may be performed by continuously flowing molecular oxygen. When flowing continuously, the flow rate of oxygen is, for example, 0.0001 to 10 Nm ³ / L per unit volume.
Min (for example, 0.1 to 10 Nm ³ / min), preferably 0.01 to ⁵ Nm ³ / min (for example, 0.1 to ⁵ Nm ³ / min).
Min).

(Reaction Solvent) The oxidation method of the present invention can be carried out in the presence or absence of an organic solvent inert to the reaction. As the organic solvent, for example, acetic acid, organic acids such as propionic acid, acetonitrile, propionitrile,
Nitriles such as benzonitrile, amides such as formamide, acetamide, dimethylformamide (DMF) and dimethylacetamide, alcohols such as t-butanol and t-amyl alcohol, aromatic hydrocarbons such as benzene, chloroform, dichloromethane, dichloroethane , Carbon tetrachloride, halogenated hydrocarbons such as chlorobenzene, nitro compounds such as nitrobenzene, nitromethane, nitroethane, esters such as ethyl acetate and butyl acetate, dimethyl ether, diethyl ether,
Examples thereof include ethers such as diisopropyl ether, dioxane, and tetrahydrofuran, and a mixed solvent thereof. As a solvent, an organic acid, a nitrile, or an amide is often used. By using an excess amount of cycloalkane, cycloalkane may be used as a reaction solvent.

[0053] In particular, cyclohexane is used as the substrate and solvent.
Oxidation reaction without using a solvent
And the solvent recovery step can be omitted. Oxidation
The amount of the catalyst (especially the imide compound of the formula (I)) used is wide.
For example, per mole of cycloalkane
0.001 mol (0.1 mol%) to 1 mol (100 mol
Mol%), preferably 0.01 mol (1 mol%) to 0.1 mol%.
5 mol (50 mol%), more preferably 0.05 mol
About 0.30 mol, 0.05 mol to 0.25 mol
In many cases.

The amount of the co-catalyst (co-oxidant) used is, for example, 0.001 mol (0.1 mol%) to 0.7 mol (70 mol%), preferably 1 mol of cycloalkane. 0.005 to 0.5 mol, more preferably 0.05 mol
It is about 1 to 0.3 mol, and often about 0.005 to 0.1 mol.

When a heteropolyacid or a salt thereof is used as a co-oxidizing agent, 0.1 to 25 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of cycloalkane,
More preferably, it is about 1 to 5 parts by weight.

The oxidation reaction of the present invention is characterized in that the oxidation reaction proceeds smoothly even under relatively mild conditions. The reaction temperature is, for example, 0 to 300 ° C, preferably 3 ° C.
The reaction is performed at a temperature of about 0 to 250 ° C, more preferably about 50 to 200 ° C, and usually about 70 to 180 ° C in many cases. The reaction can be carried out under normal pressure or under pressure. When the reaction is carried out under pressure, usually 1 to 100a
tm (for example, 1.5 to 80 atm), preferably 2 to
It is often 70 atm, more preferably about 5 to 50 atm. The reaction time (residence time in a flow reaction) is, for example, 1 minute to 4 minutes depending on the reaction temperature and pressure.
8 hours, preferably 1-36 hours, more preferably 2 hours
It can be appropriately selected from a range of about 24 hours.

The reaction temperature and / or reaction pressure is high.
In some cases, the oxidation reaction rate can be increased,
Carboxylic acids and peroxides may be by-produced. Antioxidant
The reaction is in batch or semi-batch in the presence or distribution of molecular oxygen.
It can be performed by a conventional method such as a formula or a continuous formula.
The reaction may be carried out by reactive distillation while removing water.
Decanter 5 in the below-described low boiling point component separation step.
a to remove water in combination with a water separator such as
You may go by stay. Conventional equipment can be used.
In continuous or semi-batch reactors, cycloalkanes
And molecular oxygen (or a gas containing molecular oxygen)
Even if one of the components or each component is supplied from one or more locations
Good. In addition, to increase the mixing efficiency, supply the reaction components.
The supply port may be formed in a nozzle shape. Addition order of each component
Is not particularly limited. One or more reactors
They may be connected continuously.

[Catalyst Separation Step (B1)] Oxidation reactor 2
The reaction mixture is cooled by cooling the reaction mixture if necessary.
Alternatively, the catalyst (e.g., N-hydroxyphthalimide) that is filtered using a plurality of filtration devices 3 and precipitated is filtered out. The cooling temperature or the filtration temperature is about 0 to 100 ° C, preferably about 5 to 70 ° C, and more preferably about 10 to 50 ° C. The processing operation of this step can be performed continuously, batchwise or semi-batchwise, and as a filtration device, a conventional device,
For example, centrifugal filtration, filter press and the like can be used.

Further, the separated catalyst (including the co-oxidizing agent)
May be recycled to the reaction system, provided for incineration,
The co-oxidant (eg, a transition metal such as cobalt) may be recovered and reused. In this example, the reaction mixture from which the catalyst component has been separated by the filtration device 3 is subjected to the acid component separation process (B2) and then to the low boiling component separation process (C1).

In the catalyst separation step, the catalyst can be separated by a conventional method (eg, filtration, distillation, crystallization, etc.). [Acid Component Separation Step (B2)] The reaction mixture may contain by-produced high-boiling acid components or derivatives thereof (eg, esters). For this reason, the reaction mixture is usually subjected to a step of separating low-boiling components by removing high-boiling acid components by extraction or distillation in the extraction column 4. When water or the like is used as the extraction solvent, the extracted component containing a high-boiling acid and water may be reused in an impurity removal step by hydrolysis or the like described later.

The extraction may be performed by distillation (extraction distillation). As the extraction device, a conventional device can be used, and these devices may be used alone or in combination of two or more.

[Separation Step of Low Boiling Components (C1)] The reaction mixture of the oxidation reactor 2 contains low boiling components (unreacted cycloalkane, water, solvent, low boiling impurities, etc.) and high boiling components (cycloalkane, etc.). Canon, cycloalkanol, high-boiling impurities, etc.). In FIG. 1, low-boiling components (including low-boiling impurity components) are separated from a reaction mixture from which an acid component has been removed by using one or more distillation columns (distillation column 5,
6). By this distillation operation, components (high-boiling components) containing cycloalkanone and cycloalkanol are distilled off from the bottom of the first distillation column 5, and a distillate containing low-boiling components such as cycloalkane and water is distilled off from the top of the column. Distills. In the second distillation column 6, the distillate from the top of the first distillation column 5 is separated into cycloalkane distilled from the bottom and low-boiling impurities distilled from the top. The distillate from the top of the first distillation column 5 is supplied to the second distillation column 6 via a decanter 5a in order to separate water.

Further, the cycloalkane separated in the second distillation column 6 is recycled to the mixing tank 1 or the oxidation reactor 2. The water separated by the decanter 5a is
Although it may be subjected to wastewater treatment, it may be used as extraction water for recovering nitrogen oxides in the production process of the catalyst raw material (hydroxylamine).

The number of distillation towers (recovery towers) is, for example, 5 to 5.
The number of stages may be 80, preferably around 20 to 60.
Depending on the type of cycloalkane, the distillation operation is performed at a tower top temperature of about 5 to 180 ° C. (preferably 40 to 120 ° C.), a tower bottom temperature of about 50 to 250 ° C. (preferably 70 to 150 ° C.), and a pressure of 1 mmHg to 20 atm. (Preferably 100m
mHg to 5 atm), a conventional method,
For example, it can be carried out while refluxing the distillate at an appropriate reflux ratio (for example, about 0.1 to 50, preferably about 1 to 20).

The low-boiling components are separated by conventional separation means, for example, separation means such as concentration, distillation, evaporation and extraction.
Alternatively, separation means combining these can be used. The low-boiling components may be separated from the reaction mixture by azeotropic distillation, for example. Further, although only distillation may be performed to separate low-boiling components from the reaction mixture, it may be performed in one separation step to separate cycloalkane, but it is advantageous to combine a plurality of separation steps. is there. If necessary, water and a cycloalkane fraction are combined by cooling a fraction (low-boiling point component) distilled in the distillation column 5 and a liquid separation (such as a decanter) for removing water in the fraction. It may be separated. Further, the cycloalkane fraction may be reused as a reaction raw material in the oxidation reaction system without purification, but it is also possible to separate impurities into high-purity cycloalkane and reuse it as a reaction raw material. Good.

[Impurity Separation Step (Step of Separating Derivative of Acid Component) (B3)] The mixture obtained by separating the low-boiling components by the first distillation column 5 has a high-boiling acid component (for example, , Carboxylic acid, etc.) (eg, esters, etc.). In order to separate these impurities, it is preferable to subject the reaction mixture from which low-boiling components have been separated to an impurity separation step. By this operation, higher purity cycloalkanone and cycloalkanol can be obtained.

In FIG. 1, the reaction mixture from which the low-boiling components have been separated is supplied to a hydrolysis column 7 where it is subjected to a hydrolysis treatment, and the treated liquid is passed through a neutralization and / or saponification column 8 to remove the water contained in the mixture. Is refluxed and neutralized and / or saponified with an alkali (or a salt thereof). In addition,
The aqueous phase of the hydrolysis tower 7 contains high-boiling impurities (such as catalyst components).
Is supplied to the catalyst recovery device 11 because
The organic phase of the neutralization and / or saponification tower 8 (the reaction mixture from which impurities have been removed) is subjected to a high-boiling-point component separation step after separating water with a liquid separator (decanter 8a).

The removal of impurities by hydrolysis, neutralization and / or saponification may be performed by distillation or the like, or may be performed by reactive distillation. Further, it can be carried out by evaporation, extraction, extractive distillation, neutralization, saponification or the like using water, alkali or a salt thereof. In order to remove impurities more efficiently, it is advantageous to perform these operations in combination. The methods of evaporation, extraction, extractive distillation, neutralization, and saponification may be performed in a continuous, batch, or semi-batch manner using water, an alkali or a salt thereof. Further, it may be performed in one or more separation steps.

The saponification temperature in this step is 50 to 200
° C, preferably about 80 to 150 ° C. The pressure is 0.
001 to 20 atm and 0.1 to 15 atm. The alkali or salt is not particularly limited, for example,
Alkali metals (lithium, sodium, potassium, etc.)
Or hydroxides or salts of alkaline earth metals (magnesium, calcium), such as alkali metal hydroxides (eg, lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), alkali metal bicarbonates (eg, carbonic acid) Lithium hydrogen, sodium hydrogen carbonate, potassium hydrogen carbonate, etc.), alkali metal carbonates (lithium carbonate, sodium carbonate, potassium carbonate, etc.), alkaline earth metal hydroxides (magnesium hydroxide, calcium hydroxide, etc.), alkaline earths Metal carbonates (magnesium carbonate, calcium carbonate, etc.) and the like. If necessary, ammonia or an organic base (such as amines) may be used.
Preferred alkalis are alkali metal hydroxides (lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.).

As the alkaline aqueous solution (or slurry), an aqueous solution having a pH of about 7 or more (preferably 7 to 10) can be used. The concentration of the alkaline aqueous solution (or slurry) can be selected from a wide range, but usually, can be selected from a range having good operability.
%, Preferably about 5 to 60% by weight, more preferably about 10 to 30% by weight.

[Step of Separating High Boiling Component (Cycloalkanone Separating Step) (C2)] The reaction mixture from which the low boiling component and impurities have been removed contains cycloalkanone and cycloalkanol, (Including co-catalyst)
And other high boiling point impurities may remain. for that reason,
The reaction mixture is subjected to a high boiling point component separation step (distillation towers 9, 10).
To separate cycloalkanone and cycloalkanol, and also to separate high-boiling impurities (by-products, oxidation catalysts, co-oxidants, etc.).

That is, in FIG. 1, the high-boiling components were separated by feeding the distillate from the bottom of the first distillation column 9 to the second distillation column 10, and adding cycloalkanone and column bottom from the top of the column. From the high boiling point impurities. In the distillation column 10, the cycloalkanol is separated by side cutting (for example, from the bottom of the number of stages, from 10 to 80% of the height). In this example, the cycloalkanol separated in the distillation column 10 is recycled to the reaction system of the reactor 2 to convert the cycloalkanol to cycloalkanone. Therefore, cycloalkanone can be efficiently produced without going through the dehydrogenation step. From the top of the first distillation column 9, low boiling impurities contained in the organic phase in the saponification step are distilled off.

When the first distillation column 9 is used, as described above, the reaction mixture is subjected to extraction, hydrolysis, saponification or neutralization treatment (medium boiling point impurities) in the impurity removal step.
If remains, the medium boiling impurities can be removed by distillation prior to separation of the cycloalkanone and the cycloalkanol. The number of stages of the distillation column (recovery column) is, for example, 5 to 5.
The number of stages may be 80, preferably around 20 to 60.
According to the type of cycloalkanone, the distillation operation is performed at a tower top temperature of about 5 to 200 ° C. (preferably 40 to 120 ° C.), a tower bottom temperature of about 50 to 250 ° C. (preferably 70 to 150 ° C.), and a pressure of 1 mmHg to 1 mm. 20atm (preferably 100m
mHg to 5 atm), a conventional method,
For example, it can be carried out while refluxing the distillate at an appropriate reflux ratio (for example, about 0.1 to 50, preferably about 1 to 20).

The high-boiling impurities separated from the bottom of the distillation column 10 may be incinerated as they are, but when they contain a co-oxidizing agent (for example, a transition metal such as cobalt), they are supplied to the catalyst recovery unit 11. They may be separated and reused in the catalytic oxidation reaction system.

The separation of the high-boiling components is not limited to the above-mentioned distillation means, and any conventional separation means, for example, separation means such as concentration, distillation, evaporation, extraction or a combination thereof can be employed. Preferred separation means include at least distillation means. In addition, the medium boiling impurities can be distilled off from the top of the distillation column 9 and the cycloalkanol can be distilled off from the bottom of the column, and the cycloalkanone can be separated by side cutting.

Further, the separation of the high boiling components may be carried out in one or more distillation or separation steps. In order to obtain high purity cycloalkanes and cycloalkanols, it is advantageous to carry out a combination of the separation of high- and medium-boiling impurities.

[Recycling Step] In the present invention, the distillation column 1
The cycloalkanol separated in the reaction apparatus 2
To convert cycloalkanol to cycloalkanone. Therefore, cycloalkanone can be generated with high efficiency by a simple operation of recycling without going through a dehydrogenation step.

[Catalyst Regeneration Step] The catalyst component in the reaction mixture is subjected to the catalyst separation step (B1) and the impurity removal step (B1).
And B2) and a high boiling point component separation step (C2). The separated oxidation catalyst is supplied to the catalyst regeneration device 13 and can be regenerated. The regeneration of the oxidation catalyst whose quality or activity has been reduced by the reaction is mainly based on the fact that the deteriorated oxidation catalyst is mainly composed of a polycarboxylic acid or an acid anhydride corresponding to the imide compound (for example, phthalic imide, phthalic anhydride, etc.). The oxidation catalyst can be regenerated by treating or reacting with hydroxylamine, noting that it is constituted. As the hydroxylamine, the hydroxylamine produced in the above-mentioned hydroxylamine production step may be used. Also,
The regeneration reaction may be performed by reactive distillation performed while removing generated ammonia and the like.

The reaction is carried out in the same manner as in the oxidation catalyst production step.
Batch, semi-batch, and continuous methods can be used in a conventional manner. As the reaction device, the same device as described above can be used,
These devices may be used in one or more tanks. Also,
Conventional reactors can be used for these reactors.
The apparatus used in the catalyst production step may be used as it is.

The obtained oxidation catalyst (such as N-hydroxyphthalimide) may be used as it is as a catalyst in a catalyst solution preparation step. The co-oxidizing agent may recover the metal component as described above, and may be used as it is as a catalyst in the catalyst solution preparation step.

FIG. 2 is a flowchart showing another example of the present invention. The process of this example is basically the same as the process shown in FIG. 1 except for a catalyst regeneration process for regenerating a catalyst whose quality has been reduced or its activity has been reduced by the reaction.
That is, the catalyst component separated from the reaction mixture by the catalyst separation device 3 such as a filtration device is supplied to the catalyst regeneration device 13. In the catalyst regenerating apparatus 13, a catalyst component whose activity has been reduced or altered (a polycarboxylic acid corresponding to the imide compound or an acid anhydride thereof (for example, phthalic imide, phthalic anhydride, etc.)) is treated or reacted with hydroxylamine. It is playing by letting it. The regeneration reaction is performed while supplying oxygen or air and removing generated ammonia and the like.

The hydroxylamine can be obtained as follows. That is, the ammonia oxidizer 14
In this step, ammonia (which may be ammonia generated from the catalyst regeneration device 13) is oxidized by molecular oxygen to generate nitrogen oxide NOx. As a catalyst for this oxidation reaction, a platinum-based catalyst is generally used. The generated nitrogen oxides NOx are recovered in the recovery tower 15. NO
The recovery of x can be performed using an extraction operation with an extraction solvent (eg, water), a crystallization operation, a distillation operation, and the like. In the reactor 16, the recovered nitrogen oxides NOx
Can be used to produce hydroxylamine. The hydroxylamine thus obtained is
It is supplied to the catalyst regeneration device 13.

The catalyst (imide compound) regenerated by the catalyst regenerating device 13 is separated by a separator 17 such as a filtering device, mixed with cycloalkane or the like, if necessary, and stored in a tank 18. The catalyst in the tank 18 is supplied to a dehydration tower 19 when used, dehydrated, and then supplied to the mixing tank 1 for preparing the catalyst. On the other hand, the non-catalyst component separated in the separator 17 is supplied to the distillation column 20, and the distillate (low-boiling component) from the top of the column can be subjected to the step of separating the low-boiling component. [Solvent removal or recovery step] When a solvent is used in the oxidation reaction of the present invention, the solvent is separated and recovered in an appropriate step (for example, the low boiling point or high boiling point component separation step) according to its boiling point. Alternatively, a solvent recovery device may be further added to separate and recover the solvent. The separated solvent may be recycled to the reaction system or used as a solvent for preparing the catalyst solution.

FIG. 3 is a flowchart showing still another example of the present invention. In this example, a solvent having a higher boiling point than a low boiling distillate, such as cycloalkane (eg, acetic acid)
, A process for separating and recovering a solvent is shown.

That is, the reaction mixture from the reactor 2 is supplied to the evaporator 21, and the low-boiling distillate from the top of the evaporator 21 is supplied to the same low-boiling component separation step as described above. You. On the other hand, the distillate (catalyst component, high-boiling component, solvent, etc.) distilled from the bottom of the evaporator 21 is removed from the desolvation column 2
2 and the distillate from the bottom of the desolvation tower 22 is supplied to the catalyst separation device 3, and the catalyst component separated by the separation device 3 is supplied to the same catalyst regeneration device 13 as described above. The high-boiling component from which the catalyst component has been separated by the catalyst separating device 13 is supplied to the same high-boiling component separation process as described above through the hydrolysis column 7 and the saponification column 8 without being subjected to the acid component separation process. ing.

On the other hand, the distillate from the top of the desolvation tower 22 is recycled to the reaction system as a solvent, and the mixture recovered in the catalyst tank 13 in the catalyst regeneration unit 13 and the low boiling point component It is mixed with the distillate from the bottom of the first distillation column 5 in the separation step,
Is supplied to a distillation column 24 for recovering and dehydrating the catalyst component. The distillate from the top of the distillation column 24 is supplied to the low-boiling component separation step, and the distillate from the bottom of the distillation column 24 is supplied to a mixing tank for preparing the catalyst solution. Is done.

When a solvent having a boiling point equal to or lower than that of a low-boiling component such as cycloalkane is used as the solvent, the solvent is recovered in a step of separating the low-boiling component (for example, a first distillation column). It can be recycled as a reaction solvent. When using a solvent having a higher boiling point than cycloalkanone and cycloalkanol,
After separating cycloalkanone and cycloalkanol, the component containing the solvent may be subjected to an oxidation step or a catalyst solution preparation step.

In the present invention, the reaction mixture of the oxidation reactor 2 can be separated into a low-boiling component containing cycloalkane and a high-boiling component containing cycloalkanone and cyclolucanol without being subjected to the catalyst separation step. Good.

FIG. 4 is a flowchart showing another example of the present invention. In this example, the reaction mixture of the oxidation reactor 2 is supplied to the distillation column 32 to separate into a low-boiling component and a high-boiling component. The low-boiling fraction from the top of the distillation column 32 is
In order to separate the cycloalkane from the low-boiling impurities in the same manner as described above, the cycloalkane is supplied to the first distillation column 5 and the second distillation column 6 and subjected to the low-boiling-point separation step (C1).

On the other hand, the high-boiling fraction (catalyst component, high-boiling component, etc.) from the bottom of the distillation column 32 is cooled, if necessary, by filtering the reaction mixture using one or a plurality of filtration devices 33. The precipitated catalyst is filtered off. The reaction mixture from which the catalyst component has been separated is supplied to a distillation column 39 in order to separate high-boiling components and high-boiling impurities. The distillate from the top of the distillation column 39 is supplied to the distillation column 40 and subjected to a high-boiling-point component separation step (C2) for separating cycloalkanone and cycloalkanol in the same manner as described above. The cycloalkanol is recycled to the reactor 2. The high-boiling impurities from the bottom of the distillation column 39 include a catalyst and a high-boiling acid component or a derivative thereof. Therefore, in this example, the high-boiling distillate from the bottom of the distillation column 39 is supplied to the catalyst recovery device 41. The high-boiling impurities are subjected to a catalyst, an acid component or a derivative thereof separation step as described above,
Each component may be separated.

In the present invention, the catalyst production step, hydroxylamine production step, catalyst solution preparation step,
The catalyst separation step, the impurity separation step, the separation step of low-boiling components, the catalyst regeneration step, the solvent removal or recovery step, etc. are not necessarily performed, but in order to obtain cycloalkanone with high efficiency, the oxidation step, In addition to the boiling component separation step and the recycling step, it is advantageous to carry out the combination of the low boiling point component separation step and the impurity separation step. Can be.

The order of each step is not particularly limited.
It may be different from the above method. For example, after separating the low-boiling component from the reaction mixture, the catalyst, the acid component or its derivative and the high-boiling component are separated from the reaction mixture from which the low-boiling component has been separated, and the cycloalkanone and the cycloalkanol are separated from the high-boiling component. And a catalyst, an acid component or a derivative thereof may be separated from the reaction mixture, and a low-boiling component and a high-boiling component may be separated from the reaction mixture from which these impurities have been separated. Furthermore, the operation of separating the catalyst, by-produced acid component or its derivative does not need to be performed individually, and may be performed in one step.

In the oxidation, hydrolysis and saponification steps, a conventional apparatus can be used as the reaction apparatus, and the apparatus may have a spherical or circular shape. Although no special equipment is required inside the reactor, equipment that controls mixing inside such as a draft or equipment that divides the interior into multiple chambers such as a perforated plate may be provided. Good.
Further, in order to increase the stirring efficiency, a mechanical stirring device such as a stirring blade may be provided. One or more reaction vessels may be used for the reaction. Further, as the distillation column and the extractive distillation column, a tana plate column, a perforated plate column, a packed column (regular packed column, irregular packed column), a bubble column, a valve column and the like can be used. Examples of the extraction apparatus include a conventional apparatus such as a mixer settler, a perforated plate tower, a spray tower, a packed tower, a ring & plate tower, a rotating disk extraction tower, and a curl column. As the evaporator, a conventional device, for example, a natural circulation type, a horizontal tube type evaporator, a natural circulation type vertical short tube type evaporator, a horizontal tube falling film evaporator, a vertical long tube falling film evaporator, forced circulation Examples include a horizontal tube evaporator, a forced circulation vertical tube evaporator, and a stirred film evaporator. These devices may be used alone or in combination, or may be used alone or in combination of two or more.

[0094]

According to the present invention, cycloalkanone, which is a by-product of the cycloalkane oxidation reaction, is recycled to the oxidation reaction system, whereby cycloalkanone can be obtained with high efficiency without dehydrogenation. . Furthermore, by using a separation (distillation) device, cyclohexanol can be separated and effectively converted to cycloalkanone.

[0095]

The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 (1) Catalyst solution preparation step Cyclohexane 10000 g / H, N-hydroxyphthalimide 10 g / H, cobalt acetonate 64 g / H
Of the catalyst solution. (2) Oxidation Step The ratio of the catalyst solution, cyclohexane is 840 g / H, air is supplied to the reactor 2 at a supply rate of 1.3 Nm ³ / H, and
The reaction was carried out at 60 ° C., 40 atm and a residence time of 2 hours. The conversion of cyclohexane was 11%, the selectivity of cyclohexanone was 40%, and the selectivity of cyclohexanol was 49%.
%. (3) Catalyst Separation Step The crude reaction solution was cooled to 20 ° C., the catalyst was separated by filtration, the separated catalyst was incinerated, cobalt was recovered, recycled to the reaction system, and reused. In the extraction tower 4,
The filtrate was subjected to an extraction step with water at 20 ° C. using a ring and plate to extract high boiling acid and the like. (4) Low-boiling point component separation step The organic phase is separated into cyclohexane / cyclohexanol (KA oil) and high-boiling point components by azeotropic distillation of water and cyclohexane in a perforated plate tower 5 having 30 stages, and a distillate Was separated into an aqueous phase and a cyclohexane phase by a decanter, and water was removed. The cyclohexane phase was separated into low boiling components in a 30-stage perforated plate tower 6, and the cyclohexane obtained from the bottom was recycled to the reaction system and reused. (5) Impurity removal step The KA oil and the high-boiling component liquid are hydrolyzed with the acidic aqueous solution of the high-boiling acid obtained above using a 30-stage perforated plate tower 7 to hydrolyze the high-boiling ester. Part of the acid was separated and incinerated. The distillate was a liquid obtained by further mixing a 5% by weight aqueous solution of sodium hydroxide and a 5% by weight aqueous solution of sodium carbonate at a ratio of 1: 1. Was saponified or neutralized and removed. The distillate is separated from the aqueous phase and K
The A oil phase was separated and the water was refluxed. (6) Separation Step of High Boiling Point Components The KA oil phase was separated from medium boiling point components using a 20-stage bubble bell tower 9. The cyclohexane product and the high-boiling components were collected from the product cyclohexane using a perforated plate tower 10 having 60 stages. Purification efficiency by this method is 90%, product purity is 99%
It was. (7) Recycling Step Further, cyclohexanol was collected from the 50th stage from the top and recycled to the reaction system. As a result, cyclohexanone could be easily converted with a 98% yield. The high boiling components from the bottom of the perforated plate tower 10 were incinerated without using a dehydrogenation reactor.

Example 2 (1) Catalyst solution preparation step Cyclohexanone 1000 g / H, N-hydroxyphthalimide 160 g / H, cobalt acetonate 64 g / H
A catalyst solution was prepared at a H ratio. (2) Oxidation step Catalyst solution ratio, cyclohexane 840 g / H, air 1.
It is fed to the reactor 22 at a feed rate of ³ Nm ³ / H,
The reaction was carried out at 0 ° C. and 40 atm with a residence time of 4 hours. As a result, a conversion of cyclohexane was 32%, a selectivity of cyclohexanone was 89%, and a selectivity of cyclohexanol was 5%. (3) Catalyst separation step The reaction crude liquid was cooled to 20 ° C, and the catalyst was separated by filtration. In the extraction tower 24, the filtrate was subjected to an extraction step at 20 ° C. water using a ring & plate to extract high boiling acid and the like. (4) Low-boiling point separation step The organic phase is separated from KA oil and high-boiling components by azeotropic distillation of water and cyclohexane in a perforated plate tower 25 having 30 stages.
The distillate was separated into an aqueous phase and a cyclohexane phase by a decanter. The cyclohexane phase was separated into low-boiling components in a 30-stage perforated plate tower 26, and the cyclohexane obtained from the bottom was recycled to the reaction system and reused. (5) Impurity removing step The KA oil and the high boiling component liquid are hydrolyzed with a high boiling acid aqueous solution using a 30-stage perforated plate tower with the high boiling acid aqueous solution obtained above to obtain a high boiling acid solution. The parts were separated and incinerated. The distillate was further mixed with a 5% by weight aqueous solution of sodium hydroxide and a 5% by weight aqueous solution of sodium carbonate at a ratio of 1: 1. Using a 40-stage perforated plate tower, high boiling acid and high boiling ester were removed. Saponified or neutralized and removed. The distillate is separated in a decanter into an aqueous phase and a KA oil phase,
Water was refluxed. (6) High Boiling Point Separation Step The KA oil phase was subjected to separation of a medium boiling component using a 20-stage bubble bell tower 29. KA oil and high boiling components are 60
The product was collected using the perforated plate tower 210 of the stage. In this production method, the purification yield was 91%, and the product purity was 99%. (7) Recycling Step In addition, cyclohexanol was collected from the 50th stage from the top and recycled to the reaction system. As a result, cyclohexanone could be easily converted with a 97% yield. The conventionally required dehydrogenation reactor can be omitted. High boiling components are incinerated, cobalt is recovered and recycled to the reaction system,
Used again. (8) Catalyst regeneration step and catalyst raw material production step The catalyst was regenerated using hydroxylamine and a 30-stage perforated plate tower. The water was removed from the regenerated catalyst using a 30-stage perforated plate tower, and then recycled to the reaction system and reused. Cyclohexane in the catalyst was also recycled to the reaction system and reused. Hydroxylamine used for catalyst regeneration and catalyst production oxidizes ammonia by-produced during catalyst regeneration using a platinum catalyst in a tube reactor to produce NO _x (NO ₂ , N ₂ O ₃ , N _2
2 O ₅ ) was produced and absorbed by a ring & plate using water separated in the low boiling point component separation step, and hydroxylamine was produced by a hydrogenation reaction.

Example 3 (1) Catalyst solution preparation step Acetic acid 10,000 g / H, N-hydroxyphthalimide 1
A catalyst liquid was prepared at a rate of 60 g / H and 64 g / H of cobalt acetonate. (2) Oxidation Step Catalyst solution ratio, cyclohexane 840 g / H, air 1.
It is fed to the reactor 32 at a feed rate of ³ Nm ³ / H,
When the reaction was performed at 40 ° C. and a residence time of 4 hours,
At a conversion of cyclohexane of 31%, cyclohexanone was obtained at a selectivity of 90% and cyclohexanol was obtained at a selectivity of 5%. (3) Low-boiling-point component separation step The reaction crude liquid was separated into low-boiling components such as cyclohexane and water and high-boiling components such as acetic acid, KA oil and catalyst by a forced circulation evaporator. Water and cyclohexane were azeotropically separated from low boiling components such as cyclohexane and water using a 30-stage perforated plate tower, and separated into a water phase and a cyclohexane phase by a decanter. The cyclohexane phase is 3
The low-boiling components were separated in a zero-stage perforated plate tower, and the cyclohexane obtained from the bottom was recycled to the reaction system and reused. (4) Solvent Separation Step Acetic acid was separated from high boiling components such as acetic acid, KA oil, and catalyst using a 30-stage perforated plate tower, recycled to the reaction system, and reused. (5) Impurity Removal Step High boiling components such as KA oil and catalyst were cooled to 20 ° C., and the catalyst was separated by filtration. The filtrate was hydrolyzed with a high-boiling ester with an acidic aqueous solution using a 30-stage porous column, a part of the high-boiling acid was separated, and incinerated. The distillate was a mixture of a 5% by weight aqueous solution of sodium hydroxide and a 5% by weight aqueous solution of sodium carbonate at a ratio of 1: 1. Neutralized and removed. (6) High boiling point separation step The distillate was separated into an aqueous phase and a KA oil phase by a decanter, and the water was refluxed. The medium boiling point component of the KA oil phase was separated using a 20-stage bubble column. The products of the KA oil and the high boiling point component were collected using a perforated plate tower having 60 stages. In this production method, the purification yield was 91%, and the product purity was 99%. (7) Recycling Step In addition, cyclohexanol was collected from the 50th stage from the top and recycled to the reaction system. As a result, cyclohexanone could be easily converted with a 97% yield. The conventionally required dehydrogenation reactor can be omitted. High boiling components are incinerated, cobalt is recovered and recycled to the reaction system,
Used again. (8) Catalyst regeneration step The catalyst was regenerated using hydroxylamine and a 30-stage perforated plate tower. The water was removed from the regenerated catalyst using a 30-stage perforated plate tower, and then recycled to the reaction system and reused. Cyclohexane in the catalyst was also recycled to the reaction system and reused. Hydroxylamine used for catalyst regeneration and catalyst production oxidizes ammonia by-produced during catalyst regeneration by using a platinum catalyst in a tube reactor to produce NO _x (NO ₂ , N ₂ O ₃ , N _2
2 O ₅ ) was produced, absorbed with water using a ring & plate, and hydroxylamine was produced by a hydrogenation reaction.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a method of the present invention.

FIG. 2 is a flowchart for explaining another method of the present invention.

FIG. 3 is a flowchart for explaining still another method of the present invention.

FIG. 4 is a flowchart for explaining another method of the present invention.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 ... Mixing tank 2 ... Oxidation reaction apparatus 3 ... Catalyst separation apparatus (filtration apparatus) 4 ... Acid component separation apparatus (extraction tower) 5 ... Low boiling point component separation apparatus (distillation tower) 5a ... Liquid separation apparatus 6 ... Cycloalkane separation apparatus (Distillation column) 7 ... Hydrolysis device 8 ... Saponification device 8a ... Separation device 9 ... Medium boiling point separation device (distillation column) 10 ... High boiling point separation device (distillation column) 11 ... Catalyst recovery device 21 ... Separation device (evaporator) 22) Separation device (desolvation column) 32 ... Separation device (distillation column) 33 ... Separation device (filtration device) 39 ... Separation device (distillation column) 40 ... Separation device (distillation column)

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Claims (10)

[Claims] 1. A method for producing cycloalkanone by a reaction system for reacting cycloalkane and molecular oxygen in the presence of an oxidation catalyst, wherein cycloalkanone is recycled to the reaction system. Manufacturing method. 2. The method according to claim 1, wherein the cycloalkane is cyclohexane. 3. The method according to claim 1, wherein the oxidation catalyst is a compound having an imide unit represented by the formula (I). Embedded image (In the formula, X represents an oxygen atom or a hydroxyl group.) 4. An oxidation catalyst represented by the formula (II):
2. The method according to claim 1, which is a compound. Embedded image(Where R¹And R^TwoAre the same or different
Atom, halogen atom, alkyl group, aryl group, cycloa
Alkyl group, hydroxyl group, alkoxy group, carboxy
R, alkoxycarbonyl, or acyl;¹
And R^TwoAre bonded to each other to form a double bond, or aromatic or
May form a non-aromatic ring;¹And R ^TwoBy shape
The aromatic or non-aromatic ring formed is represented by the above formula (I)
It may have at least one imide unit shown. X
Is the same as above) 5. An oxidation catalyst comprising N-hydroxysuccinimide, N-hydroxymaleimide, N-hydroxyhexahydrophthalimide, N, N'-dihydroxycyclohexanetetracarboxylic imide, N-hydroxyphthalimide , N-hydroxytetrabromophthalimide, N-hydroxytetrachlorophthalimide, N-hydroxyhettimide, N-hydroxyhymic imide, N-hydroxytrimellitic imide, N, N'-dihydroxypyromellit The method according to claim 1, wherein the compound is at least one compound selected from the group consisting of acid imide and N, N'-dihydroxynaphthalenetetracarboxylic imide. 6. The use amount of the oxidation catalyst is cycloalkane 1
The production method according to claim 1, wherein the amount is 0.001 to 1 mol per mol. 7. The method according to claim 1, further comprising using a co-oxidizing agent. 8. The method according to claim 7, wherein the co-oxidizing agent is a transition metal compound or a boron compound. 9. A temperature of 0 to 300 ° C. and a pressure of 1 to 100 at.
The method according to claim 1, wherein the reaction is carried out with m. 10. A method for producing cycloalkanone by a reaction system for reacting cycloalkane with molecular oxygen in the presence of an oxidation catalyst, wherein cycloalkane and cycloalkanol by-produced are separated by a distillation column. And a method for producing cycloalkanone, wherein cycloalkanol is recycled to the reaction system.