CN102083777B - Process for producing phenol - Google Patents

Abstract

In a process for producing phenol, cyclohexylbenzene is oxidized to produce cyclohexylbenzene hydroperoxide and then the resultant cyclohexylbenzene hydroperoxide is cleaved to produce an effluent stream comprising phenol and cyclohexanone. At least a portion of the effluent stream is then fed to at least one dehydrogenation reaction zone, where the effluent stream portion is contacted with a dehydrogenation catalyst under conditions effective to convert at least part of the cyclohexanone in the effluent portion into phenol and hydrogen.

Description

Produce the method for phenol

The cross reference of related application

The application requires the rights and interests of the European application submitted in U.S. Provisional Application sequence number formerly on November 18th, 61/093,042 and 2008 that on August 29th, 2008 submits to number 08169307.9, and the full content of these two sections of applications is combined in herein by reference.

Field

The present invention relates to produce the method for phenol.

Background

Phenol is product important in chemical industry, and can be used for for example production of resol, dihydroxyphenyl propane, ε-caprolactam, hexanodioic acid and softening agent.

At present, be Hock method for the most frequently used route of phenol production.This is a kind of three one step process, and wherein first step relates to benzene propylene alkylation to produce isopropyl benzene, and isopropyl benzene is oxidized to corresponding hydroperoxide subsequently, and then described hydroperoxide are cleaved to produce phenol and the acetone of equimolar amount.But the demand growth of world Pyrogentisinic Acid's demand comparison acetone is rapider.In addition, due to the exploitation shortage of propylene, the cost of propylene probably increases.Therefore, use higher alkene more replace propylene as charging and coproduction more the method for higher ketone instead of acetone may be to produce the attractive alternative route of phenol.

For example, the oxidation of phenylcyclohexane (similar with cumene oxidation) can be provided for the alternative route of phenol production, and there is no the problem of cogeneration of propanone.This alternative route is undertaken by phenylcyclohexane hydroperoxide, and described phenylcyclohexane hydroperoxide are cleaved to produce phenol and the pimelinketone of equimolar amount substantially.

But a problem of producing in phenol in the cracking by phenylcyclohexane hydroperoxide is that pimelinketone and phenol produce the azeotropic mixture being made up of 28wt% pimelinketone and 72wt% phenol.Therefore, any trial by simple distillation separating and cracking effluent all causes this azeotropic mixture.And, although pimelinketone is the valuable product with growing market, at present pimelinketone is not had to large world commerce market; Most of pimelinketone are produced and are consumed at the scene as intermediate.Therefore, in some cases, may wish to increase the amount of phenol in the product mixtures that derives from phenylcyclohexane oxidation, or even produce all phenol and there is no pimelinketone.According to the present invention, provide a kind of for produced the integrated approach of phenol by phenylcyclohexane, the method contributes to control the amount of pimelinketone in final product.

Especially, the invention provides and be a kind ofly oxidized to phenylcyclohexane hydroperoxide and phenol is produced in the cracking of phenylcyclohexane hydroperoxide subsequently method by phenylcyclohexane, wherein make at least a portion derive from the effluent experience dehydrogenation step of cleavage step.Described dehydrogenation not only makes at least a portion pimelinketone in described effluent part change into other phenol, and generating hydrogen as by product, described hydrogen for example can be recycled to the initial benzene hydrogenation alkylation step for the production of phenylcyclohexane charging.In addition, although the cracking effluent part of experience dehydrogenation step can be the pure pimelinketone cut substantially of producing from the phenol of original effluent and lightweight and heavy tailing by separating, but consider the cost of this separation, described method also can be applied to the effluent part that contains some or all phenol that produce in cleavage step.With which, if the total cost of the final pimelinketone logistics of the final phenol stream of purifying and existence can be minimized.

General introduction

In one aspect, the invention reside in a kind of method of producing phenol, the method comprises:

(a) by phenylcyclohexane oxidation, to produce phenylcyclohexane hydroperoxide;

(b) will derive from (a) phenylcyclohexane hydroperoxide transform, to produce the effluent logistics that comprises phenol and pimelinketone;

(c) effluent logistics described at least a portion is fed to at least one dehydrogenation reaction zone; With

(d) make the logistics of described at least a portion effluent with dehydrogenation catalyst in described dehydrogenation reaction zone, contact under the dehydrogenation condition that effectively at least a portion pimelinketone in the logistics of described at least a portion effluent is changed into phenol and hydrogen, described dehydrogenation condition comprises the temperature of approximately 250 DEG C-Yue 500 DEG C.

In one embodiment, the described at least a portion effluent logistics that is fed to described dehydrogenation reaction zone has the composition identical with the effluent logistics producing by described conversion (b).

In another embodiment, described method further comprises makes the effluent logistics producing by described conversion (b) experience at least one separating step, and the described at least a portion effluent logistics that is fed to described dehydrogenation reaction zone is comprised than the few phenol of effluent logistics producing by described conversion (b).Expediently, make the effluent logistics producing by described conversion (b) experience at least one separating step, the described at least a portion effluent logistics that makes to be fed to described dehydrogenation reaction zone comprises and is less than 50wt%, for example, be less than 30wt%, for example, be less than the phenol of 1wt%.In addition, before the logistics of described at least a portion effluent is fed to described dehydrogenation reaction zone, can make by described conversion (b) produce effluent logistics experience at least one separating step with remove boiling point lower than 155 DEG C (101kPa measure) component and/or boiling point higher than 182 DEG C (101kPa measure) component.

Expediently, the described dehydrogenation condition in (d) comprises the temperature of approximately 300 DEG C-Yue 450 DEG C.

Expediently, the described condition in (d) comprises the about 20atm of about 0.01atm-(1kPa-2000kPa), for example pressure of the about 3atm of about 1atm-(100kPa-300kPa).

Expediently, hydrogen is fed to described dehydrogenation reaction zone together with the logistics of described at least a portion effluent, conventionally making the mol ratio of hydrogen and pimelinketone in the charging of dehydrogenation reaction zone is approximately 0: 1-approximately 4: 1.Expediently, at least a portion hydrogen that is fed to described dehydrogenation reaction zone is the hydrogen producing in described contact (d).

In yet another aspect, the invention reside in a kind of method of being produced phenol by benzene, the method comprises:

(a1) benzene is contacted under hydroalkylation condition with catalyzer with hydrogen, to produce phenylcyclohexane;

(a) will derive from the phenylcyclohexane oxidation of (a1), to produce phenylcyclohexane hydroperoxide;

(b) will derive from (a) phenylcyclohexane hydroperoxide transform, to produce the effluent logistics that comprises phenol and pimelinketone;

(c) effluent logistics described at least a portion is fed to at least one dehydrogenation reaction zone; With

(d) make the logistics of described at least a portion effluent with dehydrogenation catalyst in described dehydrogenation reaction zone, contact under the dehydrogenation condition that effectively at least a portion pimelinketone in the logistics of described at least a portion effluent is changed into phenol and hydrogen; With

(e) at least a portion hydrogen gas recycle that will produce in described contact (d) is to described contact (a1).

Brief Description Of Drawings

Fig. 1 based on calculation of thermodynamics, under the condition that adds and do not add nitrogen dilution agent and hydrogen at the transformation efficiency of the lower pimelinketone dehydrogenation of normal pressure (101kPa) figure to temperature.

The detailed description of embodiment

This paper describes a kind of method of producing phenol, the method allows the pimelinketone of coproduction partly or entirely to be changed into other phenol.In the method, conventionally the phenylcyclohexane of preparing by the shortening alkylation of benzene is oxidized to produce phenylcyclohexane hydroperoxide, and then the cracking of described phenylcyclohexane hydroperoxide is comprised to the phenol of equimolar amount and the effluent logistics of pimelinketone substantially to produce.Then, effluent described at least a portion is fed to dehydrogenation reaction zone, described a part of effluent logistics contacts under the dehydrogenation condition that effectively pimelinketone in described a part of effluent is changed into other phenol and hydrogen with dehydrogenation catalyst there, and described hydrogen can be recycled to described benzene hydrogenation alkylation step (in the time existing).The production of phenylcyclohexane

Can pass through any routine techniques for the phenylcyclohexane of present method, be included in acid catalyst as under zeolite beta or the existence of MCM-22 family molecular sieve with tetrahydrobenzene by benzene alkylation, or become biphenyl subsequently biphenyl hydrogenation to be produced by benzene oxidative coupling.But, in practice, phenylcyclohexane conventionally by make benzene with hydrogen under hydroalkylation condition, contact to produce under hydroalkylation catalyzer exists, wherein following react (1) of benzene experience is to produce phenylcyclohexane (CHB):

The benzene charging of any commercially available acquisition can be used in described hydroalkylation step, but preferably, described benzene has at least purity level of 99wt%.Similarly, although hydrogen source is not critical, conventionally wish that described hydrogen is that at least 99wt% is pure.

Expediently, the combined feed total feed of described hydroalkylation step comprises and is less than 1000ppm, for example, be less than 500ppm, for example, be less than the water of 100ppm.Expediently, described combined feed total feed conventionally comprises and is less than 100ppm, for example, be less than 30ppm, for example, be less than the sulphur of 3ppm.Expediently, described combined feed total feed conventionally comprises and is less than 10ppm, for example, be less than 1ppm, for example, be less than the nitrogen of 0.1ppm.

Described hydroalkylation can, at the structure of reactor of wide region, comprise in fixed bed, slurry-phase reactor and/or catalytic distillation tower and carrying out.In addition, described hydroalkylation can carry out in single reaction zone or in multiple reaction zones, in described multiple reaction zones, introduces and reacts to the classification of major general's hydrogen.Suitable temperature of reaction is approximately 100 DEG C-Yue 400 DEG C, for example approximately 125 DEG C-Yue 250 DEG C.Suitable reaction pressure is about 100-approximately 7,000kPa, for example about 500-approximately 5,000kPa.The desired value of the mol ratio of hydrogen and benzene is approximately 0.15: 1-approximately 15: 1, for example approximately 0.4: 1-approximately 4: 1, for example about 0.4-approximately 0.9: 1.

Catalyzer for described hydroalkylation preferably comprises the molecular sieve of MCM-22 family and the dual-function catalyst of hydrogenation metal.Term used herein " MCM-22 family material " (or " material of MCM-22 family " or " molecular sieve of MCM-22 family ") comprises one or more in following material:

● build by first common degree (first degree) crystallinity the molecular sieve that piece (buildingblock) structure cell forms, this structure cell has MWW framework form.(structure cell is the spatial disposition of atom, if it spreads in three-dimensional space, has described crystalline structure.At " Atlasof Zeolite Framework Types ", the 5th edition, such crystalline structure is discussed in 2001, the whole content of the document is incorporated herein by reference);

● build by common the second degree (second degree) molecular sieve that piece forms, described structure piece is the 2-dimension tiling of such MWW framework form structure cell, has formed a structure cell thickness, the preferred individual layer of a c-structure cell thickness;

● build by the second common degree the molecular sieve that piece forms, described structure piece is the layer of one or more than one structure cell thickness, wherein the layer of more than one structure cell thickness by the individual layer of at least two structure cell thickness stacking, tamp (packing) or bonding (binding) and make.It can be regular mode, irregular mode, random mode or their arbitrary combination that the second degree like this builds piece stacking; With

● tie up by thering is any rule of structure cell of MWW framework form or random 2-dimension or 3-the molecular sieve constituting.

The molecular sieve of MCM-22 family has the peaked x-ray diffraction pattern of d-spacing that is included in 12.4 ± 0.25,6.9 ± 0.15,3.57 ± 0.07 and 3.42 ± 0.07 dusts conventionally.The K α two-wire that uses copper for the X-ray diffraction data that characterize described material by standard technique is as incident radiation and scintillometer is housed and the diffractometer of correlation computer obtains as gathering system.The molecular sieve of MCM-22 family comprises that MCM-22 (is described in U.S. Patent number 4, 954, 325), PSH-3 (is described in U.S. Patent number 4, 439, 409), SSZ-25 (is described in U.S. Patent number 4, 826, 667), ERB-1 (being described in european patent number 0293032), ITQ-1 (is described in U.S. Patent number 6, 077, 498), ITQ-2 (being described in International Patent Publication No. WO 97/17290), MCM-36 (is described in U.S. Patent number 5, 250, 277), MCM-49 (is described in U.S. Patent number 5, 236, 575), MCM-56 (is described in U.S. Patent number 5, 362, 697), UZM-8 (is described in U.S. Patent number 6, 756, 030), with their mixture.Preferably, described molecular screening is from (a) MCM-49, (b) MCM-56 and (c) isotype (isotype) of MCM-49 and MCM-56, for example ITQ-2.

Any known hydrogenation metal can be used in described hydroalkylation catalyzer, although suitable metal comprises palladium, ruthenium, nickel, zinc, tin and cobalt, palladium is particularly advantageous.Usually, the about 10wt% of approximately 0.05-that the amount of the hydrogenation metal existing in catalyzer is catalyzer, for example about 5wt% of about 0.1-.MCM-22 family molecular sieve is in an embodiment of silico-aluminate therein, and it is about 1.5-approximately 1500 that the amount of the hydrogenation metal of existence makes aluminium in molecular sieve and the mol ratio of hydrogenation metal, for example about 75-approximately 750, for example about 100-approximately 300.

Hydrogenation metal can be by for example flooding or ion-exchange is directly supported on MCM-22 family molecular sieve.But, in a preferred embodiment, at least 50wt%, for example 75wt% at least, and conventionally substantially whole hydrogenation metal be supported on the inorganic oxide independent but compound with it with described molecular sieve.Especially, find, by hydrogenation metal is supported on inorganic oxide, be supported on the catalyzer of equal value on molecular sieve with hydrogenation metal wherein compared with, the activity of catalyzer and its selectivity to phenylcyclohexane and dicyclohexyl benzene increase.

Inorganic oxide for so compound hydroalkylation catalyzer needn't straitly limit, as long as it is stable and is inertia under the condition of hydroalkylation.Suitable inorganic oxide comprises the oxide compound of the periodic table of elements the 2nd, 4,13 and 14 families, for example aluminum oxide and/or titanium dioxide and/or zirconium dioxide.Numbering plan for periodictable family used herein is disclosed in Chemical and Engineering News, 63 (5), 27 (1985).

By metallic inorganic oxide and described molecular sieve compound before, described hydrogenation metal is deposited on described inorganic oxide, expediently by dipping.Conventionally, described catalyst composite is produced by common granulation, the mixture of wherein said molecular sieve and described metallic inorganic oxide is by high pressure (common about 350-approximately 350,000kPa) compacted under is pellet, or described catalyst composite is produced by coextrusion, wherein said molecular sieve and described metallic inorganic oxide, optionally and independent tackiness agent, slurries be forced through die orifice.If desired, can subsequently other hydrogenation metal be deposited on the catalyst composite of gained.

Suitable adhesive material comprises that synthetic or naturally occurring material and inorganic materials are as clay and/or silicon-dioxide and/or metal oxide.The latter can be naturally occurring or be the form of gelatinous precipitate or gel, comprise the mixture of silicon-dioxide and metal oxide.The naturally occurring clay that can be used as tackiness agent comprises those of polynite and kaolin families, described family comprises the change wilkinite and the kaolin that are commonly referred to Dixie, McNamee, Georgia and Florida clay, or wherein essential mineral component is other material of halloysite, kaolinite, dickite, nakrite or anauxite.Such clay can use with the virgin state of initially exploiting, or first experiences calcining, acid treatment or chemical modification, is then used.Suitable metal oxide binder comprises that silicon-dioxide, aluminum oxide, zirconium dioxide, titanium dioxide, silica-alumina, silica-magnesia, silicon-dioxide-zirconium dioxide, silica-thorium oxide, silica-beryllia, silica-titania and ternary composition are as silica-alumina-Thorotrast, silica-alumina-zirconium dioxide, silica-alumina-magnesium oxide and silica-magnesia-zirconium dioxide.

Although described hydroalkylation step is high selectivity to phenylcyclohexane, the effluent that derives from described hydroalkylation contains the product of some dialkyl group conventionally, and unreacted aromatic feed and desirable monoalkylation species.Unreacted aromatic feed is conventionally by Distillation recovery and be recycled to alkylation reactor.The bottom material that derives from benzene distillation is further distilled, so that monocycle hexyl benzene product is separated with other heavy constituent with any dicyclohexyl benzene.Depend on the amount of the dicyclohexyl benzene existing in reaction effluent, may wish to make described dicyclohexyl benzene and other benzene to carry out alkyl exchange, so that the maximum production of desirable monoalkylation species.

With the alkyl exchange of other benzene conventionally in the transalkylation reactor of separating with described hydroalkylation device, at suitable alkyl exchange catalysts if the molecular sieve of MCM-22 family, zeolite beta, MCM-68 are (referring to U.S. Patent number 6,014,018), on zeolite Y or mordenite, carry out.Transalkylation reaction is being carried out under liquid-phase condition at least partly conventionally, about benzene/dicyclohexyl benzene weight ratio of 5: 1 that described condition comprises the temperature of approximately 300 DEG C of about 100-and/or the pressure of the about 3500kPa of about 800-and/or the weight hourly space velocity and/or approximately 1 based on the about 10hr-1 of the about 1-of whole feed charging meter: 1-aptly.

Phenylcyclohexane oxidation

In order to make phenylcyclohexane change into phenol and pimelinketone, first phenylcyclohexane is oxidized to corresponding hydroperoxide.This is by introducing oxygen-containing gas in the liquid phase that contains phenylcyclohexane and complete as air.Different from isopropyl benzene, not having, the atmospheric oxidn of phenylcyclohexane under catalyzer is very slow, and therefore oxidation is carried out conventionally under catalyzer exists.

Suitable catalyst for phenylcyclohexane oxidation step is to be described in U.S. Patent number 6,720, the cyclic imide that the N-hydroxyl of 462 (being combined in by reference herein) replaces, for example HP, 4-amino-HP, 3-amino-HP, tetrabromo-HP, tetrachloro-HP, N-hydroxyl hetimide, N-hydroxyl himimide, N-hydroxyl trimellitic acid imide, N-hydroxybenzene-1,2,4-tricarboxylic acid imide, N, N '-dihydroxyl (pyromellitic diimide), N, N '-dihydroxyl (BP-3,3 ', 4,4 '-tetracarboxylic acid diimide), N-hydroxyl maleimide, pyridine-2,3-dicarboxylic acid imide, N-hydroxy-succinamide, N-hydroxyl (tartrate imide), N-hydroxyl-5-norbornylene-2,3-dicarboxylic acid imides, outward-N-hydroxyl-7-oxabicyclo [2.2.1] heptan-5-alkene-2,3-dicarboxylic acid imides, N-hydroxyl-cis-hexanaphthene-1,2-dicarboxylic acid imides, N-hydroxyl-cis-4-tetrahydrobenzene-1,2-dicarboxylic acid imides, N-hydroxyl naphthalimide sodium salt or N-hydroxyl-adjacent benzene disulfonyl imines.Preferably, described catalyzer is HP.Another kind of suitable catalyzer is N, N ', N " trihydroxy-isocyanuric acid.

These materials can use separately or use under radical initiator exists, and can be used as the homogeneous catalyst use of liquid phase, or can be supported on solid carrier so that heterogeneous catalyst to be provided.Usually, " trihydroxy-isocyanuric acid is with the 0.0001mol%-15wt% of phenylcyclohexane, and the amount of for example 0.001-5wt% is used for cyclic imide or N that described N-hydroxyl replaces, N ', N.

Conditions suitable for described oxidation step comprises approximately 70 DEG C-Yue 200 DEG C, for example temperature and/or the about 50-10 of approximately 90 DEG C-Yue 130 DEG C, the pressure of 000kPa.Any oxygen-containing gas, preferably air can be used as oxidizing medium.Reaction can be carried out in batch reactor or continuous flow reactor.Can add ealkaline buffer, to react with the acidic by-products that may form between oxidation period.In addition, can introduce water, it can help dissolve basic compounds, for example sodium carbonate.

The cracking of hydroperoxide

Change at phenylcyclohexane the cracking that final reaction step in phenol and pimelinketone relates to phenylcyclohexane hydroperoxide, its expediently by make described hydroperoxide and catalyzer in liquid phase at approximately 20 DEG C-Yue 150 DEG C, for example temperature and/or the about 50-approximately 2 of approximately 40 DEG C-Yue 120 DEG C, 500kPa, for example, contact under the pressure of the about 1000kPa of about 100-and carry out.Described phenylcyclohexane hydroperoxide are preferably diluted in the organic solvent of described scission reaction inertia as in methylethylketone, pimelinketone, phenol or phenylcyclohexane, to contribute to heat extraction.Described scission reaction is carried out expediently in catalytic distillation device.

Catalyzer for described cleavage step can be homogeneous catalyst or heterogeneous catalyst.

Suitable homogeneous cleavage catalyst comprises sulfuric acid, perchloric acid, phosphoric acid, hydrochloric acid and tosic acid.Iron(ic) chloride, boron trifluoride, sulfurous gas and sulphur trioxide are also effective homogeneous cleavage catalyst.Preferred homogeneous cleavage catalyst is sulfuric acid, and preferred concentration is 0.05-0.5wt%.For homogeneous acid catalyst, after cleavage step, be preferably neutralization procedure.Such neutralization procedure is usually directed to contact with basic component, will be rich in the water decantation of salt subsequently.

The suitable heterogeneous catalyst that is used for the cracking of phenylcyclohexane hydroperoxide comprises smectic clays, for example be described in U.S. Patent number 4,870,217 acid polynite silica-alumina clay, whole disclosures of this patent are combined in herein by reference.

The aftertreatment of cracking effluent

The effluent that derives from scission reaction comprises phenol and the pimelinketone of equimolar amount substantially.Present method, by making at least a portion cracking effluent contact that with dehydrogenation catalyst some or all pimelinketone in effluent are changed into other phenol according to reaction (2), provides the favourable route of the amount that increases the phenol of being produced by original CHB or benzene charging:

Any suitable dehydrogenation catalyst can be used to reaction (2), for example, be described in U.S. Patent number 4,417, the nickel catalyzator of the promotion in 076.Conditions suitable for described dehydrogenation step comprises the temperature of approximately 250 DEG C-Yue 500 DEG C and/or the pressure of the about 20atm of about 0.01atm-(1kPa-2000kPa), for example temperature of approximately 300 DEG C-Yue 450 DEG C and the pressure of the about 3atm of about 1atm-(100kPa-300kPa).

Within the scope of said temperature, the dehydrogenation of pimelinketone is equilibrium-limited.Fig. 1 is the maximum figure that is presented at dehydrogenation reaction under specified requirements, described figure is based on using D.R.Stull, E.F.Westrum, and G.C.Sinke, The Chemical Thermodynamics ofOrganic Compounds, Robert E.Krieger Publishing Company publishes, Malabar, the calculation of thermodynamics that the free energy data in Florida (1987) are carried out.Use standard thermodynamic to calculate (referring to for example Chemical Engineering Thermodynamics, R.E.Balzhiser, M.R.Samuels, and J.D.Eliassen; Prentice-Hall, Englewood Cliffs, NJ (1972) estimates the equilibrium conversion of pimelinketone to phenol.Fig. 1 indicates, and under 1 normal atmosphere (101kPa) stagnation pressure and adopt pure fed cyclohexanone, in order to realize at least 90% pimelinketone to phenol conversion, must under the temperature more than 275 DEG C or 275 DEG C, operate.Operation or use the gas of reactionlessness as the dilution of nitrogen and/or methane under lower stagnation pressure, increased equilibrium conversion, and co-fed hydrogen tends to reduce equilibrium conversion.But co-fed hydrogen contributes to be extracted in the hydrogen generating in described dehydrogenation reaction, for other processing step, especially for (optional) benzene hydrogenation alkylation step, and conventionally also improve catalyst stability.Hydrogen by co-fed to the described dehydrogenation reaction in the situation that, it is approximately 0 that the speed that hydrogen adds makes the mol ratio of hydrogen and pimelinketone in the charging of dehydrogenation reaction conventionally: 1-approximately 4: 1.

Reactor configuration for described method of dehydrogenating generally includes one or more fixed-bed reactor that contain the solid catalyst with dehydrogenation functionality.The single of pimelinketone is greater than 70% conventionally by transformation efficiency, and is preferably greater than 90%.Can be ready to the heat absorption of reaction, preferably by thering is the multiple heat insulation bed of interstage heat exchanger.The temperature of reactant flow reduces when by each catalyst bed, and then raises by described heat exchanger.Preferably, use 3-5 bed, wherein reduce to 30-100 DEG C by the temperature of each.Preferably, last in this series moved under the temperature out of first height of bed than in this series.

As previously mentioned, pimelinketone and phenol produce the azeotropic mixture being made up of 28wt% pimelinketone and 72wt% phenol, are therefore separated from any trial of the effluent of phenylcyclohexane hydroperoxide cleavage step and are caused this azeotropic mixture by simple distillation.But, by least part of vacuum, conventionally under the pressure lower than 101kPa, distill, can improve separation efficiency.In addition, known extractive distillation process can be used for separating ring hexanone and phenol, referring to for example U.S. Patent number 4,021,490,4,019,965,4,115,207,4,115,204,4,115,206,4,201,632,4,230,638,4,167,456,4,115,205 and 4,016,049.But phenol/pimelinketone separates and remains expensive process, therefore in one embodiment, the charging of dehydrogenation step has the composition identical with cracking effluent, has avoided thus the needs to initial expensive separating step.Depend on the efficiency of pimelinketone dehydrogenation, final product can contain substantially whole phenol, has at least reduced thus the problem of separating phenol from cracking effluent.

In another embodiment, before dehydrogenation, make cracking effluent experience one or more sepn processes, to reclaim or to remove one or more components of described effluent.Especially, make described cracking effluent experience expediently at least the first separating step, to reclaim some or all phenol from described effluent, the effluent logistics that conventionally makes to send into described dehydrogenation reaction comprises and is less than 50wt%, for example be less than 30wt%, for example, be less than the phenol of 1wt%.The separation of phenol is undertaken by vacuum and/or extractive distillation expediently.Before described effluent logistics is sent into dehydrogenation reaction, can use other distilation steps, with remove boiling point lower than 155 DEG C (101kPa measure) component as benzene and tetrahydrobenzene, and/or boiling point higher than 185 DEG C (101kPa measure) component as 2-phenylphenol and phenyl ether.

By adopting method of dehydrogenating of the present invention, the whole pimelinketone substantially in phenylcyclohexane hydroperoxide cracking effluent can be converted to phenol.But, in practice, depend on market situation, may there is the remarkable demand of pair pimelinketone product.This can adopt present method to depend on the reversible character of reaction (2), by least some phenol hydrogenation winding hexanones are easily met.This can be for example easily realizes in the following manner: make phenol and hydrogen hydrogenation catalyst as platinum or palladium existence under, under the condition that for example comprises the temperature of approximately 20 DEG C-Yue 250 DEG C and/or the pressure and/or approximately 1 of the about 10000kPa of about 101kPa-: 1-hydrogen/phenol mol ratio of approximately 100: 1, contact.

Although describe with reference to particular and for example understand the present invention, it will be appreciated by the skilled addressee that the present invention is suitable for not necessarily illustrational modification in this article.Therefore, in order to determine true scope of the present invention, should be only with reference to the appended claims.

Claims (15)

1. a method of producing phenol, the method comprises:

(a) oxidation phenylcyclohexane, to produce phenylcyclohexane hydroperoxide;

(b) will derive from (a) phenylcyclohexane hydroperoxide transform, to produce the effluent logistics that comprises phenol and pimelinketone;

(c) the effluent logistics that comprises phenol and pimelinketone described at least a portion is fed to at least one dehydrogenation reaction zone together with hydrogen; With

(d) logistics of described at least a portion effluent is contacted in described dehydrogenation reaction zone under the dehydrogenation condition that effectively at least a portion pimelinketone in the logistics of described at least a portion effluent is changed into phenol and hydrogen with dehydrogenation catalyst, described dehydrogenation condition comprises the temperature of 250 DEG C-500 DEG C.

2. the process of claim 1 wherein that the described at least a portion effluent logistics that is fed to described dehydrogenation reaction zone has the composition identical with the effluent logistics producing by described conversion (b).

3. the method for claim 1, further comprise and make the effluent logistics producing by described conversion (b) experience at least one separating step, the described at least a portion effluent logistics that is fed to described dehydrogenation reaction zone is contained than the few phenol of effluent logistics producing by described conversion (b).

4. the method for claim 3, further comprise and make the effluent logistics producing by described conversion (b) experience at least one separating step, make the described at least a portion effluent logistics that is fed to described dehydrogenation reaction zone contain the phenol that is less than 50wt%.

5. the method for claim 3, further comprise and make the effluent logistics producing by described conversion (b) experience at least one separating step, make the described at least a portion effluent logistics that is fed to described dehydrogenation reaction zone contain the phenol that is less than 1wt%.

6. the method for claim 1, before being further included in the logistics of described at least a portion effluent being fed to described dehydrogenation reaction zone, make the effluent logistics producing by described conversion (b) experience at least one separating step, to remove the component lower than 155 DEG C at 101kPa measurement boiling point.

7. the method for claim 1, before being further included in the logistics of described at least a portion effluent being fed to described dehydrogenation reaction zone, make the effluent logistics producing by described conversion (b) experience at least one separating step, to remove the component higher than 182 DEG C at 101kPa measurement boiling point.

8. the process of claim 1 wherein that described dehydrogenation condition comprises the temperature of 300 DEG C-450 DEG C.

9. the process of claim 1 wherein that described dehydrogenation condition comprises the pressure of 1kPa-2000kPa.

10. the method for claim 9, wherein said pressure is 100kPa-300kPa.

11. the process of claim 1 wherein that at least a portion hydrogen that is fed to described dehydrogenation reaction zone in described charging (c) is the hydrogen producing in described contact (d).

12. the process of claim 1 wherein that the mol ratio of hydrogen and pimelinketone is greater than 0:1 and is less than or equal to 4:1 in the charging of dehydrogenation reaction zone.

13. the process of claim 1 wherein the logistics of described at least a portion effluent and hydrogen feed to the multiple dehydrogenation reaction zones that are connected in series.

Produced the method for phenol by benzene for 14. 1 kinds, the method comprises:

(a1) benzene is contacted under hydroalkylation condition with catalyzer with hydrogen, to produce phenylcyclohexane;

(a) will derive from the phenylcyclohexane oxidation of described contact (a1), to produce phenylcyclohexane hydroperoxide;

(b) will derive from described oxidation (a) phenylcyclohexane hydroperoxide transform, to produce the effluent logistics that comprises phenol and pimelinketone;

(c) effluent logistics described at least a portion is fed to at least one dehydrogenation reaction zone together with hydrogen;

(d) logistics of described at least a portion effluent is contacted in described dehydrogenation reaction zone under the dehydrogenation condition that effectively at least a portion pimelinketone in effluent described in described at least a portion is changed into phenol and hydrogen with dehydrogenation catalyst; With

(e) at least a portion hydrogen gas recycle that will produce in (d) is to described contact (a1).

The method of 15. claims 14, wherein said dehydrogenation condition comprises the temperature of 250 DEG C-500 DEG C.