CN106167451A - The method that meta-xylene produces aromatic carboxylic acids with ethylbenzene multistep cooxidation - Google Patents
The method that meta-xylene produces aromatic carboxylic acids with ethylbenzene multistep cooxidation Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
- C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
- C07C51/255—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting
- C07C51/265—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting having alkyl side chains which are oxidised to carboxyl groups
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/04—Purification; Separation; Use of additives by distillation
Abstract
The invention discloses a kind of method that meta-xylene produces aromatic carboxylic acids with ethylbenzene multistep cooxidation, comprise the following steps: the xylol raffinate containing xylol, meta-xylene, o-Dimethylbenzene and ethylbenzene is carried out rectification and removes o-Dimethylbenzene by (1), obtains the mixture A containing meta-xylene and ethylbenzene；(2) mixture A carrying out multistep oxidation generate containing M-phthalic acid and benzoic mixture B, go out the thick product of M-phthalic acid by Crystallization Separation, crystalline mother solution obtains benzoic acid by evaporation and concentration；(3) it is respectively adopted acetic acid and distilled water product thick to M-phthalic acid to wash, dried acquisition essence M-phthalic acid.Each step of production process of the present invention and each unit operate all simple possible, discharge without organic wastewater simultaneously, are a kind of economic and environment-friendly new technologies.
Description
Technical field
The present invention relates to the production method of a kind of aromatic carboxylic acids, particularly relate to a kind of meta-xylene and ethylbenzene multistep cooxidation
The method producing aromatic carboxylic acids.
Background technology
Essence M-phthalic acid (PIA) is the raw material of polyester resin, is mainly used in polyester bottle slice, fiber, unsaturated-resin, low
The preparation of melt polyester product.The production method of PIA is as raw material with meta-xylene (MX), obtains thick isophthalic by liquid phase oxidation
Dioctyl phthalate (CIA), the latter removes the trace impurity in product by hydrofinishing again, it is thus achieved that polymer grade PIA.At Review literature
(Process EconomicsProgram Report 9E, Terephthalic Acid and Dimethyl
Terephthalate, SRI Consulting, Menlo Park, California, 94025, January 1997.) in detail
Describe various oxidation and refined method, document (He Zuoyun, meta-xylene and M-phthalic acid production Technology, synthesis
Fiber industry, the 2nd phase of volume 23,41～45,2000.) supplement domestic progress further.Producer due to PIA
Method is similar to the technique of p-phthalic acid (PTA) at a lot of aspects, and production scale is again less than PTA, and therefore some are public both at home and abroad
Department is generally by the PIA that changes the line of production after small-sized PTA plant modification.
Meta-xylene is the raw material of PIA, and the method overwhelming majority obtaining MX at present is with mixed xylenes as raw material.Mesh
Before be the main production process of mixed xylenes with oil for raw material production mixed xylenes.Crude oil obtains after atmospheric and vacuum distillation
Naphtha cut, this fraction send into reformer unit generate a large amount of aromatic hydrocarbons, reformate be re-fed into Aromatics Extractive Project unit aromatics separation with
Non-aromatics, then the heavy aromatics by the benzene in rectifying and separating aromatic hydrocarbons, toluene and carbon more than 9, final carbon 8 aromatic hydrocarbons mixture obtained
In containing meta-xylene (MX), xylol (PX), o-Dimethylbenzene (OX), 4 kinds of compositions of ethylbenzene (EB), its substantially content and physical property
Matter is as shown in table 1.
The table 1 carbon 8 each constituent content of aromatic hydrocarbons with reformate as waste and physical property
| Component | MX | PX | OX | EB |
| Content (%) | 45% | 20% | 20% | 15% |
| Boiling point (DEG C) | 139.1 | 138.4 | 144.4 | 136.2 |
| Fusing point (DEG C) | -47.8 | 13.2 | -25.2 | -95.0 |
It will be seen that the boiling point of 4 kinds of components is sufficiently close to, in addition to o-Dimethylbenzene, other three kinds of materials are all difficult to pass through
Rectification separates.Although the fusing point of 4 kinds of aromatic hydrocarbons has marked difference, can be separated by cryogenic crystallization in theory, but this system exists
Multiple multi-component eutectic points, it is difficult to by Crystallization Separation, this all has been reported that in many monographs and document.Therefore, current work
Main or employing adsorbing separation acquisition MX raw material in industry.
Using adsorption separating method highly selective absorption MX, then use desorbing agent eluting MX, this method can obtain
The MX of high-purity (MX ＞ 99.5%).Patent CN200980125280.6, CN200610164101.8 individually disclose the special of MX
With adsorbent elements and adsorption conditions, patent CN200810100400.4 discloses structure and the absorbing process of MX adsorbent equipment.
(Zhao Yuzhang, Yang Jian, dimethylbenzene adsorbing separation-isomerization group technology produces between high-purity for patent CN98102372.X and document
Dimethylbenzene, petrochemical industry, the 1st phase of volume 29,32～36,2000.) technique that then discloses a kind of vapor phase method adsorbing separation MX.
Absorption method is the meta-xylene production method of the most industrializing implementation, and its advantage is that the MX product purity obtained is high, to former
The wide adaptability of material.But absorption method operating process is complicated, need to use a large amount of expensive adsorbent, the most also need to take off with special
Attached dose of desorbing MX, the mixture desorbed reclaims strippant by multiple tracks rectification step again and purifies MX product.Therefore, use
It is high that absorption method prepares MX cost, and gained MX is expensive, limits the popularization and application in its market.
As the PIA of polyester raw material, it is the most all as copolyesters composition and p-phthalic acid (PTA)
Rise and use.Such as, as the copolyesters of bottle chip level, PIA only accounts for the 2～3% of PTA, in low-melting point polyester PIA the most only account for 20～
40%.Therefore, some patents in order to avoid separate MX a difficult problem, use mixed xylenes cooxidation method obtain PIA with
The mixed dicarboxylic acid product of PTA prepares the cost of PIA to reduce.First patent CN200610154821.6 proposes to mix diformazan
Benzene is that raw material carries out liquid phase cooxidation, it is thus achieved that p-phthalic acid, M-phthalic acid, the mixture of phthalic acid, recycling neighbour
Phthalic acid and to, two kinds carboxylic acids significant difference on dissolubility, obtains the mixture of PTA Yu PIA by Crystallization Separation,
Raw material as copolyesters.Similar scheme is repeatedly mentioned in patent subsequently.Such as, patent CN201210014597.6
Propose the mixture with xylol (PX) and MX as raw material, add after part PX is deployed into the composition of special ratios and aoxidize
With refined, produce the special raw material of various copolyesters.Patent CN200980109527.5 proposes with containing mixed xylenes and ethylbenzene
C8 aronmatic be raw material, first pass through suitable separation method and remove the ethylbenzene in C8 aronmatic, then remove neighbour by rectification
Dimethylbenzene, remaining PX Yu MX mixture carries out liquid phase oxidation again and obtains PTA Yu PIA mix product.But this patent does not carry
Go out clear and definite ethylbenzene separation method, concrete cooxidation condition is not the most provided.Ethylbenzene and xylol boiling point differ only by 1.8
DEG C, the most also it is sufficiently close to, is difficult to separate.In view of this, patent CN200810022473.6 proposes the carbon containing ethylbenzene
Eight aromatic hydrocarbons carry out the scheme of cooxidation, it is thus achieved that phenylacetic acid and the mixture of three kinds of dicarboxylic acids.But it is actually general after ethylbenzene oxidation
Can generate benzoic acid and be hardly produced phenylacetic acid, the scheme carried is difficult to carry out, and the mixed polycarboxylic acid purposes of generation the most extremely has
Limit.Therefore, in order to obtain MX and PIA at low cost, it is necessary to look for another way, new thinking and method are used.
Summary of the invention
The invention provides a kind of method that meta-xylene produces aromatic carboxylic acids with ethylbenzene multistep cooxidation, the method can be low
Cost produces meta-xylene and reclaims o-Dimethylbenzene (OX) simultaneously, and obtains M-phthalic acid by the oxidation of meta-xylene.
A kind of method producing xylol co-production meta-xylene, including: will be containing xylol (PX), meta-xylene
(MX), the carbon 8 aromatic hydrocarbons mixture adsorbing separation of o-Dimethylbenzene (OX) and ethylbenzene (EB) go out xylol, obtain containing to diformazan
The xylol raffinate of benzene, meta-xylene, o-Dimethylbenzene and ethylbenzene, after part xylol raffinate carries out isomerization reaction
Merge with carbon 8 aromatic hydrocarbons mixture；Another part xylol raffinate carries out rectification and removes o-Dimethylbenzene, diformazan between being contained
Benzene and the mixture of ethylbenzene.
Described isomerization reaction is that meta-xylene, o-Dimethylbenzene and part ethylbenzene are converted into the mixing containing xylol
Dimethylbenzene, the ethylbenzene being simultaneously difficult to part change removes ethyl and removes.
A kind of method that meta-xylene produces aromatic carboxylic acids with ethylbenzene multistep cooxidation, comprises the following steps:
(1) the xylol raffinate containing xylol, meta-xylene, o-Dimethylbenzene and ethylbenzene is carried out rectification removal
O-Dimethylbenzene, obtains the mixture A containing meta-xylene and ethylbenzene；
(2) mixture A is carried out multistep oxidation and generates containing M-phthalic acid and benzoic mixture B, by crystallization
Isolating the thick product of M-phthalic acid, crystalline mother solution obtains benzoic acid by evaporation and concentration；
(3) it is respectively adopted acetic acid and distilled water product thick to M-phthalic acid to wash, dried acquisition essence isophthalic two
Formic acid.
In step (1):
Xylol raffinate is after adsorbing separation goes out xylol, containing meta-xylene, o-Dimethylbenzene, ethylbenzene and a small amount of
Carbon 8 aromatic hydrocarbons mixture of xylol.
In terms of mass percent concentration, in xylol raffinate, xylol content is less than 1%, and meta-xylene content is
65～70%, ortho-xylene content is 20～30%, and ethyl-benzene level is 3～10%.Further, in xylol raffinate
Xylol content is less than 1%, and meta-xylene content is 65～69%, and ortho-xylene content is 25～28%, and ethyl-benzene level is 5
～8%.
The boiling point of OX differs 5.3 DEG C with MX, as preferably, uses rectifying column rectification separation o-Dimethylbenzene, and operating condition is:
Feeding from rectifying column middle and lower part, theoretical cam curve is 70～120, overhead reflux ratio 10～20, tower top temperature 139～141 DEG C, tower
End temperature 155～170 DEG C.
Under the operating conditions described above, obtain the mixture A of the OX content MX Yu EB less than 0.3% from rectifying column tower top, its
Middle MX content is more than 90%, and EB content is less than 10%, as producing essence M-phthalic acid (PIA) and benzoic former further
Material；Obtaining the heavy distillat of OX content ＞ 85% at the bottom of rectifying tower, heavy distillat can be sent into isomerization unit and be converted into mixed xylenes
Merge with carbon 8 aromatic hydrocarbons mixture and be used for adsorbing PX processed, it is possible to the OX product of rectification high-purity further.
In step (2):
From carbon 8 aromatic hydrocarbons, separate EB be always a technical difficult point.The boiling point of EB Yu MX only differs from 3 DEG C, it is difficult to rectification
Cutting.Although the two different melting points is relatively big, can separate with cryogenic crystallization in theory, but the feature of Crystallization Separation to be yield relatively low,
Having quite a few MX to be still difficult to reclaim in mother solution, cryogenic separation is relatively costly.
Mixture A containing MX and EB is carried out multistep cooxidation by the present invention, as preferably, during oxidation mixture A, with vinegar
Acid is solvent, and cobalt salt, manganese salt, hydrogen bromide are catalyst, and oxidant is oxygen-containing gas.
As preferably, described cobalt salt is cobaltous acetate, and manganese salt is manganese acetate.
As preferably, oxygen-containing gas is air.
As preferably, the operating condition of main oxidation is: temperature is 180～210 DEG C, and pressure is 1.0～1.5MPa, with solvent
The mean residence time meter response time be 45～90 minutes, the weight ratio of charging acetic acid and meta-xylene is 2～4: 1, with former
Sub-densitometer catalyst concn is: Co is 200～500ppm, and Mn is 200～500ppm, and Br is 400～1000ppm.
Under above-mentioned oxidizing condition, two methyl on MX are oxidized to corresponding alcohol, aldehyde, acid, between being finally translated into successively
Phthalic acid (IA), MX conversion ratio is more than 98%, and the yield of coarse isophthalic acid is more than 94%.
Proving after deliberation, the ethyl on ethylbenzene is relatively more active, and under above-mentioned oxidizing condition, ethyl can be by progressively oxidation transformation
Becoming mono carboxylic, ethylbenzene is converted into benzoic acid (BA), and EB conversion ratio is more than 99%, and BA yield is more than 96%.
The benzoic acid generated dissolubility in acetate solvate is very big, and the two constitutes dicarboxylic acids cosolvent, this common
Solvent has facilitation to the oxidation of alkylaromatic hydrocarbon, it is possible to accelerated oxidation is reacted.Therefore, benzoic generation is a kind of favourable
Factor in meta-xylene Yu ethylbenzene oxidation.On the other hand, the biggest due to benzoic acid dissolubility in solvent acetic acid and water
In M-phthalic acid, both oxidation products are easy for by Crystallization Separation, make M-phthalic acid be enriched in solid phase and benzoic acid
It is enriched in liquid phase, thus obtains two kinds of acid product respectively.
Reactant liquor after main oxidation is carried out follow-up multistep oxidation, by a small amount of reactant converted the most completely and middle product
Object depth degree is oxidized to product.
Through multistep oxidation can by main oxidation after reactant in reactant liquor and intermediate product be completely converted into product isophthalic
Dioctyl phthalate and benzoic acid, refine from without repeated hydrogenation.After deliberation, this is feasible, because the isophthalic diformazan that oxidation generates
Acid dissolubility in acetate solvate is the biggest, and under suitable oxidizing condition, reactant, intermedium all dissolve with product
In a solvent, not having or rarely solid separates out, this unreacted reactant allowing for dissolving in liquid phase can aoxidize several by multistep
It is completely converted into end product, without being wrapping in solid become impurity.
It should be noted that multistep oxidation technology was the most once suggested in the past, produce benzene for p xylene oxidation
The process of dioctyl phthalate, such as patent US4877900, US 4772748, JP 59-93029 just proposes employing 3 as far back as the 1980's
～4 step oxidation PX is converted into polymer grade p-phthalic acid without hydrofinishing step；Patent US2002/0183546A1,
CN02810929.5 also discloses the scheme of its two-step oxidation before more than ten years and prepares medium purity TPA, and the present inventor is also
The method proposing cascade raising temperature oxidation in patent CN201210238659.1 before the several years.But, these multisteps or multistage
One common feature of oxidation technology, is that the oxidizing condition of subsequent step is harsher than first step oxidizing condition, such as, the
The temperature of second oxidation will be higher 40～60 DEG C than the first step, pressure high 1～3MP.This is because oxidizing process generates one
A little intermediums such as p-carboxybenzaldehyde (4-CBA) and foreign pigment and product terephthalic acid's dissolubility in acetic acid are the most very
Little, after generation, cocrystallization separates out immediately is solid, and in solid, the impurity of parcel can ooze out solid the most at higher temperatures
Body enter liquid phase and oxidized.But it is significantly different to aoxidize then situation for meta-xylene, the intermedium of reaction dissolves with product
Degree is big, seldom has solid in main oxidation and the liquid phase of secondary oxidation step, therefore by multistep oxidation easily by liquid phase
Between thing be totally converted.Therefore, the multistep method for oxidation that the present invention uses is substantially distinguished from the scheme of proposition in the past, it is simply that main oxidation
Secondary or three oxidation steps afterwards all use the temperature, pressure condition more relaxed than main oxidation, are so more convenient for implementing,
Reduce the consumption of equipment investment and raw material simultaneously.
As preferably, the present invention uses two-step oxidation, but be not restricted to that two-step oxidation.
As preferably, the operating condition of secondary oxidation is: temperature is 170～207 DEG C, and pressure is 0.8～1.4MPa, with molten
The mean residence time meter response time of agent is 45～90 minutes, and charging acetic acid is 2～4: 1 with the weight ratio of meta-xylene, with
Atomic concentration meter catalyst concn is: Co is 200～500ppm, and Mn is 200～500ppm, and Br is 400～1000ppm.
The operating condition of secondary oxidation is more relatively mild than the operating condition of main oxidation, and temperature is low 3～10 DEG C, and pressure is low by 0.1
～0.2MPa.
After two-step oxidation, solids content ＜ 5% in slurry, concentration ＜ of carboxyl benzaldehyde (3-CBA) between impurity
40ppm。
After above-mentioned two-step oxidation, MX Yu EB is the most oxidized completely, and its representational intermedium 3-CBA is in mother solution
Concentration have been reduced to the level of trace.
Oxidation reactor can be bubble tower, gas-liquid agitation still and other kinds of gas-to-liquid contact and reaction unit.
The part of reaction output contains M-phthalic acid and benzoic mixture B sends into crystalline element decompression cooling, with
Separate out solid IA.
As preferably, using multistage crystallizer during crystallization, crystallizer decompression step by steps at different levels are lowered the temperature to separate out M-phthalic acid.
Using the purpose of multistage crystallization is to control the degree of supersaturation of crystallizer at different levels thus beneficially the growing up of crystal.
As preferably, the first crystallizer is passed through oxygen-containing gas by reactant remaining in mixture B and intermediate product
Deep oxidation.
In the first crystallizer, it is passed through oxygen-containing gas makes reactant remaining in mixture B and intermediate product deep oxidation,
So that the M-phthalic acid separated out reaches polymer grade requirement.
The temperature of afterbody crystallizer decides the response rate of solid product.For the crystallization process of M-phthalic acid,
The pressure of afterbody crystallizer typically wants evacuation to form negative pressure to reduce temperature, to greatest extent crystallization IA product.
As preferably, the operating condition of afterbody crystallizer is: pressure is-0.05～-0.08MPa, temperature be 80～
100 DEG C, in the slurry of solids obtained, solid holdup is 36～40%.
Described solid holdup is the quality of solid and the ratio of slurry of solids gross mass in slurry of solids.
Owing to benzoic acid dissolubility in acetic acid is far longer than M-phthalic acid, it is solid that product M-phthalic acid separates out
Body, product benzoic acid is still enriched with in the liquid phase, just can be separated both products by solid-liquor separation.
The output slurry of above-mentioned afterbody crystallizer is sent into liquid/solid separation unit, by filtering, being centrifuged or other liquid
Solid separation method obtains M-phthalic acid filter cake and containing benzoic oxidation mother liquor.A part of oxidation mother liquor directly returns oxidation
Reactor, another part oxidation mother liquor is sent into benzoic acid separative element and is evaporated solvent acetic acid, it is thus achieved that solid benzoic acid product.
Extracting out in oxidation mother liquor for separating the mass ratio of total oxidation mother liquor shared by benzoic stream stock A is 15～95%, extracts stream out
The ratio of stock A is the highest, and in oxidation mother liquor, benzoic concentration is the lowest, and the benzoic acid carried secretly in M-phthalic acid cake solids is also
The lowest.The crude benzol formic acid purity that oxidation mother liquor evaporation obtains is 95～98%, can be by further rectification under vacuum or recrystallization
Obtain the product of higher purity.The solvent acetic acid evaporated from benzoic acid separative element is all sent to follow-up pickling unit conduct
The pickling cleaning mixture of M-phthalic acid filter cake.
Heat and water that main oxidation reactor and secondary oxidation reactor produce remove reactor by the evaporation of solvent, by
Oxidized tail gas carrier enters solvent dehydration tower, its function water that mainly abjection reaction generates.
Solvent dehydration tower can be directly installed on the top of main oxidation reactor and be connected with reactor, it is also possible to individually
External.
The amount of the oxidized tail gas of secondary oxidation reactor is much smaller than the oxidized tail gas of main oxidation reactor, and pressure is relatively low, can
With with sending into solvent dehydration tower after compressor boost, it is also possible to individually will not coagulate tail gas after condensation and be sent directly into tail gas treating unit
Purified treatment.
Dehydration acetate partial reflux at the bottom of solvent dehydration tower tower enters main oxidation reactor, and part is extracted out as step (3)
The cleaning mixture of middle pickling.
The tower top steam containing inertia tail gas enters condenser, and condensed fluid about 1/3 is back to solvent dehydration as recirculation water
Tower, about 2/3 extracts out as the washings of washing in step (3).
Incoagulable gas in condenser is sent into after tail gas treating unit purifies and is discharged.
Condenser typically uses multi-stage condensing mode so that producing different grades of steam to reclaim the heat of tail gas.
In step (3):
Containing 10～the oxidation mother liquor of 30% in the M-phthalic acid filter cake obtained by liquid/solid separation unit, in oxidation mother liquor
Containing benzoic acid and other trace impurity, it is necessary to removed.
M-phthalic acid filter cake is sent to pickling unit, to remove the oxidation mother liquor carried secretly in M-phthalic acid filter cake.
The regenerated solvent acetic acid that the pickling cleaning mixture part employing benzoic acid separative element of pickling unit evaporates, one
Dividing the dehydration acetate used at the bottom of solvent dehydration tower tower, pickling cleaning mixture is 1～3 with the butt mass ratio of M-phthalic acid filter cake:
1。
Pickling mother solution after pickling returns main oxidation reactor and makees solvent, and the M-phthalic acid solid after pickling is sent to washing
Unit.
The equipment of pickling unit can use at present conventional wash mill, as making beating tank, filter, countercurrent washing tower,
Belt spray washing device, etc., can be single-stage washing, it would however also be possible to employ multi-stage countercurrent washs to improve efficiency, wherein liquid
Gu countercurrent washing is the most efficient mode of washing, can wash referring to the adverse current that inventor introduces in patent CN201010241238.5
Wash apparatus and method for.
The oxidation mother liquor carried secretly in M-phthalic acid solid after the pickling overwhelming majority (95～99.5%) is removed,
But in filter cake residual micro-benzene formic acid and acetic acid need nonetheless remain for removing further so that product reaches polymer grade requirement.To this end,
Also need to a water-washing step.
It is sent to wash unit by the M-phthalic acid solid that pickling unit exports, uses solvent dehydration tower overhead condenser to produce
Raw distilled water washs again, and distilled water used is 1～3: 1 with the butt mass ratio of M-phthalic acid solid.
The equipment and technology of washing unit can also use the device similar with pickling unit and technique, is not repeated to chat
State.
Washing mother solution after washing all sends into the solvent dehydration top of tower recirculation water as solvent dehydration tower.
If the M-phthalic acid solid after pickling is sent to wash unit the most again, then the washing mother solution washing unit contains
Acid amount is extremely low, can send into solvent dehydration tower top with the recirculation water of condenser after merging；And if the M-phthalic acid after pickling
Solid is not dried and is sent to wash unit in filter cake mode, then washing mother solution contains a small amount of acetic acid, and two strands of backflow are the most preferably
Individually sending into solvent dehydration tower, the reflux inlet washing mother solution in this case should be lower than the backflow of condenser by 2
～5 blocks of column plates, the concrete backwash deployment of washing mother solution easily determines according to its acid concentration when solvent dehydration Deethanizer design.
M-phthalic acid solid after washing is the most i.e. essence M-phthalic acid product, major impurity 3-in this product
CBA content ＜ 20ppm, benzoic acid content ＜ 20ppm, terephthaldehyde's acid content ＜ 1%, meet the matter of most polyester product
Amount requirement.
If improving the ratio for separating benzoic oxidation mother liquor Extract further, increase pickling and washing solvent
Consumption, improves the efficiency of multi-stage countercurrent washing, then in product, impurity content also can reduce further.
Compared with prior art, the invention have the benefit that
(1) present invention is only just obtained rich in meta-xylene also by rectification separation OX from xylol (PX) raffinate
Containing the oxidic raw materials of a small amount of ethylbenzene, avoid the MX adsorption separating method of costliness, more just washed by two step cooxidation and two steps
Obtain meeting the fine terephthalic acid products that production of polyester requires, the benzoic acid product of by-product technical grade, eliminated condition severe
The hydrofinishing step carved, it is possible to large-scale production M-phthalic acid and benzoic acid product in inexpensive manner, it is achieved PX produces
During the higher value application of raffinate that produces；
(2) method that the present invention provides is used, per ton containing meta-xylene 91.5%, ethylbenzene 7.5%, xylol 1.0%
Material liquid washed by two-step oxidation and two steps and can obtain about 1.4 tons of smart M-phthalic acids (PIA) and 0.085 ton of benzoic acid
(BA), 3-CBA content ＜ 20ppm in gained PIA, benzoic acid content ＜ 20ppm, p-phthalic acid about 1%, benzoic acid product is pure
Degree > 98%, productivity and the purity of product are the highest；
(3) each step and each unit of production process of the present invention operates all simple possible, discharges without organic wastewater simultaneously, is
A kind of economic and environment-friendly new technology.
Accompanying drawing explanation
Fig. 1 is that the present invention is with carbon 8 aromatic hydrocarbons for raw material production meta-xylene and the flow chart of ethylbenzene；
Fig. 2 is the present invention with meta-xylene and ethylbenzene for raw material production essence M-phthalic acid and benzoic flow chart.
Detailed description of the invention
With embodiment, the present invention is described in further detail below in conjunction with the accompanying drawings, it should be pointed out that the following stated is real
Execute example and be intended to be easy to the understanding of the present invention, and it is not played any restriction effect.
1, the production of meta-xylene
As it is shown in figure 1, a typical PX process units, naphtha reforming process is used to produce aromatic hydrocarbons and absorption method from carbon
Separating PX in 8 aromatic hydrocarbons, its main flow includes adsorbing separation and two modules of isomerization.Mix containing carbon 8 aromatic hydrocarbons of composition shown in table 1
The equiulbrium flow stock S104 that compound S100 exports with isomerization unit mix after together with send into PX absorbing unit U101, through adsorbing separation
Rear acquisition purity is the PX product of 99.5%, stream stock S101 export system, and raffinate S102 sends into isomerization reactor U102
Raw material S102 is converted into the equilibrium composition S104 containing PX, simultaneously removing part ethylbenzene, then absorption divides after mix with raw material S100
From PX, so move in circles, until raw material converts completely.In order to obtain MX, the present invention draws one from PX raffinate S102
Point, it is labeled as S105, after being separated off OX by rectification, obtains the stream stock S107 rich in MX.
The composition of the PX raffinate S105 drawn is as follows:
MX 67%, OX 27.5%, EB 5%, PX 0.5%.
The S105 of above-mentioned composition being sent into rectifying column U103, removes o-Dimethylbenzene OX, rectifying column condition is:
Theoretical cam curve 100, feed tray position is the 65th piece (order from top to bottom), feeding temperature 158 DEG C, tower top
Reflux ratio 16, column bottom temperature 167.8 DEG C, tower top temperature 139.2 DEG C, tower top pressure is normal pressure.
Under these conditions, charging S105 per ton can obtain 0.70 ton of overhead fraction S107,0.3 ton of tower bottom distillate S106,
The composition of two kinds of fractions is respectively as follows:
S107:MX 91.5%, EB 7.5%, PX 0.7%, OX 0.3%
S106:MX 10.6%, EB0.01%, PX 0.1%, OX 89.3%
Obtained stream stock S107, rich in MX, contains a small amount of EB and trace P X and OX simultaneously, and the raw material as cooxidation is sent into
Oxidation unit.
2, multistep cooxidation
The material liquid S107 obtained by said method adds as the feed stream stock S200A of oxidation reactor U201 in Fig. 2
This reactor, be simultaneously introduced also has catalyst S200B and circulating mother liquor S200C (predominantly acetic acid).It is blown into air to enter simultaneously
Row liquid phase oxidation.Main oxidation reactor is a bubbling column reactor without stirring, and its condition is listed in table 2.
Table 2 main oxidation reactor U201 operating condition
MX and the mass ratio of acetic acid (HAc) during in table, MX/HAc represents feed stream stock S200, pressure is tower top gauge pressure, solution
The time of staying=volume of mixture/solvent acetic acid flow, tail gas oxygen concentration refers to the butt concentration of oxygen in S210.
Under these conditions, the reaction result of reactor U201 is listed in table 3.
Table 3 main oxidation reactor U201 reaction result
In table, 3-CBA refers to carboxyl benzaldehyde between main reaction intermediates, and it is all to need to remove together with foreign pigment
Major impurity.The stream stock S201 of output also has a small amount of raw material and intermediate product completely of not aoxidizing, feeding two rich in IA simultaneously
Secondary oxidation reactor U202, this reactor is a gas-liquid agitation still, and reaction condition is listed in table 4, and oxidation results is listed in table 5.
Table 4 secondary oxidation reactor U202 operating condition
Table 5 secondary oxidation reactor U202 reaction result
Crystalline element U203 uses three grades of crystallizers, solvent is evaporated under reduced pressure step by step, separates out solid IA, wherein the first knot simultaneously
Brilliant device is passed through a small amount of air and supplements oxidation, and oxidation reactor U202 fails the liquid phase reactor thing deep conversion converted.Three grades of knots
The condition of brilliant device is listed in table 6 with result.
6 three grades of crystallizer U203 conditions of table and result
Liquid/solid separation unit U204 sent into by the slurry of crystallizer U203 output, is filtered oxidation mother liquor and solid by vacuum
IA separate, obtain M-phthalic acid filter cake S204A, this filter cake contain oxidation mother liquor 15%, in mother solution containing 4.5% benzoic acid and its
Its trace impurity, sends into pickling unit U206 washing.
The mother solution of liquid/solid separation unit U204 output is divided into two strands, and it is anti-that the mother solution S204B of 50% is recirculated directly back to oxidation
Answering device U201, second half mother solution S204C extracts out and is sent to benzoic acid separative element U205, in this unit, by the solvent in mother solution
Acetic acid evaporates, and acetic acid S205 sends into pickling unit U206 and is used as washing liquid, and the benzoic acid fused solution of concentration passes through vacuum fine further
Evaporate and be purified to 98% or higher purity, discharge after a small amount of high boiling point Slag recovering catalyst at the bottom of rectifying column.Extracting 50% out
Under conditions of mother liquid evaporation Separation of Benzene formic acid, the benzoic concentration of liquid phase in oxidation reactor can be controlled and be less than 5%.
3, pickling, washing
The filter cake S204A of the water capacity 15% of liquid/solid separation unit U204 output sends into pickling unit U206, with clean
The mother solution that acetate solvate carries out washing to remove in filter cake reduces the impurity content in solid product.Washing liquid acetic acid has two to come
Source a: part is the solvent S205 of benzoic acid separative element U205 evaporation, adds secondary oxidation reactor U202 and three grades of crystallizations
The acetic acid of device tower top evaporation, this part acetic acid amount and the mass ratio about 1: 1 of dry basis；Part II is from dehydrating tower backflow vinegar
Acid S208B draws a part of S208C, this part acetic acid amount and the mass ratio about 0.5: 1 of dry basis.Two parts acetic acid heat exchange
Temperature is adjusted to about 120 DEG C after recovering energy by cooling, is then fed into scrubbing tower and washs with filter cake counter current contacting.Scrubbing tower is one
The vertical mixing that individual inventor introduced in patent CN201010241238.5 is liquid-solid counter-flow moving bed, and filter cake adds from tower top
Entering, bottom is discharged, and washing liquid adds from tower bottom, and top is discharged, and is further cooled to 90 DEG C of a small amount of solids that precipitation is recovered by filtration
Rear feeding main oxidation reactor U201.After the acetic acid using 1.5 times of weight carries out countercurrent washing to solid, the mother carried secretly in filter cake
Liquid more than 99.5% is replaced by fresh acetic acid, is dried by filter cake, after removing major part acetic acid, and the benzoic acid of residual in solid
Concentration still has about 300ppm, acetic acid residual 60ppm, also needs to wash benzoic acid and the acetic acid removing residual further.
The solid S206A exported by pickling unit sends into washing unit U207 after drying and washes away the micro-benzene formic acid of remaining,
Washing unit washing liquid uses the distilled water S209 that dehydrating tower evaporator overhead condenser U209 produces, and draws it out 2/3 feeding scrubbing tower
U207 bottom, with solid S206A counter current contacting.Washing unit U207 is also a liquid-solid adverse current similar with pickling unit U206
Moving bed, washings still use 1.5: 1 with the mass ratio of solid, and the feeding temperature of cleaning mixture is adjusted to 100 DEG C, adds from tower bottom
Enter top output, the most all send into dehydrating tower as backflow S207.Solid is carried out inverse by the distilled water using 1.5 times of weight
After stream washing, filter cake is dried, and obtains essence M-phthalic acid solid product.The most benzoic butt residual quantity about 15ppm,
In solid, the content of remaining component is: PIA99.3%, PTA0.7%, 3-CBA 20ppm.
The tail gas S201B of main oxidation reactor top output sends into the water that rectifying column U208 elimination reaction generates, rectifying column
Dehydration acetate S208B partial reflux at the bottom of U208 tower enters oxidation reactor, and part is extracted out and is sent to acid as pickling washing liquid S208C
Wash unit；The tower top steam containing inertia tail gas enters condenser U209, and condensed fluid S209 partial reflux to dehydrating tower U208 is made
For recirculation water S209C, part is extracted the washings S209B as washing unit out and is sent into washing unit U207.In condenser U209
Incoagulable gas send into tail gas treating unit U210 purify after discharge.The parameter of solvent dehydration tower U208 is: 60 pieces of theoretical towers
Version, column bottom temperature 196 DEG C, tower top temperature 180 DEG C, in rectifier column reflux liquid, overhead condensate reflux liquid S209C returns with washing mother solution
The ratio of flow liquid S207 is 1: 2, acetic acid content ＜ 50ppm in the fixed gas of discharge, can be by condensing recovery further.Secondary oxygen
Changing reactor U202 top tail gas amount less, use condenser directly to condense, lime set merges with S208C and is sent to pickling unit
U206, does not coagulate tail gas and is routed directly to Tail gas cleanup unit U210.
In the present embodiment, solvent dehydration tower is divided into two sections: one section and is directly installed on main oxidation containing 5～15 blocks of theoretical trays
The top of reactor U201, is connected with bubble tower, collectively forms main oxidation unit U201, if the present inventor is conventional special
Profit CN200420107473.3, as CN200510048977.1 is introduced；Another section of rectifying column is the most external, containing 45～55
Block theoretical plate, constitutes dehydrating tower unit U208.The tail gas of main oxidation reactor U201 generation and the steam dehydration by its top
After section separate section acetic acid and the drop carried secretly of tail gas or particulate matter, enter dehydrating tower U208 and separate acetic acid and water, steam with
Incoagulable gas enters condenser U209 from tower top and obtains distilled water S209, after incoagulability tail gas sends into U210 Recovery Purifying pressure energy
Discharge, in condensed water U209,1/3 is back to U208, and 2/3 extraction is delivered to wash unit U207 as washings, the mother solution after washing
S207 returns dehydrating tower U208 together with recirculation water S209C.The water-containing acetic acid S208B produced at the bottom of dehydrating tower tower extracts 0.5 times out admittedly
Pickling unit U206 is sent into, acid together with the liquid S208C of body S204A weight, the acetic acid S205 produced with benzoic acid segregation apparatus
Mother solution S206B after washing sends main oxidation reactor back to.The distilled water by this way dehydrating tower U208 produced and fresh acetic acid
To greatest extent for the washing of solid filter cake, thus on the one hand decrease the impurity content that solid is carried secretly, the most greatly
Decrease the discharge of organic wastewater.
In the present embodiment, per ton pass through containing meta-xylene 91.5%, ethylbenzene 7.5%, xylol material liquid O.5%
Two-step oxidation and the washing of two steps can obtain about 1.4 tons of smart M-phthalic acids (PIA) and 0.085 ton of benzoic acid (BA), gained PIA
Middle 3-CBA content ＜ 20ppm, benzoic acid content ＜ 20ppm, p-phthalic acid ＜ 1%, benzoic acid product purity ＞ 98%.This
Each step of invention production process and each unit operate all simple possible, discharge without organic wastewater simultaneously, are a kind of economic and environment-friendly
New technology.
Technical scheme and beneficial effect have been described in detail by embodiment described above, it should be understood that
The foregoing is only the specific embodiment of the present invention, be not limited to the present invention, all done in the spirit of the present invention
Any amendment, supplement and equivalent etc., should be included within the scope of the present invention.
Claims (10)
1. the method that a meta-xylene produces aromatic carboxylic acids with ethylbenzene multistep cooxidation, it is characterised in that comprise the following steps:
(1) the xylol raffinate containing xylol, meta-xylene, o-Dimethylbenzene and ethylbenzene is carried out rectification and removes adjacent two
Toluene, obtains the mixture A containing meta-xylene and ethylbenzene；
(2) mixture A carries out multistep oxidation generate containing M-phthalic acid and benzoic mixture B, pass through Crystallization Separation
Going out the thick product of M-phthalic acid, crystalline mother solution obtains benzoic acid by evaporation and concentration；
(3) it is respectively adopted acetic acid and distilled water product thick to M-phthalic acid to wash, dried acquisition essence M-phthalic acid.
The method of production aromatic carboxylic acids the most according to claim 1, it is characterised in that in terms of mass percent concentration, right
In dimethylbenzene raffinate xylol content be less than 1%, meta-xylene content is 65～70%, ortho-xylene content be 20～
30%, ethyl-benzene level is 3～10%.
The method of production aromatic carboxylic acids the most according to claim 1, it is characterised in that in step (1), uses rectifying column essence
Fraction from o-Dimethylbenzene, operating condition is: feeding from rectifying column middle and lower part, theoretical cam curve is 70～120, overhead reflux ratio 10
～20, tower top temperature 139～141 DEG C, column bottom temperature 155～170 DEG C.
The method of production aromatic carboxylic acids the most according to claim 1, it is characterised in that during oxidation mixture A, with acetic acid be
Solvent, cobalt salt, manganese salt, hydrogen bromide are catalyst, and oxidant is oxygen-containing gas.
The method of production aromatic carboxylic acids the most according to claim 1, it is characterised in that in step (2), mixture A is entered
Row two-step oxidation generates containing M-phthalic acid and benzoic mixture B.
The method of production aromatic carboxylic acids the most according to claim 5, it is characterised in that the operating condition of main oxidation is: temperature
Degree is 180～210 DEG C, and pressure is 1.0～1.5MPa, and in terms of the mean residence time of solvent, the response time is 45～90 minutes,
Charging acetic acid is 2～4: 1 with the weight ratio of meta-xylene, and in terms of atomic concentration, catalyst concn is: Co is 200～500ppm,
Mn is 200～500ppm, and Br is 400～1000ppm.
The method of production aromatic carboxylic acids the most according to claim 5, it is characterised in that the operating condition of secondary oxidation is:
Temperature is 170～207 DEG C, and pressure is 0.8～1.4MPa, and in terms of the mean residence time of solvent, the response time is 45～90 points
Clock, the weight ratio of charging acetic acid and meta-xylene is 2～4: 1, and in terms of atomic concentration, catalyst concn is: Co be 200～
500ppm, Mn are 200～500ppm, and Br is 400～1000ppm.
The method of production aromatic carboxylic acids the most according to claim 1, it is characterised in that in step (2), uses many during crystallization
Level crystallizer, the operating condition of afterbody crystallizer is: pressure is-0.05～-0.08MPa, and temperature is 80～100 DEG C,
To slurry of solids in solid holdup be 36～40%.
The method of production aromatic carboxylic acids the most according to claim 1, it is characterised in that in step (2), produces oxidation reaction
Raw oxidized tail gas sends into the water that solvent dehydration tower rectification elimination reaction generates, and the dehydration acetate part at the bottom of solvent dehydration tower tower is returned
Stream enters oxidation reactor, and part is extracted out as the cleaning mixture of pickling in step (3)；The tower top steam containing inertia tail gas enters
Condenser, partial condensation liquid is back to solvent dehydration tower as recirculation water, and another part condensed fluid is as washing in step (3)
Washings, washing mother solution is back to solvent dehydration tower again as recirculation water.
The method of production aromatic carboxylic acids the most according to claim 1, it is characterised in that in step (2), crystalline mother solution steams
When sending out concentrating and separating benzoic acid, evaporation recovered solvent acetic acid is as the cleaning mixture of pickling in step (3), and pickling mother liquor reflux is extremely
Oxidation reactor is as solvent.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107935811A (en) * | 2017-11-17 | 2018-04-20 | 杭州多向流化学科技有限公司 | A kind of method using meta-xylene oxidation reaction thermal rectification separating mixed dimethyl |
| CN108003006A (en) * | 2017-11-17 | 2018-05-08 | 杭州多向流化学科技有限公司 | A kind of method that terephthalic acid (TPA) and M-phthalic acid are produced using C8 aronmatic as raw material |
| CN108046971A (en) * | 2017-11-17 | 2018-05-18 | 杭州多向流化学科技有限公司 | Using mixed xylenes as raw material aromatics separation and the method for preparing M-phthalic acid |
| CN109251139A (en) * | 2018-11-02 | 2019-01-22 | 中国石油天然气集团有限公司 | Using the PIA production method and production system of deep oxidation |
| CN109865493A (en) * | 2019-01-31 | 2019-06-11 | 浙江大学 | A kind of twin drum bubble column reaction unit and reaction process for p xylene oxidation |
| WO2021196386A1 (en) * | 2020-03-31 | 2021-10-07 | 南京延长反应技术研究院有限公司 | Built-in micro-interface oxidation system and method for preparing terephthalic acid from p-xylene |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1512976A (en) * | 2001-06-04 | 2004-07-14 | �Ϻ���ͨ��ѧ | Two stage oxidation process for production of aromatic dicarboxylic acids |
| CN1962598A (en) * | 2006-11-23 | 2007-05-16 | 浙江大学 | Method for producing benzene dicarboxylic acid by mixed dimethylbenzene cooxidation |
| US20070208192A1 (en) * | 2006-03-01 | 2007-09-06 | Wonders Alan G | Polycarboxylic acid production system employing hot liquor removal downstream of oxidative digestion |
| CN101318890A (en) * | 2008-07-15 | 2008-12-10 | 中国石油化工股份有限公司 | Method for preparation of mixed benzol dimethanoic acid and benzene acetic acid |
| CN101508638A (en) * | 2008-02-13 | 2009-08-19 | 周向进 | Method for preparing mixed benzol dioctyl phthalate and benzene acetic acid |
| CN101575284A (en) * | 2008-05-05 | 2009-11-11 | 周向进 | Novel method for manufacturing PIA |
| US20110057147A1 (en) * | 2008-03-18 | 2011-03-10 | Ball George A | Systems and processes for the production of isophthalic acid and terephthalic acid |
-
2016
- 2016-07-25 CN CN201610590523.5A patent/CN106167451B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1512976A (en) * | 2001-06-04 | 2004-07-14 | �Ϻ���ͨ��ѧ | Two stage oxidation process for production of aromatic dicarboxylic acids |
| US20070208192A1 (en) * | 2006-03-01 | 2007-09-06 | Wonders Alan G | Polycarboxylic acid production system employing hot liquor removal downstream of oxidative digestion |
| CN1962598A (en) * | 2006-11-23 | 2007-05-16 | 浙江大学 | Method for producing benzene dicarboxylic acid by mixed dimethylbenzene cooxidation |
| CN101508638A (en) * | 2008-02-13 | 2009-08-19 | 周向进 | Method for preparing mixed benzol dioctyl phthalate and benzene acetic acid |
| US20110057147A1 (en) * | 2008-03-18 | 2011-03-10 | Ball George A | Systems and processes for the production of isophthalic acid and terephthalic acid |
| CN101575284A (en) * | 2008-05-05 | 2009-11-11 | 周向进 | Novel method for manufacturing PIA |
| CN101318890A (en) * | 2008-07-15 | 2008-12-10 | 中国石油化工股份有限公司 | Method for preparation of mixed benzol dimethanoic acid and benzene acetic acid |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107935811A (en) * | 2017-11-17 | 2018-04-20 | 杭州多向流化学科技有限公司 | A kind of method using meta-xylene oxidation reaction thermal rectification separating mixed dimethyl |
| CN108003006A (en) * | 2017-11-17 | 2018-05-08 | 杭州多向流化学科技有限公司 | A kind of method that terephthalic acid (TPA) and M-phthalic acid are produced using C8 aronmatic as raw material |
| CN108046971A (en) * | 2017-11-17 | 2018-05-18 | 杭州多向流化学科技有限公司 | Using mixed xylenes as raw material aromatics separation and the method for preparing M-phthalic acid |
| CN109251139A (en) * | 2018-11-02 | 2019-01-22 | 中国石油天然气集团有限公司 | Using the PIA production method and production system of deep oxidation |
| CN109251139B (en) * | 2018-11-02 | 2021-06-25 | 中国石油天然气集团有限公司 | PIA production method and production system adopting deep oxidation |
| CN109865493A (en) * | 2019-01-31 | 2019-06-11 | 浙江大学 | A kind of twin drum bubble column reaction unit and reaction process for p xylene oxidation |
| WO2021196386A1 (en) * | 2020-03-31 | 2021-10-07 | 南京延长反应技术研究院有限公司 | Built-in micro-interface oxidation system and method for preparing terephthalic acid from p-xylene |
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