CN104276937B - Adipic acid and the method for C* binary acid is prepared by cyclohexane oxidation by-product - Google Patents
Adipic acid and the method for C* binary acid is prepared by cyclohexane oxidation by-product Download PDFInfo
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- CN104276937B CN104276937B CN201410301645.9A CN201410301645A CN104276937B CN 104276937 B CN104276937 B CN 104276937B CN 201410301645 A CN201410301645 A CN 201410301645A CN 104276937 B CN104276937 B CN 104276937B
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- C07—ORGANIC CHEMISTRY
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- 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
- C07C51/27—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with oxides of nitrogen or nitrogen-containing mineral acids
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- C—CHEMISTRY; METALLURGY
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Abstract
The invention belongs to technical field of organic synthesis, be specifically related to be prepared adipic acid and C by cyclohexane oxidation by-product4～6The method of binary acid.The technical problem to be solved in the present invention is to provide one and is prepared adipic acid and C by cyclohexane oxidation by-product4～6The method of binary acid, prepares adipic acid and C with the by-product of cyclohexane oxidation for raw material4～6Binary acid.The technical scheme is that and prepared adipic acid and C by cyclohexane oxidation by-product4～6The method of binary acid, comprises the steps: the separation of by-product in a, cyclohexane oxidation liquid；B, by-product are converted into adipic acid and C4～6Binary acid；C, adipic acid and C4～6The separation and recovery of binary acid.The by-product produced during alkali saponified for air oxidation of cyclohexane decomposition technique is separated by the present invention, and successful conversion is important chemical products adipic acid and C4～6Binary acid, reaches the effect that consumption reduction reduces discharging, makes full use of resource, turns waste into wealth.
Description
Technical field
The invention belongs to technical field of organic synthesis, be specifically related to be prepared adipic acid and C by cyclohexane oxidation by-product4 ~ 6The method of-binary acid.
Background technology
Adipic acid is important aliphatic dibasic acid, is important industrial chemicals and intermediate, mainly for the manufacture of nylon-66, polyurethane, plasticizer, lubricant, insecticide and binding agent etc..
C4 ~ 6-binary acid refers to the mixed dibasic acid being made up of succinic acid, 1,3-propanedicarboxylic acid, adipic acid, also known as nylon acid, is also important industrial chemicals, can be used as producing the raw material of multiple polyurethane foam plastics；If utilizing C9 ~C10Primary alconol can obtain high-quality softening agent, for polrvinyl chloride to mixed dibasic acid esterification so that it is has excellent cold conditions shock resistance；Mixed dibasic acid dimethyl ester (DBE) can be obtained as paint solvent with methanol esterification, have use safely, prevent from polluting the performances such as environment；If mixed dibasic acid is carried out isolated adipic acid, 1,3-propanedicarboxylic acid, succinic acid, then purposes is wider.
In existing industrial production technology, the production technology of adipic acid is divided into hexamethylene technique, cyclohexene technique and Butadiene Extraction Process by raw materials used, its cyclohexane technique is the main technique producing adipic acid, all uses hexamethylene technique in the world in more than the 70% of adipic acid production.Hexamethylene technique is also known as two-step penetration method: first passes through air oxidation of cyclohexane and obtains containing cyclohexyl hydroperoxide and the cyclohexane oxide solution of a small amount of by-product, then carry out catalytic decomposition in the basic conditions, rectification separates and to obtain Hexalin and cyclohexanone mixture (KA oil)；Then adipic acid is prepared with nitric acid oxidation KA oil, and by crystallization of adipic acid mother solution obtains C4 ~ 6-binary acid.Wherein, the first step air oxidation process of hexamethylene is non-catalyst oxidation, and the conversion ratio of hexamethylene is 3.5～5.0%, and KA oil selectivity is 80～88%, and KA oil consumption hexamethylene amount per ton is 970～1040kg；The selectivity of KA oil nitric acid oxidation production adipic acid is 89～93%, and adipic acid per ton consumption KA oil mass is 730～760kg；During hexamethylene two-step penetration method produces adipic acid, obtain C simultaneously4 ~ 6The yield of-binary acid is the 3.5～5% of adipic acid yield.Comprehensively, hexamethylene two-step penetration method produce adipic acid overall selectivity 71～81%, will obtain C4 ~ 6The yield of-binary acid adds up, then hexamethylene two-step penetration method produces adipic acid and C4 ~ 6The overall selectivity of-binary acid is 76～84.5%.This shows to produce adipic acid, coproduction C at hexamethylene two-step penetration method4 ~ 6During-binary acid, there are about 15.5～24% hexamethylene generate by-product or carbon dioxide or have a small amount of loss.Analyze the operating process of hexamethylene two-step penetration method, its hexamethylene generates the process of by-product and is mainly first step air oxidation process, as produced a large amount of spent lye (Organic substance accounts for the 10～20% of adipic acid yield) containing acylate in the alkali saponified catalytic decomposition process of cyclohexyl hydroperoxide, the light oil (accounting for the 1.2～1.8% of adipic acid yield) obtained during Hexalin and Ketohexamethylene and X oil (accounting for the 2.5～3.8% of adipic acid yield) is separated with rectification at Distillation recovery hexamethylene, wherein the spent lye containing acylate is the maximum place to go of the by-product that air oxidation of cyclohexane process generates.According to hexamethylene non-catalytic oxidation reaction mechanism, the reaction that hexamethylene occurs oxidation to generate cyclohexyl hydroperoxide belongs to the free radical type reaction mechanism mechanism of reaction having branch, the deep oxidation that a small amount of hexamethylene the most inevitably occurs reacts, thus generate some organic acid, ester and other oxidized byproduct, such as C1 ~C6Monoacid (including the acid of 6 hydroxycaproic acid, hexanal), C2 ~C6Binary acid, esters, the derivant (such as cyclohexanediol, hexamethylene alcohol ketone, cyclohexenol or cyclonene etc.) etc. of cyclohexanol/cyclohexanone.These by-products during the heterogeneous catalysis decomposition reaction of further cyclohexyl hydroperoxide, with NaOH aqueous solution be neutralized, major part proceeds in alkali liquor after saponification, especially organic acid and esters, thus generates the spent lye containing organic acid sodium.This type of spent lye can not discharge, need to carry out burning disposal, therefore this technical process to consume a large amount of alkali liquor, produce a large amount of reluctant industrial caustic simultaneously, more it's a pity and wasted the inevitable by-product (such as above-mentioned Organic substance) being converted into useful chemical products generated in cyclohexane oxidation process.
In sum, since hexamethylene liquid phase air oxidation technique is applied, the processing method of the most many researcheres spent lye to producing in air oxidation of cyclohexane-alkali saponified catabolic process has carried out numerous studies, in addition to industrial commonly used burning method processing method, also have and use acid adding neutralize and then reclaim organic chemical method.Though burning method is industrial commonly used processing method, but it it not a kind of good method.Though acid adding neutralizes and then reclaims organic chemical method is a kind of conventional processing method, but the processing procedure three wastes are more, use in sulphuric acid such as patent US3859335, US3993691, US4052441 and after spent lye separates black acid liquid, black acid liquid is first dehydrated, esterification is carried out after separated goes out monoacid under low temperature and high vacuum condition again, separated available Glutaric Acid Dimethyl ester, dimethyl adipate, hydroxycaproic acid methyl ester product, complex technical process, there is more waste water to generate, and the organic by-products response rate is low；The technical characterstic of patent CN1177576A is need not be in fresh mineral acid and spent lye, use instead in by-product hydrochloric acid and Waste Sulfuric Acid and spent lye, it is that saponated sewage is extracted by extractant with isooctanol and isomer thereof the most again, but still it is low to there is organic by-product recovery rate.The general thought of these patented technologies is: neutralize with acid (various mineral acid), then reclaims Organic substance therein with proper method.So in circulation, first employ a large amount of alkali liquor when processing the by-product during cyclohexane oxidation cyclohexanol/cyclohexanone, after from spent lye reclaim Organic substance time consume again substantial amounts of mineral acid, therefore this processing procedure is the most uneconomical, and not environmentally, the three wastes are more, and the organic by-products response rate is low.
Patent CN101045682A (2007) is according to the ultimate principle of liquid-liquid extraction, water extraction oxidation solution is used to obtain acidic aqueous solution, then catalysis oxidation is carried out, again through evaporation and concentration, carry out esterification with alcohols material in the presence of a catalyst, after processing further, obtain mixed organic acid ester.The processing procedure of this patent, not only cost is high, three waste discharge is many, and by-product recovery rate low (other the nonacid organic by-products as generated in cyclohexane oxidation process is not reclaimed), reclaim product (mixed organic acid ester) surcharge low simultaneously.
Patent CN1184802A (1998) introduces a kind of method preparing diacid from similar cyclohexane oxidation product washing sour water, propose to use catalytic hydrogenation, evaporation and concentration, the method for nitric acid oxidation to process washing sour water, processing procedure exists the most not enough: (1) catalytic hydrogenation uses the catalyst such as noble metal such as Pd, and it is high to operate pressure, adds production cost；(2) it is reduced into alcohol compound after making the catalytic hydrogenations such as the existing carbonyl compound in former acid waste water, thus when using nitric acid oxidation, increases nitric acid dosage.Patent CN1193009A (1998) uses evaporation and concentration, ω-HPOCaP to decompose, the method for nitric acid oxidation processes this type of washing sour water, obtains adipic acid and succinic acid, 1,3-propanedicarboxylic acid, adipic acid mixed dibasic acid.Compared with patent CN1184802A (1998), this patent has the advantages such as technological process is short, need not high pressure equipment, easy and simple to handle, nitric acid consumption is low, but the purity of obtained succinic acid, 1,3-propanedicarboxylic acid, adipic acid mixed dibasic acid is relatively low, and after obtaining adipic acid and binary acid, still there is a certain amount of residual liquid to process further, the most the Organic substance in washing sour water is not completely converted into useful products and reclaims.
Patent CN1927804A (2007) is on the basis of CN1193009A (1998), there is provided a kind of washing sour water containing HPOCaP produced during cyclohexane oxidation Hexalin and Ketohexamethylene is produced non-metallic ion 4,5, the method for 6-carbon dicarboxylic acid, this patented method does not has the deficiency of above-mentioned patent (CN1193009A, CN1184802A), not only during nitric acid oxidation, nitric acid unit consumption is low, do not have a residual liquid discharge, and obtain purity higher 4,5,6-carbon dicarboxylic acid.But patent CN1193009A (1998), CN1927804A (2007) and patent CN1184802A (1998) etc. are all to produce C for the acid waste water produced in hexamethylene oxygen deprivation oxidation process4 ~ 6-binary acid, the separation of the by-product for producing during air oxidation of cyclohexane-alkali saponified decomposition technique, reclaims, is converted into adipic acid and mixed dibasic acid (C4 ~ 6-binary acid) technique be all not directed to.Owing to hexamethylene oxygen deprivation oxidizing process is different with the technological parameter of air oxidation of cyclohexane process, oxidant oxygen content different, the by-product kind produced is different with amount, the recycling of the by-product therefore produced for air oxidation of cyclohexane process, is especially translated into adipic acid and C4 ~ 6-binary acid, improves hexamethylene two-step penetration method and produces adipic acid and C4 ~ 6The method of-binary acid yield does not also have patent and document report.
Summary of the invention
The technical problem to be solved is to provide one and is prepared adipic acid and C by cyclohexane oxidation by-product4 ~ 6The method of-binary acid, prepares adipic acid and C with the by-product of cyclohexane oxidation for raw material4 ~ 6-binary acid.The technical scheme is that
Adipic acid and C is prepared by cyclohexane oxidation by-product4 ~ 6The method of-binary acid, comprises the steps:
A, cyclohexane oxidation；
In b, step a, the by-product in oxidation liquid separates: the oxidation liquid oil phase obtained by cyclohexane oxidation process, the 1st extraction tower it is continuously introduced into from bottom, it is made to carry out reverse extracting and washing, by the 1st extraction tower bottom collection wash water solution with the desalted water aqueous phase from tower top in the 1st extraction tower；The aqueous phase wash water solution of the 1st extraction tower bottom collection is continuously introduced into from top the 2nd extraction tower so that it is in the 2nd extraction tower with carry out reverse back extraction washing from the oil phase fresh cyclohexane at the bottom of tower, by the 2nd extraction tower bottom collection wash water solution；During reverse extraction pressure be 0.1～0.6MPa, the volume ratio of extraction temperature 60～90 DEG C, oil phase cyclohexane oxide solution aqueous phase be 80～110 1；During reverse back extraction pressure be 0.1～0.5MPa, 60～90 DEG C, the volume ratio of oil phase fresh cyclohexane aqueous phase be 2～6 1；
C, by-product are converted into adipic acid and C4 ~ 6-binary acid: wash water solution step b obtained is evaporated concentrating under decompression or condition of normal pressure, and evaporation capacity is 40～75wt%；It is that oxidant carries out oxidation reaction by the concentrated solution nitric acid obtained, use gradient nitric acid oxidation reaction process, reaction temperature is 50～95 DEG C, the intermittently operated response time is 3～5h, the continuous operation time of staying is 10～15h, the concentration range of oxidant nitric acid is 55～95%, and in concentrated solution, Organic substance is 1.0 1.5～2.5 with the quality rate of charge of nitric acid；
D, adipic acid and C4 ~ 6The separation of-binary acid: nitric acid oxidation reaction liquid step c obtained carries out crystallisation by cooling, sucking filtration, obtains crystal and filtrate；Crystallization final temperature controls at 15～25 DEG C, and crystallization time is 2～8h；Gained crystal is thick crystallization of adipic acid, and gained filtrate is C4 ~ 6-binary acid solution；
E, thick adipic acid refined: thick adipic acid crystals step d obtained carries out recrystallization and produces essence adipic acid；Recrystallization condition is: addition 0.1～1.5% activated carbon are made into 30% solution, and bleaching temperature is 70～90 DEG C, bleaching time 0.5～1.5h, and crystallization final temperature is at 20～30 DEG C, and crystallization time is 4～6h；Or the thick crystallization of adipic acid obtained in step d is sent into recovery in adipic acid recrystallization commercial plant, to increase essence adipic acid yield；
f、C4 ~ 6The recovery of-binary acid: filtrate step d obtained carries out concentrating under decompression or condition of normal pressure, melts, cuts into slices and produce C4 ~ 6-binary acid；Concentrate, melted final temperature controls at 130～160 DEG C；Or the filtrate obtained in step d is sent in binary acid recovery commercial plant to increase binary acid yield.
Concrete, the non-catalyst oxidation being oxidized to air, oxygen denuded air, oxygen-enriched air or pure oxygen described in step a.
Concrete, in step b, extraction tower is packed tower or plate column.
Concrete, in step b, during reverse extraction, the volume ratio of pressure 0.3～0.5MPa, extraction temperature 65～75 DEG C, oil phase cyclohexane oxide solution aqueous phase is 90～100 1.
Concrete, in step b during reverse back extraction pressure be 0.3～0.5MPa, the volume ratio of extraction temperature 65～75 DEG C, oil phase fresh cyclohexane aqueous phase be 3～4 1.
Concrete, the nitric acid oxidation reaction in step c is continuous operation, and reaction temperature is 60～90 DEG C, the time of staying 12～15h, and the concentration range of nitric acid is 60～65%.
Wherein, the nitric acid oxidation reaction intermittently operated in step c is gradient increased temperature or continuous operation employing multi-floating bodies.
Preferably, crystallizing final temperature in step d is 20 DEG C, crystallization time 4～8h.
Preferably, concentrate in step d, melted final temperature controls at 140～150 DEG C.
Beneficial effects of the present invention:
Current industrial commonly used air oxidation of cyclohexane-alkali saponified decomposition technique technology can be efficiently solved by the present invention and produce problem present in Hexalin and Ketohexamethylene method.The by-product produced during air oxidation of cyclohexane-alkali saponified decomposition technique is separated by the present invention, and successful conversion is important chemical products adipic acid and C4 ~ 6-binary acid, turns waste into wealth.Owing to being efficiently separated by the by-product produced during air oxidation of cyclohexane, therefore in the alkali saponified decomposition technique of principal product cyclohexyl hydroperoxide of air oxidation of cyclohexane reaction, decrease raw material alkali 30～the consumption of 50%；Meanwhile, minimizing 20～the discharge of 40% spent lye, during burning disposal spent lye, save the energy resource consumption of about 20～40%.
The inventive method is by by-product obtaining adipic acid and C present in air oxidation of cyclohexane liquid4 ~ 6-binary acid, there is the advantages such as technological process is short, need not high pressure equipment, easy and simple to handle, nitric acid consumption is low, and the separation efficiency of by-product reaches 40～70% present in air oxidation of cyclohexane liquid, in the by-product separated, total organic content is 15～25wt%.Wherein, in Organic substance, ω-HPOCaP content is 40～60wt%, C2～C6Diacid content is 20～50wt%, C1～C6Monoacid content is 10～20wt%, neutrals (including esters, cyclohexanediol, hexamethylene alcohol ketone, cyclohexenol or cyclonene, aldehydes etc.) content is 20～50wt%), the by-product separated be converted back into yield ＞ 90%.
The method using the present invention, on the premise of not increasing the consumption of raw material hexamethylene, the process units of a set of 70,000 tons of adipic acids of annual output, the by-product separated in hexamethylene first step oxidation reaction process can produce essence adipic acid 1400～2000 tons, C4 ~ 6-binary acid 2500～3500 tons, so that hexamethylene two-step penetration method produces adipic acid, coproduction C4 ~ 6The adipic acid yield of the prior art of-binary acid and C4 ~ 6-binary acid yield has been respectively increased 2～3% and 80～110%, improves resource utilization.
Detailed description of the invention
Oxygen denuded air refers to use nitrogen by Dilution air to oxygen content less than the oxygen content in air.No matter but use oxygen denuded air, air or oxygen-enriched air or even pure oxygen, it is identical to oxidation reaction process and the mechanism of hexamethylene, it it is all the reaction carried out between oxygen molecule and hexamethylene molecule, therefore the principal product and the by-product kind that are generated are identical, simply the amount of various by-products is incomplete same, so the technology of the present invention all can be used to process.
In the case of a small amount of production or laboratory, nitric acid oxidation process can use intermittently operated；The inventive method industrially can be used to operate continuously, be suitable for large-scale production.But continuous process is also not limited, and is more suitable for continuous prodution.
In step c of the present invention, wash water solution step b obtained is evaporated concentrating under decompression or condition of normal pressure, and when evaporation capacity is 40～75wt%, in obtained concentrated solution, content of organics is 40～50wt%, it is adaptable to carry out subsequent operation.
Owing to being 80 DEG C under the boiling point normal pressure of hexamethylene, the temperature therefore washing cyclohexane oxide solution preferably controls below 80 DEG C, as hexamethylene volatilization loss can be caused more than 80 DEG C or cause danger, and therefore should be less than 80 DEG C under extracting operation temperature normal pressure.If but when operating under elevated pressure, operation temperature can be properly increased.As at laboratory treatment cyclohexane oxide solution, in the case of not using supercharging equipment, atmospheric extraction can be used.In the industrial production, after cyclohexane oxide solution washes out by-product, it is also performed to the decomposition reaction of next step cyclohexyl hydroperoxide, this reaction need certain pressure and at a temperature of carry out, therefore for ensureing seriality and the operability of technological operation, extract the most under a certain pressure, therefore in the industrial production, preferably extracting pressure is 0.3～0.5MPa.
Below by way of specific embodiment, the present invention is described in further detail, but the present invention is not restricted to embodiment.
Embodiment 1 uses the inventive method to produce adipic acid and C4 ~ 6-binary acid
80kg air oxidation of cyclohexane liquid is taken from air oxidation of cyclohexane device, in extraction tower, it is in a ratio of 100 with deionized water by oil/water wash, the wash water solution fresh cyclohexane obtained is 3 to carry out backwash and wash by oil/water, there are wash water solution 1.26kg, wherein content of organics is 20.6% (weight), wash temperature is 70 DEG C, operates pressure normal pressure.The washings obtained are carried out atmospheric evaporation concentration, and the light group component distilled out is 60%, obtains concentrated solution and is divided into 2 parts:
(1) 1 part is the nitric acid oxidation of 60% with content, reaction temperature employing gradient increased temperature: 55 ± 5 DEG C, 65 ± 5 DEG C, 75 ± 5 DEG C, 85 ± 5 DEG C, total reaction time is 3h, and nitric acid dosage is 270g, the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtaining thick adipic acid crystals and add 1% activated carbon and be made into 30% solution, recrystallization after 80 DEG C of conditions decolour 1h, crystallization and recrystallization final temperature control at 20 DEG C, and crystallization time is 4h.The adipic acid crystals being recrystallized to give is dried to obtain 38.2g white essence adipic acid product；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 155 DEG C, cooling section obtains 78.5g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.48%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 28.52%, 1,3-propanedicarboxylic acid 50.5%, succinic acid 21.43%, and binary acid total content is 94.6%；
(2) 1 parts is the nitric acid oxidation of 55% with content, and reaction temperature uses gradient increased temperature: 60 ± 5 DEG C, 70 ± 5 DEG C, 80 ± 5 DEG C, 90 ± 5 DEG C, total reaction time is 4h, and nitric acid dosage is 285g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtaining thick adipic acid crystals and add 1.5% activated carbon and be made into 30% solution, recrystallization after 70 DEG C of conditions decolour 0.5h, crystallization and recrystallization final temperature control at 15 DEG C, and crystallization time is 3h.The adipic acid crystals being recrystallized to give obtains 37.6g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 160 DEG C, cooling section obtains 79.9g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.57%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 27.02%, 1,3-propanedicarboxylic acid 50.25%, succinic acid 22.73%, and binary acid total content is 93.9%.
Embodiment 2 uses the inventive method to produce adipic acid and C4 ~ 6-binary acid
85kg air oxidation of cyclohexane liquid is taken from air oxidation of cyclohexane device, in extraction tower, it is in a ratio of 110 with deionized water by oil/water wash, the wash water solution fresh cyclohexane obtained is 4 to carry out backwash and wash by oil/water, there are wash water solution 1.28kg, wherein content of organics is 21.8% (weight), wash temperature is 65 DEG C, and operation pressure is normal pressure.The washings obtained are carried out atmospheric evaporation concentration, and the light group component distilled out is 58%, obtains concentrated solution and is divided into 2 parts:
(1) 1 part is the nitric acid oxidation of 60% with content, and reaction temperature uses gradient increased temperature: 60 ± 5 DEG C, 70 ± 5 DEG C, 80 ± 5 DEG C, 90 ± 5 DEG C, total reaction time is 4h, and nitric acid dosage is 275g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 0.5% activated carbon and be made into 30% solution, recrystallization after 90 DEG C of conditions decolour 1h.Crystallization and recrystallization final temperature control at 20 DEG C, and crystallization time is 3.5h.The adipic acid crystals being recrystallized to give obtains 41.2g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 155 DEG C, cooling section obtains 79.6g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.58%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 28.17%, 1,3-propanedicarboxylic acid 51.5%, succinic acid 20.33%, and binary acid total content is 95.1%；
(2) 1 parts is the nitric acid oxidation of 65% with content, and reaction temperature uses gradient increased temperature: 60 ± 5 DEG C, 70 ± 5 DEG C, 80 ± 5 DEG C, 90 ± 5 DEG C, total reaction time is 3h, and nitric acid dosage is 260g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 0.6% activated carbon and be made into 30% solution, recrystallization after 80 DEG C of conditions decolour 1.5h.Crystallization and recrystallization final temperature control at 15 DEG C, and crystallization time is 4h.The adipic acid crystals being recrystallized to give obtains 42.1g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 160 DEG C, cooling section obtains 80.1g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.52%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 27.52%, 1,3-propanedicarboxylic acid 50.22%, succinic acid 22.26%, and binary acid total content is 94.9%.
Embodiment 3 uses the inventive method to produce adipic acid and C4 ~ 6-binary acid
75kg air oxidation of cyclohexane liquid is taken from air oxidation of cyclohexane device, in extraction tower, it is in a ratio of 95 with deionized water by oil/water wash, the wash water solution fresh cyclohexane obtained is 4 to carry out backwash and wash by oil/water, there are wash water solution 1.209kg, wherein content of organics is 18.5wt%, wash temperature is 65 DEG C, operates pressure normal pressure.The washings obtained are carried out atmospheric evaporation concentration, and the light group component distilled out is 62%, obtains concentrated solution and is divided into 2 parts:
(1) 1 part is the nitric acid oxidation of 65% with content, and reaction temperature uses gradient increased temperature: 60 ± 5 DEG C, 70 ± 5 DEG C, 80 ± 5 DEG C, 90 ± 5 DEG C, total reaction time is 4h, and nitric acid dosage is 275g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 1% activated carbon and be made into 30% solution, recrystallization after 75 DEG C of conditions decolour 1h.Crystallization and recrystallization final temperature control at 20 DEG C, and crystallization time is 3.5h, and the adipic acid crystals being recrystallized to give obtains 37.8g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 160 DEG C, cooling section obtains 68.2g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.48%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 28.67%, 1,3-propanedicarboxylic acid 51.2%, succinic acid 20.13%, and binary acid total content is 94.7%；
(2) 1 parts is the nitric acid oxidation of 60% with content, and reaction temperature uses gradient increased temperature: 60 ± 5 DEG C, 70 ± 5 DEG C, 80 ± 5 DEG C, 90 ± 5 DEG C, total reaction time is 3h, and nitric acid dosage is 280g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 0.5% activated carbon and be made into 30% solution, recrystallization after 85 DEG C of conditions decolour 1.5h.Crystallization and recrystallization final temperature control at 15 DEG C, and crystallization time is 4h, and the adipic acid crystals being recrystallized to give obtains 36.5g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 160 DEG C, cooling section obtains 69.8g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.52%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 27.52%, 1,3-propanedicarboxylic acid 50.22%, succinic acid 22.26%, and binary acid total content is 94.6%.
Embodiment 4 uses the inventive method to produce adipic acid and C4 ~ 6-binary acid
70kg air oxidation of cyclohexane liquid is taken from air oxidation of cyclohexane device, in extraction tower, it is in a ratio of 90 with deionized water by oil/water wash, the wash water solution fresh cyclohexane obtained is 4 to carry out backwash and wash by oil/water volume ratio, there are wash water solution 1.225kg, wherein content of organics is 18.4wt%, wash temperature is 65 DEG C, operates pressure normal pressure.The washings obtained are carried out atmospheric evaporation concentration, and the light group component distilled out is 63%, obtains concentrated solution and is divided into 2 parts:
(1) 1 part is the nitric acid oxidation of 65% with content, and reaction temperature uses gradient increased temperature: 60 ± 5 DEG C, 70 ± 5 DEG C, 80 ± 5 DEG C, 90 ± 5 DEG C, total reaction time is 3.5h, and nitric acid dosage is 270g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 1.5% activated carbon and be made into 30% solution, recrystallization after 80 DEG C of conditions decolour 1h.Crystallization and recrystallization final temperature control at 15 DEG C, and crystallization time is 4h, and the adipic acid crystals being recrystallized to give obtains 36.2g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 155 DEG C, cooling section obtains 68.2g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.38%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 28.27%, 1,3-propanedicarboxylic acid 50.5%, succinic acid 21.23%, and binary acid total content is 94.1%；
(2) 1 parts is the nitric acid oxidation of 60% with content, and reaction temperature uses gradient increased temperature: 60 ± 5 DEG C, 70 ± 5 DEG C, 80 ± 5 DEG C, 90 ± 5 DEG C, total reaction time is 4h, and nitric acid dosage is 280g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 1% activated carbon and be made into 30% solution, recrystallization after 85 DEG C of conditions decolour 1h.Crystallization and recrystallization final temperature control at 20 DEG C, and crystallization time is 3h.The adipic acid crystals being recrystallized to give obtains 36.4g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 160 DEG C, cooling section obtains 68.5g milky, flake binary acid.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.42%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 27.22%, 1,3-propanedicarboxylic acid 51.12%, succinic acid 21.66%, and binary acid total content is 94.1%.
Embodiment 5 uses the inventive method to produce adipic acid and C4 ~ 6-binary acid
70kg air oxidation of cyclohexane liquid is taken from air oxidation of cyclohexane device, in extraction tower, it is in a ratio of 80 with deionized water by oil/water wash, the wash water solution fresh cyclohexane obtained is 4 to carry out backwash and wash by oil/water, there are wash water solution 1.348kg, wherein content of organics is 16.9wt%, wash temperature is 70 DEG C, operates pressure normal pressure.The washings obtained are carried out atmospheric evaporation concentration, and the light group component distilled out is 55%, obtains concentrated solution and is divided into 2 parts:
(1) 1 part is the nitric acid oxidation of 95% with content, and reaction temperature uses gradient increased temperature: 55 ± 5 DEG C, 65 ± 5 DEG C, 75 ± 5 DEG C, 85 ± 5 DEG C, 95 ± 5 DEG C, total reaction time is 4h, and nitric acid dosage is 190g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 1% activated carbon and be made into 30% solution, recrystallization after 80 DEG C of conditions decolour 1.5h.Crystallization and recrystallization final temperature control at 20 DEG C, and crystallization time is 4h, and the adipic acid crystals being recrystallized to give obtains 36.4g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 155 DEG C, cooling section obtains 70.2g milky, flake dicarboxylic acid product.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.28%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 28.17%, 1,3-propanedicarboxylic acid 51.52%, succinic acid 20.31%, and binary acid total content is 92.1%；
(2) 1 parts is the nitric acid oxidation of 80% with content, and reaction temperature uses gradient increased temperature: 60 ± 3 DEG C, 66 ± 3 DEG C, 72 ± 3 DEG C, 78 ± 3 DEG C, 84 ± 3 DEG C, 90 ± 3 DEG C, total reaction time is 3h, and nitric acid dosage is 210g.By the nitric acid oxidation reaction liquid crystallisation by cooling obtained, sucking filtration.Wherein, obtain thick adipic acid crystals and add 1.5% activated carbon and be made into 30% solution, recrystallization after 85 DEG C of conditions decolour 1h.Crystallization and recrystallization final temperature control at 20 DEG C, and crystallization time is 3h.The adipic acid crystals being recrystallized to give obtains 36.5g white essence adipic acid product after being dried；Twice crystallization filtrate being merged, evaporation and concentration to final temperature 160 DEG C, cooling section obtains 69.7g milky, flake binary acid.Through liquid-phase chromatographic analysis: in essence adipic acid product, adipic acid content is 99.42%；In dicarboxylic acid product, the relative amount of three kinds of binary acid is followed successively by adipic acid 27.28%, 1,3-propanedicarboxylic acid 51.36%, succinic acid 21.36%, and binary acid total content is 93.1%.
Result according to embodiment 1～5, in 70,000 tons of adipic acid plants of a set of annual output, enforcement the inventive method consumption the year before last NaOH30% alkali liquor amount is that 2.8 ten thousand tons of (wherein in air oxidation of cyclohexane liquid, the alkali number of acid and ester consumption accounts for 65%～75%, is calculated as 1.96 ten thousand tons by 70%), salkali waste liquid measures of discharge are about 50,000 tons.As cyclohexane conversion be 3.5%, Hexalin and Ketohexamethylene selectivity be 82%, adipic acid selectivity be 92%, C4 ~ 6-binary acid yield is the 4% of adipic acid yield, then air oxidation of cyclohexane liquid measure is 147.1458 ten thousand tons, and after producing by the inventive method, the NaOH30% alkali liquor consumption of reduction is shown in Table 1 with reducing spent lye emission result, the adipic acid of increase and C4 ~ 6-binary acid yield the results are shown in Table 2 with yield.
Table 1 reduces soda consumption and reduces spent lye emission result table (year)
Each index explanation in table 1:
(1) index such as " H+/% ", " ester/% ", " mistake/% " is the analysis indexes that current adipic acid manufacturer normally produces.Wherein: " H+/% " is the percentage molar concentration of the carboxyl of all organic acid by-product in cyclohexane oxide solution；" ester/% " is the weight/mass percentage composition that in cyclohexane oxide solution, organic acid esters by-product is calculated by adipic acid dicyclohexano ester；" mistake/% " refers to the weight/mass percentage composition that in cyclohexane oxide solution, peroxide is calculated by cyclohexyl hydroperoxide；
(2) " quality/t " refers to the quality of NaOH30% alkali liquor or the quality of few waste discharge alkali liquor reduced, unit be ton (symbol t), wherein:
The computing formula of the quality of the NaOH30% alkali liquor reduced=[(enter out H+ in cyclohexane oxide solution poor × cyclohexane oxide solution total amount+enter out the difference of ester content × cyclohexane oxide solution total amount × 2/310 in cyclohexane oxide solution)/100] × 40/30%；
The NaOH30% alkali liquor quality of the reduction of the computing formula of the quality of few waste discharge alkali liquor=obtain+enter out H+ differential conversion in cyclohexane oxide solution becomes the quality (w1) of organic acid+enter out the differential conversion of ester content in cyclohexane oxide solution to become the quality (w2) of organic acid esters+enter out the differential conversion of peroxide content in cyclohexane oxide solution to become the quality (w3) of ω-HPOCaP.Example: w1=147.1458 × (0.0056-0.0023) × 70 (mean molecule quantity of organic acid)/100 in embodiment 1, w2=147.1458 × (0.10-0.08)/100, w3=147.1458 × (3.03-2.97)/100.
(3) " than/% " for reducing alkali liquor consumption or the percentage ratio of few waste discharge alkali liquor, wherein:
Reduce quality × 100%/(28000 × 70%) of the NaOH30% alkali liquor of computing formula=reduction that alkali liquor consumes；
Few waste discharge alkali liquor quality × 100%/50000 of computing formula=few waste discharge alkali liquor.
Table 2 improves adipic acid and C4 ~ 6-binary acid yield result table (year)
Claims (17)
1. prepared adipic acid and C by cyclohexane oxidation by-product4~6The method of-binary acid, it is characterised in that: comprise the steps:
A, cyclohexane oxidation；
In b, step a, the by-product in oxidation liquid separates: the oxidation liquid oil phase obtained by cyclohexane oxidation process, the 1st extraction tower it is continuously introduced into from bottom, it is made to carry out reverse extracting and washing, by the 1st extraction tower bottom collection wash water solution with the desalted water aqueous phase from tower top in the 1st extraction tower；The aqueous phase wash water solution of the 1st extraction tower bottom collection is continuously introduced into from top the 2nd extraction tower so that it is in the 2nd extraction tower with carry out reverse back extraction washing from the oil phase fresh cyclohexane at the bottom of tower, by the 2nd extraction tower bottom collection wash water solution；During reverse extraction pressure be 0.1 ~ 0.6MPa, the volume ratio of extraction temperature 60～90 DEG C, oil phase cyclohexane oxide solution aqueous phase be 80～110 1；During reverse back extraction pressure be 0.1 ~ 0.5MPa, 60～90 DEG C, the volume ratio of oil phase fresh cyclohexane aqueous phase be 2～6 1；
C, by-product are converted into adipic acid and C4~6-binary acid: wash water solution step b obtained is evaporated concentrating under decompression or condition of normal pressure, and evaporation capacity is 40 ~ 75wt%；It is that oxidant carries out oxidation reaction by the concentrated solution nitric acid obtained, use gradient nitric acid oxidation reaction process, reaction temperature is 50～95 DEG C, the intermittently operated response time is 3～5h, the continuous operation time of staying is 10 ~ 15h, the concentration range of oxidant nitric acid is 55～95%, and in concentrated solution, Organic substance is 1.0 1.5～2.5 with the quality rate of charge of nitric acid；
D, adipic acid and C4~6The separation of-binary acid: nitric acid oxidation reaction liquid step c obtained carries out crystallisation by cooling, sucking filtration, obtains crystal and filtrate；Crystallization final temperature controls at 15 ~ 25 DEG C, and crystallization time is at 2 ~ 8h；Gained crystal is thick crystallization of adipic acid, and gained filtrate is C4~6-binary acid solution；
E, thick adipic acid refined: thick adipic acid crystals step d obtained carries out recrystallization and produces essence adipic acid；Recrystallization condition is: adding 0.1 ~ 1.5% activated carbon and be made into 30% solution, bleaching temperature is 70 ~ 90 DEG C, bleaching time 0.5 ~ 1.5h, and crystallization final temperature is at 20 ~ 30 DEG C, and crystallization time is at 4 ~ 6h；Or the thick crystallization of adipic acid obtained in step d is sent into recovery in adipic acid recrystallization commercial plant, to increase essence adipic acid yield；
f、C4~6The recovery of-binary acid: filtrate step d obtained carries out concentrating under decompression or condition of normal pressure, melts, cuts into slices and produce C4~6-binary acid；Concentrate, melted final temperature controls at 130～160 DEG C；Or the filtrate obtained in step d is sent in binary acid recovery commercial plant to increase binary acid yield.
2. the method for claim 1, it is characterised in that: the non-catalyst oxidation being oxidized to air, oxygen denuded air, oxygen-enriched air or pure oxygen described in step a.
3. such as the method for claim 1 or 2, it is characterised in that: in step b, extraction tower is packed tower or plate column.
4. the method for claim 1, it is characterised in that: in step b, during reverse extraction, pressure 0.3 ~ 0.5MPa, extraction temperature 65 ~ 75 DEG C, the volume ratio of oil phase cyclohexane oxide solution aqueous phase are 90 ~ 100 1.
5. the method for claim 1, it is characterised in that: in step b during reverse back extraction pressure be 0.3 ~ 0.5MPa, extraction temperature 65 ~ 75 DEG C, the volume ratio of oil phase fresh cyclohexane aqueous phase be 3 ~ 41.
6. method as claimed in claim 1 or 2, it is characterised in that: the nitric acid oxidation reaction in step c is continuous operation, and reaction temperature is 60～90 DEG C, the time of staying 12 ~ 15h, and the concentration range of nitric acid is 60～65%.
7. method as claimed in claim 3, it is characterised in that: the nitric acid oxidation reaction in step c is continuous operation, and reaction temperature is 60～90 DEG C, the time of staying 12 ~ 15h, and the concentration range of nitric acid is 60～65%.
8. the method as described in claim 4 or 5, it is characterised in that: the nitric acid oxidation reaction in step c is continuous operation, and reaction temperature is 60～90 DEG C, the time of staying 12 ~ 15h, and the concentration range of nitric acid is 60～65%.
9. method as claimed in claim 1 or 2, it is characterised in that: crystallizing final temperature in step d is 20 DEG C, crystallization time 4 ~ 8h.
10. method as claimed in claim 3, it is characterised in that: crystallizing final temperature in step d is 20 DEG C, crystallization time 4 ~ 8h.
11. methods as described in claim 4 or 5, it is characterised in that: crystallizing final temperature in step d is 20 DEG C, crystallization time 4 ~ 8h.
12. methods as claimed in claim 6, it is characterised in that: crystallizing final temperature in step d is 20 DEG C, crystallization time 4 ~ 8h.
13. methods as claimed in claim 1 or 2, it is characterised in that: concentrate in step d, melted final temperature controls at 140～150 DEG C.
14. methods as claimed in claim 3, it is characterised in that: concentrate in step d, melted final temperature controls at 140～150 DEG C.
15. methods as described in claim 4 or 5, it is characterised in that: concentrate in step d, melted final temperature controls at 140～150 DEG C.
16. methods as claimed in claim 6, it is characterised in that: concentrate in step d, melted final temperature controls at 140～150 DEG C.
17. methods as claimed in claim 10, it is characterised in that: concentrate in step d, melted final temperature controls at 140～150 DEG C.
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| CN113735703A (en) * | 2021-09-16 | 2021-12-03 | 宁夏瑞泰科技股份有限公司 | Method for effectively recovering dibasic acid and nitric acid from adipic acid wastewater |
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