TWI352079B - Process and apparatus for manufacturing aromatic c - Google Patents

Description

IX. INSTRUCTIONS: C TECHNICAL FIELD OF THE INVENTION The present invention relates to a method and apparatus for preparing an aromatic acid retardant by oxidizing an aromatic feed material to an impurity in a liquid phase oxidation reaction mixture. The aromatic carboxylic acid product 'is separated from the high temperature and high pressure off-gas from the liquid phase oxidation reaction to recover the liquid water and liquid reaction solvent used for the oxidation reaction, and is divided between the liquid and the gas phase also obtained from the separation step Soluble oxidation by-product. C Prior Art 3 Background of the Invention Terephthalic acid and other aromatic carboxylic acids are widely used for the preparation of poly-glycols, which are usually converted by reaction with ethylene glycol, high carbon alkylene glycol or the like. Fibers, films, containers, bottles and other packaging materials and molded parts. In commercial practice, 'aromatic carboxylic acids are usually in the presence of a cobalt- and manganese-containing catalyzing catalyst, using air or another source of oxygen (which is usually gaseous oxygen) to be substituted with methyl groups in aqueous acetic acid solvents. A raw material of benzene and naphthalene, wherein the position of the methyl substituent corresponds to the position of the slow base in the acid-releasing product of the desired group, and is prepared by liquid phase oxidation reaction. The oxidation reaction is exothermic and can produce aromatic citric acid and by-products, including partial or intermediate oxidation products of the aromatic raw material, and acetic acid reaction products such as methanol, methyl acetate, and methyl bromide. It is also produced as a by-product. The resulting aromatic carboxylic acid, which is typically produced with the oxidation by-product of the feedstock, is typically dissolved or suspended in the liquid phase reaction mixture and is typically recovered by crystallization and solid-liquid separation techniques. The exothermic oxidation reaction is usually carried out in a suitable reaction vessel at elevated temperature and pressure. The liquid phase reaction mixture is maintained in the vessel, and the gas phase formed by the exothermic oxidation is evaporated from the liquid phase, and then -5 g (d) is self-reacted to control the reaction temperature. The phase depletion includes water vapor, vaporized acetic acid reaction '☆ agent and a small amount of by-products of the oxidation reaction' which include both solvent and raw materials. It usually also contains oxygen that is not consumed in the oxidation reaction, a small amount of ruthenium-reacted raw materials, carbon oxides, and when the oxygen source of the method is air or a mixture of three oxygen gases, it is the source gas. Nitrogen, oxidized 1 〇 carbon and other inert gaseous components. For the manufacture of polyesters for important applications such as fibers and bottles, it is often preferred to use aromatic carboxylic acids in pure form, as impurities are known, such as aromatics derived from oxidation processes such as By-products of the starting materials, and more broadly, various aryl-substituted aromatic species are known which can result in the coloration of the polyester from the acid or its color formation, and subsequently also the polyester The discoloration of the converted φ material. As is known from U.S. Patent Nos. 4,877,900, 4,772,748 and 4,286,101, a pure open acid of a type with a small amount of impurities can be obtained by one or more progressive types. The lower temperature and oxygen content are further oxidized from the crude product of the above liquid phase oxidation reaction, and the conversion of the raw material partial oxidation product to the desired acid product is recovered, and the oxidation products are recovered during the crystallization. Preferably, the pure form of terephthalic acid and other aromatic carboxylic acids having a lower impurity content, such as purified p-dicarboxylic acid or "PTA", are prepared by using a precious metal catalyst at a high temperature and a high pressure. The acid is catalytically hydrogenated in an ultra-pure form, such as a crude product of an aromatic carboxylic acid and a by-product produced by liquid phase oxidation of an aromatic 6-member material, or a so-called medium purity product. In commercial practice, the liquid phase oxidation reaction of the aromatic aromatic feed material into a crude aromatic carboxylic acid and the purification of the crude product are generally carried out in a continuous integration process in which the crude product obtained from the liquid phase oxidation reaction It is used as a starting material for the purification reaction. The high temperature and high pressure gas phase produced by the liquid phase oxidation reaction in these processes are recoverable acetic acid reaction solvents, unreacted substances and reaction by-products, and potential sources of energy; however, their high water content , high temperature and high pressure and technical and economic problems due to the corrosive nature of components such as gaseous bromine, acetic acid solvent and water for separating or recovering components for recycling and recycling their energy content. Moreover, if impurities can adversely affect other process aspects or product quality, then even impurities that have not been separated in the process stream can interfere with the reuse of the stream. As described in U.S. Patent No. 5,200,557, for example, monocarboxylic acids can adversely affect the hydrogenation catalyst used in the purification process, even low levels of acetic acid residues such as those present in the crude aromatic carboxylic acid product recovered from the oxidation reaction liquid. Things are also considered harmful. British Patent Specification No. 1,373,230, U.S. Patent Nos. 5,3,4,676, 5,723,656, 6,143,925, 6,504,051, European Patent Specification 0 498 591 B1, and International Patent Application No. 97/27,168 A method for preparing an aromatic tetrandic acid by a liquid phase oxidation reaction of an aromatic feed material, wherein the high pressure exhaust gas is removed from the oxidation reaction, and the exhaust gas is treated to recover and recycle a part or a component thereof, and in some In the case of recycling energy. The condensing action of the exhaust gas as described in U.S. Patent No. 5,304,676 can effectively recover water, acetic acid and other condensable components of the exhaust gas, but the separation of water, acetic acid and other components in the formed condensate is technically complicated. And it is not economically viable. The high-pressure exhaust gas separation method of the method described in U.S. Patent Nos. 5,723,656, 6,143,925, 6,504,051 and W097/27168 can effectively separate the exhaust gas to recover an acetic acid-rich liquid and water vapor suitable for further processing. gas. However, in such separations, the specific by-products of the oxidation reaction tend to be soluble in the liquid phase and the gas phase, which complicates their recovery and potentially adversely affects other process streams and steps. These difficulties are due to the process 'which allows the by-product-containing material stream (such as the liquid residue obtained after recovering the aromatic carboxylic acid in pure form from the purified liquid reaction mixture or the liquid obtained by condensing the exhaust gas from the high pressure separation method) In the separation method, the accumulation of such by-products becomes more serious. None of the above patents uses a liquid condensed from a high pressure exhaust gas obtained from a liquid phase oxidation reaction as a solvent or other aqueous liquid required for purifying an impure aromatic carboxylic acid' and in these processes a 'recovery of substances and energy sources' By sacrificing each other, for example, if the high temperature and high pressure gas phase derived from the oxidation reaction are not cooled or depressurized to remove such substances, once cooled or depressurized to recover the substances, combustion substances to control the atmospheric emissions This can result in loss of energy content and loss of oxidizing solvents, raw materials and by-products. Impurities remaining in the recycle stream can disrupt process operation and impair product quality. Additional equipment and process steps for recovering materials, energy, or both can further increase process complexity and limit or hinder its practical use because it adds more cost than the material and energy saved. The effects of these factors, lost energy and lost material will increase depending on the scale of the process operation. In the annual production of the product is 5 〇〇, 〇〇〇 to 1, 〇〇〇, 〇〇〇 ton or higher, world-class commercial money, even fractional percentage of green _ raw materials and solvent loss or conversion into non- Desire or instability (4) Substance, slight inefficiency in energy recovery and discharge water treatment (4) The cost of addition and replacement will be due to the difference in cost and change in energy, materials and demand for processing C-state and liquid discharges and effluent. Process steps that result in significant physical loss of material, increased consumption and increase in fuel or electricity consumption, and non-reversible process efficiency and economic conditions. [Inventive Summary] The present invention provides a method and a device, and their implementation and feature is that the aromatic buffer can be provided or prepared by liquid phase oxidation reaction of an aromatic hydrocarbon feed material. Further, the high-pressure gas phase obtained from the liquid phase oxidation reaction can be treated to separate and recover the oxidation reaction solvent, water, and oxidation by-products. In some embodiments, the present invention may also advantageously recover energy from the oxidizing off-gas. The present invention also provides an improved process and apparatus for the preparation of an aromatic carboxylic acid which selectively controls by-products of the aromatic feed material produced in the liquid oxidation reaction and by-products of the monodecanoic acid reaction solvent for oxidation And by-products present in the gasification reaction off-gas or by-products present during the treatment of the offgas to separate the water and its oxidation reaction solvent. According to an aspect of the present invention, it is preferred that the by-products are dissolved in a liquid phase containing one or more oxidation reaction solvents or water from a high-pressure gas phase of a liquid phase oxidation reaction under high pressure, or In the high pressure gas from the separation step. If the other conditions are the same, the control of such by-products according to the present invention can reduce the amount of impurities present in the liquid or vapor stream derived from the off-gas. The control method can also be used in the process of preparing the product phase, and the product is used in comparison with the undissolved in the gas phase or in the gas phase directly or at a higher concentration. 'In the integrated method wherein the by-products are more energy-stable, the inclusions are used in the preparation of the pure form to produce an aromatic-containing carboxyl group, and the aqueous liquid can be removed or reduced in the present invention. Included in the liquid reaction mixture, the crude product of the oxidation source acid and the oxidation by-product of the feed material, wherein the solution is purified by the solution of the solution, and the hair is obtained from the filamentous cut water or The demand for pure water, and the balance between the water produced in the liquid phase oxidation reaction and the water consumed in the purification, which is not achieved by known methods, is obtained, and the method of the present invention is substantially superior to such Known methods. In addition to the auto-oxidation reaction off-gas separating the hydrazine and water into a liquid phase suitable for return or for the oxidation and purification steps, the process of the invention comprises the step of recovering the aromatic carboxylic acid from the purified reaction solution by refluxing. Examples of liquids containing liquefied mother liquor remaining after the acid product. In these examples, not only oxidation by-products, such as terephthalic acid or isophthalic acid, which are desired as aromatic acid products, can be converted. Carboxybenzaldehyde a methyl benzoic acid oxidizing intermediate' and a solvent monocarboxylic acid such as a solvent residue in the impure aromatic carboxylic acid product used to form the purification solution, and a solvent by-product remaining in the gas obtained from the separation step, The oxidation reaction can be returned. The solvent monocarboxylic acid, the reaction product produced in the liquid phase oxidation reaction, the unreacted aromatic feed material obtained from the oxidation reaction or the gas which is present in a large amount from the oxidation reaction The recovery of the combination of the solvent monocarboxylic acid in the phase and the high pressure gas phase remaining after the water can be further improved according to other examples, wherein the high pressure gas system obtained from the separation step is condensed to recover the aqueous liquid, and remains Lower high pressure condenser off-gas which is cooled to one or more oxygen scavengers effective to remove one or more of the feed material, solvent and oxidation by-products of the solvent. The formed gas may be further treated to separate the feed Substances and/or such solvent by-products, and in another embodiment, the feed-containing material, solvent by-products, or a combination thereof may be subjected to a liquid phase oxidation reaction. In one aspect, the invention provides a device for preparing aromatic tetamine. The device can improve energy recovery rate and avoid material loss during process operation. In some of the embodiments, the device can be constructed by a reduced process. The corrosive nature of the gas stream provides additional advantages, so that the components of the device and, in some cases, the components of the accessory or other process equipment can be made of metals and alloys having suitable corrosion resistance, such as stainless steel, mild steel or dual precision. Steelmaking (as a substitute for titanium), nickel alloy steel, and other more highly resistant high-impact metals used in the manufacture of aromatic carboxylic acids. In short, the apparatus of the present invention is used for separation a reactor off-gas component produced by subjecting a substituted aromatic hydrocarbon feed to liquid phase oxidation in a liquid phase reaction mixture to produce an aromatic carboxyl group I, and comprising a substantially columnar closed vessel comprising (a) At least one lower gas inlet for receiving the high pressure overhead gas phase removed from the reaction vessel and sent to the first stage of the sub-zone of the apparatus to maintain the liquid phase reaction mixture and a liquid phase oxidation reaction of the substituted aromatic hydrocarbon feed material with gaseous oxygen in a liquid phase reaction mixture containing a mono-steamed acid solvent and water under conditions in which a high pressure overhead gas phase containing a solvent of monosulfide is produced in the vessel; (b) a fractionation zone for contacting the gas with a countercurrent flowing liquid phase in a number of theoretical equilibrium stages, and comprising (第一) a first portion of 1,352,079 parts which can be separated in large quantities and intermediate stages from the fractionation zone Receiving a refluxing liquid component of the refluxing liquid component in contact with the water and the solvent monocarboxylic acid in the high pressure gas phase, whereby the first liquid phase rich in the solvent monoterpene acid is transferred into the reflux liquid and forms an aqueous phase The solvent of the vapor monocarboxylic acid is depleted in the first 5 intermediate gas phase, wherein the first portion is in circulation with the intermediate portion of the residing zone to receive its reflux liquid and pass the first intermediate gas phase, and includes Means for delivering the reflux liquid to which the first liquid phase has been transferred to the liquid reservoir;

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20 (2) an intermediate portion 'which is separable from the water of the first intermediate gas phase t which is contacted with the reflux liquid containing the reverse flow of the liquid component received from the upper portion of the separation device (4) a liquid phase oxidation by-product of the hydrocarbon feedstock f, whereby the by-product of the aromatic hydrocarbon precursor can be transferred into the reflux liquid and form a water vapor containing substantially no solubilizer and a by-product of the Wei precursor a second intermediate gas phase wherein the intermediate portion is circulated to the upper portion of the branching area to transfer the back seam and the second intermediate gas phase is passed; and (3) the upper pumping # can be supplied to the upper portion in large quantities And a liquid phase oxidation by-product of a single mirror of water and a solvent contained in at least one of the second intermediate gas phase and the reflux (four) of the reverse flowing liquid, whereby the substantially solvent-free single and its vice The aqueous second phase of the product is transferred to the second high pressure gas phase of the reflux liquid 'filaments into a nucleus-containing material and a by-product substantially free of aromatic hydrocarbon precursors, wherein the upper portion includes = Collecting the second liquid phase into which at least a portion of the liquid is refluxed a collecting device; (4) a liquid for removing the liquid from the first liquid phase in the first-part receiving portion of the fractionation zone (4) one less liquid circulated with the liquid reservoir to remove the liquid obtained from the body of the device And (12) at least one liquid inlet for introducing the reflux liquid into the upper portion of the fractionation zone; (f) at least one for introducing the reflux liquid to the lower portion of the fractionation zone a liquid inlet in the upper region; (g) at least one liquid outlet circulated with the collection device to remove at least a portion of the reflux liquid from which the second liquid phase has been moved from the device. In a more specific embodiment Preferably, the fractionation zone provides from about 20 to about 80 theoretical equilibrium stages. According to another embodiment, the first portion of the fractionation zone is separable from water and solvent monoterpic acid in the high pressure steam of the liquid phase oxidation reaction. Thereby at least about 95% by weight of the solvent monocarboxylic acid is transferred to the reflux liquid. In another embodiment, the first portion of the landing zone preferably provides from about 2 Torr to about a theoretical equilibrium stage. In another implementation In the example, the second liquid phase for discharging has been moved to Preferably, the at least one outlet of the reflux liquid flowing through the collection means and the at least one inlet for introducing the reflux liquid into the upper portion of the portion below the fractionation zone are preferably separated by from about 1 to about 10 theoretical equilibrium stages. In one embodiment, at least one of the outlets and at least one of the inlets for introducing the reflux liquid into the upper region of the upper portion of the sub-saturated zone are preferably separated into a theoretical equilibrium phase. The apparatus of the present invention preferably comprises a method for reducing the combined weight of the solvent containing the monodecanoic acid and the weighting liquid, in the condition that the mixture can be reduced and the high pressure overhead gas phase containing the solvent alone in the reaction vessel is generated. a reaction vessel for subjecting a substituted aromatic (four) feed (iv) gaseous oxygen to a liquid phase oxidation reaction, wherein the reaction _ "at least one_from the exhaust gas σ from which the high pressure overhead gas phase is removed, the exhaust port is at least - a first stage in which the lower gas population circulates to receive the high-up gas (four) to the fractionation zone of the separation unit 1352079. In other embodiments, the apparatus according to embodiments of the present invention is preferably suitable for use in the preparation of pure quality Form of Fang A method for integrating a carboxylic acid method comprising: contacting a solution containing an aromatic carboxylic acid and 5 impurities dissolved in an aqueous liquid with hydrogen at a high temperature and a high pressure in the presence of a hydrogenation catalyst to form a purified liquid reaction mixture, and A solid aromatic carboxylic acid product having reduced impurities is removed from the purified reaction mixture. The preferred method for producing purified aromatic carboxylic acid by this method

Providing at least one reactor suitable for high temperature and high pressure, contacting the liquid purification reaction solution with nitrogen in the presence of a hydrogenation catalyst to form a purified liquid reaction mixture 10, more preferably at least one which can be circulated with the reactor A product recovery vessel is received from the purified liquid reaction mixture removed from the reactor and from which a solid aromatic tremolite product having a reduced level of impurities is recovered. Preferably, the apparatus further comprises one or more, such as a solid or purified separation step of the aromatic carboxylic acid 15 from the liquid medium for dissolving the crude or impure aromatic carboxylic acid in the purification reaction solvent, and other solid separation steps. An additional container such as a wash of the carboxylic acid product. The apparatus according to an embodiment of this aspect of the invention may also include means for recovering energy in the form of work or recovering energy from the second high pressure gas phase extraction heat removed by the separation device. 20 Another aspect of the invention provides a method of preparing an aromatic tannic acid. The method comprises, under high temperature and high pressure, in the reaction zone, in the presence of a paper product containing at least one heavy metal component, in the liquid phase oxidation of the anti-aircraft in the material axis and the water, so as to contain at least The aromatic flavoring material is in contact with gaseous oxygen, and the high temperature and high pressure can effectively maintain the liquid phase oxidation

14 should be > a compound and an aromatic carboxylic acid and a reaction by-product impurity dissolved or suspended in the liquid phase oxidation reaction mixture, and a solvent-containing monocarboxylic acid, water and a small amount of the aromatic hydrocarbon precursor and vice a high pressure gas phase of the product; transferring the high pressure gas phase removed from the reaction zone to a first liquid phase capable of separating a solvent monocarboxylic acid, water and oxidation by-products into at least one solvent-rich monocarboxylic acid and substantially a separation zone of at least one water-rich second liquid phase of the solvent-free monocarboxylic acid and at least one aqueous vapor-containing solvent monocarboxylic acid-depleted second high-pressure gas phase, whereby the oxidation by-product of the aromatic hydrocarbon precursor can be Preference is given to the first liquid phase, and the oxidation by-product of the solvent monocarboxylic acid can be preferentially dissolved in the second high-pressure gas phase, and the solvent-rich monocarboxylic acid in the individual stream is removed from the separation zone. The first liquid phase and the substantially water-free second liquid phase of the solvent-free monocarboxylic acid and its oxidation by-products and the second high pressure gas phase substantially free of oxidation by-products of the aromatic hydrocarbon precursor. In other embodiments, the condensate is recovered from a liquid having a reflux liquid, preferably an aqueous liquid, and is more preferably a water condensed by a second high pressure gas phase removed from the silk zone. The mother liquor obtained from the aromatic pure form of the solid pure form or a combination thereof, the separation zone of the water, the solvent and the service are carried out in the separation zone. In a more detailed implementation, the separation is divided into several stages, and the first reflux liquid supplied to the material to separate the water and the solvent monoacid phase comprises a purification mother liquor, and is supplied to a solvent by-product. Another reflux liquid that is dissolved in the second high pressure gas phase contains the condensate recovered from the second high pressure gas phase. In another embodiment, a method for preparing an aromatic carboxylic acid of the present invention comprises the steps of: at least a liquid phase oxidation step comprising: at a high temperature and a high pressure, containing at least one heavy metal component in the reaction zone a feed material comprising at least one substituted aromatic hydrocarbon (wherein the substituents can be oxidized to a carboxylic acid group) in a liquid phase oxidation reaction mixture containing a monocarboxylic acid solvent and water in the presence of a catalyst composition In contact with gaseous oxygen, the high temperature and high pressure can effectively maintain the liquid phase oxidation reaction mixture, and form impurities of the aromatic carboxylic acid and reaction by-products dissolved or suspended in the liquid phase oxidation reaction mixture, and the aqueous, monocarboxylic acid, An unreacted substituted aromatic hydrocarbon, oxygen, and a by-product gas phase of the reaction by-product; and at least one purification step comprising, under high temperature and high pressure, in the presence of a catalyst containing a hydrogenation catalytic metal, the argon and the water containing And contacting the purified reaction solution of the liquid of the aromatic carboxylic acid and the impurity recovered from the liquid phase oxidation reaction mixture of the at least one liquid phase oxidation step to form the containing a purified liquid reaction mixture of W-pot acid and hydrogenated impurities of Solvent Water (4); and at least an exhaust gas treatment step comprising transferring a high pressure gas phase removed from the reaction zone having at least one liquid phase oxidation step to The amount of the fresh_water, oxidation by-product A can be separated into at least one solvent-rich single-phase liquid phase and at least one kind of solid solution, the water-rich second liquid phase of the monocarboxylic acid Separating the acid-depleted second high-pressure gas phase with at least a solvent containing water vapor, whereby the oxidation by-product of the feedstock precursor can be preferentially dissolved (4) the first liquid phase, the oxidation of the domain solvent single lin The by-product may be preferentially dissolved in the second high-volume phase, and the water-rich second liquid phase substantially free of solvent and its oxidation by-products and substantially free of oxidation of the aromatic (tetra)f are removed from the separation zone. a second high-pressure gas phase of the by-product; and at least m comprising: feeding the water-rich second liquid phase from the at least one waste gas separation step to the purification zone a step for at least one purification step or for recovery, separation or washing The aqueous liquid of the product contains the condensate. The liquid phase oxidation, purification, and off-gas separation steps of the method according to the embodiment of the present invention are preferably integrated, whereby the liquid phase oxidation product containing the aromatic carboxylic acid and the by-product and the high pressure obtained from the single liquid phase oxidation reaction, respectively The gas phase is subjected to purification and off-gas separation, and the aqueous second liquid phase of the substantially solvent-free monocarboxylic acid and its by-product obtained from the liquid phase oxidation reaction recovered in the exhaust gas separation step is sent to the purification step as Aqueous liquid. In another embodiment, the method of the present invention comprises the steps of: (a) in the presence of a catalyst composition containing a heavy metal component in a reaction zone at a high temperature and a high pressure, in a solvent containing a monocarboxylic acid and water. In the liquid phase oxidation reaction mixture, the feed material containing the aromatic hydrocarbon precursor of the aromatic carboxylic acid is contacted with gaseous oxygen, the high temperature and high pressure can effectively maintain the liquid oxidation reaction mixture, and form dissolved or suspended in the liquid phase. An aromatic carboxylic acid in the oxidation reaction mixture and an impurity containing a by-product of the substituted aromatic hydrocarbon, and a high pressure of a solvent-containing monocarboxylic acid, water, the substituted aromatic hydrocarbon by-product, and a by-product of the solvent monocarboxylic acid reaction a gas phase; (b) recovering a solid product containing an aromatic carboxylic acid and an impurity containing a reaction by-product from the liquid phase oxidation reaction mixture; (c) a self-containing aromatic carboxylic acid and a by-product of the substituted aromatic hydrocarbon The solid product recovered by the liquid phase oxidation reaction mixture of impurities is dissolved or suspended in an aqueous liquid (at least a portion of which comprises the second liquid phase recovered according to step (1)) to form a purified solution; (d) at a high temperature and a high pressure under The purified solution is contacted with hydrogen in the presence of a hydrogenation catalyst to form a purified liquid reaction mixture; (e) a solid purified product containing 1352079 of an aromatic carboxylic acid having a small amount of impurities is recovered from the purified liquid reaction mixture, and the aqueous and a small amount of substituted a liquid purification mother liquor of a by-product of an aromatic hydrocarbon precursor, a hydrogenated derivative thereof or a combination thereof; (1) a solvent-containing monocarboxylic acid obtained from the step (a), water vapor, a by-product of the substituted aromatic hydrocarbon, and the solvent list The high pressure gas 5 phase of the by-product of the carboxylic acid is transferred to a first liquid phase which has a refluxing liquid and which can largely separate the solvent monocarboxylic acid, water and by-products into at least one solvent-rich monocarboxylic acid and at least one substantially The water-rich second liquid phase of the solvent monocarboxylic acid and the at least one aqueous vapor solvent monocarboxylic acid are depleted in the second high pressure gas phase, whereby the oxidation by-product of the substituted aromatic hydrocarbon can be substantially soluble in the a first liquid phase, and the oxidation by-product of the solvent 10 monocarboxylic acid is substantially soluble in the second high pressure gas phase; (g) removing the solvent-rich monocarboxylic acid from the individual streams of the separation zone First liquid phase and a second water-rich liquid phase of a solvent-free monocarboxylic acid and an oxidation by-product thereof, and a second high-pressure gas phase substantially free of by-products of the aromatic hydrocarbon precursor; and (h) from step (g) The water-free second liquid phase of the substantially solvent-free monocarboxylic acid 15 and its by-product removed from the separation zone is sent to at least one of the steps (c), (d) or (e), whereby The aqueous liquid in at least one of the steps (c), (d) or (e) comprises the second liquid phase. In a more detailed embodiment, a liquid stream from the separation zone containing the solvent-rich monocarboxylic acid-containing liquid is transferred to the reaction zone. In other embodiments, the second high pressure gas phase containing the oxidation by-product of the substantially aromatic-free starting material is cooled for liquid phase oxidation and removed from the separation zone, from the second gas phase to The heat exchange medium is condensed by steam generated under pressure or another hot fluid to recover the aqueous condensate; the vapor or hot fluid formed under pressure can be used for heating of other steps or methods. Or, such 18

The SJ second high pressure gas phase or a portion thereof or the high pressure exhaust gas remaining after the second high pressure gas phase gas is condensed may be treated in one or more additional steps to recover unreacted feed material and solvent or solvent by-product By extracting heat, such as by the heat of the father to replace 'recycling energy' by converting into mechanical energy, such as by using the machine 5 or other suitable device or a combination thereof, energy is recovered. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be described with reference to the drawings, wherein: FIG. 1 is a flow diagram illustrating an apparatus and method in accordance with a preferred embodiment of the present invention, which includes the apparatus and is used to prepare and purify 10 in accordance with the present invention. For example, the integration of other equipment for aromatic carboxylic acids. Figure 2 is a more general (10) & expansion diagram of a device in accordance with a preferred embodiment of the present invention and adapted to perform the method according to embodiments thereof. C embodiment; j DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 15 The aromatic acid of the present invention comprises single or multiple having one or more aromatic rings and capable of reacting gaseous and liquid reactants in a liquid phase system. , acidified species. Examples of such aromatic linings include terephthalic acid, the present dicarboxylic acid, 1,2,4-benzenetridecanoic acid, guaic acid, isophthalic acid, benzoic acid, and ca. The invention is particularly suitable for the preparation of terephthalic acid in pure form, which comprises the purification of terephthalic acid and the so-called intermediate purity terephthalic acid. The oxidation step of the method of the present invention is a liquid phase oxidation reaction comprising, in the presence of a catalyst composition containing a component of a heavy metal component of J, in an aqueous reaction mixture containing a mono-steamed acid solvent and water to provide oxygen and a The feed material of the aryl fumes which can be oxidized to the substituents of the acid-suppressing group is contacted. The oxidation step is based on 1352079

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20 can effectively remove the phase reaction mixture cut into high temperature, high pressure _ and high pressure. In the liquid phase oxidation step, the aromatic feed (4) and the anti-product, the miscellaneous or intermediate oxidation product of the correction material feed material and the related f material are mixed and continuous The method is linked to the method. The oxidation step is called - (4). The aromatic feed material suitable for the oxidation reaction is usually contained in - or at multiple positions, usually corresponding to the position of the m acid group of the aromatic (4) to be prepared. At least one aromatic hydrocarbon substituted with a group which can be oxidized to a mild acid group. The oxidizable substituent or group of substituents may be a silk, such as a methyl, ethyl or isopropyl group or a group already containing oxygen, such as a hydroxyalkyl group, a decyl group or a ketone group, the substituents may be the same or The aromatic moiety of the different starting material compounds may be a benzene ring or it may be a double ring, such as a naphthalene ring. The number of oxidizable substituents on the aromatic portion of the starting compound may be equal to the aromatic portion. The number of parts used, but usually less than all such parts, is preferably from about 4 to about 2 and most preferably 2. Examples of useful feed compounds which may be used alone or together, including abenz, ethylbenzene and other trans-group substituted stupid, ortho-xylene, p-xylene, m-xylene, tolualdehyde, toluic acid, alkyl Benzyl alcohol, 1-methyl ketone methyl benzene, ι_Μ methyl glacial methyl benzene, methyl phenyl _, i, 2, 4 - trimethyl benzene, 1-methyl decyl 2, 4- dimethyl Benzene, 1,2,4,5-tetramethylbenzene, alkyl-, mercapto-, decyl-, and hydroxymethyl-substituted naphthalenes, such as 2,6-dimethylnaphthalene, 2, 6·diethylnaphthalene, 2,7-dimethylnaphthalene, 2,7-diethylnaphthalene, 2-methylindolyl-6-indenylnaphthalene, 2-mercapto-6-methylnaphthalene, 2-methyl a -6-ethylnaphthalene and a partial oxidized derivative as described above. 20 0V) For the preparation of an aromatic acid by the oxidation reaction of a correspondingly substituted aromatic hydrocarbon precursor of an aromatic carboxylic acid, for example, a benzoic acid is prepared from a monosubstituted one, and a benzoic acid is prepared from a disubstituted benzene. Formic acid, from the ortho-disubstituted stupid acid, and from 2,6- and 2,7-disubstituted naphthalene to 2,6 or 2,7 naphthalene after-acid, preferably using a relatively pure feed. The material, and more preferably the feed material having a precursor content of at least about 95% by weight, more preferably at least % by weight or even higher. A preferred aromatic hydrocarbon feed suitable for the preparation of terephthalic acid comprises para-xylene. A preferred feed material for the preparation of benzoic acid comprises toluene. The solvent for the liquid phase reaction for the conversion of the aromatic feed material to the aromatic acid retardation product in the liquid phase oxidation step comprises a low molecular weight monobasic acid, preferably a Ci to Cs mono-acid, such as acetic acid, C. Acid, butyric acid, valeric acid and benzoic acid. The low carbon aliphatic monocarboxylic acid and the benzoic acid are preferred because, under the reaction conditions for the liquid phase oxidation reaction of the aromatic carboxylic acid, the reactivity to the undesired reaction product is lower than that for the high molecular weight monocarboxylic acid. And the catalytic effect of the oxidation reaction can be enhanced. The best acetic acid. Solvents in the form of their aqueous solutions, for example from about 80 to about 95% by weight of the acid, are most commonly used in commercial operations. Ethanol and other cosolvent materials which can be oxidized to monodecanoic acid under such liquid phase oxidation conditions can also be used as is or used with monocarboxylic acids to obtain good results. When a solvent of a mixture of a monocarboxylic acid and such a cosolvent is used, it is preferred to use a cosolvent which can be oxidized to the same monocarboxylic acid, so that the solvent separation step is no longer complicated. With respect to the solvent used in the liquid phase oxidation reaction of the present invention, the term "solvent monocarboxylic acid" as used herein with respect to the components having various gaseous or liquid streams means having a solvent as the liquid phase oxidation reaction. The mono-acid of the same chemical composition of the monocarboxylic acid. This usage also distinguishes between these chemical constituents and other monocarboxylic acids which may be present as oxidation by-products. By way of example, when the liquid phase oxidation mixture used in the oxidation reaction comprises an acetic acid solvent, the term "solvent monocarboxylic acid" refers to the general or intermediate oxidation of acetic acid rather than the aromatic feed material used in accordance with the present invention. Other monocarboxylic acid species of by-products such as benzoic acid and toluic acid. Moreover, as it is understood from the disclosure, the word "solvent" as used in the term "solvent monocarboxylic acid" may, but does not necessarily, refer to the utility of such carboxylic acids. Thus, by way of example, a "solvent monocarboxylic acid" described as a component of a liquid phase oxidation reaction mixture is present as a solvent for the mixture; however, it is described as being present in the high pressure gas produced by the oxidation reaction. The "solvent monocarboxylic acid" of one component of the phase or one component of the liquid phase separated from such a gas phase is not intended to mean that the monocarboxylic acid is used as a solvent. The catalyst for the liquid oxidation reaction comprises a substance which is effective for catalyzing the oxidation reaction of the aromatic feed material to produce an aromatic carboxylic acid. The preferred catalyst is soluble in the liquid phase reaction mixture for the oxidation reaction because the soluble catalyst promotes contact between the catalyst, oxygen and liquid feed materials; however, heterogeneous catalyst or catalyst can also be used. Share. Typically, the catalyst comprises at least one heavy metal component ' such as a metal having an atomic weight ranging from about 23 to about 178. Examples of suitable heavy metals include cobalt, manganese, vanadium 'molybdenum, chromium, iron, lanthanum, cerium, lanthanum or lanthanide metals such as cerium. Suitable forms of these metals include, for example, acetates, hydroxides, and carbonates. Preferably, the catalyst comprises a combination of cobalt, smear, and the like, and a combination of one or more other metals, and more preferably a decoration, a decoration, and a knot. 1352079

In a preferred embodiment, the catalyst composition for liquid phase oxidation also includes an agonist which promotes the oxidizing activity of the catalytic metal and preferably does not produce undesirable types or amounts of by-products. An agonist which is soluble in the liquid reaction mixture for oxidizing the anti-deer is preferably used to promote contact between the catalyst, the promoter 5 and the reactants. Self-priming compounds are often used as agonists, such as hydrohalides, sodium complexes, potassium cations, ammonium sulphates, sulphur-substituted sulphuric acid-substituted carboxylic acids, and other halogenated compounds. Preferably, the agonist package & contains at least one source of bromine. Suitable bromine sources include bromine bismuth, Br2, HBr, NaBr, KBr, NH4Br, molybdenum, desert acetic acid, di-ammonic acid, tetra-methane, di-H), eththene, desert, and combinations thereof. Other suitable agonists include aldehydes and ketones such as acetaldehyde and methyl ethyl _. The reactants used in the liquid phase reaction of the oxidation step also include a gas containing 15 20 oxygen. Air is a source of oxygen. It is also possible to use oxygen-rich H pure oxygen, typically at least about 1% by volume, and other gaseous mixtures containing molecular oxygen. As can be appreciated, as the molecular oxygen content of the oxygen source increases, the compressor demand for the reverse gas and the treatment of the inert gas can be reduced. Although air or a mixture of helium 3 oxygen is used as the oxygen source of the process, the high pressure gas phase produced by the liquid phase reaction in the oxidation step contains the gas or other inert gas component of the oxygen source. For the present invention, the ratio of S 'aromatic feed material, catalyst, oxygen and solvent is not important' and may vary according to the following factors, including the reactants ★ and the composition of the catalyst and the intended Details of lysine product, process design and operational factors. Fan @自约i: : i The solvent is better for aromatic raw materials. ‘about 2:1 to about 5:1 is better, but also 23 higher and lower ratio, even in the range of hundreds of W. The family feed material takes at least a stoichiometric amount to take into account, the oxygen H reverses the anti-secret part of the high-yield phase, the rate and the organic group = the preferred aromatic feed material, the solvent single bond, the catalyst composition and the operating conditions In the commercial operation, oxygen is supplied at a rate that is effective to provide about 3 to about 5-6 moles of oxygen per mole of the mole, and is supplied to the liquid phase oxidation reaction. The oxygen content of the gas phase which results in a reaction is removed from the reaction at a rate of from about 5 to about 8 volume percent, as determined on a solvent free basis, from the high pressure gas phase of the liquid phase oxidation reaction. If other conditions are the same, a change in the oxygen content of the gas phase, such as by increasing or decreasing the reaction rate by using a larger or smaller amount of catalyst in the liquid phase oxidation reaction, may affect the product of by-products in the oxidation reaction, and Lower gas phase oxygen content, for example up to about 3% by volume or from about 0.5 to about 152.5% by volume, tends to help convert the aromatic hydrocarbon feed more completely into aromatic slow acid, and in turn reduces the aromatic Oxidation by-products of the family feed, but with increased solvent by-products By way of example, when the liquid phase oxidation reaction is carried out using the p-dimethylbenzene feed 20 substance and the acetic acid as the oxidizing solvent, about 0.5 to about 3 vol% is produced for the production of the aromatic carboxylic acid product. The gas phase oxygen content is better, and the content of the terephthalic acid by-product can be reduced compared with the operation under the higher gas phase oxygen content, but the acetic acid by-product can be increased. The aromatic hydrocarbon feed and solvent are The benchmark 'suitable for use with a catalyst metal having a concentration greater than about 100 ppmw' is preferably greater than about 5 ppmww and less than about 1 Torr, 〇〇〇 ppmw, preferably less than about 6, 〇〇〇 ppmw, More preferably less than about 3,000 ppmw. 24

SJ preferably contains a dentate agonist and more preferably a bromine agonist. The agonist is present in an amount such that the atomic ratio of dentate to catalytic metal is preferably greater than about 0.1:1, preferably greater than about 0.2:1, and most preferably less than about 4:i, preferably less than about 3:1. . The atomic ratio of dentate to catalyst is optimal from about 25:1 to about 2:1. If the other conditions are the same 'in the concentration of the catalyst in the oxidation reaction mixture, the reaction rate and consumption of oxygen in the liquid phase oxidation reaction are increased and the unreacted oxygen content in the gas phase derived from the oxidation reaction is decreased. The liquid phase reaction for subjecting the aromatic feed material to an oxidation reaction to obtain a product containing an aromatic carboxylic acid is carried out in a suitable oxidation reaction zone, which typically comprises one or more oxidation reactors. Suitable oxidation reactors are assembled and constructed to withstand high temperature and pressure conditions and corrosive liquids and gases present in the reaction zone, and provide addition and mixing of catalysts, liquids, and gaseous reactants with solvents. The aromatic carboxylic acid product or the liquid containing the product may be removed for recovery thereof, and the pressurized gas phase produced by the liquid phase reaction may be removed to control the heat of reaction. Types of reactors that can be used include continuous stirred tank reactors and plug flow or reactors. Typically, the oxidation reactor comprises a cylindrical vessel having one or more mixing devices for mixing the liquid reactants and distributing the oxygen within the liquid phase boiling reaction mixture, the central axis of the vessel being used for operational use. It extends vertically. Typically, the mixing device includes one or more impellers mounted on a rotating or moving shaft. For example, the impeller can extend from the center of rotation of the rotating shaft. The reactor can be made of a material that is designed to withstand specific temperatures, pressures, and reactive compounds used. In general, suitable oxidation reactors are made using an inert, corrosion resistant material such as titanium or at least the surface may define an internal space or volume in which the liquid reaction mixture and the reaction offgas are, such as sharp or Materials such as glass are side by side. The reaction mixture used in the liquid phase emulsification reaction is formed by combining a component containing an aromatic feed material, a solvent and a catalyst, and adding gaseous oxygen to the mixture. In a continuous or semi-continuous process, it is preferred to combine the components in one or more mixing vessels prior to introduction to the oxidation zone; however, the reaction mixture may also form in the oxidation zone. The oxygen source can be introduced into the reactor at a plurality of locations, and typically introduced in a manner that promotes contact between the molecular oxygen and other reactive components, for example, by directing compressed air or other gaseous oxygen source. The person should react within the liquid in the lower (4) part of the H (four) volume. The oxidation reaction carried out by the aromatic feed material to produce the product containing the aromatic acid is carried out under the oxidation reaction conditions, and the oxidation reaction conditions can effectively maintain the liquid reaction mixture and the shaped filaments and the dissolved or suspended The liquid city should be a by-product of aromatic tobacco precursors and produce high temperature and pressure gas phase. The gaseous component thereof is mainly a solvent monoacid (for example, when the oxidation reaction solvent includes acetic acid, it is acetic acid) and Oxidation reaction of water with a small amount of the solvent, such as low-lying and its fresh vinegar (for example, methanol and methyl acetate when the solvent includes acetic acid) and the aromatic hydrocarbon feed material Oxidized reversed-phase filaments, such as partial and inter-flavonic oxidation products (Example 2: when the aromatic feed material comprises p-biphenylene, it is benzoic acid and p-formic acid). The solvent by-product content of the gas phase typically ranges from about 0.5 to about 2% by volume. The content of the cigarette by-product by-product is typically from about G.01 to about 0.05% by weight. The gas phase gas phase usually also contains It can be used in the gas phase without the anti-1352079 aromatic feed material and oxygen. When using air, such as oxygen is generally implemented in commercial specifications. When using air (as in commercial specifications - The manner in which it is carried out) or the source of nitrogen or other inert gas components. The gas phase may also contain such inert components. By heating the mixture to the boiling and self-reaction zone The heat generated by gas phase oxidation on top of the shift. Generally, the temperature of the liquid phase reaction is maintained at about 12 G ° C or more, preferably about (10) or higher, but less than about 25. (TC and preferably small = about 2 Torr. In the preparation of aromatic new products (such as terephthalic acid, benzyl H) acid and naphthalene dicarboxylic acid), about 145t to about 23 (reaction temperature in the range of rc) Preferably, at a temperature below about 12 〇 (the temperature of the liquid phase oxidation reaction can be economical. 丨 not attractive or The rate or conversion rate affecting the quality of the product is: • For example, the method for preparing terephthalic acid from p-xylene starting material at a temperature lower than about _ can take more than 24 hours to be substantially completed, and the shape is 15 lang. The benzoic acid product needs to be treated separately due to the impurity content. The temperature above 2 thief is not good 'because it may produce undesired burning phenomena and dissolve. The pressure is controlled to control the temperature at which the liquid phase reaction mixture boils and is selected to maintain a large amount of the liquid phase reaction mixture. The pressure of from about 5 to about 40 ng/cm 2 is preferred, and the preferred method is preferably followed by the feed and The solvent composition, temperature and other factors vary, and more preferably range from about 10 to about 30 kg/cm. Containing acetic acid as a solvent at a reaction pressure of from about 7 to about 21 kg/cm2 And the temperature of the reaction mixture obtained from the gas phase of the liquid phase reaction is from about 17 Torr to about 2 〇 Qc. If appropriate, the residence time in the reaction vessel can be based on the specific throughput and <9) 27 1352079 Different conditions - For some methods, the usual residence time is about 2 〇 to m. The clock is used in the reaction mixture, such as the use of acetic acid solvent for the reaction mixture, from the clamp _ 岔 岔 - material preparation pair = The method of dicarboxylic acid, the solid content of the boiling liquid reaction mixture may be as high as about 5 G weight% of the liquid reaction mixture, more generally the content = about 10 to 35% by weight. In the method of dissolving in the reaction solvent, the concentration of the solid in the liquid object is extremely small. As is well known in the art of aromatic acid (4), the preferred conditions and operating parameters vary with the 10 products and methods, and the changes thereof It may be within the above range or even exceed the ranges. The liquid phase oxidation reaction product includes an aromatic oxidized from an aromatic feed material, an impurity containing a by-product produced by the liquid phase oxidation reaction, and, as described above, derived from the liquid phase reaction, which comprises causing the liquid The phase reaction mixture boils to remove the gas phase to control the reaction temperature, which is a high pressure gas phase. Specific examples of by-products of the aromatic feed material include partial or intermediate oxidation products such as benzoic acid, toluic acid, thiobenzophenone and methylbenzoic acid. The by-product of the liquid phase reaction also includes a solvent reaction product such as methanol and other low-carbon aliphatic alcohol oxidized from the reaction/mixture, and an ester produced by reacting the alcohol with the solvent, and examples thereof include acetic acid. Methyl esters, decyl propionate, 2 〇曱sn by-products are typically present in the liquid phase oxidation reaction mixture and in the gas phase formed therefrom. The carbon oxide by-product can be obtained from the oxidation reaction of a solvent, a feed material or by-products thereof. In the embodiment of the invention wherein the liquid phase reaction uses a source of odor as an agonist, the by-product also typically comprises a low carbon, odorant, such as when acetic acid is used as the reaction solvent, the product of the secondary 28 1352079 is Bromodecane, which is usually formed by the reaction of a bromide ion with acetic acid. As mentioned above, these bromine-containing by-products and impurities may be present in one or both of the liquid phase reaction mixture and the high pressure gas phase produced therefrom. In certain embodiments of the process of the invention, for example, wherein the solid product obtained from the liquid phase oxidation reaction is purified and directly or indirectly transferred to the mother liquor or other recycle stream containing the purification step liquid or its components to The liquid phase oxidation reaction or transfer to the off-gas separation step as a reflux liquid may also be carried out by hydrogenation of other by-products such as benzoic acid and benzoic acid which are continuously produced in the purified liquid, and various by-product compounds obtained from the purification step. The feed and the unreacted aromatic hydrocarbon feed fed to the 10 oxidation reaction in the purification reaction results in the liquid phase oxidation reaction mixture and the exhaust gas. Water is also produced as a by-product of the liquid phase reaction in the oxidation step. However, water may also be present in the liquid due to the addition of water, such as when using an aqueous monocarboxylic acid solvent or in a recycle stream from other process steps, and due to the large amount of water present in the step of oxidation step 15. In the phase reaction mixture, whether water system such as by-products is produced or deliberately added, since it is impossible or unnecessary to distinguish between the reaction water and the deliberately added water, unless otherwise specified, the phrase "the liquid phase reaction" is used herein. Product, 'and similar terms do not refer to water. Similarly, when water or water vapor is described in the text as a component of various process liquids, gases, or vapors, unless otherwise specified or as described in the text, Irrespective of whether the water is derived from by-product water from the liquid phase oxidation reaction or water or both deliberately added to the process. The portion of the liquid reaction mixture that has been obtained from the liquid phase oxidation can be treated using conventional techniques. The aromatic or chelating reaction product is recovered or recovered to recover the aromatic acid retardation reaction product contained therein. Typically, it is slurried, dissolved or has been slurried and dissolved in the liquid reaction mixture. The by-products produced by the oxidation reaction of the aromatic carboxylic acid and the aromatic feed material are removed from the reaction zone used in the liquid phase reaction and recovered by a suitable technique. Therefore, in addition to the oxidation reaction step, The liquid phase oxidation reaction of the inventive method may comprise recovering a product comprising an aromatic carboxylic acid and an impurity containing a reaction by-product from the liquid phase oxidation reaction mixture. The product is preferably recovered as a solid product. The soluble product dissolved in the liquid It can be recovered by crystallization, which is usually achieved by cooling and releasing the pressure on the liquid slurry or solution from the oxidation reaction zone. The solid product which is slurried in the liquid and the crystal from the reaction liquid or the self-crystallization solvent The solids are preferably separated from the liquid by centrifugation, filtration or a combination thereof, whereby the solid product recovered from the reaction liquid comprises an aromatic carboxylic acid and a subsidiary containing the aromatic feed material. Impurity of the product. The liquid remaining after recovering the solid product from the liquid reaction mixture, also known as the oxidizing mother liquor, comprising the solvent monocarboxylic acid, water, catalyst and agonist, a soluble by-product of the liquid phase oxidation reaction, and may be derived from impurities such as a recycle stream. The mother liquor also typically contains a small amount of aromatic (IV) and a portion or intermediate of the aromatic feed material that is not recovered from the liquid. Oxidizing product. Preferably, at least a portion of the mother liquor is returned to at least one reaction zone for liquid phase oxidation, whereby components thereof, such as catalysts, agonists, solvents, and by-products, which can be used in the liquid phase reaction, can be converted into The desired aromatic carboxylic acid to be reused. In a preferred embodiment of the invention, the liquid phase reaction mixture of the aromatic carboxylic acid derived from the oxidation reaction and the by-product of the liquid phase oxidation reaction is carried out in one or more stages. The crystallization reaction, such as in a single crystallization vessel or a series (whose temperature and pressure are continuously reduced from the previous stage to the later stage to increase product recovery), is recovered from the liquid. In 2 to 4 stages, for example, from range to about 丨Temperatures ranging from 4 Torr to about 250 C and ranging from about 5 to about 40 kg/cm2 to a final crystallization temperature ranging from about 110 to about 15 01 and ambient to a dust force of about 3 kg/cm. crystallization The reaction can crystallize a large amount of solid aryl product. The mother liquor separated from the solid product by the crystallization reaction can be returned to the liquid phase reaction as described above. The heat is removed from the vessel used for the crystallization reaction by removing the gas phase formed by the sudden boiling or other pressure drop of the reaction liquid, and the gas phase removed from the one or more stages is preferably as follows, directly or indirectly Condensation is carried out via one or more additional recovery stages, and at least a portion is returned to the reaction zone for the liquid phase oxidation reaction. The solid product removed from the liquid phase oxidation reaction typically comprises a noble acid and an oxidation-containing by-product, such as an intermediate oxidation product of the aromatic feed material, which may be recovered by any suitable technique. The liquid formed by the solid product is oxidized and separated. Examples include centrifugation, vacuum filtration, compression, and filtration using a belt filter. Preferably, after separation, an aqueous liquid, such as pure water, or a small amount of a solvent, a monocarboxylic acid, a catalyst, an aromatic raw material, preferably directly or with other liquids (such as an oxidized mother liquor recycle or other reaction zone) The liquid product is recycled together to the oxidation by-product of the oxidation reaction or a combination of the washings of the mixture to form a solid product. The separation of the solid impure aromatic carboxylic acid recovered from the oxidizing mother liquor and the washing of the solid product are preferably carried out by solvent exchange filtration under pressure using a press filter as disclosed in U.S. Patent Nos. 5,679,846 and 5,200,557. A preferred filtration device for such separation steps is a BHS Fest filter as described in more detail in U.S. Patent No. 5,200,557. The mother liquor and washing removed from the filter cake can be transferred directly or indirectly to a liquid phase oxidation reaction. Filtration and use of a multi-stage and use of a purely increasing lotion, for example as a liquid removed from the filter cake in the downstream stage as a washing of the previous stage, the washing of the solid product can be replaced by a concentrated self-filter cake The solvent monocarboxylic acid provides an additional benefit in returning it to the oxidation reaction. In a more specific embodiment, the filter cake wetted by such a displacement filtered wash is sent to a drying stage from the final wash stage where it is contacted with an inert gas, typically at low levels. The residual liquid is removed in large quantities from the filter and the cake under moderate pressure. After washing and purging the lotion from the solid product containing aromatic acids and by-products, the solid formed may be dried and sent to storage or other steps, which may include preparing a reaction solution for purifying the solid product. . The residual solvent to the purified solid product preferably has a monoacid content of 5,000 parts per million by weight ("ppmw,") or less. The solid product can be dried by a flowing stream of nitrogen or other inert gas. In order to reduce the residual solvent content. In addition to the aromatic acid retardation reaction product formed in the liquid phase reaction of the oxidation step of the method of the present invention, the above-mentioned solvent-containing mono-acid, water and the liquid phase oxidation reaction are also produced. The south pressure gas phase of the product. The gas phase also typically contains a small amount of unreacted aromatic feed material, unconsumed oxygen and, if present, an inert component of the oxygen source. The temperature and pressure are equivalent to the conditions of the liquid phase reaction. The exhaust gas separation step of the present invention can be combined with high temperature and high pressure exhaust gas recovery materials and energy sources (in some embodiments) and combinations thereof removed from the liquid phase oxidation reaction. The exhaust gas separation step comprises transferring the gas phase removed from the 1352079 reaction zone of the liquid phase oxidation reaction to separate the solvent mono-remediation, water and oxidation-products into at least one solvent-rich solvent. (d) the first - liquid phase and / / substantially solvent-free single (four) water-rich second liquid phase disk solvent of at least one age of water vapor (four) consumption of the second high-pressure gas phase separation 5 @ ' The oxidation reaction by-product of the aromatic hydrocarbon (10) can be preferentially dissolved in the: 帛-liquid phase: and the oxidation reaction by-product of the solvent can be preferentially dissolved. (4) The second high-pressure gas phase. The ruthenium is removed from the separation zone. The second liquid phase containing the water-soluble and substantially solvent-free mono-Wei and its oxidation by-products and the 10th high pressure of the by-product of the oxidation reaction without the aromatic precursor a gas phase. The separation step is carried out using the high pressure gas phase at a temperature and pressure substantially lower than the temperature and pressure of the gas phase in the liquid phase oxidation step of removing the gas phase. t Detailed, separation step The utility model comprises the steps of: sending high pressure and high temperature gas phase removed from the reaction benefit for liquid phase oxidation to a separation zone which can be used under high temperature and high pressure 15 in the gas phase operation to largely separate water and solvent in the gas phase. And dissolving the by-products from the oxidation reaction from the separation step Between the liquid phase and the gas phase, thereby reducing the content of the lysate product in the liquid phase removed from the separation step and the by-product content of the IU target flue oxidation reaction. The high pressure gas phase can be directly The liquid phase oxidation reaction zone is moved 20 to the separation zone, wherein the separation device is directly installed therein or is closely connected to the oxidation reaction vessel or other reaction zone, or indirectly by, for example, suitable conduits and valves suitable for feeding and feeding Connected to a pump, etc. A small portion of the high pressure and high temperature gas phase derived from the liquid phase oxidation reaction can be sent to other uses, such as the production of high pressure steam or heat exchange fluid. Preferably, it is transferred to the separation unit 33 S Maintaining the gas phase at a temperature and pressure high enough to at least substantially retain the energy content of the gas phase entering the separation zone, and the gas phase can provide contact with the reflux liquid supplied to the separation zone The heat required for separation is sufficient. Preferably, the gas phase is transferred to the separation zone either directly through the reaction zone or through a suitable pressure-rated pipe, whereby the temperature of the gas phase entering the separation zone is lower than the reaction temperature in the liquid phase oxidation reaction. Above about 10 C, the pressure of the gas phase entering the separation zone is no more than about 3 kg/cm 2 less than the pressure within the liquid phase oxidation reaction. The reaction zone is also designed to operate at elevated temperatures and pressures, and is preferably operated at substantially no lower temperature and pressure than the temperature and pressure of the high pressure gas phase present in the reaction zone to avoid obtaining from the reaction zone. Loss of energy content in the gas phase. Preferably, the separation zone is designed to treat the gas phase at a pressure of at least about 8%, more preferably at least about 90%, and still more preferably at least about 95% of the gas phase pressure in the oxidation step. The pressure rating of the separation zone apparatus is preferably at least about, preferably from about 90 to about 110%, of the oxidation reaction vessel or zone of the oxidation step of the process of the present invention for separating the gas phase. The temperature of the gas phase in the separation zone is preferably from about 200 ° C and more preferably from about 16 Torr to about 185 ° C. The pressure is preferably from about 5 to about 4 kg/cm 2 , and more preferably from about 10 to about 20 kg/cm 2 . The separation zone can largely separate the solvent monocarboxylic acid and water vapor which are led to the high pressure gas phase of the separation step. Preferably, the separation zone separates water and solvent in the high pressure gas phase, whereby the solvent monocarboxylic acid content of the high pressure gas obtained from the separation step does not exceed about the solvent (four) content of the gas phase leading to the separation zone. 10%, and more preferably no more than about 5〇/. . The solvent (4) content of the high pressure gaseous effluent from the separation step is preferably no more than about 2%, and more preferably no more than about 1%, of the solvent monocarboxylic acid content of the gas to the separation zone. The separation zone is also suitable for preferentially dissolving at least one liquid by-product of the aromatic feed material of the oxidation reaction and a second high-pressure gas phase by-product of the solvent monocarboxylic acid, which is usually at a temperature at which the separation is carried out. And under pressure will be dissolved in the gas phase and liquid phase 5. For example, in the liquid phase oxidation reaction of the p-xylene feed material in the liquid phase reaction mixture containing the acetic acid solvent, the p-xylene benzoic acid and the p-nonyl benzoic acid by-product and the hydrazine of the acetic acid Alcohol and decyl acetate by-products can be substantially dissolved in a large amount between the gas phase and the liquid phase. The separation device is capable of dissolving by-products whereby the second high pressure gas phase is substantially free of by-products of the aromatic precursor and 10 is preferably present in an amount of no more than about 10% by weight, and most preferably from about 1 to about 5% by weight. . The aromatic hydrocarbon precursor by-product which is transferred to the first, solvent-rich monocarboxylic acid-containing liquid phase and the second, water-rich liquid phase is preferably preferentially dissolved in the first phase, and more preferably by this 75 wt%, still more preferably at least about 85% by weight, to about 100% by weight, is present in the first liquid phase, and it is no more than about 25% by weight, and more preferably no more than about 2 to about 10% by weight. It is present in the second liquid phase. The by-product of the alcohol-containing solvent monocarboxylic acid and its solvent acid ester is preferably preferentially dissolved in the second high-pressure gas phase formed by separating the water in the high-pressure gas phase of the inlet and the solvent monocarboxylic acid, which preferably causes the The second, water-rich liquid phase contains no more than about 10% by weight, and more preferably no more than about 1 to about 4% by weight of such by-products. The separation zone used for the separation of the exhaust gas of the present invention may comprise a solvent monocarboxylic acid and water suitable for separation in a large amount from the high temperature and high pressure gas phase removed by the liquid phase oxidation reaction, and is obtainable as described above. Any device or structure for the oxidation reaction by-products present in the liquid phase of the solvent monocarboxylic acid, the second liquid phase rich in water, and the second high pressure gas phase containing water at a high temperature and a high pressure 35 1352079

10 15

Pieces. In an embodiment, the preferred separation zone is adapted to be contacted in a reverse direction through the gas phase and the reflux liquid phase, whereby the solvent alone in the high pressure gas phase leading from the liquid phase reaction zone to the separation zone may be substantially Moved from the gas phase: (4) enriched with the solvent, and thus obtained from the solvent, the acid is absorbed by the high-pressure IU, and the water can be transferred to the water. The second liquid phase. Under the conditions of the separation step, the oxidation by-product of the aromatic feed to the liquid phase oxidation reaction is dissolved in the liquid phase oxidation reaction from the liquid phase oxidation reaction to the separation zone. In the gas phase, it can also be introduced into the liquid in the separation zone. These by-products which are dissolved in the liquid phase to which the solvent of the high-pressure gas phase derived from the oxidation reaction is transferred may be removed in the first liquid phase. The by-products present in the solvent monocarboxylic acid-depleted gas phase may be further soluble in the liquid phase, and may also enter the solvent-depleted rolling phase due to contact with the reflux liquid phase. The water is moved into the liquid phase. The solvent monocarboxylic acid by-product which tends to be dissolved between the vapor and the liquid phase may be present in the high pressure gas phase derived from the oxidation reaction leading to the separation zone. It may also be present in the reflux liquid supplied to the separation zone. The by-products present in the split liquid phase present in the separation unit can be stripped from the gas phase by the reflux liquid. The flow of the reflux liquid in such a separation apparatus includes a liquid component which is moved from the gas phase to or into the liquid phase, and a component which is supplied to the separation zone as a liquid phase or a reflux liquid which maintains a liquid phase. The preferred separation zone in accordance with a more detailed embodiment of the present invention is configured to contact the liquid phase and gas phase in a reverse direction through a portion or region of the separation zone in stages, <y> 36 1352079. The gas phase stream is preferably an upflow flowing through a portion of the separation zone, and the liquid phase stream is preferably a downflow flowing therethrough. The first portion of the separation zone can be directed to the vapor phase by removal from the separation zone. The reflux liquid is directed to the third portion of the separation zone. Thereby, the first portion of the self-separating zone flows through the second portion to the third portion of the gas phase system and the third portion from the separation region flows through the second portion to the first portion The refluxing liquid of the stream is contacted to separate water, solvent monocarboxylic acid and by-products. The reflux liquid supplied to the third portion contains water, and preferably has substantially no oxidation by-products of the aromatic feed materials for liquid phase oxidation. The 10 water and the solvent monocarboxylic acid in the reverse flowing gas phase and the reflux liquid phase are substantially separated in the first portion, thereby forming a first liquid phase and a high pressure rich in the solvent monocarboxylic acid, The solvent monocarboxylic acid is depleted in the intermediate gas phase. The solvent-rich first liquid phase from the first portion is collected for removal from the separation zone. The gas phase flowing from the first portion of the separation device to the second portion includes the intermediate gas phase from the first portion. In the second part, the reverse flow of the gas phase and the water and by-products in the reflux liquid phase are separated, whereby the by-product of the aromatic hydrocarbon precursor can be moved to the reflux liquid phase, and the formation is substantially A high pressure second intermediate gas phase of a solventless single core and water vapor of the aromatic by-product by-product. The gas phase flowing from the second portion of the separation zone to the third portion includes the second intermediate gas phase. The gas phase of the reverse flow 20 in the third portion is separated from the water and solvent by-products in the reflux liquid phase, thereby forming a water-rich first substantially solvent-free single core and its by-products. The second liquid phase is separated from the aqueous vapor and the solvent by-product and is substantially free of the second high off-gas phase of the aromatic by-product by-product. Collecting the second aqueous liquid phase derived from the third portion to extract and discharge the second liquid phase from the separation device

37 The liquid material stream separated by the liquid material stream is discharged. The second high pressure gas phase is removed from the separation device with the exhaust gas. The reflux phase flowing through the separation zone may be replenished by supplying additional reflux liquid containing water to one or more portions of the separation zone. In a preferred embodiment, the aqueous liquid system is supplied with additional reflux between the second and third portions of the separation zone. In such a stepwise operation, the first portion of the separation zone is preferably separable from the solvent monocarboxylic acid and water, whereby at least 95% by weight, and more preferably at least about 98% by weight, of the solvent can be moved to the first a liquid phase. The second portion preferably dissolves the aromatic precursor by-product for the liquid phase oxidation reaction in the first and second liquid phases' whereby the second high pressure gas phase contains no more than about 1 Torr. %, and more preferably from about 1 to about 5% by weight of such by-products present in the first and second liquid phases, and the second high pressure gas phase. Preferably, the third portion of the separation zone is soluble in the second high pressure gas phase of the liquid phase oxidation by-product of the solvent monocarboxylic acid, whereby the second liquid phase contains no more than about 10% by weight, and more preferably From about 1 to about 4 weights 0/0 of such by-products present in the first and second liquid phases, and the second high pressure gas phase. In a preferred embodiment, the first portion of the separation zone is defined as an inlet for receiving a high pressure gas phase that is moved from the liquid phase oxidation reaction into the separation zone and for introducing the aqueous liquid to the reflux The area of the separation zone between the inlets of the separation zone. The second portion of the separation zone is defined as an inlet for directing the aqueous liquid to reflux to the first portion and a second liquid enriched for collecting water from the second portion The area of the separation zone between the outlets of the phase. The three parts are defined as being located at the outlet for removing the second liquid phase collected from the third portion and for oxidizing the reaction containing substantially no liquid 1352079. The liquid of the oxide water of the material f is directed to the region between the inlets of the separation device.

According to the present invention, the separation zone for separating and preferentially dissolving water, pre-solving the solvent, and the product of the field ij comprises having at least about 2 可 a large amount of separation 5 from the high-altitude gas obtained from the liquid phase oxidation reaction. The sub-district area of the theoretical balance phase of water and solvent. Such a sub-district area preferably has a theoretical balance of about 2 〇 to about fiber. Preferably, the separation water and the oxidation by-product of the aromatic feed material are at least about 2 theoretical equilibrium stages. Such a sub-district area preferably provides about 2 to about 1 theoretical balance phase. The fractionation zone for separating the water 10 and the oxidation by-product of the solvent monocarboxylic acid preferably has at least one, and more preferably from about 1 to about a theoretical equilibrium stage. Preferred separation devices are various columns or columns, which are commonly referred to as steam columns and

The tower, the dehydration tower, the fine column, the water removal column and the high-efficiency separation device are designed to make the gas phase flowing through the liquid phase contact with the liquid phase to be separable in the configuration thereof and to preferentially dissolve the flowing gas phase and liquid first. Mass transfer between the gas phase and the liquid phase in several theoretical equilibrium stages of the component (sometimes referred to as the "theoretical plate"). The contact between the flowing gas phase and the liquid phase can be facilitated by internal structures, such as the surface provided by the disk or packing for gas-liquid contact and the theoretical equilibrium stage for separation. The temperature of the high pressure gas phase removed by the oxidation reaction is usually sufficiently high, so that the reboiling ability does not need to be higher than the reboiling ability provided by the liquid phase oxidation reaction. In order to promote the contact between the gas phase and the liquid phase in the separation device, the reverse flow of the gas phase and the liquid phase, such as by introducing the high pressure gas phase derived from the oxidation reaction to the lower portion of the device, and refluxing Preferably, the liquid is directed to at least one, and preferably two or more portions.

39 The separation zone of the present invention may comprise a single device or multiple devices, such as columns, columns or other structures in series. When two or more devices in series are used, the configuration, and their individual inlets and outlets can be communicated, whereby the pressurized gas phase removed from the oxidation reaction vessel can flow into the series and can be separated and dissolved. The solvent in which the vapor flows and the countercurrent reflux liquid are single-repulsive, water, and by-products. The reflux liquid supplied to the separation zone contains water. Any suitable source of liquid which is aqueous and substantially free of impurities which are detrimental to the separation can be used. Demineralized water or other source of purification may be used, but is preferably a source of reflux liquid comprising a liquid condensed by a high pressure gas phase removed from the separation zone and/or condensation zone of the process of the invention. In another preferred embodiment, the purified mother liquor obtained from the recovery of the purified aromatic carboxylic acid product from at least one of the purified liquid reaction mixture is sent to a separation zone' whereby the reflux of the separation zone comprises the purification mother liquor. The reflux liquid for separation preferably comprises such a purified mother liquor and a liquid containing water condensed from the high pressure gas removed from the separation zone, which may be supplied to the separation zone individually or in combination with one or more individual streams. In the step of the separation step of the preferred embodiment of the invention as described above, the reflux liquid containing the purified mother liquor is introduced to the separation zone to flow the liquid phase component through the second portion of the zone and is introduced The condensate recovered from the second high pressure gas phase removed from the separation zone is introduced to flow through the third portion. The purified mother liquor typically contains by-products of the aromatic hydrocarbon feed material fed to the liquid phase oxidation reaction, including the hydrogenated derivatives formed from the purification step, but such by-products are preferably dissolved in the separation step. The liquid phase is mainly dissolved in a first liquid phase rich in a solvent monocarboxylic acid, and the first liquid phase is adapted to return to an oxidation reaction to make a replenishing solvent. The liquid containing the water condensed by the second high pressure gas phase removed from the separation zone is substantially free of by-products of the aromatic feed (4), but may be stripped in the second high pressure gas phase in the separation step The solvent single (four) secondary yarn may be sequentially present in the liquid containing the water condensed by the second high pressure gas. The by-products which are returned to the separation step in the form of a reflux liquid and supplied to the third portion of the partition are stripped back to the second high phase of the separation step. In the preferred embodiment of the present invention, the secondary yarns can be prevented, wherein the _ portion is washed from the second high-pressure gas phase of the separation step or subjected to a recovery to recover such by-products. . It is preferred to supply a reflux liquid at a rate and temperature at which the gas phase transferred from the oxidation reaction to the separation zone is subjected to heat generated by the liquid phase oxidation reaction. When the separation zone is connected to a liquid phase oxidation reaction vessel to substantially transfer the gas phase to the separation zone by a substantial autooxidation reaction, the reaction vessel can serve as a reboiler. In such embodiments, the rate at which the supply liquid is refluxed to the separation zone is preferably expressed as the weight of the liquid supplied to the zone relative to the weight of the aromatic feed material that is directed to the liquid phase oxidation reaction. Preferably, a reflux liquid is provided to the separation zone at a temperature of from about 120 to about 17 (at a temperature in the range of TC, and more preferably from about 13 Torr to about 160 ° C) according to the process of the present invention. Preferably, the liquid is supplied to the separation zone at a rate of from about 4 to about 5 weights of liquid per part by weight of the aromatic precursor of the liquid phase oxidation reaction. When the reflux system is individually supplied to different stages of the separation zone, Preferably, the fraction is dissolved between the different stages, whereby the reflux of the first stage supplied to the separation zone can constitute at least 4%, and more preferably from about 60 to about 90% of the volumetric flow of the reflux liquid. The high-pressure gas stream removed by the oxidation step is separated by the water introduced into the separation zone and the solvent monocarboxylic acid vapor, whereby the first liquid phase rich in the solvent-rich monocarboxylic acid and depleted in water can be recovered. The first liquid phase preferably comprises at least about 60% by weight of solvent monocarboxylic acid and no more than about 35% by weight water. The separated liquid phase preferably has a water content of from about 15 to about 30% by weight. The liquid stream also contains a small amount of heavier impurities, such as the aromatic feed. Intermediate oxidation by-products and hydrogenated derivatives thereof, such as benzoic acid, and depending on the aromatic precursor used for the oxidation reaction, m-toluic acid and/or p-toluic acid may be washed or transferred to the separation zone. In a liquid phase, the first liquid phase may also comprise other components, such as aromatic carboxylic acids and catalytic metals. The content of such comparative components may be as high as about 2% by weight, but preferably not more than about 0.5% by weight. The liquid phase of the rich solvent monocarboxylic acid condensed in the gas phase from the separation zone is a source of valuable solvent for the liquid phase oxidation reaction. As described above, it may also include oxidation by-products of the aromatic feed material and Other components suitable for returning to the oxidation reaction and converting to the desired aromatic acid. Other suitable uses of the liquid condensate include a rotary vacuum filter for solid-liquid separation of the recovered solid product from the liquid phase oxidation reaction of the recovered solid product. Or a replenisher of a vapor or crystallization solvent and a scrubber used by other devices, such as an oxidative dryer scrubber used in the process. In a preferred embodiment of the method of the invention, at least a portion, And more All or substantially all of the separated first liquid phase removed from the separation zone is returned to the liquid phase oxidation reaction and sent directly to the reaction vessel or to a supply vessel for supplying the replenishing solvent to the reaction zone. In these embodiments Preferably, the water and the solvent monocarboxylic acid in the high pressure gas phase of the separation zone are separated, whereby the liquid phase derived from the separation zone contains from about 15 to about 30% by weight of water, and more The water content and the (4) rhyme from the method ^ back to the oxidation reaction of the water f can offset the water vapor removed from the oxidation reaction of the high-pressure top gas phase and self-service and separate the oxidation reaction of the aromatic ^ The liquid water removed by the acid product. The second liquid phase recovered from the separation zone is enriched in water and substantially free of solvent mono-product by-product from the liquid phase oxidation reaction. These by-products are preferably dissolved in the liquid phase, so that the second liquid phase can also be fed by 4 S to the by-product of the aromatic feed material in the liquid phase oxidation reaction. The solvent monoton content of the second liquid phase is typically less than and wt% and preferably from about 1/2 to about 3% by weight. The solvent by-product content is typically not more than about 5% by weight, and preferably from about 0.5% to about 0.2% by weight. The by-product content of the aromatic feed material present in the second liquid phase typically ranges from about 3 to about 1% by weight and preferably from about ostrich to about 8% by weight. Such liquids are suitable as aqueous liquids in the process or in a multi-step process for purifying the aromatic form of the aromatics in more detail. Other uses of the second liquid phase include a seal rinsing liquid as a solid-liquid separation device for isolating the oxidized mother-reduced oxidized mother product recovered from the liquid phase oxidation reaction mixture. The second high pressure gas contains a substantial amount of water and is substantially free of solvent single bonds. Preferably, the gas comprises at least about 55% by volume, and more preferably less than about 65% by volume water. The solvent typically has a solvent monone content of less than about 5' and more preferably less than about 3% by weight. The gas also contains unreacted aromatic feed materials and by-products of oxidative oxidation of the bribes, but (4) it is present in minor or minor amounts of no more than about 2% by weight. The pressurized gas from the separation zone typically has an oxygen content ranging from about 4% by volume, preferably from about i to about 4% by volume. The oxygen-like nucleus (10), which typically wraps around and oxidizes carbon, can constitute up to about 45% by volume of the pressurized gas; when air is used as the source of gas L and oxygen, the nitrogen content of the pressurized gas typically ranges from From about to about 40 volumes 〇 / 〇. The pressure of the second high pressure gas from the separation zone is preferably less than the pressure within the liquid phase oxidation reaction to a gauge of about 1 kg/cm. The temperature of the argon gas from the separation zone is preferably less than about C and more preferably from about 5 C to about 15 ° C above the temperature of the liquid phase oxidation reaction. The temperature of the high pressure gas from the separation zone is preferably greater than about loot, more preferably greater than about 12 Torr, and less than about 25 Torr C. more preferably less than about 23 (rc. The pressure of the pressurized gas remaining after separation is a gauge of about 4 to about 4 kg/cm 2 . The second high pressure gas phase removed from the separation zone can be led to the condensation zone to contain no organic impurities f from the gas phase condensation, such as a solvent And a liquid condensate of the water obtained from the aromatic feed material and the solvent of the oxidation reaction. The condensation zone may comprise water which is capable of self-conducting to the condensation zone and condensing the water substantially free of organic impurities Any device which preferably includes one or more indirect transfer condensing enthalpy or thermal field devices capable of effectively providing a bulk material (4) U, preferably a heat exchange fluid. A single device or several devices in series can be used. Shell and tube heat exchangers and pin condensers are examples of preferred devices. Preferably, all or substantially the Gaussian vapor from the separation zone is sent to the condensation zone to recover energy and materials therefrom. Preferably, after the liquid condensate is condensed and removed from the condensing unit, the condensing zone exhaust gas remaining at a pressure of 1352079 is substantially cooled by not less than the exhaust gas in the gas leading to the condensing zone. The pressurized condensing zone exhaust gas includes a non-condensable component of the high pressure gas obtained from the separation zone, a gaseous reaction by-product, and may also contain a reflux liquid obtained from the liquid phase oxidizing exhaust gas or sent to the separation zone and at the second A small amount of aromatic feed material that has not been separated is maintained in the high pressure gas phase. The exhaust gas from the condensation zone is preferably from about 50 to about 15 Torr. The pressure at the temperature of the crucible and the pressure of the inlet gas in the condensing zone is not more than about 3 kg/cm 2 . The condensation zone is condensed after the gas removed from the separation device is condensed with the liquid condensate

The pressure difference between the air is about 2 kg/cm 2 or less, and is preferably about 5 to about 10 kg/cm 2 . A. The cold IS of the high pressure gas exchanged with the heat sink material in the condensation zone is also heated by the heat sink material. The heat sink material is preferably hot and is preferably water. When water is used as the heat exchange fluid, the disk β can be sent to other parts of the process of the invention (10)^ == 7. Similarly, heat exchange between the pressurized gas and the other gases can be used to heat the liquids. Therefore, the heat exchange between the high pressure gas and the water containing the liquid from the separation zone to the condensation zone can be made at different pressures and between the bodies. : Operation at continuous colder temperatures - Series heat exchangers = water change applications. Preferably, the steam at different pressures is sent to the actual process of the bamboo, where the corresponding pressure or pressure group = process steps. The aqueous liquid condensate under the I's degree is derived from the gas produced by the condensing gas from the exhaust gas from the condensing zone to recover the energy in the form of heat and force. Recycling the energy source as heat for use in the process reduces the fuel consumption required to produce the heat for use in the process. The power recovered by the power can be converted to power suitable for the method to reduce the power consumption of the external source used in the method. Although a preferred embodiment of the invention includes condensing all or substantially all of the high pressure gas transferred to the condensation zone, in some embodiments of the invention, the separation is performed by extracting the thermal energy source from the gas. In addition to the condensation of the high-pressure gas', only a portion of the water content of the gas is passed through, suspected, or sent to the condensing unit by a portion of the second high-pressure gas phase from the separation zone, and the other portion It is sent to a device for recycling energy by converting it into mechanical energy. Partially condensing or diverting the second high pressure gas phase removed from the separation zone to condense only a portion thereof, and recovering the liquid condensate containing substantially pure water having a low organic impurity content and As a reflux liquid for use in the separation zone as described above; and recovering the heat source transferred to the heat exchange fluid when the liquid condensate is condensed by cooling the high pressure gas, and the uncondensed water may be left in the exhaust gas of the high pressure condensation zone To further recover the energy form in the form of a work. According to other embodiments of the present invention, all or substantially all of the second high pressure gas phase of the monocarboxylic acid and water in the high pressure gas phase from the separation oxidation reaction and oxidation by-products The condensation of all or substantially all of the condensable components of the high pressure gas from the separation by the heat exchange with the heat sink fluid can reduce the volumetric flow of the residual gas after condensing to the subsequent processing step, and can Use only metals with low or moderate resistance to surnames, such as stainless steel, mild steel or double refined steel 'as required for subsequent exhaust gas treatment steps (which may be included in the process) More expensive equipment t, alternative high resistance of pure metal or alloy. The substantially complete condensing action of the condensable component of the high pressure gas removed from the separation can also increase the volume of the liquid condensate containing water substantially free of organic impurities produced by the process of the present invention, and can enhance aromaticity The recovery of the liquid phase oxidation by-products of the unrefined towel after the feed material and the solute or condensed. Condensation can be performed in a single step. It can also be carried out in multiple steps, wherein in the first stage, the gas stream containing the high pressure gas removed from the separation zone is cooled to a first temperature to produce a first stage condensate, followed by a second stage The uncondensed portion of the rolled body is condensed at a lower temperature to obtain a second stage condensate, and the uncondensed portion of the gas is led to the second stage, and one or more additional steps may be selected as needed, wherein The uncondensed portion of the gas from the previous stage is condensed to form a liquid condensate and a residual uncondensed gaseous portion at a lower temperature than in the previous stage. The gas exchange gas and its heat exchange between the uncondensed portions of the staged condensers can be used to obtain heat exchange fluids at different temperatures or pressures, such as medium and low pressure steam, which can be used in other process steps or Heating is carried out outside the process. In a preferred embodiment of the invention, 2 or more stages of steam are produced for energy recovery, preferably using condensing or other low pressure steam turbines. In these embodiments, 'the condensate removed at different temperatures can be sent to other operational uses having the corresponding temperature' to avoid additional heating or cooling of the condensate portion, and in some cases, must The accumulation of impurities, such as solvent monocarboxylic acid oxidation by-products, in the step of recycling the condensate is limited. For example, in the case of almost no pounds, it is carried out at a relatively high temperature, for example, within about 130 to about 160 ° C, to recover the condensate itself or with an aqueous liquid obtained from other process steps (such as In the purification step, the aromatic recovery and/or separation = residual mother liquor together are well suited as reflux for separation. When the high-temperature liquid β is used as the separation of the separation, the low content of the light component (such as the low alcohol and its solvent produced by the solvent by-product in the liquid phase oxidation reaction) is so low (4) External benefits, and tend to condense at a lower concentration at a lower temperature, condensate at a lower temperature, such as condensate in the range of about 9 〇C, which is also suitable for thermal coagulation (4) such as for product Knife separation and use of the silk and liquid phase oxidation reaction, the purification reaction or the sealing rinse used in both' and the lower temperature condensate, for example, in the scope of the treaty, suitable for condensate use, such as washing Gas wash. Although it is possible to send the condensate to other methods with suitable temperatures at different temperatures, the method of the invention can be difficult. (4) Management selection method should be understood, if necessary, can be borrowed, for example, for other steps. The exchange method will cool or heat the condensate portion or rhythm of the job at a temperature higher or lower than the other steps required or preferred. According to a preferred embodiment of the present invention, the exhaust gas obtained from the condensation zone under pressure and substantially anhydrous steam preferably retains a portion of the second high pressure gas phase obtained from the separation according to the degree of condensation in the condensation step. Water. In addition to the water vapor in the exhaust gas, the gas may comprise a non-condensable component derived from the liquid phase oxidation exhaust gas, such as unreacted oxygen from the oxidation reaction, if present in the oxidation reaction. Nitrogen, carbon oxide and other inert gas components of the oxygen source, and carbon oxide, and may contain a small amount of solvent monocarboxylic acid by-product obtained from the oxidation reaction and a trace amount of solvent monocarboxylic acid which has not been removed in other steps. , other oxidation by-products and unreacted aromatic hydrocarbon feed materials. Even when the water in the exhaust gas is substantially completely condensed into a liquid condensate, so that the uncondensed exhaust gas remaining after condensing is substantially free of water, the pressure of the exhaust gas is also high enough, and especially when used for liquid phase oxidation reaction. The oxygen source is air or another gaseous mixture having a large amount of inert gas, whereby the gas phase removed from the oxidation reaction and the pressurized gas obtained from the separation zone and the condensation zone contain a large amount of inert gas, the condensation zone The volume of the exhaust gas makes it a useful source for energy recovery. According to some embodiments of the invention, the energy source is recovered from the pressurized exhaust gas resulting from condensation. Energy is preferably recovered in the form of work. In these embodiments, the pressurized gas stream containing the offgas from the condensation zone is transferred directly or indirectly to the means for recovering the energy in the form of work. Preferably, the energy recovery device is an expander or a gas stream adapted to be received under pressure and equipped with blades that can be rotated by the flowing gas to generate work that can be used for other process steps or processes and for cooling under reduced pressure. Gas_like device. The work can be extracted from the pressurized gas train, for example, to generate electric power or to operate a compressed air or a gaseous oxygen source for liquid phase oxidation or other equipment requiring mechanical work. This extracted source can be used in other steps of the process or other methods. Alternatively, it can be stored or transferred to the grid for transmission to other locations. Exhaust gas that can be discharged after recycling energy in the form of force is preferably subjected to additional treatment, such as condensing to remove if present in an appreciable amount (4) cold (four) pure k from Saki (4) gas to remove unfavorable atmospheric release Honest other compounds, after the discharge. If necessary, energy recovery can be performed after scrubbing or treating the gas to remove corrosive compounds. The removal of corrosive components prior to energy recovery facilitates the fabrication of internal components of expanders or other power recovery devices from materials having lower corrosion resistance than preferred materials. However, the removal process for such components is also The electric power that can be recovered from the gas can be reduced as an alternative to the exhaust gas from the condensation zone or, more preferably, as an alternative step of recovering the energy in the form of work as described above, the exhaust gas obtained from the condensation can be treated to remove Organic and other combustible compounds and corrosive components. In certain embodiments, such treatments are particularly useful for recovering a small amount of a reaction product of a solvent monorexic acid derived from an oxidation reaction and a trace amount of unreacted aromatic hydrocarbon feed material that may remain in the exhaust gas. In an embodiment of the invention, wherein the condensing action of the high pressure gas from the separation comprises performing one or more condensations at a temperature low enough to cause the water in the gas to be substantially, and preferably at least about 80% condensed. And the volatile impurity 'such as a lower alcohol, and the ester reaction product of the peracetic acid monodecanoic acid substantially retains the uncondensed exhaust gas phase at a temperature which is sufficiently cooled to a temperature of preferably about 40 to about thief. Since the uncondensed exhaust gas which is known to be self-condensing is cold enough, it can be used as a liquid scrubber for recycling, thereby facilitating the recovery of the separation of such impurities. Reducing or removing organic species, such as unreacted feed materials and solvent by-products that are not removed, and liquid phase oxidation reactions derived from the use of silk sources as agonists for liquid phase oxidation catalysts The mascara should be a by-product, and the high-pressure gas phase which is continuously produced in the liquid phase oxidation reaction and then the 5-pressure gas removed from the separation and the exhaust gas removed by the self-condensation are treated 1352079. It should be understood that such treatments may affect the amount of energy recovered from the off-gas after condensation. Therefore, in the embodiment of the invention in which the exhaust gas in the condensing zone is treated before the energy in the form of work is recovered, the preferred treatment is carried out without a large loss of pressure or volume of the gas. When the condensing zone exhaust gas has an appreciable water content of 5', it is also preferred that the water does not condense or cool from the gas in large quantities until the recovery of the energy source in the form of work does not cause a large amount of condensation of water.

Reason. In such embodiments, it is preferred to carry out the preheating of the treated gas prior to energy recovery. The present invention includes a process for treating a feed gas obtained from a condensing action to remove unreacted 10 and a solvent by-product produced in the liquid phase oxidation reaction, such as a lower alkyl alkoxide of the solvent monocarboxylic acid The treatment in the examples helps to return these components to the oxidation reaction. The process also reduces the presence of these impurities in the process recycle stream and its steady state equilibrium content during total process operation. Preferably, the uncondensed gas removed from the condensation by the self-condensing action 15 is contacted with the liquid scrubber at a temperature of about 35 to about 7 to obtain a small amount of aromatic feed material and/or solvent by-product. a liquid gas phase and a liquid product comprising the gas scrubber and at least one of an unreacted aromatic feed material and a solvent derived from a liquid phase oxidation. Preferably, the liquid product is returned to the reaction zone in the liquid phase oxidation step. Any suitable 2 〇 scrubber and scrubber may be used to purge the gas stream containing the high pressure condensed exhaust gas from which the volatile component 'such as unreacted feed material and derived from the oxidation reaction The solvent monocarboxylic acid by-product is transferred to the liquid phase. A high pressure absorption column having an internal structure such as a disk or a packed bed for promoting contact between the gas to be scrubbed and the liquid scrubber is used. Suitable scrubbers of <9» 51 1352079 are those which are liquid at the temperature of the gas to be scrubbed, and wherein the materials to be recovered have a large degree of solubility. Examples include lower alcohols and Ci.8 retarding acids such as acetic acid, propionic acid, butyric acid and the like. The preferred liquid scrubber is a monocarboxylic acid which can be used as a solvent for the liquid phase oxidation reaction and a mixture thereof with water 5. Suitable scrubbers, apparatus and their use for the liquid phase oxidation reaction of aromatic feedstocks to aromatic carboxylic acids to recover exhaust gas components are described in detail in US 6,143,925, here Incorporating this case into a reference. The pressurized condenser off-gas, with or without prior treatment of the scrubbing of the untreated feed material or solvent by-products as described above, may also be treated to remove corrosive or other combustible materials. Although any method which can perform this removal step without a large loss of pressure and volume of the gas can be used, it is preferred to subject the gas to an oxidation reaction and to optimally carry out a catalytic oxidation reaction to remove organic, flammable and Corrosive component. These treatments are generally packaged at a high temperature which is effective to oxidize organic, flammable and corrosive components to a low corrosive or more environmentally compatible gas containing carbon dioxide and water, and substantially not lower than The uncondensed gas under pressure is heated under the pressure of the pressurized gas pressure and includes exhaust gas under pressure from self-condensation or scrubbing or other treatment, and gaseous oxygen in the combustion zone. Preferably, the heating of oxygen is carried out under pressure in the presence of a suitable oxidation catalyst disposed in the combustion zone so as not to interfere with the flow of the heating gas therebetween. The pressurized gas may be optionally preheated prior to oxidation. Preheating can be carried out by any suitable means, such as by heat exchange, direct steam injection, or other suitable method. The combustion treatment may also optionally include the addition of 52 1352079 pressurized gas scrubbed from the combustion to remove acidic, inorganic materials, such as when the source is subjected to liquid phase oxidation as described above, by the condensation In the exhaust gas = bromine or fill gas generated by the oxidation reaction of bromine. Catalysts for catalytic oxidation reactions typically comprise at least one transition group element of the element (IUPAC). Preferably, the first metal, more particularly = the beginning, and the combination of them with - or a plurality of additional or auxiliary metals. It can be used in the form of a composite such as an oxide, such a catalytic metal. Typically, the catalyst metal is disposed on a carrier material having a low or no catalytic activity but having a strength and stability which is such as to withstand the high temperature and high pressure oxidation environment of the combustion zone. Suitable catalyst carrier materials include metal oxides containing one or more metals, examples of which include mullite, spinel, sand, cerium oxide, aluminum oxide, vermiculite alumina, titanium oxide. Positive zirconia. Various crystal forms of such materials can be used, such as alpha, r6 and ?? alumina, rutile and anatase titanium oxide. The amount of catalytic metal loading on the carrier group 15 is preferably a fraction of a few percent by weight, and when processing a gas having a large amount of water vapor content (such as about 20% by volume or more), it is preferred to use a higher filling amount. p can use any convenient configuration, shape or size of the catalyst. For example, the catalyst may be in the form of small particles, particles, rings, spheres, and preferably formed into a hard blister, honeycomb, porous or pore 20-hole structure or configured thereon. Promotes contact with gases present in the combustion zone without interfering with gas flow through the zone. A specific example of a catalytic oxidation catalyst for use in a combustion process to remove exhaust gas removed from the condensing action of the exhaust gas treatment of the present invention comprises about 5 to about 5% by weight of the shoulder carried on the alumina monolith support. The form of work is from the actual closure of the present invention containing gas from the exhaust gas removed from the condensation zone, and especially if the gas contains an appreciable amount of water (e.g., at least about 5 volumes. / (>), The gas may optionally be heated to prevent the gas sent to the energy recovery from containing liquid water. This heating step may be carried out after other treatments or processing steps, such as thermal or catalytic oxidation reactions. In an embodiment, heating may be carried out by any suitable technique, such as by heat exchange or direct injection of steam or other hot gases. Heating to about 2 (K) t or higher can effectively prevent water condensation, preferably at about 250 to Approximately 350. (:: In addition to the condensing zone exhaust gas remaining after the high pressure gas removed from the separation zone is condensed, the condensing action of the exhaust gas treatment step according to the present invention can condense the liquid obtained from the pressurized gas The ingot comprises high purity water as described above and, according to a preferred embodiment of the invention, the condensate is at least partially delivered to the separation zone whereby the reflux liquid supplied to the separation zone comprises such a condensate. The liquid is also suitable for other uses, such as a lotion for the solid-liquid separation of the impure aromatic new product from the liquid phase oxidation reaction. Due to the nature of the liquid, the condensate is removed from the off-gas separation step of the process according to the invention. Between the first liquid phase of the rich K, because the solvent mono-acid oxidation by-product content is lower than the condensate recovery solvent obtained by the second high-pressure gas phase obtained from the knife-off action, (4) The second method is in an integrated process comprising purifying an impure aromatic _, such as an impure aromatic carboxylic acid recovered from a liquid phase oxidation reaction. In an embodiment of the invention comprising purifying or preparing a purified aromatic acid, At least the purification step comprises contacting a hydrogen purification reaction solution containing a liquid having an aromatic carboxylic acid and impurities dissolved therein in the presence of a hydrogenation catalyst metal-containing catalyst at a high temperature and a high pressure at 1352079 to form a hydrogen-containing solution. Purified liquid reaction mixture β of aromatic carboxylic acid and hydrogenated impurities in an aqueous liquid. In a preferred embodiment, the crude solid product recovered from the liquid phase oxidation reaction is dissolved in an aqueous liquid to form a purification reaction. a solution comprising an aromatic carboxylic acid and an impurity comprising an oxidation by-product of an oxidation reaction of the aromatic feed material. Preferably, the aromatic carboxylic acid formed by recovering a pure substance containing a small amount of impurities is recovered from the purified liquid reaction mixture by crystallization. An acid product, which may be obtained by recovering the liquid purification mother liquor remaining after the product of the pure form and/or from one or more aqueous liquids, such as a crystallization solvent and a washing liquid, to separate the product in a pure form. The invention includes an embodiment in which at least one aqueous liquid is used in a purification step comprising removing a water-rich second liquid phase from a separation zone of the exhaust gas separation step of the present invention. As mentioned above, in other embodiments, the system will be derived from The purified mother liquor of at least one purification step is sent to an off-gas separation step to introduce the aqueous reflux liquid into the sub-zone. As described above, the aromatic carboxylic acid product obtained by the liquid phase oxidation reaction of a feed material containing an aromatic compound having an oxidizable substituent is sometimes referred to as a crude aromatic carboxylic acid product or from liquid phase oxidation. The crude product of the reaction, comprising an aromatic conjugate and/or a plurality of oxidizing intermediates or by-products. Although the specific chemical composition of the intermediate 20 product and by-products may vary depending on the composition of the oxidized feed material, the oxidation reaction conditions, and other factors, and may not even be fully understood, it is known to comprise a Or a plurality of aromatic compound-based compounds, such as an undesired color which can cause the desired aromatic-product or the poly-energy produced therefrom, to have a benzene color (4)

55 1352079. Aldehydes, ketones and oximes, and such compounds can be hydrogenated to a species which is more soluble in aqueous solutions or less colored or tinted than these aromatic carbonyl compounds and aromatic carboxylic acids. According to an embodiment of the present invention, the preferred impure aromatic carboxylic acid product to be purified is an aromatic carboxylic acid-containing, and the aromatic feed material is subjected to liquid phase oxygenation, and the best liquid phase oxidation reaction and purification are carried out. step. The crude product of the liquid phase oxidation reaction is the crude product of the by-product produced by the liquid phase oxidation reaction in a continuous process for the starting material for purification. However, it should also be understood that the starting materials for use in the purification reaction may be or include impure products containing aromatic carboxylic acids and aromatic carbonyl impurities as described above, which are derived from the integration of aromatic feed materials or Non-integrated liquid phase oxidation reactions or by-products from other processes or sources are present or produced. Therefore, the present invention includes an impure aromatic acid retardation product starting material for purification comprising aromatic lining and less one which can form an aqueous solution having a solubility greater than the unhydrogenated aromatic group impurity or less color Or aromatic hydrogenation of the coloration tendency, the aromatic county impurity of the aromatic product substituted by the prison 15 base. An aromatic new product suitable as an impure form of a starting material for purification, which comprises a crude product recovered from a liquid phase oxidation reaction of an embodiment of the present invention, and a small amount of a solvent single vessel remaining in the impure product. the remains. Purification of the process of the invention is not adversely affected, as is ubiquitous in the production of products from commercially available liquid phase oxidation reactions ranging from hundreds to thousands of 20 ppm. The monomeric (tetra) content of the aromatic carboxylic acid product to be purified is optimal * more than about % by weight. More preferably, the preferred purification step of the present invention comprises dissolving a solid product containing aromatic tickic acid and impurities in an aqueous liquid, at least a portion of which is optimally 56 1352079, which is included in the separation step of the exhaust gas according to the present invention. In addition to the aqueous second liquid phase, a purified reaction solution is formed, and the purified solution is contacted with hydrogen in the presence of a gasification catalyst at a high temperature and a high pressure to form a purified liquid reaction mixture, and the purified liquid reaction mixture is recovered. A solid purified product containing a small amount of impurities of the aromatic lysine 5 acid and separating an aqueous liquid purification mother liquor containing oxidation by-products, hydrogenated products thereof, and combinations thereof from the recovered solid purified product. The impure nitriding reaction of the impure aromatic nucleus is carried out in an aqueous solution using an impure acid to reduce the impurity content. Preferred solvents for the purified solution in some of the embodiments of the present invention comprise a second liquid phase removed from the separation zone of the offgas separation step of the present invention. Although in order to avoid increasing the cost, complexity and additional equipment for the use, storage or handling of the condensate, it is preferred to directly self-condense the condensate in a continuous and integrated process and not to increase or intermediate the feed product or miscellaneous f, However, it should be understood that such increased processing is not excluded, although it does not require that the second liquid phase be suitable as a solvent for purification, although it is not desirable to obtain a purification solvent of sufficient purity to be suitable as the purification solvent of the present invention. The liquid 'except for the second liquid phase derived from the offgas separation step or its replacement, it will be appreciated that the invention encompasses the use of other suitable water sources, such as fresh demineralized water, or other sources of purified water. The water-rich second liquid phase obtained from the separation step of the present invention preferably constitutes at least about 5 Torr of the solvent 20 for the purification reaction solution. /0, and more preferably about 8 〇 to about 丨〇〇%. The concentration of the purification solvent of the impure aromatic carboxylic acid to be treated in the purification step is generally low enough to substantially dissolve the impure acid, and the concentration is sufficiently high for practical process operations and efficient applications, and It can be used as a solvent for the liquid and after recovering the aromatic (4) in pure 57 form with a small amount of impurities from the purified reaction mixture, it can still be used as a purification mother liquid. From about 5 to about 5 parts by weight per 100 parts by weight of the impure aromatic retardation solution at the process temperature is suitable to provide the proper solubility required for practical operation. The preferred purification reaction solution contains from about 10 to about 40% by weight and more preferably from about 2G to about 35% by weight of the impure aromatic acid at the temperature used for purification by the hydrogenation reaction. Catalysts suitable for use in the purification hydrogenation reaction comprise one or more catalytic activities required for hydrogenation of impurities in impure aromatic acid retardation products, such as oxidized intermediates and materials and/or aromatic weigen heavys. metal. The catalyst metal is preferably supported or transferred to water and is not redant than the reddish material fJi under the purification process conditions. Suitable medium metal is the first metal of the Periodic Table of the Elements (IUPAC version), which includes a combination of Ji, Shi, Yi, Hungry, Sui, Silver and Fresh. The materials including mosquitoes are the best for heterozygous metals. Under the operating conditions, it can be used for a long time. The surface area and sufficient strength and anti-wear _ carbon and charcoal are better. The true charge is not important, but in fact, the better filling amount is the carrier and the touch. The total amount of the metal or metal group is from 5% by weight to about 5% by weight. A preferred catalyst for converting impurities in the impure aromatic carboxylic acid product of the crude terephthalic acid obtained in the liquid phase oxidation reaction of the borrowed feed material (which comprises para-xylene) contains about (U to About 3% by weight, and more preferably about 〇2 to about 9% by weight of hydrogenated metal. For the purposes of such use, the metal is preferably contained. For practical use, the best use is in the form of particles, for example, small particles, extruded. The catalyst of the material, the sphere or the particle, but other solid forms are also suitable. The contact particle size can be easily maintained in the appropriate purification reaction (4), but the purified anti-cancer can be passed through. The 1352079 bed does not produce an undesired pressure drop. The preferred average particle size allows the catalyst particles to pass through the 2_ mesh screen, but can be retained on the 24-Sieve sieve (US Sieve Senes) and, preferably, 4 Mesh screen, but retained on the 12 mesh and the best 8-mesh sieve. 5 Under high temperature and high pressure, the aqueous purification reaction solution is contacted with hydrogen for purification in the presence of a catalyst. The temperature range is from about 2〇〇. Up to about 37 ° C, preferably from about 225 to about 325 ° C And preferably from about 240 to about 30 (TC. The pressure is sufficient to maintain the liquid phase containing the aqueous reaction solution. The total pressure is at least equal to, and preferably exceeds, the hydrogen gas introduced to the process and dissolved from the aqueous reaction at the operating temperature. 1 The sum of the partial pressures of the water vapor boiling. Preferably, the pressure is about 35, and more preferably about 7 to about 105 kg/cm 2. Suitable for accepting the reaction temperature and the acidic properties of the Lili and its liquid contents. The aqueous purification reaction solvent is contacted with hydrogen in a reaction vessel under the hydrogenation conditions as described above. Preferably, the reactor is configured to have a substantially central I5 axis 'the column is erect when the reactor is used for operation, the columnar shape The reactor can be used in both upflow and downflow reactors. The catalyst is typically maintained by a mechanical carrier to maintain the catalyst particles in the bed and can pass relatively anti-secret- or multiple (four) The bed is present in the reactor. It is generally preferred to use a single-catalyst bed, but it is also possible to use multiple beds or media having the same or the same, for example, in terms of particle size, hydrogenation catalyst metal or metal loading. Words of different catalysts a layer, or a single bed having a catalyst and other materials such as a material that protects the catalyst, and which provides benefits, (a parallel metal wire shaped mechanical carrier. Other suitable catalyst retention tools include, For example, a tubular 59 Johnson (Joh_) sieve or a multi-well plate. The internal components and surfaces of the reactor and the mechanical support are made of a material having suitable resistance to the rot caused by contact with the Wei reaction solution and the reaction product mixture. The carrier for the catalyst bed preferably has an opening of about or less and is composed of a metal such as a non-recorded steel or a hydrogen chloride-resistant alloy (Hastell®) c. In a preferred embodiment, the aqueous solution of the impure aromatic Wei to be purified is added to the reactor vessel at or above the portion of the reactor vessel at a high temperature and pressure, and the solution may be present in the hydrogen gas. Down to the bottom of the drum should contain the catalyst bed, which is in many

If hydrogen is used, the impurities are reduced to a hydrogenation product having a solubility in the reaction mixture greater than the desired aromatic bond or having a lesser color or coloration tendency. The preferred material <RTIgt;</RTI><RTIgt;</RTI><RTIgt;</RTI>></RTI> The reactor used for purification can be operated in several modes. The predetermined liquid content is maintained in the reactor in a mode and hydrogen is fed at a rate sufficient to maintain the predetermined liquid content at a particular reactor pressure. The difference between the actual reactor pressure and the vapor pressure of the vaporized purification solution present in the headspace of the reactor is the hydrogen separation of the headspace. Alternatively, hydrogen may be fed in combination with an inert gas such as nitrogen or water vapor, in which case the difference between the actual reaction H pressure and the K pressure of the vaporization reaction solution present is hydrogen and an inert gas mixed therewith. Combine partial pressures. In such cases, the hydrogen partial pressure can be calculated from known relative amounts of hydrogen and the inert gas present in the mixture. 1352079. In another mode of operation, the reactor can be filled with an aqueous liquid reaction solution whereby there is substantially no reactor vapor space, but there are hydrogen bubbles that expand or contract at the top or top of the reactor, thus The volume of the top of the reactor is provided whereby the hydrogen added to the reactor is soluble in the purified reaction solution of input 5. In this embodiment, the reactor is operated in a hydraulic full load system where the dissolved hydrogen is fed to the reactor by flow control. The concentration of hydrogen in the solution can be adjusted by adjusting the hydrogen flow rate fed to the reactor. If necessary, the pseudo hydrogen partial pressure value can be calculated from the solution hydrogen concentration, which can then be corrected by the hydrogen flow rate fed to the reactor. Ίο When the operation is such that the process control can be achieved by adjusting the partial pressure of hydrogen, the pressure rating of the reactor, the impurity content of the impure aromatic carboxylic acid, the activity of the catalyst, and other considerations known to those skilled in the art. Factors The hydrogen partial pressure within the reactor is preferably in the range of from about 0.5 to about 15 kg/cm2. In the mode of operation including direct adjustment of the hydrogen concentration in the feed solution, the hydrogen of the solution is not saturated, and the reactor itself is fully charged. Therefore, the adjustment of the hydrogen flow fed to the reactor can well control the concentration of hydrogen in the diagnostic solution. During the hydrogenation reaction, the space velocity is expressed by the weight of the impure aromatic acid in the purified reaction solution per hour by weight of the catalyst, and the crack is 20 for about 1 hour 1 to about 25 hours 1 'and preferably. About 2 hours "to about 15 hours -1. The residence time of the purified liquid stream in the catalyst bed may vary depending on the spatial density. The removal of impurities from the liquid purification reaction mixture is lower than that used to prepare the purification. a solution of crude or other impure aromatic carboxylic acid product in the pure form of the aromatic 61 1352079 family of carboxylic acid products. The purified reaction mixture comprising the dissolved aromatic rim and having a higher solubility in the aqueous reaction liquid than it is hydrogenated An aqueous reaction solvent of a precursor of hydrogenated arsenic impurities, which is cooled to separate a solid impurity of a low aromatic solid aromatic carboxylic acid from the reaction mixture, leaving a liquid purification mother liquid having hydrogenated impurities dissolved in 5. By cooling to the crystallization temperature, which is low enough, the aromatic carboxylic acid can be crystallized to produce crystals in the liquid phase, and the separation is carried out. The crystallization temperature is high enough, so the dissolved impurities and their obtained from hydrogen The reaction product of the reaction is still soluble in the liquid phase. The crystallization temperature is usually up to 16 ° C, and preferably up to about 15 (TC ^ in continuous operation, the separation step is usually included in the purification reactor to remove the liquid purification reaction The mixture is subjected to an aromatic acid crystallization reaction in one or more of the crystal containers. When carried out in a series of stages or in individual crystallization vessels, the temperatures in the different stages or vessels may be the same or different, and Preferably, the crystallization begins to decrease from the various stages or from the vessel to the next. Crystallization can also typically result in a liquid boiling from the purified liquid reaction mixture, which can be recovered by condensation and recycled to one or more stages of purification, or a plurality of upstream crystallization stages or, in a preferred embodiment of the invention, separating the solvent monocarboxylic acid and water vapor from the high pressure gas phase of the liquid phase oxidation reaction. It is preferred to add the aqueous liquid to the crystallization in the subsequent stage. The crystallization product recovered from the purified liquid reaction mixture of 20, which is directly or more preferably indirectly treated with one or more washing liquids for use in the crystallization product, the aqueous liquid Preferably, the water-rich liquid 0 recovered from the exhaust gas separation step in the second liquid phase is thereafter dissolved from the purified mother liquor, including hydrogenated impurities, and the crystallization and purification of the aromatic carboxylic acid product is usually carried out. Separation of the 62 crystallization product is carried out by centrifugation or filtration. Preferably, the separation process comprises pressure filtration and use of an aqueous slurry of an aromatic acid in a pure form, as described in U.S. Patent No. 5,175,355, which is incorporated herein by reference. The aqueous liquid is washed from the filtered filter cake. The water-rich second liquid phase obtained from the exhaust gas separation step as described in the document is used as an aromatic acid for the pure form. A preferred aqueous liquid for the washing of the solids. The purified mother liquor remaining after the solid purified aromatic acid retardation is recovered from the purified reaction mixture, comprising water and a hydrogenated derivative of a by-product or impurity present in the impure aromatic acid-initiating starting material. . The mother liquor also typically includes a minor amount of aromatic carboxylic acid remaining in the solution. Such hydrogenated derivatives include compounds which are suitable for conversion to aromatic retinoic acid by liquid phase oxidation, and thus in the preferred embodiment of the invention 'directly or indirectly transfer this specialized gasified derivative to liquid phase oxidation In the reaction. Or, preferably, together with the hydrogenated derivatives, after separation, the residual aromatic decanoic acid present in the mother liquor may be directly or indirectly transferred to the liquid phase oxidation reaction, preferably by separating the solid pure form. At least a portion of the purified mother liquor remaining after the aromatic carboxylic acid is sent to the liquid phase oxidation step to carry out the step of transferring the derivative and the aromatic carboxylic acid to the oxidation reaction. Unless the water from the purified mother liquor sent to the oxidation reaction can be used as a stream to return to the oxidation reaction, the water content of the purified mother liquor will destroy the water balance in the oxidation reaction. Preferably, the hydrogenated impurities in the purified mother liquor are transferred to the liquid phase oxidation reaction alone or preferably together with the aromatic decanoic acid present in the mother liquor without disrupting the water balance in the oxidation reaction. More preferably, directly or indirectly, at least a portion, and most preferably substantially all, of the liquid mother liquor remaining after solid purification of the aromatic carboxylic acid is separated from the liquid purification reaction mixture, and transferred to the waste gas separation step according to the invention of 1352079. In the separation zone, it serves as a reflux liquid as described above. Purification reactors, catalyst bed configurations, operational details, crystallization, and product recovery techniques and apparatus suitable for use in the process of the present invention are described in further detail in U.S. Patent Nos. 3,584,039, 4,626,598, 5,629,715, US 4,782,181 ' US 4, 892, 972, US 5, 175, 355, US 5, 354, 898, US 5, 362, 908, and US Pat. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a more detailed illustration of an embodiment of a process for the preparation of an aromatic carboxylic acid and an apparatus for the step of separating the exhaust gas according to the present invention. Although Figure 10 illustrates (and specifically with reference to the following), the liquid phase is carried out in a liquid phase reaction mixture of water and acetic acid (as a solvent for the oxidation reaction) by l-xylene as a preferred starting material. Oxidation reaction to prepare a specific aromatic carboxylic acid, terephthalic acid' and according to the oxidation reaction and the exhaust gas separation step, further preferred embodiments and features and additional steps of the invention, including recovery from the liquid phase oxygenation reaction And the separation of the crude product, the purification of the liquid phase oxidation product, and various additional by-products, and the recovery of energy, integration, and the description of specific examples, features, details, and preferences should be understood to assist in understanding the invention and not limiting the invention or Its features are limited to any aspect or embodiment. The method illustrated in Fig. 1 also shows a preferred embodiment of the method of the present invention, wherein the liquid phase oxidation reaction, the exhaust gas separation step and the purification step are integrated, whereby the crude aromatics derived from the liquid phase oxidation reaction can be obtained. The carboxylic acid product is sent to a purification step to form a purification solution, and the high pressure exhaust gas from the oxidation reaction can be sent to the exhaust gas separation step, and the liquid phase sent to the separation step contains the mother liquor obtained from the purification step; however, it should be understood The present invention is not limited to the specific integrated flow diagrams described in the specification of 64 1352079, and it is understood that the present invention also encompasses various multi-column, shared columns, and other integrated and unintegrated configurations. By way of example, the product containing the aromatic carboxylic acid and the reaction by-product obtained from the multi-liquid phase oxidation reaction can be sent to a single purification step, wherein one or more liquid phase oxygenation reactions or other liquids are obtained. The liquid phase recovered by the exhaust gas separation in the high-pressure gas phase of the phase oxidation reaction can be used as a process liquid. As a further such example, the crude product from a single liquid phase oxidation reaction can be purified in a separate purification column of the parallel operation, wherein the high pressure gas phase from the liquid oxidation reaction is subjected to offgas separation to recover substantially solvent free The water-rich liquid phase of the product is transferred to either or both of this purification column, or as another feasible method or additionally, the water-rich liquid phase is transferred to it from individual oxidation Or a process for purifying the impure aromatic carboxylic acid in a purification process or in a process step as described herein. The illustration shows the integration of a device according to the invention and according to other embodiments of the invention wherein the device is associated with other equipment, such as a reaction vessel for liquid phase oxidation reactions. The liquid and gaseous streams and materials used in the method described in Figure 1 are typically transferred and transferred by suitable transfer lines, conduits and tubing made of materials suitable for operational use and safety. It should be understood that the physical components can be juxtaposed and, if appropriate, can have a singular region, a rigid region or both. When transferring a material stream or component, it may include the processing steps to be selected in the middle. For example, suitable fruit, read, ambiguous and liquid flow meters and distributors, sampling and sensing devices, and for monitoring, controlling, adjusting, and transferring pressure, flow, and other operational parameters may be included: 65 1352079 Equipment. Referring to the figure, the separation device 330 is a high pressure gas phase that can define a closed interior space and is adapted to receive the material stream m from the oxidation reactor 11 and to remove the second high pressure gas phase via the gas outlet 334.枉 (four) structure. It also includes an inlet for the introduction of a reflux liquid supplied from an external source, such as a material stream obtained from a process or from a storage vessel, with a state and an inlet. The outlet, indicated at 345, is located between the reflux inlets 336 and 344 for removing the second liquid phase collected in the column. A structure in the interior space of the column and located between the inlet for receiving the high pressure gas phase from the oxygen reactor 11 and the return port 10 may provide a fractionation zone therein. The separation device is designed to enable a large amount of Gw mono-acid and water to be introduced into the gas at the top of the device and to the gas in the top of the warm oxidation reactor during operation, and to preferentially dissolve the liquid oxidation reaction. a product whereby a second liquid phase enriched in the first liquid phase of the monocarboxylic acid, enriched in water but substantially free of the solvent and 15 by-products produced in the liquid phase oxidation reaction, and aqueous and substantial There is no solvent and the second high pressure gas phase of the by-product produced by the liquid phase oxidation reaction of the aromatic feed. In a preferred embodiment, the direct or intimate coupling of the oxidation reactor and the separation device is by direct connection or by one or more of the exhaust ports and the separation device in the oxidation reactor. A suitable pressure rating tube or other conduit between the mouthpieces is achieved whereby the gas phase in the liquid phase reaction conditions is removed from the reactor and introduced into the separation at the same or substantially the same temperature and pressure as in the reaction zone. Inside the device. The fractionation zone of the separation apparatus is equipped with a number of theoretical equilibration stages, such as a combination of internal discs, structural packing, discs and packing, or a surface may be provided within the apparatus of the 66 1352079 to be present in the apparatus. The structure of the mass transfer between the gas phase and the liquid phase or a combination thereof is provided. Provide at least about 2 theoretical balance phases. If the other conditions are the same, the separation efficiency increases with an increase in the theoretical equilibrium phase, and thus the number of equilibrium stages included in the separation apparatus 5 used in accordance with the present invention has no theoretical upper limit. However, for practical purposes, the separation may be such that the solvent monocarboxylic acid introduced into the high pressure gas phase of the separation apparatus can be substantially moved into the liquid phase. At least about 2, and preferably at least about 25, can be used. The balance phase is achieved, and the degree of separation provided by about 7 such stages makes the other stage become impractical or not! Preferred separation devices having structured packing have at least about 3 packed bed or packed zones, and more preferably from about 4 to about 6 such beds, to provide the appropriate surface and theoretical equilibrium stages required for separation. An example of a suitable packing is 15 20

Flexipac structured fillers are obtained from KGGPLLC in the form of sheets of wrinkled metal arranged in a cross-correlation arrangement which produces flow channels whereby the parent line can produce a mixing distance suitable for liquid and gas phases. A preferred separation device having a disk comprises from 30 to about 90 disks, of which at least about 7 〇 q/. The high pressure gas is directed from the reaction vessel to the inlet of the separation device (as shown in Figure 2, 338) and at least one reflux liquid inlet. Preferably, the tray is in the form of a sieve tray, and preferably has a separation efficiency of from about 3 Torr to about 6%. The number of phases required for a particular theoretical equilibrium phase can be calculated by dividing the number of stages by the efficiency of the disk. $ In operation, it is introduced into the separation device and is present in the gas phase and liquid phase at high temperature, and includes water, solute and other rot 67 1352079 erosive components, such as compounds and their uncombined The product, such as hydrogen bromide present in the gas above the oxidation reaction, when the catalyst used in the oxidation reaction comprises a source of bromine. Thus, in a preferred embodiment of the invention, the internal structure of the separation device that contacts the gas with the liquid during the process operation and the other components are made of a suitable metal that prevents corrosion and other damage due to such contact. production. With respect to such surfaces, the titanium, which is included in the fractionation zone, the filler, or other structures, is a preferred material for construction. The titanium surface of this structure readily aggregates solid deposits undesirably, and the solid deposits contain iron oxides derived from impurities present in the liquids circulated through the apparatus. A method of controlling the concentration of iron oxide deposits or the amount of soluble iron impurities in a process liquid is described in commonly-assigned U.S. Patent No. 6,852,879, the disclosure of which is incorporated herein by reference.

In the embodiment of the invention represented in the drawing, the separating means 33 〇 15 has a plurality of discs, and the individual instances thereof are most often represented by 333 and 337 in Fig. 2, which is a high pressure steaming column. As also shown in Figure 2, the column includes at least one outlet for moving liquid from the column to ', e.g., an oxidation reaction, as indicated at 332. The gas inlet 3 is located in the lower portion to receive the oxidizer exhaust gas, and the exhaust port 334 is located in the upper portion to remove the second high pressure gas phase as the exhaust gas. In the case of the staged operation of the invention of the root county, the region between the (10) inlet and the reflux liquid inlet 344 includes a liquid phase oxidation reaction which can be provided in the first stage or part of the separation of the self-standing 330. The theoretical equilibrium phase of the dissolution of fresh water in the Korean milk phase. Between the reflux inlet 3 and the second liquid * Π 234 and may provide a by-product for the separation of the aromatic feed 68 1352079 for oxidation reaction, and water to dissolve the by-products in the reflux liquid phase The disc of the theoretical equilibrium stage provides a second portion of the separation zone within the column. A tray located between the liquid outlet 345 and the reflux inlet 336, such as trays designated 333 and 337, provides solvent monocarboxylic acid oxidation by-products and water for separation in the third portion of the third portion of the separation zone. The liquid outlet 332 is positioned to remove the bottom liquid of the first liquid phase of the solvent-rich monocarboxylic acid separated from the oxidizing off-gas in the first portion of the separation zone. A tray, indicated by 339 at its peripheral boundary, with a dust cover, trough, collection channel or other collection device, circulates with the liquid outlet 345 and is adapted to collect a reflux liquid that flows through the separation zone to be removed by the outlet 345 Two liquid phase. An outlet 345 in combination with an associated internal structure (such as collection device 339) for separation means for collecting the liquid or liquid separation zone from the tray or packed bed or fractionation zone may provide a side cut from the column To collect and remove the water-rich second liquid phase recovered in the apparatus. Referring again to Figure 1, the separation apparatus is adapted to receive a pressurized gas phase from the liquid phase oxidation reaction zone 110. In some embodiments, the apparatus of the present invention comprises a separation unit in combination with at least one liquid phase oxidation reactor, the liquid phase oxidation reactor being permeable to the separation apparatus, whereby at least one overhead gas represented by U6 can be passed The high pressure overhead gas from which the exhaust port is removed from the vessel is added to the separator. In such embodiments, the reaction vessel 11A preferably comprises a substantially cylindrical shell that defines a substantially enclosed interior volume. In use, the portion below the internal volume contains a liquid reactant, and the portion of the internal volume above the liquid level of the liquid contains overhead reaction gases. The internal volume is via a plurality of inlets, an example of which is indicated at 112 in the figure, and flows outside the reaction vessel, through which the liquid aromatics can be introduced from the liquid filling container (not shown). Feeding material 'solvent and soluble form of catalyst, and introducing compressed air or another source of oxygen from a compressor or other suitable device (not shown) via a suitable transfer line (not shown) Preferably, the configuration results in the liquid and gaseous components being directed to a level below the liquid level within the interior of the container. The reaction vessel also includes at least one outlet for the removal of the liquid phase reaction mixture comprising the crude product comprising aromatic decanoic acid and oxidation by-products, indicated at 114. The reaction vessel 110 also includes at least one vent or outlet for the removal of the high pressure gas phase evaporating from the liquid reactant from the interior of the vessel. When the vent 116 is in a position suitable for operational use, its position preferably corresponds to the upper portion of the container. Preferably, the reaction vessel is designed to be a substantially cylindrical vessel having a central axis that extends substantially vertically when it is in a position suitable for operational use. The granulator is adapted to use a stirring device 12 〇 comprising a liquid having - or a plurality of impellers mounted thereon and which can be rotated in the interior of the reaction thief during operation and use The axis of the reaction mixture. In a preferred embodiment of the invention, at least two impellers or mixing devices are mounted on the shaft to mix gaseous and liquid groups within the liquid reaction body and do not adversely settle solids beneath the container. Within. Axial two impellers' which are usually designed to ride (four), radial flow mixers, such as flat blade turbines and dispersing discs, screw (four) mixing elements, pitch vane turbines with blade pitches that can be up or down, The (4) mixer and other configurations which provide the main tangential flow are suitable for mixing the liquid phase oxidation reaction system, preferably in various combinations to illustrate the higher solids content in the region below the liquid mixture 1352079. The higher body content in the upper zone and other characteristics of the liquid phase reaction mixture that can vary within the liquid entity.

Other designs are disclosed in US Pat. No. 5,198,156 and US Pat. No. 5,904, the entire disclosure of which is incorporated herein by reference. a mixing element of a leading edge, a continuous trailing edge, an outer concave surface and an open outer end, and preferably a vertical tube or a porous gas sprayer for distributing gas; and US 5,904,423 describes a mixer. Wherein the agitating element is mounted on the central axis of rotation at a downward angle and passes the liquid in a wedge shape along the direction of movement, and the radially inner end of the trailing edge 10 of the blade is angled outwardly along the direction of movement of the blades, And the means for introducing gas from the agitating elements into a central cavity formed by a conical disk at one end of the shaft. At least the reaction vessel, the agitator shaft, and the mixing element that allows the liquid reaction mixture to contact the overhead gas during operation are comprised of a substantially corrosion resistant material. Examples include titanium (which is preferred), alloys, and dual precision steels. A preferred method embodiment, represented by Figure 1, is through the inlet, wherein - for the purpose of U2, the liquid is added to the oxidation reactor no (which is pressure) In the rated, continuous search tank, the liquid para-xylene feed material comprises at least about 99 wt%, aqueous acetic acid solution, preferably from about 70 to about 95 wt% acetic acid, wrong. And a soluble compound of the bell, such as a single acetate as a source of oxidized metal, and a desert compound such as hydrogen bromide as an agonist for the catalyst. The solvent and p-biphenylene are charged at a rate which provides a feed weight ratio of from about 2:1 to about S) 71 1352079 5:1. Preferably, the manganese source is used in an amount of from about 1 Torr to about 800 ppmw, based on the weight of the p-xylene feed material. The bromine is preferably used in an amount such that the atomic ratio of bromine to catalytic metal is from about 0.1:1 to about 1.5:1. 5 providing agitation by rotation of the shaft 120, driven by an external power source (not shown) such that the impeller mounted on the shaft and in the liquid object of the reactor is used to mix the liquid object Liquid and gas dispersions and avoid the forces of solids settling in the lower region. The catalyst and agonist, each preferably in the form of a solution in an acetic acid solvent, are introduced into the liquid body of the reactor. Air is supplied from the sweep path of the lower impeller and at a rate effective to obtain at least about 3 moles of oxygen per mole of aromatic feed material. The p-xylene in the feed liquid reaction mixture of reactor 110 is primarily oxidized to p-phenylene carboxylic acid, but is also reacted to form by-products, 15 which include partial and intermediate oxidation products such as 4-enylbenzene. Kushiro, ι, 4- thiol decanoic acid and p-f benzoic acid, and other acids such as benzoic acid. The solid reaction product containing terephthalic acid and p-xylene oxidation by-product precipitates from the liquid reaction mixture, and only a small amount is still dissolved in the liquid. The solids content of the liquid is typically up to about 4% by weight and preferably from about 2% to about 205% by weight. Water is also produced as a product of this oxidation. The oxidation reaction is exothermic, and the heat generated by the reaction may cause boiling of the liquid phase reaction mixture and vaporization of acetic acid, water vapor, and gaseous by-products/carbon oxides derived from the oxidation reaction, obtained from the addition. The nitrogen in the air of the reaction and the formation of an overhead gas phase of unreacted oxygen. The water vapor may also include a small amount of unreacted 72 para-xylene feed. The internal volume of the reactor 110 is maintained at a pressure sufficient to maintain the liquid phase properties of the reaction mixture, preferably from about 5 to about 21 kg/cm. The overhead vapor is removed from the reactor via vent 116. Depending on the rate of gas phase removal, the temperature and flow rate of the stream from the reactor removed and returned to the reactor as described below are also contemplated, and the reaction is maintained at an operating temperature in the range of from about 160 to about 225 °C. Contents. The solid p-xylene oxidation product is contained from the reactor 11 via the slurry outlet 114, which is included in the benzene which is also slurried in a liquid phase reaction mixture which is dissolved in para-xylene, oxidation by-products and catalytic metal. The dicarboxylic acid, liquid effluent is sent to the crystallization zone in stream 115 to recover the oxidized solid product containing the p-dicarboxylic acid and the oxidation by-product of the p-xylene feed. In the embodiment of the invention illustrated in Figure 1, the crystallization reaction is carried out in a multi-stirred crystallization vessel 152 and 156 which is associated with and circulated to transfer the product slurry from crystallization vessel 152 to crystallization vessel 156. The cooling in the crystallization vessel can be carried out by pressure release 'where the slurry in the crystallization vessel 152 is cooled to a temperature in the range of about 150 to 19 (TC) and then cooled to about U0 in the crystallization vessel 156. 15: (: discharge one or more of the crystallization vessels in streams 154 and 158, respectively, to remove steam from the pressure drop in the heat exchange device (not shown) and from the surge steam Preferably, the condensation is carried out from one or more upstream crystallization vessels, such as crystallization vessel 152, to the steam of the heat exchanger and may deliver the condensate of the aqueous, acetic acid solvent and soluble products and by-products of the oxidation reaction to One or more downstream crystallization vessels 156 are crystallizable components, such as terephthalic acid, and oxidation by-products, which are recovered and condensed from the boiling vapor of one or more upstream crystallization vessels. Crystallization vessel 156 and g] liquor The separation device (9) is circulated, and the solid-liquid separation is suitable for receiving a solid product slurry containing the p-dicarboxylic acid and the oxidizing agent in the mother liquor containing acetic acid and water obtained from the oxidation reaction from the crystallization vessel, and is suitable for self-contained The hetero-separation contains a crude product of p-tricarboxylic acid and by-products. The separation device is a centrifuge, a rotary vacuum or a (four) device. In the preferred embodiment of the invention, the separation device is adapted to be subjected to water under pressure. The washing liquid is taking the money of the money (4), and the oxidizing mother liquid formed from the separating step leaves the separating device 19 in the material stream 191 and moves to the mother liquid cylinder. From the cylinder 192, most of the mother liquid is transferred to the oxidation reactor n.液相 to return acetic acid, water, _ and the liquid phase oxidation reaction of the oxidation reaction by-products which are dissolved in the mother liquor or dissolved fine particles in the mother liquor, with or without intermediate drying and storage steps, Separating device 190 transfers the crude S] product containing terephthalic acid and impurities containing the oxidation by-product of the p-dimethyl stearate to stream 197 to the purified solution replenishing vessel 2〇2. The crude solid product is slurried in a purification reaction solvent, all or at least a portion thereof, and preferably from about 6 Torr to about 1% by weight, contained in the gas phase moved from the reactor 110 to the column 330, and the oxidation group Water and B in the product The acid off-gas is separated 300 to obtain a second liquid phase. If used, a solvent such as fresh demineralized water or a suitable recycle stream, such as the following, can be used to purify the terephthalic acid product. The liquid condensed from the steam due to the pressure drop is sent to the supply tank 2〇 2. The temperature of the slurry in the supply tank is preferably about 8 〇 to about 1 〇〇 。. By heating in the supply tank 202, For example, to about 26 Torr to about 29 Torr, or passed through a heat exchanger (not shown) while transferring to the purification reactor 210, the crude product is dissolved to form a purified reaction solution. In the reactor 210, The purified reaction solution is contacted with hydrogen at a pressure of preferably from about 85 to about 95 kg/cm. A portion of the purified liquid reaction mixture is continuously passed from the hydrogenation reactor 210 to a crystallization vessel 220 as a stream 211. In which the terephthalic acid and a small amount of impurities are crystallized from the reaction mixture by reducing the pressure on the liquid. The purified p-dicarboxylic acid and liquid formed in the crystallization vessel 220 is sent to the solid-liquid separation device 230 in a material flow line 221. The vapor formed from the pressure drop in the crystallization reactor can be transferred to a heat exchanger (not shown) for cooling to condense' and the resulting condensate is sent to the process, for example via a suitable transfer line. (not shown) is passed to the purified feed supply tank 202. Purified terephthalic acid exits the solid-liquid separation unit 23(R) in stream 231. The solid-liquid separation device may be a centrifuge, a rotary vacuum filter, a pressure filter, or a combination of one or more thereof. The second liquid phase removed from column 330 can be sent to the separation unit as a wash solution for use in the separation step to replace or reduce the demineralized water demand for the final strip of the purified product. Purifying the mother liquor, wherein the solid purified terephthalic acid product is separated in a solid-liquid separator 230, comprising water, a small amount of dissolved and suspended terephthalic acid, and hydrogenated oxidation comprising dissolved or suspended in the mother liquor. Impurities of by-products. Preferably, at least some, and preferably all or substantially all of the purified mother liquor is sent as a stream 233 to the oxidation reaction off-gas separation step in the high pressure distillation column 330, in accordance with the preferred method embodiment illustrated in FIG. Imported in ', in. The purified mother liquor sent to column 330 is directed to a lower portion 344 of the column to provide reflux for the liquid used for separation. The step of moving the purified mother liquor to the high-pressure distillation column from the solid-liquid separation device 23 can also be used to oxidize terephthalic acid and impurities such as benzene-f-acid and p-non-benzoic acid by-product in the mother liquor. The reactor 110' is oxidized or converted to terephthalic acid, and the water content of the purified mother liquor is vaporized and refluxed in the distillation column to pressurize the gas and/or the second liquid removed from the column 5. The phase leaves without significantly affecting the water balance in the oxidation reaction. The step of transferring the purified mother liquor to the distillation column by the solid-liquid separation device 230 can also reduce the volume of the liquid discharge liquid required for the treatment of the liquid waste and return the shellfish terephthalic acid to the oxidation reaction, and then move it therefrom. In addition, recovery is performed in the oxidizing crystallizers 152 and 156. 10 The reaction off-gas generated by the liquid phase oxidation reaction of the p-xylene feedstock in the reactor 1 is removed from the reactor by the exhaust port 116 and sent to the separation zone in the column 330 as a stream 111. As shown in Figure 2, the column represents a high pressure distillation column having a plurality of disks preferably providing from about 28 to about 63 theoretical plates, and the liquid for reflow is supplied to the liquid 15 via liquid inlets 336 and 344. Preferably, respectively, at a temperature of from about 150 to about 225 ° C and a pressure of from about 4 to about 21 kg/cm 2 , which is substantially not lower than the temperature and pressure in the oxidation reactor 11 ' will be derived from the oxidation reaction The steam material is conducted into the column 33. As indicated above, Figure 1 illustrates a preferred embodiment wherein the reflux liquid leading to the column comprises a purification mother liquor from which the solids can be purified in a solid-liquid separation unit 230. Column 330 includes 80 disks, of which about 50 to about 70 are disposed below return inlet 344' while the remaining disks are above return inlet 344, but below the inlet of the second flowing liquid indicated at 336. The locations of inlets 336 and 344 can be separated into discs corresponding to at least about 3 theoretical equilibrium stages, and preferably from about 3 to about 20 such stages. According to a preferred embodiment of the invention as set forth at i, 76, the reflux liquid supplied to the column 336 is preferably a high pressure and a high temperature second gas phase removed from the distillation column 330 in the 350 after condensation. The condensate is recovered and introduced into the condensate of the column by stream 355, and the reflux liquid supplied from the stream 23 3 to the reflux inlet port 344 is preferably sent to the column to allow purification of the product from the liquid phase oxidation reaction. Purified mother liquor required for solid-liquid separation. The reflux supplied to the inlet of the column preferably provides from about 70 to about 85% by volume of the reflux liquid added to the inlets 344 and 366 of the column. The acetic acid solvent recovered from the high-pressure inlet gas sent to the column 330 for use in the liquid phase oxidation reaction and the para-xylene dissolved in the liquid phase in the column 33〇 are collected at a portion below the column. A first liquid phase of oxidation reaction by-products such as benzoic acid and p-toluic acid. A second liquid, which is primarily water, is collected, but also contains a small amount of benzoic acid and p-nonyl benzoic acid by-product which are soluble in the liquid phase and are removed from the side outlet outlet 345 of the column. The water vapor, the non-condensable component of the oxidizing waste gas, and the second high pressure steam which is preferentially soluble in the acetic acid by-products of the gas phase, such as methanol and methyl acetate, are supplied from the top exhaust port 334 in the form of exhaust gas. Please remove it. The first phase of the acetic acid-rich phase formed from the separation zone in distillation column 330 exits from the lower portion of the column and is preferably returned directly or indirectly to oxidation reactor 110 by stream 331. Returning the liquid phase to the oxidation step provides a supplemental solvent for the oxidation reaction, acetic acid, and can convert the intermediates and by-products condensed from the oxidizing gas phase into desired products and reflux the intermediates and by-products from the purified mother liquor. Recycling to the column reduces feedstock losses. The second liquid phase discharged from the side fraction outlet 345 of the column is sent to the purification solution replenishing vessel 202 in a stream 357 to form the crude product slurry and is sent to the purification reactor 210 to purify the reaction solution 'other purification The container and the liquid receiving device and the use for transporting the water-rich second liquid phase include a crystallization vessel 220' for use as a cleaning supplement solvent to replace the purified reaction liquid vaporized in the crystallizer and for use as a lotion or The solid-liquid separation device 23〇 used for sealing and rinsing. The condensate «4", such as the washing solution used for the #1 exchange buffer. The exhaust gas discharged from the exhaust port 334 of the column is sent to a condensing unit 350, which, as shown in Fig. 1, includes condensers 352 and 362, and a discharge cylinder 3 72. Condensation is preferably carried out, whereby it is from about 4 Torr to about 6 Torr. The liquid condensate water can be recovered in at least one stage at a temperature of 〇. In the embodiment illustrated in the Figure, condensation is effected by indirect heat exchange with water in a condensing unit 352 at a temperature of from 120 to about 170 C, and the resulting liquid condensate is sent to stream 355. The return inlet 336 of the column 330. The liquid from the condenser 352 and the uncondensed gas are sent to the condenser 362 in stream 361 to effect condensation using cooling water at about 30 to about 40 °C. The gas and liquid effluent from condenser 362 is sent to stream 372 as stream 363 where the aqueous condensate is collected and removed as stream 373 which can be sent to other uses, such as as a seal rinse Or flush the material stream. The condenser off-gas under pressure is discharged as stream 375. The water as a heat exchange fluid for condensing the second high pressure gas from the steam column 330 is heated by heat exchange in the condensing device 350 to produce a method that can be sent to the energy recovery device, such as described in FIG. The pressurized steam of the steam turbine 450' in the embodiment. The use of a heat exchange fluid at successively lower temperatures, condensing with two or more condensers in series can produce steam at different pressures, whereby different amounts of heat or energy can be used in conjunction with the operation of the steam. Effectively use steam at different pressures. The uncondensed off-gas removed from stream 375 from the condensing action comprises a non-condensable component, such as unconsumed oxygen from the oxidation reaction, nitrogen from the air source as the oxygen source for the oxidation reaction, Since the air and the carbon oxides of the reactants obtained from the oxidation reaction, and a trace amount of unreacted p-xylene and its oxidation by-products, methyl acetate and methanol, and the self-use of the oxidation reaction Moxibustion formed by the agent. In the embodiment illustrated in the illustration, the uncondensed gas is substantially free of water vapor since it is substantially completely condensed into the condensate recovered by the condensing unit. The uncondensed exhaust gas from the condensing unit 350 is at a pressure of from about 1 Torr to about 15 kg / _ 2 cm and can be transferred directly to an energy recovery unit or directly to a pollution control device to remove rot money prior to energy recovery. Sexual and flammable species. As described in Figure 2, the non-condensed gas is first treated to remove uncondensed feed material and traces of solvent acetic acid and/or their reaction products remaining in the gas. The uncondensed gas is therefore moved in stream 375 to high pressure absorber 380 to strip p-xylene, acetic acid, decyl alcohol and methyl acetate at substantial loss of pressure. The absorption column 380 is adapted to receive a substantially water-depleted gas remaining after condensation and adapted to separate p-biphenyl, solvent acetic acid and the like from the oxidation reaction of the gas in contact with the one or more liquid scrubbers reaction product. The preferred absorber configuration illustrated by the illustration includes a tower 38 having a plurality of internal configuration discs or beds or structural packings (not shown) that provide surface for mass transfer between gas and liquid phases. . The inlets (not shown) for adding the scrubber to streams at streams 381 and 383, respectively, are disposed at one or more of the towers, and one or more lower portions. The absorber also includes an upper vent 382 from which the scrubbing gas system containing the non-condensable component of the inlet gas to the absorber is transferred via line 385 and lower outlet 384 for removal. Wherein the component from the gas phase comprises one or more streams of liquid acetic acid which are scrubbed to dimethyl benzene, acetic acid, methanol and/or methyl acetate. The bottoms liquid is removed from the lower portion of the column and can be sent to reactor 110 for reuse of the recovered components. The pressurized gas removed from the venting port 382 of the high pressure absorber may be sent to the pollution control device 39 from the condensing device 350 or as described in Fig. i to extract the gas from the condenser or absorber. The preferred organic control component and carbon monoxide are converted to carbon dioxide and water. The preferred pollution control device is adapted to receive the gas and can be selectively heated to promote combustion and to stabilize the gas with a high temperature disposed on a porous or other support. The oxidizing catalyst contacts, whereby the gas flowing through the device is substantially unaffected by the catalytic oxidation unit. The gas from the top of the absorber 380 is sent to a pollution control system 390 comprising a preheater 392 and a catalytic oxidation unit 394. The gas is heated to about 250 to 450 ° C in the preheater and sent to the oxidation unit 394 at a pressure of about 10 to 15 kg/cm 2 , wherein the organic components and by-products are oxidized to be more suitable. The oxidized high pressure gas system is sent from the catalytic oxidation unit 394 to the expander 400 connected to the generator 420. The energy from the oxidized high pressure gas is successfully converted in the expander 4'. Generator 420 converts this work into a power source. The expanding gas exits the expander, preferably after alkali scrubbing and/or other treatment, and is released to the atmosphere to properly manage this release step. 1352079, BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart illustrating an apparatus and method in accordance with a preferred embodiment of the present invention, including the apparatus and other apparatus for preparing and purifying an aromatic carboxylic acid according to an embodiment of the present invention. Integration of equipment. Figure 2 is an expanded view of a preferred form of apparatus in accordance with a preferred embodiment of the present invention and adapted to carry out the method according to an embodiment thereof. [Main component symbol description]

110...oxidation reactor 300...exhaust gas treatment zone 111, 115, 154, 158, 19, 197, 330... high pressure distillation column 21 231, 233, 331, 361, 363, 333 > 337... 373 373, 375, 381, 383.... material flow 334... exhaust ports 112, 336, 338, 344... inlet 350... condensation devices 114, 332, 345, 382, 384 352, 362. .. condenser...outlet 372...release cylinder 116...exhaust port 380...high pressure absorber 120...shaft 385...line 152,156,220...crystallization vessel 390.. pollution control device 190, 230... solid-liquid separation device 392... preheater 192... mother liquor cartridge 394.. catalytic oxidation unit 202... purification solution supply container 400... expander 204... container 420 ...generator 210...purification reactor 211.. material flow line 450···steam turbine 81

Claims (1)

1352079 100.8.15 Announcement 15 20 Double-sided photocopying No. 095112713 Patent Application Patent Revision No. Patent Application No.: 1. A method for preparing an aromatic carboxylic acid, which comprises at a high temperature and a high pressure in a reaction zone, containing at least one atomic weight range Contacting a feed material comprising at least one substituted aromatic hydrocarbon with gaseous oxygen in the presence of a catalyst composition of a heavy metal component of from about 23 to about 178 in a liquid phase oxidation reaction mixture comprising a monocarboxylic acid solvent and water The substituent in the substituted aromatic hydrocarbon can be oxidized to a carboxylic acid group, the high temperature and high pressure can effectively maintain the liquid phase oxidation reaction mixture, and form an aromatic carboxylic acid dissolved or suspended in the liquid phase oxidation reaction mixture and An impurity containing a by-product of the reaction, and a high-pressure gas phase containing a solvent monocarboxylic acid, water, and a small amount of the oxidation by-product of the substituted aromatic hydrocarbon and the substituted aromatic hydrocarbon and the solvent monocarboxylic acid; The removed high pressure gas phase is transferred to a separation zone which separates the solvent monocarboxylic acid, water and oxidation byproducts into at least one first liquid phase rich in solvent monocarboxylic acid And at least one water-rich second liquid phase, and the solvent monocarboxylic acid of the at least one aqueous vapor is depleted of the second high-pressure gas phase, whereby the oxidation by-product of the substituted aromatic hydrocarbon is preferentially soluble in the first a liquid phase, wherein the oxidation by-product of the solvent monocarboxylic acid is preferentially soluble in the second high pressure gas phase; and the first liquid phase of the solvent-rich monocarboxylic acid is removed from the separation zone in a separate stream The water-free second liquid phase of the solvent-free single bond and its oxidation by-products and the second high-pressure gas phase substantially free of oxidation by-products of the substituted aromatic hydrocarbon. 2. The method of claim 4, wherein the method further comprises separating the solvent monocarboxylic acid, water and oxidation by-products in the 100.8.15 zone of the patent application scope of the patent application No. 82 1352079. The separation method comprises the steps of: feeding the high pressure gas phase removed from the reaction zone to the first stage of the separation device, and sending the reflux liquid to the third stage of the separation zone, whereby the first from the separation zone The gas phase of the stage flow through the second stage to the third stage is in contact with the liquid being refluxed from the third stage of the separator through the second stage to the reverse flow of the first stage; The reversely flowing gas phase and the water and solvent monocarboxylic acid in the liquid phase being refluxed, thereby forming a first liquid phase rich in solvent monocarboxylic acid and a high pressure, solvent monocarboxylic acid depleted intermediate gas And separating the reversely flowing gas phase in the second stage and the water and by-products in the liquid phase being refluxed, whereby the by-product of the substituted aromatic hydrocarbon can be moved to the liquid phase being refluxed , Forming a high pressure second intermediate gas phase of water vapor substantially free of 15 solvent monocarboxylic acids and by-products of the substituted aromatic hydrocarbon; and separating the reverse flowing gas phase in the third stage and the liquid phase being refluxed a water and a by-product of the solvent monocarboxylic acid, thereby forming a water-insoluble second liquid 20 phase substantially free of the solvent monocarboxylic acid and its by-products, and a by-product of the aqueous vapor and the solvent monocarboxylic acid There is substantially no second high pressure gas phase of the substituted aromatic hydrocarbon by-product. 3. The method of claim 2, further comprising discharging the aqueous second liquid phase of the substantially solvent-free monocarboxylic acid and its by-products from the separation zone. </ RTI> </ RTI> </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> Thereby at least one aqueous liquid in the purification zone comprises the second liquid phase. 5) The method of claim 2, wherein the first stage of the separation device comprises a theoretical equilibrium phase of water and a solvent monocarboxylic acid in the high pressure gas phase that can be separated and moved to the separation zone, thereby At least 95% by weight of the solvent monocarboxylic acid is transferred to the refluxing liquid in the first stage. 6. The method of claim 2, wherein a reflux system is supplied to the first stage of the separation zone. 10. The method of claim 6, wherein the reflux liquid supplied to the first stage comprises a purification mother liquid sent from the purification zone to the separation zone. 8. The method of claim 2, wherein the reflux liquid supplied to the third stage of the separation zone comprises by-products of the aqueous vapor and solvent monocarboxylic acid and is substantially free of substituted aromatic hydrocarbon by-products. The second highest 15 liquid that is condensed by the liquid phase. 9. The method of claim 1, wherein the substituted aromatic hydrocarbon is para-xylene, the solvent monocarboxylic acid comprises acetic acid, and the second liquid phase removed from the separation zone comprises substantially solvent-free monocarboxylic acid. Water of acid, methanol and methyl acetate, and the second high pressure gas phase comprises 20 water vapor substantially free of p-toluene acid. 10. The method of claim 1, further comprising condensing the aqueous second high pressure gas phase substantially free of oxidation by-products of the substituted aromatic hydrocarbon removed from the separation zone to form an aqueous condensate And condensing the exhaust gas at a high pressure, and recovering at least one of the solvent monocarboxylic acid 84 1352079 100.8.15 Patent No. 095112713 from the high-pressure condensing waste gas as a by-product of the patent application scope revision. A method for purifying an impure aromatic carboxylic acid in the purification zone 11. The method of claim 4, wherein the method comprises the following step (4): forming a argonic acid containing or dissolved in an aqueous liquid and Purifying reaction solution of impurities; (b) contacting the purified reaction solution containing aromatic acid and impurities in aqueous solution with hydrogen at a high temperature and a high pressure to form a purified liquid reaction mixture; a purified liquid reaction mixture containing the aromatic acid and impurities, recovering a solidified purified product containing an aromatic carboxylic acid having a small amount of impurities and a purification mother liquid; (d) washing the aromatic carboxylic acid with at least one aqueous liquid, A solidified purified aromatic carboxylic acid product recovered from a purified liquid reaction mixture of impurities and aqueous liquid. 15 12. A method of preparing an aromatic carboxylic acid, comprising the steps of: at least one liquid phase oxidation step comprising: high temperature and high pressure In the presence of a catalytic composition comprising at least one heavy metal component having an atomic weight ranging from about 23 to about 178, in a solution comprising a monodecanoic acid solvent and water In the phase oxidation reaction mixture, the feed material containing at least one substituted aromatic 20 hydrocarbon is contacted with gaseous oxygen, and the substituent in the substituted aromatic hydrocarbon can be oxidized to a carboxylic acid group, and the high temperature and high pressure can effectively maintain the liquid phase Oxidizing the reaction mixture, and forming an aromatic acid retardant and an impurity containing a reaction by-product dissolved or suspended in the liquid phase oxidation reaction mixture, and a high-pressure gas phase, the high-pressure gas phase aqueous, monocarboxylic acid, unreacted Substituted aromatic hydrocarbons, 85 1352079 Patent Application No. 095,112,713, the entire disclosure of which is incorporated herein by reference in its entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire all all all all all all all all each In the presence of a medium, contacting hydrogen with a purified reaction solution containing a liquid of aromatic carboxylic acid and impurities recovered from the liquid phase oxidation reaction mixture containing water and having been dissolved in at least one liquid phase oxidation step Forming a purified liquid reaction mixture comprising the aromatic carboxylic acid and hydrogenated impurities dissolved in the aqueous liquid; and at least one off-gas separation step comprising Transferring the high pressure gas phase removed from the reaction zone of the liquid phase oxidation step to the first liquid phase capable of separating the solvent monocarboxylic acid, water and oxidation by-product into at least one solvent-rich monocarboxylic acid, and at least one a second aqueous phase rich in water, and a separation zone of the second high pressure gas phase depleted of the solvent monocarboxylic acid of at least one aqueous vapor, whereby the oxidation by-product of the substituted aromatic hydrocarbon is preferentially soluble in the first a liquid phase, and the oxidation by-product of the solvent monocarboxylic acid can be first dissolved in the second high pressure gas phase, and the water-free substantially solvent-free monocarboxylic acid and its oxidation by-product are removed from the separation zone. a second liquid phase and a second high pressure gas phase substantially free of oxidation byproducts of the substituted aromatic hydrocarbon; and at least one step comprising substantially removing the solvent from the separation zone in the at least one offgas separation step 20 The step of feeding the water-rich second liquid phase of the monocarboxylic acid and its oxidation by-product to the purification zone, whereby the aqueous liquid for at least one purification step or for recovering, separating or washing the product comprises the substantially Solvent list Acid and oxidation by-products of the second liquid phase rich in water. </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; The solid product containing the aromatic carboxylic acid and the impurity containing the oxidation by-product recovered from the liquid phase oxidation reaction mixture is dissolved in the aqueous liquid to form a purified solution, and the aqueous liquid contains substantially at least one exhaust gas The water-rich second liquid phase of the substantially solvent-free monocarboxylic acid and its oxidation by-product removed from the separation zone in the separation step. 14. The method of claim 12, wherein the at least one purification comprises a step of forming a slurry comprising an aromatic carboxylic acid and a minor amount of a solid product in the aqueous liquid, the solid product being The purified liquid reaction mixture is recovered, and the aqueous liquid comprises a second water-rich liquid phase substantially free of solvent-free monoacids and oxidation by-products thereof removed from the separation zone in at least one off-gas separation step. 15. The method of claim 12, wherein the at least one purification 15 comprises a step comprising washing the solid product containing the aromatic carboxylic acid and a small amount of impurities recovered from the purified liquid reaction mixture with an aqueous liquid, and The aqueous liquid comprises a second water-rich liquid phase substantially free of solvent-free monocarboxylic acid and oxidation by-products thereof removed from the separation zone in at least one off-gas separation step. The method of claim 12, further comprising at least one step, wherein the aromatic carboxylic acid in a solid pure form having a small amount of impurities and the purified mother liquid are reacted from the purified liquid in at least one purification step The mixture is recovered and the purified mother liquor is sent to at least one off-gas separation step whereby the reflux liquid supplied to the separation zone contains the liquefied mother liquor. </ RTI> </ RTI> </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> <RTIgt; The aqueous second high pressure gas phase of the unsubstituted aromatic hydrocarbon oxidation byproduct is formed to form an aqueous condensate. The method of claim 17, further comprising: delivering the aqueous condensate to the separation zone in the at least one offgas separation step, whereby the reflux liquid supplied to the separation zone comprises the aqueous condensate. 19. The method of claim 12, further comprising the second aqueous high pressure of the 10 substantially unsubstituted aromatic hydrocarbon oxidation by-product removed from the separation zone substantially in at least one off-gas separation step Gas phase recovery energy. 20. The method of claim 12, wherein the substituted aromatic hydrocarbon in at least one liquid phase oxidation reaction is para-xylene, and the solvent monocarboxylic acid of the liquid phase oxidation reaction t comprises acetic acid. The method of claim 20, wherein the second liquid phase of the substantially solvent-free monocarboxylic acid and its oxidation by-product removed from the separation zone in the at least one off-gas separation step is substantially absent Acetic acid, methanol, and methyl acetate, and the second high pressure gas phase removed from the separation zone is substantially free of p-nonylbenzoic acid. The method of claim 12, further comprising condensing the aqueous second high pressure gas phase from the substantially unsubstituted aromatic hydrocarbon oxidation byproduct removed from the separation zone in the at least one offgas separation step, To form an aqueous condensate and a high-pressure condensed exhaust gas, and recover at least one by-product of the solvent monocarboxylic acid from the high-pressure condensed exhaust gas, and the unreacted aromatics are applied in the patent application range of 88 1352079 100.8.15 No. 095112713 The substance or a combination thereof. A method for preparing an aromatic acid retardation comprising the steps of: (a) presenting a catalytic composition of a heavy metal component having an atomic weight ranging from about 23 to about 178 in a reaction zone under mild elevated pressure. In the liquid phase oxidation reaction mixture containing a monocarboxylic acid solvent and water, the feed material containing the substituted aromatic hydrocarbon is contacted with gaseous oxygen, and the substituent in the substituted aromatic hydrocarbon can be oxidized to a carboxylic acid group. The high temperature and high pressure can effectively maintain the liquid oxidation reaction mixture, and form an aromatic tetacid dissolved or suspended in the liquid phase oxidation reaction mixture and impurities containing the by-product of the substituted aromatic hydrocarbon, and a high pressure gas phase, a high pressure gas phase solvent containing monodecanoic acid, water, the substituted aromatic hydrocarbon by-product, and a solvent monocarboxylic acid by-product; (b) recovering solids containing aromatic carboxylic acid and reaction by-product impurities from the liquid phase oxidation reaction mixture a product; (c) suspending or dissolving a solid product of an aromatic carboxylic acid and an impurity containing a by-product of the reaction of the substituted aromatic hydrocarbon by the liquid phase oxidation reaction mixture in an aqueous liquid, the inclusion At least a portion of the liquid comprises a second liquid phase recovered according to step (g) to form a purified reaction solution; (d) contacting the purified solution with hydrogen at a high temperature and a high pressure in the presence of a hydrogenation catalyst to form a purification a liquid reaction mixture; (e) recovering a solid purified product containing an aromatic carboxylic acid having a small amount of impurities from the purified liquid reaction mixture, and purifying the liquid with a small amount of a substituted aromatic by-product, a hydrogenated derivative thereof, or a combination thereof a mother liquor; (0) a solvent-containing monocarboxylic acid obtained from the step (4), a water vapor, and a modified product of the patent scope of the patent application PCT Patent Application No. 096112713. The high-by-gas phase of the by-product is transferred to a separation zone, which is provided with a reflux liquid and can separate the solvent monocarboxylic acid, water and by-products into at least one first liquid phase rich in solvent monocarboxylic acid, and at least a second liquid phase enriched in water substantially free of a solvent-free monoacid, and a second high-pressure gas phase depleted with at least one solvent of a water vapor, whereby the substituted aromatic hydrocarbon The oxidation by-product may be substantially soluble in the first liquid phase, and the oxidation by-product oxime of the solvent monocarboxylic acid is substantially soluble in the second high pressure gas phase; (g) is removed from the separation zone as a separate material stream a first liquid phase enriched in a solvent monocarboxylic acid, and a second water-rich liquid phase substantially free of solvent monocarboxylic acids and oxidation by-products thereof, and second substantially free of by-products of the substituted aromatic hydrocarbon a high pressure gas phase; (h) sending the substantially water-free second liquid phase of the substantially solvent-free monorexic acid and its by-product removed from the separation zone in step (g) to steps (c), (d) At least one of ^ or (e), whereby the aqueous liquid in at least one of the steps (c), (d) or (e) comprises the second liquid phase. 24. The method of claim 23 The step of advancing comprises: feeding the purified mother liquor recovered according to step (e) to step (f) 'where the reflux liquid supplied to the separation zone in step (f) comprises the purified mother liquor. 2〇25. The method of claim 23, which further comprises the second high-pressure gas phase recovery hydrogel of the substantially unsubstituted aromatic hydrocarbon by-product removed from the separation zone according to step (g) liquid. 26. The method of claim 23, further comprising: feeding the aqueous condensate recovered from the second south pressure gas phase to step (f), thereby supplying the patent application to the patent application No. 095112713 Range Correction This 100.8.15 reflux liquid in the separation zone in step (1) contains the condensate. 27. The method of claim 26, further comprising the step of feeding the purified mother liquor recovered according to step (e) to step (1), whereby the reflux liquid supplied to the separation zone in step (1) comprises the purified mother liquor. 5. The method of claim 27, wherein the reflux liquid system containing the condensate is supplied to the upper portion of the separation zone. 29. The method of claim 28, wherein the reflux liquid system containing the purified mother liquor is supplied to a portion below the separation zone. 30. The method of claim 27, wherein the returning liquid system containing the purified mother liquor is supplied to a portion below the separation zone. 31. The method of claim 30, wherein the second liquid phase removed from the separation zone according to step (g) is removed from the intermediate portion between the upper portion and the lower portion of the separation region . 32. The method of claim 25, further comprising a second high pressure gas phase recovery energy source substantially free of substituted aromatic hydrocarbon by-products removed from the separation zone according to step (g). 33. The method of claim 23, further comprising the second high pressure gas phase recovery energy source substantially free of substituted aromatic hydrocarbon by-products removed from the separation zone according to step (g). 20 34. The method of claim 33, wherein the energy source is recovered in the form of work. 35. The method of claim 33, wherein the energy source is recovered in the form of heat. The method of any one of claims 23 to 35, wherein the aromatic hydrocarbon substituted by the 100.8.15 modified by the patent application scope of the patent application No. 91 1352079 is pp. The solvent monocarboxylic acid comprises acetic acid. The method of any one of claims 23 to 35, wherein the second liquid phase removed from the separation zone in step (g) is substantially free of acetic acid, decyl alcohol and decyl acetate, and The second high pressure gas phase removed from the separation zone is free of p-toluic acid. 38. Apparatus for separating components of a reactor off-gas produced by the liquid phase oxidation reaction of a substituted aromatic hydrocarbon feed in a liquid phase reaction mixture to produce an aromatic carboxylic acid, comprising a defined internal volume a substantially cylindrical, substantially closed vessel and comprising 10 at least one lower gas inlet for receiving the first stage of the high pressure overhead gas phase removed from the reaction vessel and sent to the fractionation zone of the apparatus for Maintaining the liquid phase reaction mixture and producing a substituted aromatic hydrocarbon in the liquid phase reaction mixture containing the monocarboxylic acid solvent and water under the conditions of a high pressure overhead gas phase containing a solvent monocarboxylic acid and water vapor in the reaction vessel a liquid phase oxidation reaction of the material with gaseous oxygen; and a fractionation zone located within the internal volume of the vessel, contacting the gas and the liquid phase opposite thereto in a plurality of theoretical equilibrium stages, and including the first portion , which is separable from water in a high pressure gas phase which is in contact with the liquid being refluxed from the reverse flow of the liquid component being received in the intermediate stage 20 of the fractionation zone. a solvent monocarboxylic acid whereby the first liquid phase enriched in the solvent monocarboxylic acid is transferred into the liquid being refluxed and forms a high pressure solvent monocarboxylic acid depleted first intermediate gas phase containing water vapor, wherein The first part is 92 1352079 Patent Application No. 095112713, the patent application scope modification, and the intermediate portion of the fractionation zone is circulated to receive the liquid in the reflux phase and pass the first intermediate gas phase, and includes And means for transferring the liquid in which the first liquid phase has been transferred to the liquid reservoir; and the intermediate portion 'which is separable and containing the portion being received from the upper portion of the separation device The reverse flow of the liquid component of the liquid, the liquid in the first intermediate gas phase in contact with the liquid being refluxed, and the liquid phase oxidation by-product of the substituted aromatic hydrocarbon feed material, whereby the substituted aromatic hydrocarbon may be added The product is transferred into the liquid being refluxed and forms a high pressure second intermediate gas phase comprising a substantially solvent free monocarboxylic acid water vaporized A and a 5 quasi-substituted aromatic hydrocarbon by-product, wherein the intermediate portion is separated from the fractionation zone Circulation upper portion thereof to receive orders and refluxing liquid through a second intermediate vapor; and on. A bruise, which can be supplied to at least a second intermediate gas phase. The upper part of the sea is in contact with the reverse flow of the liquid being refluxed. · In the liquid, the water contained in the separation and the liquid phase oxidation of the solvent monocarboxylic acid "1 product" can be substantially The solvent-free monocarboxylic acid water and the second liquid phase of the product are moved to the liquid being refluxed and also form a second step of the aqueous vapor and the by-product of the solvent monocarboxylic acid and the by-product substantially free of substituted aromatic hydrocarbons. a high pressure gas phase, wherein the upper portion includes a collection device for collecting a lower portion of the liquid in which the second liquid phase has been transferred into the reflux portion; and the first portion for receiving the self-dividing region receives Patent Application No. 93 1352079, No. 095,112, 713, the entire disclosure of which is incorporated herein by reference. a liquid outlet for the liquid of the apparatus; and at least one liquid inlet for introducing the reflux liquid into the upper portion of the fractionation zone; and at least one upper zone for introducing the reflux liquid to the lower portion of the fractionation zone The liquid inlet; and at least one circulation with the collecting means for removing the second liquid from the liquid outlet means 10 has been moved to at least a portion of the liquid is refluxed therein. 39. The apparatus of claim 38, wherein the fractionation zone provides between 20 and 80 theoretical equilibrium stages. 40. The apparatus of claim 38, wherein the first portion of the fractionation zone separates water and solvent monocarboxylic acid in the high pressure gas phase, thereby at least 95 15% by weight of the solvent monocarboxylic acid shift To the liquid that is being refluxed. 41. The device of claim 38, wherein at least one outlet connected to the collection device and at least one inlet for introducing reflux liquid into the upper portion of the fractionation zone are separated from 1 to 10 Theoretical stage. The device of claim 38, wherein at least one outlet connected to the collection device and at least one inlet for introducing reflux liquid into the upper portion of the fractionation zone are separated from 1 to 10 a theoretical stage. The apparatus of any one of claims 38 to 42 which is in the form of a distillation column of the patent application scope of the patent application No. 095112713. 44. The apparatus of claim 43, further comprising a reaction vessel for reacting the substituted aromatic hydrocarbon feed material with gaseous 5 oxygen in a maintainable liquid phase reaction mixture and producing in the reaction vessel a liquid phase oxidation reaction in a liquid phase reaction mixture containing a monocarboxylic acid solvent and water under a high pressure overhead gas phase containing a solvent monocarboxylic acid water vapor, wherein the reaction vessel contains at least one for removal therefrom The high pressure is placed on the exhaust port of the gas phase, and the exhaust port is circulated with at least one lower gas inlet for receiving the upper gas phase of the high pressure and feeding it to the first stage of the fractionation zone. 15 45. The apparatus of any of clauses 38 to 42 of claim 3, further comprising a reaction vessel for reacting the substituted aromatic tobacco feed material with gaseous oxygen in a maintainable liquid phase reaction mixture And in the reaction gas phase to produce a solvent containing monocarboxylic acid water vapor in a high pressure overhead gas phase, in the liquid phase reaction mixture containing the monocarboxylic acid solvent and water, the liquid phase oxidation reaction, wherein the reaction The vessel contains at least one exhaust port for removing the high pressure overhead gas phase therefrom, and the exhaust port is associated with at least one of the first stage for receiving the high pressure overhead gas phase and delivering it to the fractionation zone The gas inlet is circulated. 95