TW200827333A - Oxidation reaction for producing aromatic carboxylic acids - Google Patents

Abstract

A method of minimising or preventing catalyst loss and/or the precipitation of metal oxide in a catalytic synthetic oxidation reaction in an aqueous solvent comprising water under supercritical or near-supercritical conditions wherein during the oxidation reaction an oxidant is present and a metal salt is present as a catalyst, said method comprising the step of adding an acidic component comprising one or more acid(s) into the reaction such that contact of at least part of said metal salt with said oxidant is in the presence of said acidic component, particularly wherein the oxidation reaction is a process for the production of an aromatic carboxylic acid, said process comprising contacting in the presence of a catalyst, within a reactor, one or more precursors of the aromatic carboxylic acid with an oxidant, such contact being effected with said precursor(s) and the oxidant in an aqueous solvent comprising water under supercritical conditions or near supercritical conditions.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of catalytic oxidation synthesis of metal salts in supercritical waters, particularly in the oxidation of alkyl-substituted aromatic hydrocarbons to the corresponding aromatic carboxylic acids. In particular, the present invention relates to catalyst stability in such systems, and in particular to maintaining catalyst activity and/or efficiency, and to avoid reactor fouling. [Prior Art] When water approaches its critical point (374〇c & 220.9 bar), its dielectric constant is significantly reduced from a room temperature value of about 80 C2/Nm2 to a value of 5 C2/Nm2, making it soluble in organic molecules. . As a result, water thus behaves like an organic solvent in the following manner: a hydrocarbon such as toluene can be completely miscible with water under supercritical conditions or near supercritical conditions. For example, terephthalic acid is practically insoluble in water below about 200 °C. Molecular oxygen is also very soluble in subcritical and supercritical water.

Holliday RL·J. (J. Supercritical Fluids 12, 1998, 255 260) describes the synthesis of (especially) aromatics from alkyl aromatic compounds in a reaction medium of subcritical water using molecular oxygen as an oxidant in a sealed autoclave. Batch method of carboxylic acid. However, the use of supercritical water as a medium for the manufacture of aromatic carboxylic acids in a continuous flow reactor presents a serious problem. WO-02/06201-A discloses a process for the manufacture of an aromatic carboxylic acid comprising contacting one or more precursors of the aryl carboxylic acid with an oxidant in the presence of a catalyst in a continuous flow reactor, Contacting the contact system with the oxidant in the aqueous solvent comprising water at a supercritical or near supercritical condition near the supercritical point such that the or the precursor, oxidant, and aqueous solvent are The reaction zone constitutes a total of 126160.doc 200827333 phase. In the method described in WO-02/06201-A, at least the contact system of the earthworms with the oxidant and the catalyst and at least a portion of the oxidant The contact occurs simultaneously. The continuous process of WO-02/06201-A is carried out by a reactant and a solvent which form a substantially homogeneous homogeneous fluid phase, wherein the components are molecularly conjugated. Above the supercritical point, the concentration of molecular oxygen in water is increased, which helps to improve the reaction kinetics. The reaction kinetics are further increased by the high temperature present when the water solvent is under supercritical or near supercritical conditions. Strong. The combination of high temperature, high concentration and homogeneity means that the precursor is used in comparison with the residence time used in the manufacture of aromatic carboxylic acids (such as p-benzoic acid) by a conventional one-phase oxidation reactor. The reaction of converting a substance into an aromatic carboxylic acid can occur extremely rapidly. Under these conditions, the intermediate aldehyde (for example, 4-carboxybenzaldehyde (4_cba) in the case of terephthalic acid) is easily oxidized. An aromatic carboxylic acid is required which is soluble in the supercritical or near supercritical fluid, thereby significantly reducing the contamination of the recovered aromatic carboxylic acid product via the aldehyde intermediate. The process conditions of WO-02/06201-A are substantially reduced. Or avoid autocatalytic destructive reaction between the precursor and the oxidant and consumption of the catalyst. The continuous process involves short residence times and exhibits high yields and good selectivity for product formation. Supercritical oxidation for the production of aromatic carboxylic acids The preferred catalyst in the reaction comprises a stimulating salt (especially MnBh), but it has been observed that the stimulating salt is irreversibly oxidized to manganese oxide (including Μη02, Μη203 and MnO(OH)2) during the strong oxidative reaction conditions. Manganese oxidation The material forms an insoluble precipitate which adheres to the inner wall 126160.doc 200827333 after the initial contact of the catalyst with the oxidant (usually molecular oxygen), resulting in progressive fouling of the reactor and/or clogging in the pressure reducing device. Salts are oxidized in aqueous supercritical oxidation processes and this feature is used to make nanoparticles, as described, for example, by Viswanathan et al. (J. Supercritical Fluids, 2003, 27(2), pp. 187-193). Said that under certain conditions it is possible to reduce the metal oxide to a more soluble

_ lower oxidation state and dissolve it independently, and US-4645650 teaches that coal or other reducing carbonaceous materials can be used at atmospheric pressure and relatively low temperature in an amount of at least 50 〇/❶ of the mass of the metal oxide and in the inorganic acid This restore is implemented in the presence of. However, it is also known that some metal oxides are stable under supercritical water oxidation conditions. They have been developed as catalysts under extreme oxidative conditions to enhance the complete oxidation of certain organic materials, for example by Kranjnc et al. (Applied)

Catalysis, B. Environmental (1997), 13(2), 93-103). In the supercritical oxidation reaction for the production of aromatic carboxylic acids, the precipitation of manganese oxide reduces or prevents the opportunity to recycle the catalyst for efficient operation, and this catalyst loss is economically undesirable. In addition, the precipitation reduces or prevents flow in the official reactor, and the passages in the apparatus need to be cleaned or unblocked to continue operating the reactor, which is uneconomical and inefficient. Although the hybrid configuration described in W〇: 02/06201-A minimizes catalyst oxidation compared to other configurations, further improvements are needed. SUMMARY OF THE INVENTION One object of the present invention is to reduce or avoid the above. In particular, it is an object of the present invention to reduce the amount of metal oxide core and/or reduce the loss of catalyst during the metal:mid 2:super-bound (or near supercritical) water synthesis oxidation process. Thus, one of the present inventions 126160.doc 200827333 aims to improve catalyst stability in such systems, particularly to maintain catalyst activity and/or efficiency, and to avoid reactor fouling. Another object is to provide an improved process for the production of aromatic carboxylic acids via catalytic oxidation of a precursor in supercritical water, in particular a continuous process in which the amount of metal oxide precipitate is reduced and/or the loss of catalyst is reduced, In particular, this process has good selectivity for aromatic carboxylic acids and obtains high yields of aromatic carboxylic acids. According to a first aspect of the invention, there is provided an acidic group comprising one or more acids

Use of a portion in a catalytically synthesized oxidation reaction carried out under supercritical or near supercritical conditions in an aqueous solvent comprising water, wherein a metal salt as a catalyst is present during the oxidation reaction, wherein the acidic component is used for a minimum Catalyst or prevention of catalyst loss and/or precipitation of metal oxides during the reaction, wherein the reaction comprises an oxidizing agent and the acidic component is added to the reaction such that at least a portion of the metal salt and the oxidizing agent are in the acidic group Contact in the presence of a portion. According to a second aspect of the present invention, there is provided a catalyst loss and/or precipitation of a metal oxide which prevents or inhibits the catalytic filamentization reaction under supercritical or near supercritical conditions in an aqueous solvent comprising water or is reduced to a minimal method wherein an oxidizing agent is present during the oxidation reaction and a metal salt is present as a catalyst. The method comprises the steps of: adding an acidic component comprising one or more acids to the reaction such that at least y The metal salt is contacted with the oxidizing agent in the presence of the acidic component. The metal salt referred to herein is a catalyst for the oxidation process which oxidizes the oxidizable organic matrix or precursor to - or a plurality of (usually) species of the desired reaction product. The metal salt typically comprises a transition metal. 126160.doc 200827333 According to a third aspect of the invention, there is provided the use of an acidic component comprising one or more acids for minimizing or preventing catalyst loss and/or precipitation of metal oxides in a process for the manufacture of aromatic tracization The method comprises contacting the aromatic ray- or precursors with an oxidant in the presence of a catalyst comprising a metal salt, preferably a transition metal salt, in the reactor, the contact being from the precursor And the oxidizing agent is carried out in an aqueous solvent comprising water _ under supercritical conditions or near supercritical conditions, usually such that the or the precursors, oxidizing agents and aqueous solvent form a single homogeneous phase in the reaction zone, wherein the acidity A component is added to the reaction such that at least a portion of the catalyst is contacted with the oxidant in the presence of the acidic component. According to a fourth aspect of the present invention, there is provided a method for minimizing or preventing catalyst loss and/or metal oxide in a method of producing an aromatic carboxylic acid. The method package 3 comprises a metal salt in a reactor. In the case of a catalyst (preferably a transition metal salt), one or more precursors of the aromatic citric acid are contacted with an oxidizing agent from the (or) precursor and the oxidizing agent in an aqueous solvent comprising water. Supercritical or near supercritical conditions are generally achieved such that the precursor or oxidant and aqueous solvent constitute a single homogeneous phase in the reaction zone. The method comprises the steps of: comprising an acidic component comprising one or more acids Addition to the oxidation reaction is such that at least a portion of the catalyst is contacted with the oxidant in the presence of the acidic component. According to a fifth aspect of the invention, there is provided an oxidation process for the preparation of one or more target organic compounds from one or more oxidizable organic hydrazine precursors, the package: the precursors in the reactor One or more are contacted in the presence of a coating agent comprising a metal salt of a metal salt (preferably a transition metal salt), the 126160.doc 200827333 contact system from the (etc.) precursor and gasification supercritical conditions or near supercritical The precursor, the oxidizing agent and the aqueous solvent are: the agent is implemented in an aqueous solvent comprising water, usually such that the reaction zone comprises a single homogeneous phase, and (i) will comprise one or more acids - The raw, and wounded are added to the reaction mixture; and (ii) at least a portion of the catalyst is in contact with the "lambium oxide" in the presence of the acidic component.

According to a sixth aspect of the present invention, an oxidation method for producing an aromatic carboxylic acid is provided. The method comprises a catalyst comprising a metal salt (preferably a transition metal salt) in the reactor. One or more precursors of the aromatic carboxylic acid are contacted with the oxidizing agent, and the silver is in contact with the oxidizing agent in the aqueous solution containing the water in the super-fe Under conditions or near supercritical conditions, usually in order to make the or the spinning of the K: 3⁄4, the driving agent, the oxidizing agent and the aqueous solvent d constitute a single homogeneous phase in the reaction zone, and the basin () will be 匕3 or An acidic component of the ceric acid is added to the reaction mixture; and (11) to 邛 is the catalyst being contacted with the oxidizing agent in the presence of the acidic component. Preferably, the addition of an acidic component comprising - or a plurality of acids is achieved such that the (etc.) acid is present in the preferred mono-homogeneous phase referred to herein and in any position where the metal salt is contacted with the oxidizing agent oxidizing agent. At the office. Accordingly, at least a portion, and preferably substantially all, of the contact of the metal salt with the oxidant is effected in the presence of an acidic group injury, and preferably occurs after the metal salt contacts the acidic component 126160.doc •11·200827333 ( That is, the metal salt and the acidic component are mixed prior to contact with the oxidizing agent such that the acidic component already exists when the catalyst is first contacted with the oxidizing agent). As described herein, the acidic component is present in a preferred single homogeneous phase in the reaction zone. [Embodiment] According to the present invention, the use of an acid in an aqueous solvent containing water in an oxidizing method under super-critical or near-supercritical conditions can minimize or avoid oxidation in the process. Problems related to oxidative side reactions of substances. Although the inventors do not wish to be bound by theory, the presence of salty acid can minimize or prevent the oxidation of the metal salt to a metal oxide under such supercritical or near supercritical conditions. Therefore, according to the present invention, since the formation of the metal oxide and/or the destruction of the metal salt is minimized or prevented, the precipitation of the metal oxide from the metal salt is avoided, and thus the stability of the metal salt is improved, thereby Maintain catalyst activity and efficiency, reduce reactor fouling and improve process economics and efficiency. Surprisingly, the acid can achieve this result because the metal salts act in the supercritical oxidation process and the associated reaction pathways, and these paths not only follow the improper oxidation of the metal salt to the metal oxide. The conversion-related reaction pathways compete and compete with the reaction pathways associated with the interaction of acid and metal salts. Thus, the presence of acid surprisingly minimizes the production of undesirable metal oxides and solves the problems raised by the present invention. Compared with the continuous process of W〇-〇2/〇62〇1-A, the method according to the invention provides an unexpected improvement in reducing the oxidative side reaction of the metal salt to the metal oxide in this oxidation process, and a larger proportion The catalyst can be maintained in the system at 126160.doc -12-200827333 and/or can be recovered from the system. Although the configuration described in WO_02/06201_A itself presents an unexpected improvement over other potential configurations in this respect, there is still catalyst loss. The present invention demonstrates that the addition of an acid improves catalyst stability and/or recovery. This effect is completely different from any observed increase in the yield and/or selectivity of the target molecule caused by the optional addition of an oxidation promoter.

As used herein, the term "acid," means any proton donating material having a pKa value less than the PKa value of water at ambient temperature and pressure. According to the Bronsted theory of acidity (see, for example, Michael B)

Smith, Jerry March; Marchfs Advanced Organic Chemistry ^ 5th edition, Chapter 8), at ambient temperature and pressure, the acidity of the proton donor is measured by the following range of pKa values: from about _12 (for very strong acids) ) to 15.74 (for water) and up to about 5 〇 (for very weak acids). The acid selected for the acid component will depend on the metal of the catalyst system, and will depend inter alia on the solubility of the metal salt formed by the acid anion and the metal cation. Therefore, sulfuric acid and carbonic acid are the least desirable because they tend to precipitate sulfates and carbonates, respectively. The acid selected should also depend on the stability of the acid under supercritical or near supercritical conditions, and thus nitric acid is suitably avoided. The acid is preferably substantially oxidatively stable under supercritical or near supercritical conditions. Preferably, the acid is selected from the group consisting of inorganic acids (preferably HX) and is preferably selected from the group consisting of hydrogen halides (usually Hcl & HBr), and in a preferred embodiment the acidic component comprises hydrogen bromide (HBr). In another embodiment, the acidic component does not comprise HBr. The anion of the acid may be the same as or different from the anion of the metal salt. The acidic component is preferably such that [Η+]: [Μ] (where [H+] is the molar amount of the acid derived from the acidic 126160.doc -13 - 200827333 component and wherein _ during the oxidation reaction The molar ratio of the metal of the metal salt present is present in the reaction zone in an amount of at least 0.05:1, preferably at least 〇·1:1, preferably at least 〇2:ι, preferably at least 0.3: Preferably, at least 〇.5:1, preferably at least 〇75:1, preferably at least L0.1, preferably at least 1.5:1, preferably at least 2.0:1, preferably at least 2〇51, preferably at least 2·1:1, preferably at least 2.2:1, preferably at least 2.3:1 and usually not

Greater than about UO:!, more usually no more than about 7 〇: 1, more usually no more than about 6. 〇: 1, more usually no more than about 5. 〇: 1, more usually no more than 4 5: 丨, more usually not Greater than about 4·0:1, more typically no greater than about 35:1 and more typically no greater than about 3_〇:1. In a preferred embodiment, the ratio of [H+] to [Μ] is between ον" and 5·〇·1, preferably 0.1:1 to 3·〇: 1 and preferably 〇·2:1 to 3_ 〇: Within the scope of 1. The hydrogen halide can be formed in situ by adding a proton source and a source of the image to the reaction mixture. Thus, if the acidic component added to the reaction does not contain a halogenate, in one embodiment, an ion source can be added to the reaction mixture in addition to the acidic component. However, the acidic component is preferably also a halide source.

Despite the addition of HBr to improve the catalyst recovery, it also causes corrosion in the system, and therefore a balance should be achieved between the two. The amount of the inorganic acid (preferably hydrogen halide) added is preferably such that the molar ratio ([x].[m]) of the total amount of the metal ions (M) of the anion oxime (preferably the halide ion) to the catalyst. For at least ι·〇:1, preferably at least i 5:1, preferably at least 2 〇:1, preferably at least 2.05:1, preferably at least 2·ι:ι, preferably at least 2·2:1 Preferably at least 2.3:1, and usually no greater than about 12 〇: 1, more typically no greater than about 'ο', more typically no greater than about 6 〇: 1, more usually no greater than about 5 〇: 1 'more usually not greater than 4·5:1, more usually no more than about 4 (hl, more usually no more than about 3^ and 126160.doc • 14-200827333 more than ¥3:0··1. In a preferred embodiment , [χ]: [Μ] is in the range of 1.5.1 to 5.0.1, preferably 2·〇:ι to 3·5:ι and preferably 2.2:1 to 3〇:1.

The inventors of the present invention have observed two different effects that play a role in the addition of hydrogen halide to a metal catalyst in a supercritical water oxidation reaction. The first effect is the 'oxidation accelerator' effect, in which the addition of hydrogenated hydrogen has the effect of improving the yield and selectivity of the target compound, but this effect is saturated after the addition of a relatively small amount of hydrogen peroxide, that is, the effect is achieved. The platform, and as the amount of hydrogen halide increases, the yield and selectivity are not further improved. The oxidative promoter effect depends on the presence of the halide [Χ-] rather than the acid (ie [ίΓ]). The second effect is the catalyst recovery "effect, and it is the effect targeted by the present invention. The inventors have discovered that the addition of hydrogenated hydrogen has the effect of improving catalyst recovery by reducing the amount of metal oxide sinks and This effect increases with the oxidation promoter effect until the oxidation promoter effect reaches a saturation point. However, once the oxidation promoter effect is saturated, the addition of other hydrogenation continues to improve the recovery of the catalyst until the effect is saturated, but After the addition of a relatively large amount of hydrogen halide, the catalyst recovery effect is not observed unless an acid (ie, [H+]) is added to the reaction. Therefore, in one embodiment, the amount of hydrogen halide added should be Sufficient to achieve at least 60%, preferably at least 70%, preferably at least 8%, preferably at least 9%, of the catalyst recovery effect at saturation, and in one embodiment, the amount of hydrogen halide added should be sufficient to achieve a catalyst The saturation effect is saturated. In a preferred embodiment, the metal catalyst comprises manganese and the acidic component is preferably hydrogen halide (HX) and preferably HBr. 126160.doc • 15· 200827333 In the preferred embodiment A, the metal catalyst comprises an evolutionary sensation, and the amount of hydrogen halide added is preferably such that the molar ratio of all halide ions (X) to manganese (Μη) is [Χ]· [Μη] is greater than 2.0:1 and usually not more than about 12 〇: 1. [Χ]: [Μη] is preferably at least 2 〇 5:1, preferably at least 2 ι:ι, preferably at least 2·2·1 Preferably, it is at least 2·3··1, and usually not more than about 12 〇: 1, more usually not more than 7·0·1, more usually not more than about 6 〇: 1, more usually not more than about 5, ι·ι, more usually no more than 4·5:1, more usually no more than about 4〇: 1, more than no more than, force 3.5.1 and more usually no more than about 3〇: 1. The inventors have discovered The oxidation promoter effect is saturated when the Br:Mn molar ratio is 2:1 (i.e., the ratio of Μ η B r2 as a catalyst in the absence of HBr) and catalyst recovery is observed until acid is also added. Rate effect. In the embodiment, [Η]: [Μη] is preferably at least 〇〇5:1, preferably at least 〇ι:ι, preferably at least 0, 2, 1 軚 at least 0·3:1 And usually no more than about 10.0:1, more usually no more than about 5.·〇:1 More usually no more than about 4 〇: 1, more usually no more than about 3 〇: ΐ, more usually no more than 2.5:1, more usually no more than about 2 〇: 1, more overnight than no more than about 1.5:1 and more Usually not more than about 1 〇: 1. [[····· _ is preferably in the range of 〇 most 1 to 3 〇: ι, preferably 0:1 and preferably 〇m 〇]. In another embodiment In Example B, the metal catalyst comprises manganese acetate Mn(0Ac)2, which is used in combination with HBr in a conventional system (i.e., a non-SCW system) to form a catalyst ΜηΒΙ>2 in situ. In this embodiment, all A general and preferred molar ratio of halide ions (X) to manganese (Μη) [χ]: [Μη] is as described above for the general metal rhodium, ie at least 1 (hl& usually no greater than about 12 ·0·1. The inventors have found that the oxidation promoter effect is saturated at a molar ratio of about 1.5:1 at a molar ratio of 126160.doc -16 - 200827333, and the catalyst recovery effect is saturated until the Br:Mn molar ratio is greater than 2:1. As is apparent from Figure 11. In Example B, [H]:[Mn] is preferably at least 〇.5:1, preferably at least 〇75:1, preferably at least 1.0:1, preferably at least 1.5:1, preferably at least 2.05. Preferably, at least 2. 2 1:1, preferably at least 2·2:1, preferably at least 2·3:1, and usually no greater than about 1, 12:0:1, more usually no greater than about 7.0: 1, more usually no more than about 6 〇: 1, more - usually no more than about 5 · 0: 1, more usually no more than 4.5: 1, more usually no more than about 4.0: 1, more usually no more than about 3.5: 1 And more usually no more than about 3 〇:1. |^]: []\4] is preferably in the range of 2.05:1 to 5.0:1, preferably 2.1:1 to 3.0:1 and preferably 2.2:1 to 3.0:1. The invention is described herein primarily with respect to preferred embodiments of the catalytic oxidation process for the manufacture of aromatic carboxylic acids. However, it should be understood that the principles described herein are applicable to other synthetic oxidation reactions of organic compounds in supercritical or near supercritical conditions in aqueous solvents containing water. Other such methods include other metal salt catalyzed synthetic oxidation; synthetic oxidation of alkanes such as butane and ethane; and synthetic oxidation of other organic materials (such as alcohols, ketones, olefins, alkynes, ethers, etc.) that require metal catalysis. . The term "synthetic oxidation reaction" means the production of one or more target compounds from the (or) precursor by partial oxidation of one or more oxidizable precursors.

Maintenance of chemical structure. The term " selective reaction and the full gasification of the aromatic group of the precursor" means the oxidation of the compound to carbon oxide 126160.doc •17- 200827333 (for carbon dioxide), ie destructive oxidation . The pressure and temperature of the method are chosen to ensure supercritical or near supercritical conditions. In one embodiment, the term, near supercritical condition, means that the solvent is at least 1 〇〇 < t, preferably not less than 5 〇 C, preferably not less than 35 t, lower than the critical temperature at 220.9 bar of water. More preferably, it is not less than 2〇t: at the temperature. Therefore, the operating temperature is usually 300. (: to 480. (:, better 33 〇. 〇 to 45 〇 t, usually from about 35 (TC to 370 ° C lower limit to about 37 (rc to about 42 〇〇 c upper limit of the range. Operating pressure It is usually in the range of from about 4 to 35 bar, preferably from 3 to 3 bar, more preferably from 220 to 280 bar, and in one embodiment from 250 to 270 bar. In another embodiment The operating pressure is in the range of 23 mbar to bar. In a preferred embodiment, the term "near supercritical condition" means that the reactant and the solvent constitute a single-average m, which may be lower than water. Achieved under conditions of critical temperature. As used herein, the term "single homogeneous" means at least 8 〇 weight ❶ / ◦, usually at least 90 weight % / ◦, usually at least 95% by weight, more typically at least 98 weight. And most typically effective to be in the same single homogeneous phase in the reaction zone for each of the precursor, oxidant, aqueous solvent, acidic component, catalyst, and reaction product. The term as used herein. An aromatic carboxylic acid, meaning a carboxyl group (_c〇2H) and an aromatic group (A 〇 directly linked to an aromatic compound. Aromatic The carboxylic acid may contain one or more read-through groups directly attached to the aromatic group, and the present invention relates in particular to an aromatic carboxy group containing at least 2 and especially only 2 (4) (c) (8) directly attached to the aromatic group. The aromatic group (f) may comprise a single aromatic ring or may comprise two or more aromatic rings (for example two or more fused aromatic rings), 126160.doc -18 - 200827333 the ring or Each ring typically has 5, 6, 7 + or 8 ring atoms, more typically 6 ring atoms. The aromatic group is typically a monoterpene. The penta-free group may be a carbocyclic aromatic group or it may comprise One or more heterocyclic rings, for example, containing 1, 2 or 3 heteronyms selected from the group consisting of ruthenium, osmium and S', usually N; broad and heteroatoms (usually only one hetero atom) In one embodiment, the aryl A# group is a group. In another embodiment, the aromatic group is a group. Typical aromatic tracisms that can be synthesized using the present invention include benzene. Dicarboxylic acid, isophthalic acid, phthalic acid, trimellitic acid, naphthalene dicarboxylic acid and nicotinic acid.

The term "group of precursors" as used herein, means an aromatic compound which can be oxidized by an oxidizing agent to a target aromatic traculous acid under supercritical conditions or near supercritical conditions. The precursor is selected from the group consisting of aromatic compounds having at least one substituent attached to an aromatic group (Ar, as defined above) and oxidizable to a carboxylic acid moiety. Suitable substituents are generally selected from the group consisting of alkyl, alcohol, alkoxyalkyl and aldehyde groups, especially selected from alkyl, alcohol and alkoxyalkyl groups, and more preferably from alkyl groups. The alkyl group is especially selected from the group consisting of Ci-4 alkyl groups, preferably methyl groups. The alcohol group is especially selected from the group consisting of Cm alcohol groups. The alkoxyalkyl group is especially selected from the group consisting of (Ci4 alkoxy) C!·4 alkyl. The aldehyde group is especially selected from the group consisting of Cl_4 aldehyde groups. If two or more substituents are present, the substituents may be the same or different and are the same in a preferred embodiment. For example, the terephthalic acid precursor may be selected from the group consisting of p-diphenyl, 4-nonylquinal aldehyde and 4-decyl benzoic acid, with p-xylene being preferred. The nicotinic acid precursor is, for example, 3-methylpyridine. For the avoidance of doubt, the term "transition metal" as referred to herein is defined as the following: accepting or providing electrons into the d or f orbital and exhibiting a plurality of oxidation states of the metal, and including the transition metal lanthanides and actinides . 126160.doc -19· 200827333 A reactor suitable for carrying out the invention is preferably a continuous flow reactor. As used herein, "continuous flow reactor" means a reactor which, in contrast to a batch type reactor, introduces the reactants in a continuous manner and mixes them while extracting the product. For example, the reactor can be a tubular flow reactor (with a turbulent or laminar flow) or a continuous stirred tank reactor (CSTR), but the various aspects of the invention defined herein are not limited to the particular types Continuous flow reactor. The invention as defined herein is primarily described in terms of a continuous flow reactor, as this is the most likely commercial and industrial embodiment, but the invention may also be carried out using a batch reactor. By carrying out the process in a continuous flow reactor, it is possible to obtain a reaction residence time which is consistent with the conversion of the precursor to the desired aromatic acid in the absence of significant degradation products. The residence time of the reaction medium in the reaction zone is usually not more than 10 minutes, preferably not more than 8 minutes, preferably not more than 6 minutes, preferably not more than 5 minutes, preferably not more than 3 minutes, preferably not more than 2 minutes. Preferably it is no more than 1 minute. The residence time can be controlled such that the precursor is efficiently converted to an aromatic carboxylic acid such that the aromatic carboxylic acid precipitated from the reaction medium after completion of the reaction contains no more than about 5000 ppm, preferably no more than about 3 An aldehyde which is produced as an intermediate during the reaction in the case of 〇〇〇ppm, more preferably not more than about 1500 ppm, more preferably not more than about 5%, and most preferably not more than about 500 ppm (for example, in the case of terephthalic acid production) Below is 4_CBA). Typically, at least some of the aldehyde will be present after the reaction, and will typically be at least 5 Ppm. In the process of the present invention, the oxidizing agent is preferably a molecular oxygen oxygen-containing illusion, but preferably contains oxygen as a main component = 126160.doc 200827333. The body is more preferably pure oxygen or dissolved in a liquid. The use of air is not advantageous because it will be released, greatly reduced in cost, and exhaust gas treatment equipment may be required to treat a large amount of exhaust gas generated due to high air 3, but the basin is not excluded from (4) of the present invention. Another aspect is pure oxygen or oxygen-rich gas (4). The use of molecular oxygen as an oxidizing agent in the process of the present invention is particularly advantageous because it is highly soluble in water under supercritical or near supercritical conditions. Oxygen/water at &

SiS will become a single homogeneous. The oxidizing agent may comprise atomic oxygen derived from a compound having one or more oxygen atoms per molecule (e.g., a room temperature liquid phase compound) in place of the molecular oxygen. For example, one such compound is hydrogen peroxide which acts as a source of oxygen by reaction or decomposition. The oxidation reaction, particularly for the production of aromatic carboxylic acids, in accordance with the present invention is carried out in the presence of a homogeneous oxidation catalyst which is soluble in the reaction medium comprising the solvent and the precursor. As described herein, the catalyst is typically present in a single homogeneous phase in the reaction zone. The catalyst typically comprises one or more heavy metal compounds (e.g., and/or manganese compounds), and preferably comprises a manganese compound. For example, the catalyst can exhibit any of the forms already used in the liquid phase crystallization of an aromatic carboxylic acid precursor, such as a terephthalic acid precursor, in an aliphatic carboxylic acid solvent, such as cobalt and/or Or a bromide, a bromoalkanate, an alkanoate (usually a c C alkanoate such as acetate) or a benzoate (or other aromatic acid salt). Compounds of other heavy metals such as vanadium, chromium, iron, zirconium, hafnium, molybdenum, steel elements such as ruthenium and/or nickel may be used in place of the starting and/or pulverizing compounds. Advantageously, the catalyst system should include manganese bromide (MnBr2). The pre-catalyzed catalyst can be added or it can be formed in the system by adding a type of agent 126160.doc • 21 - 200827333 which can be subsequently combined to form a catalyst. For example, in the case of a ΜηΒι*2 catalyst, it is possible to introduce MnBr2 itself into the system, or to introduce reagents such as acetic acid and ηβγ into the system, which are combined under reaction conditions to form MnBr! The reactor system of the process of the invention can generally be configured as described below.

The oxidation reaction is initiated by heating and pressurizing the reactants, followed by mixing the heated and pressurized reactants in the reaction zone. This can be accomplished in a variety of ways via one or both of the reactants mixed with the aqueous solvent before or after reaching supercritical or near supercritical conditions, the mixing being effected in this manner to keep the reactants separated from each other until the reaction The districts are mixed together. In the continuous process described herein, at least a portion of the contact of the catalyst with the oxidant is effected in the presence of the acidic component. Generally all of the catalyst is contacted with the oxidizing agent preferably in the presence of an acidic component. In the continuous process for making carboxylic acids described herein, the reactor system is preferably configured such that the oxidant is at least partially and preferably at least partially and preferably substantially in contact with the catalyst and catalyst. Substantially all of the oxidant contacts are at the same point in the reactor system and are performed simultaneously, and such configurations are shown in Figures i, 2A and 2B. However, other configurations for the manufacture of carboxylic acids to > portions of the ruthenium drive in contact with the oxidant and contact of the catalyst with at least a portion of the oxidant are not excluded, and the H configuration is shown in FIG. Heat and pressurize to simultaneously oxidize the oxidant in Example I, the oxidant is mixed with the latter after the aqueous solvent has been added to ensure supercritical or near supercritical conditions, 126160.doc •22-200827333 is suitably added before mixing with the aqueous solvent Press and (if necessary) heat. The precursor is subjected to pressurization and, if necessary, heating. The catalyst-containing component is subjected to pressurization and, if necessary, heating. The acid component can be subjected to pressurization and, if necessary, heating. A separate material comprising a precursor, a catalyst, an acid component, and an oxidant/solvent mixture can now be contacted simultaneously. In one configuration, the acid is premixed with the catalyst. A schematic flow diagram showing Example I is presented in Figure i. - In Example 11 of the present invention, the precursor is mixed with the latter after the aqueous solvent has been heated and pressurized to ensure a supercritical or near supercritical state, while the precursor is suitably pressurized prior to mixing with the aqueous solvent. And (if necessary) heat. In one configuration, the homogeneous catalyst component is contacted with the aqueous solvent while being pressurized and, if necessary, heated, followed by contact of the precursor with the aqueous solvent. After pressurization and, if necessary, heating, the acid component may be contacted with the catalyst, the precursor, and the water > the first solvent or may be premixed with the catalyst. Alternatively, the acid component can be fed directly into the reaction vessel after being pressurized and (if necessary) heated (see Figures 2A and 2B). After pressurization and, if necessary, heating, the oxidant is mixed with the latter after the water solvent has been heated and pressurized to ensure supercritical or near supercritical conditions, and the oxidant/aqueous solvent mixture is subsequently combined with the precursor #, catalyst The mixture of the acid component and the aqueous solvent is contacted. The β-tanning agent is a t-type agent that is mixed with the latter after the aqueous solvent has been heated and pressurized to ensure supercritical or near-supercritical conditions, while the oxidizing agent is suitably pressurized before being mixed with the aqueous solvent ( Coronation when necessary). The catalyst can be mixed with the oxidizing agent while being mixed with the acid component. Alternatively, the acid component can be premixed with the catalyst prior to contact with the oxidizing agent. The catalyst and/or acid component is subjected to pressurization and, if necessary, heating. The precursor is subjected to pressurization and (if necessary 126160.doc • 23 to 200827333) to be heated, and then contacted with a mixture comprising an oxidizing agent, a catalyst and an acid component in the reaction zone. A schematic flow diagram showing Example III is presented in Figure 3. The contacting of the various streams can be accomplished by separate feeding into the apparatus, which are mixed to form a preferred single homogeneous fluid phase, thereby allowing the emulsifier to react with the precursor. The means for internally mixing the feeds may, for example, have a Υ, τ, χ or other configuration that allows the independent feed to be mixed in a single-flow channel that constitutes a continuous flow reactor or, in some cases, mixed: The flow channels of the plurality of flow channels 2 (four) combined feeds of one or more continuous flow reactors may comprise a portion of a tubular configuration having or having an internal dynamic or static mixing element. In a preferred embodiment, a line or static mixer is advantageously used to ensure that the oxidizer is dissolved in an aqueous solvent and is difficult to form a single phase. ❿ The oxidant feed and the precursor feed may be mixed together at a single location or = may be achieved in two or more stages to allow one feed or two (eg, a portion relative to the direction of flow through the reactor) In a gradual manner, the Ge flow channel passes through, and the other material feeds into the length of the continuous flow channel: a plurality of points are separated at two points to allow the reaction to progress through the feed. An aqueous solvent may be included, which may be a feed introduced at a position of the day. ', ,, -Π: the main J is progressively oriented with respect to the direction of flow through the reactor (eg, two injection points) The addition of the catalyst is achieved. 126160.doc -24- 200827333 In one configuration the 'oxidant system is introduced into the reaction at two or more positions. The positions are relative to the solvent and reactants passing through the oxidation zone. The flow is conveniently positioned such that the oxidant is introduced into the reaction at the initial location and at least one other location downstream of the initial location. There may be more than one reaction zone in series or in parallel. For example, if used In conjunction with a plurality of reaction zones, the reactants and solvent can form separate flow streams through the reaction zone and, if desired, product streams from the plurality of reaction zones can be combined to form a single product stream. If more than one reaction is used The conditions may be the same or different in each reactor, such as temperature. The reactor or each reactor may be adiabatically or isothermally operated. It may be maintained by heat exchange to define a predetermined temperature profile of the entire reactor as the reaction proceeds. Isothermal or controlled temperature rises. It is known from the art of the prior art and is described, for example, in WO-02/0620 (the disclosures of which are incorporated herein by reference) The technique removes heat of reaction from the reaction by heat exchange with a heat receiving fluid. The heat receiving fluid conveniently comprises water. After passing through the continuous flow reactor and after the oxidation process is completed, the reaction mixture comprises an aromatic carboxylic acid a solution which needs to be recovered from the reaction medium. At this stage 'substantially all of the aromatic carboxylic acid system produced in the reaction is in solution. In the process of the invention, Typically, at least 8% by weight, more typically at least 90% by weight, preferably at least 95% by weight, more preferably at least 98% by weight, and most preferably all of the aromatic carboxylic acid system produced in the reaction remains in solution And the solution does not begin until the solution leaves the oxidation reaction zone and undergoes cooling. The solution may also contain a catalyst and a relatively small amount of by-products 126160.doc -25-200827333 (such as an intermediate (for example, in the case of terephthalic acid) Toluic acid and 4-CBA), decarboxylated products (such as benzoic acid) and degradation products (such as trimellitic acid) and any excess reactants can be obtained by making aromatic tracing acid - or multiple p white The crystallization in the cold liquid is followed by solid-liquid separation in - or multiple stages to recover the desired product aromatic carboxylic acid (such as terephthalic acid). The product 〃IL is separated and solid-liquid separated to recover the aromatic decanoic acid and the mother liquor (which may ordinarily contain the dissolved catalyst component) is recycled to the oxidation reaction zone. Preferably, the mother liquor is heated by heat exchange with the product stream prior to reintroduction into the oxidation reaction zone, thereby cooling the product stream. One or both reactants may be mixed with the mother liquor recycle stream or the separate mother liquor recycle stream prior to reintroduction of the mother liquor into the reaction zone and the mother liquor recycle stream (or at least a portion thereof to be combined with the reactants) may be reacted with The material or the respective reactants are heated and pressurized prior to mixing to ensure supercritical/near supercritical conditions. The invention will now be further described by way of example only with reference to the accompanying drawings. Referring to Fig. 1, after the water has been heated, the pressurized molecular oxygen is mixed with water, and the mixture is pressurized in the preheater 1 and further heated as necessary to reach a supercritical state. The precursor and catalyst are added to the 〇2/water stream at or just prior to the beginning of reactor 2, and the mixture is passed through the reactor. The pressurized acid component is added to the 〇2/water stream while the catalyst is being added, or the acid component is added to the catalyst stream prior to contact with the oxidant stream. After leaving the reactor, the stream is cooled and depressurized at the back pressure regulator 3. The product is produced in a stream of cooling water. Referring to Figures 2A and 2B, the pressurized precursor and catalyst are added to the water after the water has been pressurized and optionally heated. The acid component can be added to the catalyst before, simultaneously or after mixing with 126160.doc -26 - 200827333 water. The mixture is further heated in the preheater 1A as appropriate to reach a supercritical state. Alternatively, the pressurized and optionally heated acid component can be combined with the catalyst/precursor stream as the catalyst/precursor stream is combined with the oxidant. The pressurized molecular oxygen gas is mixed with water in a supercritical state and further heated in the preheater 1 as appropriate. In Figure 2A, the streams are mixed at or just before the beginning of reactor 2 and the mixture is passed through the reactor. In Figure 2B, the 〇2/water stream is added to the reactor in a progressive manner at multiple injection points. After leaving the reactor, the stream is cooled and depressurized at the back pressure regulator 3. The product is produced in a stream of cooling water. Figure 3 corresponds to Figure 1 wherein the catalyst and oxidant are mixed prior to contacting either stream with the precursor. The pressurized molecular oxygen gas is mixed with water in a supercritical state and further heated in the preheater 1 as appropriate. The acid component is mixed with the catalyst before or at the same time as the catalyst is contacted with the oxidant. Referring to Figure 4, a raw material component comprising water, a precursor (e.g., para-xylene in the process for producing terephthalic acid), and molecular oxygen gas is pressurized to an operating pressure and passed from a respective source 10, 12, and 14 The preheater 16 is continuously supplied, wherein the components are heated to a temperature of from 300 ° C to 480 ° C, more preferably from 330 ° C to 450 ° C, and from about a lower limit of from about 350 C to 370 ° C to about 370 °. The temperature, pressure and temperature from C to the upper limit of about 420 °C are selected to ensure supercritical or near supercritical conditions. The portion of the heat used to preheat the feedstock component can be derived from the exotherm generated during the subsequent reaction of the precursor with the oxidant. Heat from other sources may be in the form of, for example, high pressure steam and/or may be heated by direct heating of the water stream with fire. The heat of reaction can be recovered in any suitable manner, for example, by means of heat exchange between a stream 126160.doc • 27-200827333 and a suitable heat receiving fluid such as water. For example, the heat receiving fluid can be configured to flow countercurrently and/or cocurrently with the reactants and solvent passing through the reaction zone in a heat exchange relationship. The passage through which the heat receiving fluid flows as it passes through the reaction zone may be external to the reaction zone and/or may extend through the interior of the reaction zone. The (etc.) internally extending flow passage may, for example, extend in parallel with and/or laterally with the reactant/solvent flow through the general direction of the reaction zone. For example, the heat receiving fluid can traverse the reaction zone by passing through one or more coils located inside the reactor. The reaction helium can be used to recover power via a suitable power recovery system, such as a turbine; for example, a heat receiving fluid (e.g., water) can be used, for example, at about 300. High pressure saturated steam is produced at temperatures and pressures of 〇/100 bar, which in turn can be superheated by external heat and fed into a high efficiency condensing steam turbine to recover power. In this way, the reactor can be maintained at the optimum temperature and effective energy efficiency can be achieved. In another method, the reaction is operable under adiabatic conditions and a suitable high velocity water stream passing through the reaction zone can be employed to limit the temperature rise of the entire reactor during operation. If desired, a combination of the two methods can be used, i.e., via a heat receiving fluid recovery reaction plus a suitable water flow rate through the reaction zone. After heating the feedstock component, the oxygen is mixed with water, which, due to preheating and pressurization, should be under supercritical or near supercritical conditions and thus be capable of dissolving the feedstock. In the embodiment illustrated in Figure 4, oxygen and water are mixed in premixer 18A. The precursor is also mixed with water in premixer 18B. Of course, the precursors can also be premixed with water independently prior to entering the preheater 16. The premixer (or premixer that premixes each reactant with water) can take a variety of forms, such as in Figures 5A, 5], 8, 5C, 5, and 6, 126160.doc -28- 200827333 Describes Y-, L- or T-type, dual-τ configuration or static mixer, respectively. In Figs. 5A to 5D and Fig. 6, reference symbol Α denotes a preheated water supply to the premixer 'B denotes a reactant (precursor or oxygen) and p denotes the resulting mixed stream. In the dual T configuration of Figure 5D, two mixed flows ρι & ρ2 are produced. The streams can be passed through a separate continuous flow reactor or combined into a single stream and subsequently passed through a single continuous flow reactor. An X-type configuration as known to those skilled in the art can also be used. It should also be understood that any suitable mixing device can be used in the present invention. It should be further appreciated that the mixing apparatus mentioned above is used in a continuous process apparatus. In a batch system, there is no continuous flow and therefore no specific flow-related mixing requirements. In a continuous vessel reactor, the reactants can also be fed independently into the vessel. It will be appreciated that one or each of the reactants is not premixed with water prior to introduction into the reaction zone, but that the reactants and water can be introduced separately into the reaction zone and in the reaction zone by means of some form of mixing device (eg a static The mixer) is mixed whereby substantially all of the mixing of the components occurs within the reaction zone. The precursor is added to the premixed oxygen/water stream just prior to entering the reactor or at the beginning of the reactor, while a homogeneous catalyst in the form of a solution from source 19 is added to the premixed oxygen/water stream (ie, Figure i)). In a preferred embodiment, as shown in Figure 4, an acid is included in the catalyst source 19. After preheating and premixing, the raw material components are combined in a reaction zone 2 to form a single homogeneous fluid phase in which the reactants are mixed together. The reaction zone 2 can be comprised of a simple mixer configuration in the form of a length of tubular flow reactor (e.g., a tube) that combines the flow rate of the combined reactants to provide a suitable reaction time to ensure, for example, high conversion efficiency and The low 4_cba content makes = 126160.doc -29- 200827333 mono toluene converted to terephthalic acid. The reactants can be combined in a progressive manner by injecting a reactant into a stream containing another reactant at a plurality of points along the length of the reactor. One way of achieving a multi/primary configuration is shown in the continuous flow reactor of Figure 7, where - the reactor consists of a tube or vessel P. In the embodiment where the premixed oxygen/water stream is added to the premixed precursor/water stream, the premixed precursor/supercritical or near supercritical water stream is supplied to the upstream end of the tube or vessel crucible. The water will also be _ will contain a homogeneous catalyst plus acid. The stream passes through the reactor tube or vessel and is supplied to the supercritical or near supercritical water via a plurality of injection channels at a plurality of locations spaced apart along the length of the tube or container. Preheating and compacting the oxygen to produce a product stream S comprising a carboxylic acid product (e.g., terephthalic acid) in a supercritical or near supercritical aqueous solution. In this way, 'incremental injection' achieves, for example, the oxygen necessary to completely oxidize p-xylene to terephthalic acid, the purpose of which is to control the oxidation of para-xylene, terephthalic acid or terephthalic acid intermediates. And reduce its side reactions and possible combustion to a minimum. Referring now again to Figure 4, after the reaction has reached a desired level, a supercritical or near supercritical fluid is passed through a heat exchanger 22 through which the heat exchange fluid system circulates through the closed loop 24 to effect heat. It is recovered for use in the preheater 16 . A post-reaction cooling process for a carboxylic acid product solution (not shown) involves using a heat exchanger network to cool the stream to, for example, a subcritical temperature of about 300 ° C to maintain the carboxylic acid product in solution and Further reducing the fouling of the heat exchange surface, followed by the use of a series of flash crystallizers (and their flashing 126160.doc -30-200827333 crystallizer used in the purification of conventional terephthalic acid by hydrogenation) Similarly) to cool and precipitate the carboxylic acid product. The cooled solution is then supplied to a product recovery zone 26 where the carboxylic acid precipitates from the solution. Any suitable product recovery method known to those skilled in the art can be used. The product recovery zone 26 can comprise one or more cooling or evaporation crystallization stages to crystallize the carboxylic acid product to form a slurry of crystals in the aqueous mother liquor. If the product recovery zone 26 comprises one or more flash crystallizers, the resulting flash stream from the crystallizers can be used to indirectly or via direct injection of flashes into the reactor water via a conventional heat exchanger and/or Or the precursor feed to preheat the inlet water and precursor stream of the reactor. It is obtained after crystallization, as described in the previously published International Patent Application No. WO-A-93/24440 and the disclosure of WO-A-94/17982, the disclosure of which is incorporated herein by reference. The polymer can be subjected to a solid-liquid separation process (with or without a washing tool) using, for example, a filtration apparatus operating under superatmospheric conditions, atmospheric conditions, or sub-atmospheric conditions. Thus, solid-liquid separation can be carried out using any apparatus suitable for this purpose and configured to operate under high pressure conditions or at atmospheric pressure, depending on the pressure after the final crystallization stage. An integrated solids separation and water scrubbing unit (such as a belt filter unit, a rotating cylindrical filter unit, or a drum filter unit (e.g., a BHS-Fest filter drum formed by a plurality of stocks receiving a single τ) may be used. , wherein the mother liquor is transferred from the filter cake by water under the water pressure supplied to the units)) for solid-liquid separation. After filtering the slurry, the recovered carboxylic acid product can be used directly to make, for example, a polyester (such as a bottle or fiber) for packaging. It can be similarly dried. If not at atmospheric pressure, the filter cake of the carboxylic acid product can be transferred to a low pressure zone (e.g., atmospheric pressure) via a suitable pressure reducing device (such as a lock hopper configuration, a rotary valve, 126160.doc -31 - 200827333) The rod feed device or the progressive feed device (such as a screw pump of the type used to pump two solids of cold paste) is dried. The knife and the degree of washing should be determined according to the impurities produced in the reaction, the way of recovering the product and the specifications of the desired product. Although generally, it may be necessary to make it pure enough so that no further purification is required (for example, by oxidation and/or hydrogenation of an aqueous solution of a dicarboxylic acid to convert 4 CBA to terephthalic acid or to For p-toluic acid) read acid product (3) such as p-benzoic acid? Acid), but I exclude the possibility of carrying out this purification after supercritical or near supercritical water oxidation. After recovery of the aromatic carboxylic acid product, at least a portion of the aqueous mother liquor can be recycled for reuse in the oxidation reaction, for example, by mixing with fresh water and/or reactants. However, if the spent circulating mother liquor contains a catalyst component, it is preferably not added to the A/water stream prior to the addition of the precursor. The amount of recycle should generally be the majority of the recovered mother liquor, which is purified to reduce the fixed concentration of by-products in the process. The purge stream can be treated to recover its catalyst contents (if applicable) and its organic contents. - Referring now to Figure 8, in this embodiment, liquid oxygen (line 3), liquid precursor (e.g., para-xylene in the case of terephthalic acid) (line 32) and water (line) 34) Supply to a mixing unit%. The oxygen and precursor supplies are pressurized by pumps 38, 38A and heated to high temperatures in the heat exchangers 4, 4, a, for example, by high pressure steam. The mixing unit is configured as shown in Figure 4 to mix the reactants with the water supply to produce... the stream contains the water/precursor mixture and the other stream package = 4 solutions 2 in the water 'to feed it' In-in-flow reactor in the form of a tube 牝 126160.doc • 32- 200827333: 'In which, for example, the streams are mixed by means of a static mixing configuration within the tube to initiate the reaction. The homogenous catalyst and acidic component in the form of a solution in water can be added to the precursor/water stream 42 just prior to entering the reactor or in a reaction using rapid mixing (e.g., by using a static mixer or the like). The start of the unit is combined with the streams 42 and 44 just in front of it. ^ The supply of fresh supplemental water for this system was achieved at various points. The most convenient one is the upstream of the main pressurized fruit 6 8 , for example via line 116 , which is described in more detail below with respect to Figure 9. It may also be pressurized in pump 38C and in the hot parent The heated water in the exchanger 40C is fed into the line 74 via line 35 or fed into line 74 prior to the parent exchanger (5〇' 70). Alternatively, it can be pressurized in pump 38B and in the heat exchanger The heated water in 4〇B is independently fed into the preheater 36 via the line '35. After the reaction under the supercritical or near supercritical conditions, the reaction product (addition of a small amount of unreacted reactants, intermediates, etc.) will be present. The product stream in the form of a solution is cooled by passing through heat exchangers 50 and 52 and may optionally be cooled down to a lower pressure and temperature in flash vessel 54. At this point or in product recovery zone 62 The method of the step may involve a single or multiple known devices, but it should be configured to avoid solid deposition by means known to those skilled in the art, such as local heating, when from the reactor 46. Logistics passes through the hot junction. When the temples 50 and 52, the temperature of the logistics is controlled and controlled so that The product does not precipitate and should not precipitate until the flash vessel 54. The solid mass of steam and some gaseous components (such as nitrogen, oxygen, carbon oxides) are supplied via line % to an energy recovery system 58, while terephthalic acid The solution is supplied via line (9) to a product recovery zone 62. 126160.doc -33- 200827333 In the product recovery zone, the solution of the carboxylic acid product is treated via a multi-stage knot combination process in which the pressure and temperature are progressively lowered. The carboxylic acid product is crystallized in crystalline form. The product of the crystallization process is a slurry of formic acid crystals in an aqueous mother liquor. After the final crystallization stage, the slurry can be at any desired pressure, such as atmospheric pressure or above atmospheric pressure. The slurry is subjected to any suitable form of solid-liquid separation to separate the crystals from the mother liquor.

In Figure 8, the recovered carboxylic acid crystals are supplied via line 64 to a dryer (not shown) or for direct manufacture of the polyester. If the solid-liquid separation is carried out under high pressure conditions, it is convenient to use a suitable device (for example, as disclosed in International Patent Application No. WO-A-95/19355 or U.S. Patent No. 5,470,473). The crystals are reduced to atmospheric pressure. The mother liquor from the solid-liquid separation is recovered via line 66, repressurized by pump 68 and recirculated via heat exchanger 70, line 72, heat exchanger 50, line 74, start/adjust heater 76, and line 34. Into the mixer unit 36. Thus, under steady state operating conditions, the recycle mother liquor can contribute to the source of water for supply to reactor 46 and the catalyst for recycling the catalyst to the process. The mixing unit 36 is configured such that if the recycle mother liquor can contain a catalyst (i.e., a homogeneous catalyst), the recycle mother liquor is preferably mixed with the precursor stream rather than the oxidant stream because the addition of the catalyst to the oxidant is preferably in the oxidant. Adding precursors simultaneously. Thus, if the recycle mother liquor contains a catalyst, the mixing unit is configured such that the oxidant stream 30 can be mixed with fresh water from line 35. Similarly, other catalyst or the acidic component may be added to the mother liquor in line 34 as needed or added directly to the reaction zone. Since the water system is produced during the reaction, water purification is performed from the system. 126160.doc -34- 200827333 : can be implemented in several ways; for example, it can be derived from the «cooling material via the pipeline (for example, it will be hereinafter:: = the latter can be more advantageous, it will be tt from two == = micro-finance Physical pollution. "The purification can be transferred to the treatment, such as aerobic and / or anaerobic treatment.

In the heat exchange H 70 'transported via one or more stages of the free crystallization stage (for example, the first P "takes the pressure and temperature crystallizer vessel"), the steam is transferred: the mother liquid temperature is raised to the boot. After passing through the heat exchange; 7 ,, the flash (tank 79) used for this purpose can be returned to the product recovery zone as condensate to wash the wash water used to wash the acid-removed product from the solid-liquid separation. In the heat exchanger 5, the mother liquor temperature is further increased (e.g., by about 100 C to 200 c) due to heat transfer from the high temperature product stream 48 from the reactor 46. In this manner, the product stream is subjected to cooling while the mother liquor The temperature of the % stream is again significantly increased. The adjustment/starting heater 76 is used to increase the temperature of the mother liquor to recirculate the flow, if necessary to ensure supercritical or near supercritical conditions. Under steady state operation, the increase It may be optional because the mother liquor may be in a supercritical or near supercritical state after passing through the hot parent for 50. Thus the heater 76 is not necessarily required under steady state conditions and the heater may be configured purely for initial use. From the source rather than the mother liquor The startup operation of pressurized water. In this embodiment, the aqueous solvent is made supercritical or near supercritical prior to mixing with one or both reactants. However, it should be understood that increasing the temperature to ensure the desired supercritical or near super The critical conditions can be achieved before, during, and/or after the mixing stage. In the embodiment of Figure 8, the anti-126160.doc -35-200827333 is generated during the reaction of the precursor with oxygen. Heat exchange (preferably water) and at least partial removal of the heat receiving flow system by means of a coil 8 or a series of generally flat tubes (as in a tube designed as a shell heat exchanger) or The analog passes through the interior of the reactor 46. The water used is pressurized and heated to a temperature high enough so that the conductive water passes through the outer surface of the conduit 8 of the reactor, otherwise components may be created (such as Local cooling of the precipitation of the terephthalic acid in the reaction medium is avoided. The water used for this purpose is derived from the energy recovery system 58. Thus, in Figure 8, the water at high pressure and temperature is supplied via line 82. To the hot father 52, wherein the heat exchanger 52 is for further cooling the product stream after passing through the hot parent exchanger 50. The water then passes through the official passage 80 via line 83, along with high pressure, high temperature steam, which is fed via line 84. Into the energy recovery system 58. Also, the recovery system 5 8 is supplied with vapor from one or more stages of the crystallization process in the month b. This is indicated by line 86. This vapor can be used, for example, for preheating via the official The water supplied by the line 82 to the heat transfer conduit 80. The condensate from the steam feed supplied to the energy recovery system 58 can be transferred via line 9 to the product recovery zone for, for example, washing in solid-liquid separation. The terephthalic acid filter cake produced. If necessary, water purification 92 can be carried out from line 90, which has the advantage that purification at this time will be less contaminated than purification from the mother liquor via line 78. In Figure 8, it is shown that after the mother liquor has been heated by heat exchange with the product stream in heat exchanger 5, the reactants are introduced into the recycle mother liquor. In one variation, the reactants can be combined with the mother liquor recycle stream upstream of the heat exchange with the product stream. If the two reactants are mixed with the mother liquor recycle stream, the latter is separated into separate streams, whereby the reactants are separately mixed to keep the reactants of 126160.doc-36-200827333 separated from each other until mixed together for reaction. . It will also be appreciated that the embodiment of Figure 8 can be modified in such a manner as to be indicated in Figure 7 by introducing one or both of the reactants via a plurality of injection points along the flow path of the reaction medium such that the reactant or The two reactants are introduced progressively into the reaction. In the energy recovery system 58, various heat recovery processes can be implemented to make the process energy efficient. For example, the high pressure steam emerging after the passage of water through the conduit 8 can be superheated in a furnace supplied with combustible fuel and the superheated vapor can then pass through one or more vapor condensation turbine sections to recover power. Part of the high pressure vapor can be diverted for preheating the reactants (heat exchangers 40, 40A and 40B) or for preheating stream 82, which is necessary to achieve a high thermal efficiency system. The condensed water recovered from the turbine section and recovered from the heat exchangers 40, 40A and 40B can then pass through a series of heating zones to preheat the water recirculated to the reactor 46 via the heat exchanger 52 to supplement the water as needed. Form a closed loop. The heating section typically comprises a cascade of heat exchangers whereby the temperature of the recycle water stream returning to reactor 46 is progressively increased. In some heating stages, the heating fluid may consist of flash vapors obtained at different stages of the self-crystallization series at different pressures and temperatures. In other heating sections, the heating fluid may be a combustion gas that is present in the furnace stack associated with the furnace used to superheat the high pressure steam supplied via line 84. The embodiment of Figure 8 uses substantially pure oxygen as the oxidant. Figure 9 illustrates a similar embodiment, but which uses compressed air (which may be enriched in oxygen) as an oxidant. The embodiment of FIG. 9 is generally similar to the embodiment of FIG. 8 and generally functions in the same manner and is generally indicated by the same reference numerals in the two figures, and will not be further described below unless the context requires otherwise. description. As shown, the air supply 100 is via an air compressor ι〇2 = 126160.doc -37- 200827333. Due to the use of air, a substantial amount of nitrogen is introduced into the process and must therefore be properly treated. In this case, after passing through the heat exchangers 50 and 52, the product stream is rapidly reduced to a lower temperature in the flash vessel 103 to condense the water to a greater extent than the embodiment of Figure 8, thereby reducing the tower. The water content of the top product. As described with respect to Figure 8, the temperature of the product stream passing through heat exchangers 50 and 52 is controlled such that product precipitation occurs only in flash vessel 1〇3. The overhead production stream is supplied to a gas turbine 11 via line 104, heat exchanger 1〇6 and fuel combustion heater 1〇8. The overhead product stream is passed through heat exchanger 1 〇 6 to transfer heat to the mother liquor recycle stream while further draining the water, which may be passed via line 112 to product recovery zone 62 for use as, for example, wash water. For this effect, it is necessary to heat the gaseous overhead product stream to a high temperature before being introduced into the turbine, and thus also to heat the overhead product stream by the heater 1〇8. There may be more than one gas turbine section, in which case the overhead product stream should be heated to a high temperature upstream of each of the turbine stages. Line i 14 represents the overhead product stream exiting turbine 110 at low pressure and low temperature. If the oxidation process results in the production of undesirable materials (such as carbon monoxide, etc.), for example for corrosion and/or environmental reasons, the following precautions can be taken: treating the overhead product stream before or after passing through the turbine and/or discharging To reduce / eliminate these group injuries. The treatment may comprise subjecting the overhead product stream to catalytic combustion and/or washing with a suitable reagent, such as a (four) wash liquor. The turbine m can be mechanically coupled to the air compressor such that the air compressor is driven by the turbine. In the embodiment of Figure 9, water exits the system via the overhead product stream. At least a portion of this water may be recovered and recycled for use as, for example, the wash water in the product recovery zone 62 as necessary. Additionally or alternatively, make-up water can be supplied to the product recovery zone via line ιΐ6 126I60.doc •38- 200827333 to compensate for the loss of water when processing large amounts of nitrogen due to the use of compressed air. The makeup water can be preheated and used as wash water, and the preheating system is achieved, for example, by diverting a portion of the flash stream (commonly by reference numeral 88) to heat exchanger 12〇 via line 116 and will self-flash The condensed water in the vapor stream is returned to the product recovery zone 62 as washing water. Although the invention has been described primarily with respect to para-xylene as a precursor to terephthalic acid, it will be appreciated that alternative precursors may be employed or other precursors other than para-toluene may be used to make the corresponding carboxylic acid, and The precursors include o- dimethyl stupene, m-xylene, carbaryl, 4 • toluic acid and 3·methylpyridine. As indicated above, the invention is also applicable to the manufacture of other aromatic traconic acids (such as isophthalic acid, phthalic acid, partial moieties) from the corresponding alkyl aromatic quinones (preferably methyl compounds) or other precursors. Benzoic acid and naphthalene dicarboxylic acid). The invention is further illustrated below by the following non-limiting examples. Examples are at about 38 Torr by having a combined catalyst and acid solution (as detailed below and typically having a ΜηΒι:2 or Mn(0Ac)2 catalyst and HBr).超 and Ba to 240 bar in supercritical water were experimentally studied by ο: continuous oxidation of o-xylene at laboratory scale. The exotherm is minimized by using a relatively dilute solution (less than 5%·5% organics, weight/weight). The basic configuration of the system is shown in Figure 1. A more detailed description of the system for these laboratory scale experiments is shown in Figure 10 (which illustrates the use of MnBr2 as the catalyst and HBr as the acid). It is produced by heating the H2〇2/H2〇 mixture in the preheater 152 to above 々(10). The AO2 decomposition releases ο" 〇2/H2 〇 fluid and then passes through the cross member 126160.doc-39-200827333 154, wherein the fluid is contacted with a solution of o-diphenylbenzene and acid from the respective pump and the catalyst. The mixture was passed through reactor 156. The other components labeled in Figure 10 were as follows: cooling coil 158; 0.5 μιη filter 159; back pressure regulator 160; valves 162 Α to 162C; pressure relief valves 163 Α and 163 Β; Valves 164Α to 164C; pressure transducers 165Α to 165D; thermocouples τ (aluminum heater blocks for preheater 152 and reactor 156 also contain thermocouples, not shown). Pumps are Gilson 302, 305, 306, and 3 03 The back pressure regulator is available from Tescom.

The maximum corrosion occurs in the region of the crucible 2 where the feedstock and catalyst solution meet, especially at the high temperature gradient where the bromide ions coincide with the introduction of the unheated catalyst feed tube. Hearst alloy (Hastell illusion is used in the last part of the catalyst feed tube and used in the reactor, and 316 stainless steel is used for other components. Your muscles are statically placed before the operation in the cold part) The force test was followed by heating with a stream of pure water (four mL mL/min). Once the operating temperature is reached (4) Μ (4) Η 2 (ν Η 2 〇 and the o-xylene and acid / catalyst pump is activated. The residence time of each operation is kept constant and usually reaches about 10-20 seconds in the case of a large number of hours. Calculate the amount of inflow of Μ from the calculated amount of manganese divided by the measurement). Leather production (in which the concentration of manganese is absorbed by the atom should be noted in these examples, the concentration of argon, yttrium, yttrium catalyst and acid is the catalyst / enthalpy / enthalpy. - because the catalyst ... corresponds to about the other three-thirds of the equivalent: to: from the table: (mass) flow about three-thirds, Wang wants to come from other streams. 126160.doc 200827333 Example 1 To investigate the role of HBr in a system using manganese acetate as a catalyst, the following experimental conditions were used to conduct the experiment: temperature was about 380 ° C; pressure was about 230 bar; acid / catalyst and o-xylene flow rate was 4.084 mL / Min; the flow rate of o-xylene is 0.061 mL/min; the flow rate of oxidant (H2〇2 in 仏0) is 8.i mL/min. (The amount provided in H2〇2 aqueous solution [〇2] is 0.276 mol.Lll.S molar equivalent of the stoichiometric amount required to completely oxidize the organic precursor to an aromatic acid, with a molar ratio of 302/organic in the case of o-xylene)). The Br/Mn mass ratio (weight/weight) was increased from the enthalpy to 4.17 (corresponding to the molar ratio) by adjusting the concentration between 1200 ppm and 1700 ppm while increasing the HBr concentration from 0 to 6000 ppm Br. ^]:[]^11] is 〇 to 2.865::1). The results are shown in Table 1 and Figure 11. The yield of phthalic acid was calculated by HPLC. Another operation was carried out using a NaBr solution as a cocatalyst of Mn(AcO)2, but due to the precipitation of the catalyst and the insolubility of NaBr in supercritical carbon dioxide, the reactor blocked extremely rapidly, indicating the need for acidity other than the bromide ion content. To avoid precipitation of the catalyst. The results generally indicate that the addition of HBr not only improves the selectivity to the target bis-acid, but also improves the recoverability of Μη. The addition of HBr produced a significant improvement, the yield of phthalic acid exhibited a significant improvement from about 8% to 65%, and the selectivity increased from about 21% to 88%. However, by increasing the Br/Mn molar ratio above a certain point, the yield of the target molecule remains unaffected. The inventors have also observed 126160.doc -41 - 200827333 that after the addition of HBr, the Μ 回收 recovery rate has increased significantly from 14% to 93%', which clearly indicates that the stabilization of the catalyst is facilitated by increasing the concentration of HBr. The data in Table 1 is presented in Figure 11 and shows two different mechanisms that can be correlated with the Br/Mn ratio. Figure 11 is a succinct illustration of how increasing the amount of HBr provides a known oxidation promoter effect (i.e., increased product yield and selectivity) until the Br/Mn molar ratio is about 1.25, at which point the effect is saturated. However, the (complete) clock recovery effect requires a HBr content that is higher than and exceeds the HBr content required for the oxidation promoter effect and which saturates at a Br/Mn molar ratio between about 2.0 and 3.0. Shoulder / · Oxidation of o-xylene with a different catalytic mixture of Mn (AeO) 2 and HBr (Example i)

Operation Μη (ΡΡ*η) Mo Erbi Br:Mn yield (%) phthalic acid γρητ^ selectivity (%)a

a: the selectivity to compounds 1 to 6 (in percent) is calculated as the molar concentration of the product of products 1 to 6 relative to the total molar concentration of the products, b: by atomic absorption calculation example 2 A series of experiments were performed to determine the effects of other acids and the effects of [Br] alone. The results are presented in Table 2 below. The experiment used the same concentration of Η+ (i.e., 6.25 ΧΗΓ 2 Μ) contained in 5000 ppm BriHBr solution unless otherwise indicated. A concentration of 1700 ppmiMn was used. The use of NaBr instead of HBr did not result in a catalyst recovery effect indicating that protons must be present in the anti-126160.doc -42 - 200827333. The addition of HC1 improves the Μ recovery of MnBr2 and Mn(OAc)2, but HBr is significantly better than HC1 due to its combined catalyst recovery effect and its effect on the yield/selectivity of the target compound. The data for operation 4 of ΒηΜη ratio (weight/weight) of 5.85:1 (corresponding to molar ratio [Br]: [Μη] is 4.02) indicates that increasing the concentration of HBr tends to produce lower target carboxylic acid yield and selectivity. And these concentrations also increase corrosion within the device. Shoulder 2. Different o-xylenes were oxidized with different catalytic mixtures (Example 2). Operating catalyst phthalic acid yield (%) selection * H(%) Μη (%) 1 phthalic acid 2 benzoquinone 3 o-carboxybenzaldehyde 4 o-nonylphthalic acid 5 o-nonylbenzaldehyde 6 benzoic acid 1 MnBr/ 59 81 1 1 0 0 17 75 2 MnBr2 + NaBr (1000 ppm Br) b 58 73 4 1 0 0 22 61 3 MnBr2 +HBr (0.0125 M) (1000 ppm Br)b 66 S8 1 0 0 0 11 95 4 MnBr2 + HBr (0.0625 M)c 65 87 1 1 0 0 12 99 5 MnBr2 + HCl (0.0625 M) 52 87 0 0 0 2 11 99 6 Mn(AcO)2 8 21 61 6 0 4 8 14 7 Mn( AcO)2 + HBr (0.0625 M) 63 80 1 0 0 0 18 89 8 Mn(AcO)2 + HC1 (0.0625 M) 17 28 54 14 0 2 2 49 3:8 factory]\411 ratio (by mass) 2.91:1 b : Br:Mn ratio (by mass) is 3.50:1 c : Br:Mn ratio (by mass) is 5.85:1 Example 3 Using a procedure similar to the previous example, in the absence of prior art In the case of HBr and in the presence of HBr or HC1, 1700 ppm Μη (in the form of MnBr2) was used. The results are shown in Table 3 and Process 1 below. In operation 1, as required by WO-02/06201-A, the o-diphenylbenzene stream is initially supplied such that the oxidant/catalyst contact is contacted with the oxidant/precursor while -43 - 126160.doc 200827333 occurs and is observed 75% catalyst recovery, the remaining 25% is lost in the form of manganese oxide precipitate (as determined by X-ray diffraction, mainly Mn〇2, but also some Mn2〇3 and MnO(OH)2). When the current purge stream is shut down, the catalyst recovery rate drops significantly, indicating that the MnBr2 catalyst is significantly more stable at the precursor. The effect of the acid is illustrated by runs 2 and 3, where the initial 'mixing is simultaneous with operation 1, and wherein the catalyst recovery is significantly increased in the presence and absence of the precursor. Operations 2 and 3 also demonstrate that the stability of the catalyst increases due to the presence of acid but in the absence of precursors, as W0-02/062 (HA simultaneous mixing scheme is desirable, but this is not required. In operation 4 And 5, the initial contact between the catalyst and the oxidant is carried out in the absence of a precursor, that is, opposite to the configuration of WO-02/06201-A, and the o-xylene precursor is after its initial contact. Introduction. Operation 5 shows again the stability and recovery of the HBr modified MnBr2 catalyst, and although the simultaneous configuration of WO-02/06201-A is desirable, the effect of the present invention is exhibited in the absence of such simultaneous mixing. Win Table 3 Operation Catalyst Organic Logistics Μ 回收 Recovery Rate (%) 1 MnBr2 1 · Organic Logistics Open 75 2 · Organic Logistics Close 18 2 MnBr2 + HBr (0.0125M) 1 · Organic Logistics Open. ------- 90 2 . Organic stream off 52 3 MnBr2 + HCl (0.0125M) 1 · Organic stream open 84 2. Organic stream 47 4 Μ π Β γ2 1. No organic stream 20 2 · Organic stream open 75 5 MnBr2 + HBr (0.0125 Μ) 1. No organic Logistics 25 2. Organic Logistics Open 92 126160.do c •44- 200827333 Process i

Operation 1 MnBr2 Operation 4 Organics-► ▼ -► 75% Flow Gossip 2 ——► 18% Off ▼ Organic Logistics IV!nBr2 20% Organic Logistics Open ψ -► 75% 〇2 Operation 2 and 3 (for 1»1 * given in %) MnBr2 + HBr (or HCI) Operation 5

MnBr2 + HBr Organics-► ▼ -► 90% Flow Gossip 2 —► 52% Off ♦ Organic Logistics Μ ii 〇2 25% Organics Open ▼ ——► 92% Example 4 Using a procedure similar to Example 1, 3- Oxidation of methylpyridine to nicotinic acid. The reaction product was separated using HPLC. The results are shown in Table 4 below. The reaction conditions are: temperature T is about 360 ° C; pressure P is about 220 bar; total flow rate is 24.368 mL / min; organic matter flow rate is 0-124 mL / min, [02] / organic matter is 1.5 equivalent; The flow rate of MnBr 2) with or without HBr was 8.168 mL/min. Table 4

Mn/Br (PPm) MnBr2 Br ppm 3-PyA yield from HBr (%) Selectivity % Conversion of 3-MPy [%] Aromatic compound yield % Μ η recovery % 3- PyA Py 3-PyAL 1719 /5000 0 41-48 60-64 33- 35 2-4 87-93 80-90 29 1719/5000 1000 39 61 35 3 89 75 38 500/1454 3546 33 62 32 6 82 71 61 3-PyA is nicotine Acid (3·pyridinecarboxylic acid); Py is pyridine; 3-PyAL is 3-pyridylfurfural; 3-MPy is 3-methylpyridine (3-methylpyridine) -45- 126160.doc 200827333 Results show acid (HBr) Stabilization of the catalyst MnBr2 resulted in a significant improvement in catalyst recovery. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic flow chart for explaining the basic configuration described in the above embodiment 1. The dotted line indicates an alternative path for the acid component. 2A and 2B are flowcharts for explaining the basic configuration of the above embodiment π. In Figure 2B, the oxidant is introduced along the reaction zone in a progressive manner at a plurality of injection points. The dotted line indicates an alternative path for the acid component. Figure 3 is a schematic flow diagram illustrating the configuration of a precursor (in the above embodiment) when the contact of the precursor with the oxidant is not the same as the contact of the catalyst with the oxidant. Figure 4 is a schematic flow diagram illustrating the configuration in which the precursor is added to the premixed stream of oxygen and water (i.e., the configuration according to the method illustrated in Figure 1). Figures 5A, 5B, 5C, 5D and 6 illustrate various premixer configurations that can be used to effect mixing of at least one of the reactants with an aqueous solvent. Figure 7 is a schematic diagram illustrating multiple injections of oxidant. 8 and 9 are schematic flow diagrams illustrating mother liquor recirculation and heat removal from a reactor for oxidizing a terephthalic acid precursor in supercritical or near supercritical water, generally in the embodiment of FIG. Pure oxygen is used as the oxidant and in the embodiment of Figure 9 the air is the oxidant. Figure 10 is a detailed illustration of a device for laboratory scale experiments. Figure 11 is a graphical illustration of two different effects of oxidation promotion and catalyst recovery observed by the inventors operating in this system. [Key component symbol description] 126160.doc -46 - 200827333

1 Preheater ΙΑ Preheater 2 Reactor 3 Back Pressure Regulator 10 Water Source 12 Precursor Source 14 〇 2 Source 16 Preheater 18 Α Premixer 18 Β Premixer 19 Catalyst Source 20 Reaction Zone 22 Heat Exchanger 24 Closed Circuit 26 Product recovery zone 30 Line 32 Line 34 Line 35 Line 35 Α Line 36 Mixing unit 38 Pump 38 泵 Pump 38 Β Pump 126160.doc -47- 200827333

38C Pump 40 Heat exchanger 40A Heat exchanger 40B Heat exchanger 40C Heat exchanger 42 Stream 44 Stream 46 Continuous flow reactor 48 Product stream 50 Heat exchanger 52 Heat exchanger 54 Flash vessel 56 Line 5 8 Energy recovery system 60 Line 62 Product recovery area 64 Line 66 Line 68 Pump 70 Heat exchanger 72 Line 74 Line 76 Start/Adjust heater 78 Line 126160.doc -48- 200827333

79 Line 80 Coil/Pipe 82 Line 83 Line 84 Line 88 Line 90 Line 92 Water Purification 100 Air Supply 102 Air Compressor 103 Flash Tank 104 Line 106 Heat Exchanger 108 Fuel Burning Heater 110 Gas Turbine 112 Line 114 Line 116 Line 120 Heat exchanger 152 Preheater 154 Cross member 156 Reactor 158 Cooling coil 159 Filter 126160.doc -49- 200827333 Back pressure regulator valve Pressure relief valve Check valve Pressure transducer Preheated water supply / injection Channel reactant (precursor or oxygen) / injection channel injection channel

Injection channel injection channel resulting mixed stream/tube or vessel mixed flow mixed stream product stream T thermocouple

160 162A/162B/162C 163A/163B 164A/164B/164C 165A/165B/165C/165D A B C D E P PI P2 S W Water Flow 126160.doc -50-

Claims (1)

200827333 X. Patent application scope: 1. Use of an acidic component containing - or a plurality of acids to prevent or minimize the precipitation of catalyst during the reaction and/or the precipitation of metal oxides. a catalytically synthesized oxidation reaction carried out in an aqueous solvent of water under supercritical or near-supercritical conditions, wherein a metal salt as a catalyst is present during the oxidation reaction, wherein the reaction comprises an oxidizing agent and An acidic component is added to the reaction such that at least a portion of the metal salt is contacted with the oxidant in the presence of the acidic component. 2. The use of claim 1, wherein the oxidation reaction is a process for producing one or more target shutdown compounds from one or more oxidizable organic precursors. 3': The use of claim 1, wherein the oxidation reaction is a method for producing an aromatic carboxylic acid hydrazine, the method comprising the presence of a catalyst comprising a metal salt (more: a metal salt) in a reactor Equivalently contacting one of the aromatic carboxylic acids or the genus precursor with an oxidizing agent from the (or) precursor and the oxidizing agent in an aqueous solvent containing water under supercritical conditions or near supercritical conditions Achieving 'wherein the acidic component is added to the reaction such that at least a portion of the catalyst is contacted with the oxidant in the presence of the acidic component. The use of the item 3, wherein the or the precursor, the oxidizing agent and the aqueous solvent constitute a single homogeneous phase in the reaction zone. The use of any one of items 1 to 4, wherein the metal salt comprises a transition metal. 6. The use of claim 5, wherein the metal catalyst comprises manganese. 126160.doc 200827333 7. The use of claim 5, wherein the metal catalyst comprises manganese bromide MnBr2. 8. The use of any one of clauses 1 to 4, wherein the addition of the acidic component is such that the acidic component is present at any position where the metal salt is in contact with the oxidizing agent of the oxidation process. 9. The use of any one of claims 1 to 4, wherein the acidic component is present in the reaction zone in an amount such that a molar ratio of [Η] and [Μ] is at least 0.05:1. [Η+] is the molar amount of the acid derived from the acidic component and μ is the metal of the metal salt present during the oxidation reaction. 10. The use according to any one of claims 1 to 4, wherein the acidic component is present in the reaction zone such that the molar ratio of [Η] and [Μ] is not greater than ΐ2·〇:1 Wherein [Η+] is the molar amount of the acid derived from the acidic component and μ is the metal of the metal salt present during the oxidation reaction. The use of any one of claims 1 to 4, wherein the acidic component is such that the molar ratio of [Η+] and [Μ] is in the range of 〇·2:ι to 3.0:1. Present in the reaction zone, wherein [Η+] is the moor of the acid derived from the acidic component and the ruthenium is the metal of the metal salt present during the oxidation reaction. The use of any one of claims 1 to 4, wherein the acidic component comprises an inorganic acid. 13_ The use of claim 12, wherein the acidic component comprises an inorganic acid selected from the group consisting of hydrazine, wherein X is a halide. 14. The use of claim 12, wherein the acidic component comprises HBr. 15. The use of claim 12, wherein the acidic component comprises hci. 16. The use of claim 13 wherein the amount of hydrogenated hydrogen added is such that the molar ratio of the molar ion (X) of the 126160.doc 200827333 ion (M) to the metal of the catalyst is greater than 2.0:1. For the purpose of claim 13, the amount of self-hydrogen added by t is such that the molar ratio of the h-halogen ion (X) to the metal ion (M) of the catalyst is not greater than 12.0:1 W as claimed in claim 3. The use of at least a portion of the precursor in contact with the oxidant and the contacting of the catalyst with at least a portion of the oxidant. 0 X 19. 20. 21. The use of claim 3, wherein at least 98% by weight is produced The aromatic acid retardation is maintained in solution during the reaction. The use of claim 3, wherein after the reaction, the aromatic (tetra) is from the reaction medium and contains no more than 5 ppm by weight of the intermediate aldehyde produced during the reaction. The use of claim 3, wherein after the reaction, the aromatic (iv)-containing solution, the second treatment, precipitates the aromatic carboxylic acid and separates the precipitate from the mother liquor. 22. The use of any of the items (1), wherein the oxidation reaction is carried out in a continuous flow reactor. 23. The use of claim 22, wherein the reaction medium has a residence time in the reaction zone of no more than 10 minutes. 24. The use according to claim 3, wherein the aromatic carboxylic acid is selected from the group consisting of p-benzoquinone isophthalic acid, o-didecanoic acid, trimellitic acid, naphthalene dicarboxylic acid, and a final acid. 25. The use of claim 24, wherein the aromatic amic acid is terephthalic acid. The use of the invention of claim 3, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent selected from the group consisting of an alkyl group, an alcohol group, an alkoxyalkyl group, and an aldehyde group. The use of claim 3, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent selected from the group consisting of an alkyl group, an alcohol group, and an alkoxy group. 28. The use of claim 3, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent selected from the group consisting of an alkyl group. 29. The use of claim 3, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent from the C-alkyl group. 30. The use of claim 25, wherein the precursor is p-xylene. A method for preventing or minimizing the precipitation of a catalyst for catalytically synthesizing an oxidation reaction and/or minimizing a metal oxide under supercritical or near supercritical conditions in an aqueous solvent comprising water, wherein during the oxidation reaction An oxidizing agent and a metal salt as a catalyst, the method comprising adding an acidic component of the one or more acids in the V to the reaction in a V step, and separating the metal salt from the oxidizing agent in the acidic component Under contact. 32. The method of claim 31, wherein the oxidizing reaction is a method for producing one or more target organic compounds from one or more oxidizable organic precursors. 33. The method of claim 31, wherein the gasification reaction is a method for producing an aromatic carboxylic acid, and the method of aging, earth-human μ comprises containing a metal salt in a reactor. In the case of a catalyst (preferably a transition metal _, a solitude), one or more precursors of the aromatic carboxylic acid 126160.doc 200827333 are contacted with an emulsifier, and the contact is made from the front 駆And the oxidizing agent in the aqueous solvent containing J隹匕a water under the supercritical near supercritical strip # 告 丄 丄 丄 或 或 或 或 或 或 或 或 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中A portion of the catalyst is contacted with the oxidant in the presence of the acidic component. 34. The method of claim 33, wherein the or the precursor, the oxidizing agent, and the aqueous solvent form a single homogeneous phase in the reaction zone. 35. The method of any of claims 31 to 34, wherein the metal salt comprises a transition metal. 3 6 · The method of claim 35, 37. The method of claim 35, MnBr2 〇 wherein the metal catalyst comprises manganese. A method in which the metal catalyst comprises manganese bromide s to any one of items 31 to 34, wherein the addition of the acidic component is carried out such that the acidic component is present in the metal salt in contact with the remote oxidant of the oxidation method Anywhere. The method of any one of claims 1 to 3, wherein the acidic component is present in the reaction zone in an amount such that a molar ratio of [H+] to [M] is at least 〇〇5:1. 'where [H勹 is the molar amount of the acid derived from the acidic component and is the metal of the metal salt present during the oxidation reaction. The method of any one of claims 1 to 3, wherein the acidic component is present in the reaction zone such that the molar ratio of [Η] to [Μ] is not more than 12.0:1. [Η+] is the molar amount of the acid derived from the acidic component and is the metal of the metal salt present during the oxidation reaction. The method of any one of claims 1 to 3, wherein the acidic component is 126160.doc 200827333 and the molar ratio of [Η] to [Μ] is 〇·2:1 to 3·〇 An amount within the range of 1 is present in the reaction zone 'where [Η勹 is the moiré of the acid derived from the acidic component and is the metal of the metal salt present during the oxidation reaction. The method of any one of clauses 1 to 3, wherein the acidic component comprises a mineral acid. 43. The method of claim 42, wherein the acidic component comprises an inorganic acid selected from the group consisting of oxime wherein X is a tooth ion. 44. The method of claim 42, wherein the acidic component comprises HBr. 45. The method of claim 42, wherein the acidic component comprises a method of 11 (: 1.46), such as π, wherein the amount of hydrogen halide added is such that the total cerium halide (X) The molar ratio [金属]··[Μ] of the metal ion (Μ) of the catalyst is greater than 2.0:1. 47. The method of claim 43, wherein the amount of hydrogen halide added is such that the total adjacent halide ion (Χ) The molar ratio of the metal ion (Μ) to the catalyst is not more than 12.0:1. The method of claim 33, wherein at least a portion of the precursor is in contact with the oxidant The method of claim 33, wherein the at least 98% by weight of the aromatic tremulin produced is maintained in solution during the reaction. The method of item 33, wherein after the reaction, the aromatic carboxylic acid is precipitated from the reaction & contains an intermediate aldehyde which is produced during the reaction by a weight of not more than 5 〇〇〇ρρηι. 200827333 51. The method of claim 33, wherein the towel contains an aromatic (four) solution after the subtraction, The treatment is carried out in a continuous flow reactor. The method of the invention is the method of the present invention, wherein the oxidation reaction is carried out in a continuous flow reactor. 53. The method of claim 52, wherein the reaction medium has a residence time in the reaction zone of no more than 1 minute. 54. The method of claim 33, wherein the aromatic carboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid, trimellitic acid, naphthalene dicarboxylic acid, and acid. 55. The method of claim 54, wherein the aromatic carboxylic acid is terephthalic acid. The method of claim 33, wherein the precursor is selected from the group consisting of aromatic compounds selected from the group consisting of alkane, glucosamine, alkoxyalkyl and vine. 57. The method of claim j, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent selected from the group consisting of P, ^, earth, and alkoxyalkyl. 58. The method of claim 3, wherein the precursor is selected from the group consisting of an aromatic compound having at least an alkyl group, wherein the precursor is selected from the group consisting of $ φ Groups selected from Cw*, 曰田舟 has at least 'aroms of the request ^ substituents. And the method wherein the precursor is difu. 61. - A method for the oxidation of organic precursors of white-standard organic species - or a method of oxidizing a plurality of compounds - the method is contained in a reactor 126160.doc 200827333 :etc: drive ... or more in the presence of In the case of a catalyst of a metal salt (preferably a transition = 里), the P contact and the oxidant are realized in an aqueous solution containing water in a supercritical or near-boundary condition, wherein: (1) will contain - Or an acidic component of a plurality of acids is added to the reaction mixture; (ii) at least a portion of the catalyst is contacted with the oxidant in the presence of the acidic component. 62. The method of claim 61, wherein the method comprises: preparing a method for producing an aromatic carboxylic acid, wherein the aromatic acid- or a plurality of precursors are contacted with the oxidizing agent in the presence of a catalyst comprising a metal salt; The contacting is carried out by the (or equivalent) precursor and the oxidizing agent in supercritical or near supercritical conditions in an aqueous solvent comprising water, wherein: (i) an acidic component comprising one or more acids is added to the In the reaction mixture; and (11) at least a portion of the catalyst is contacted with the oxidant in the presence of the acidic component. The method of claim 61 or 62, wherein the or the precursor, the oxidizing agent and the aqueous solvent constitute a single homogeneous phase in the reaction zone. The method of claim 61 or 62, wherein the metal salt comprises a transition metal. 65. The method of claim 64, wherein the metal catalyst comprises manganese. 66. The method of claim 64, wherein the metal catalyst comprises a brominated chain MnBr2 〇67. The method of claim 61 or 62, wherein the addition of the acidic component is 126160.doc 200827333 such that the acidic component is present At any position where the metal salt is in contact with the oxidant of the oxidation process. The method of claim 61 or 62, wherein the acidic component is present in the reaction zone such that the molar ratio to [M] is at least 0.05:1, wherein [H+] is self The molar amount of the acid derived from the acidic component and the enthalpy is the metal of the metal salt present during the oxidation reaction. The method of claim 61 or 62, wherein the acidic component is present in the reaction zone such that the molar ratio of [Η+] and [Μ] is not more than 12.0:1, wherein [Η +] is the molar amount of the acid derived from the acidic component and μ is the metal of the metal salt present during the oxidation reaction. 70. The method of claim 61 or 62, wherein the acidic component is present in the reaction zone such that the molar ratio of [η+] and [Μ] is in the range of 0.2:1 to 3.0:1. Wherein [Η+] is the molar amount of the acid derived from the acidic component and is the metal of the metal salt present during the oxidation reaction. The method of claim 61 or 62, wherein the acidic component comprises a mineral acid. The method of claim 71, wherein the acidic component comprises an inorganic acid selected from the group consisting of hydrazine, wherein X is a halide. The method of claim 71, wherein the acidic component comprises HBr. 74. The method of claim 71, wherein the acidic component comprises HCl. 75. The method of claim 72, wherein the amount of hydrogen halide added is such that the molar ratio [x]:[m] of the total halide ion (X) to the metal ion (M) of the catalyst is greater than 2.0:1. 76. The method of claim 72, wherein the amount of hydrogen halide added is such that the molar ratio of all halide ions (Χ) to the metal ion (Μ) of the catalyst [Χ]: [Μ] 126160.doc 200827333 Not more than 12.0:1. 77. The method of claim 61 or 62 wherein at least a portion of the precursor is contacted with the oxidant and the catalyst is contacted with at least a portion of the oxidant. 78. The method of claim 61 or 62 wherein at least 98% by weight of the aromatic carboxylic acid produced is maintained in solution during the reaction. The method of claim 61 or 62, wherein after the reaction, the aromatic citric acid is precipitated from the reaction medium and contains no more than 5 重量 by weight of the intermediate produced during the reaction. aldehyde. The method of claim 61 or 62, wherein the aromatic carboxylic acid-containing solution is treated to precipitate the aromatic carboxylic acid after the reaction and the precipitate is separated from the mother liquor. 81. The method of claim 61 or 62, wherein the oxidizing reaction is carried out in a continuous flow reactor. 82. The method of claim 81, wherein the reaction medium has a residence time in the reaction zone of no more than 10 minutes. The method of claim 61 or 62, wherein the aromatic carboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid, trimellitic acid, naphthalic acid, and acid. 84. The method of claim 83, wherein the aromatic carboxylic acid is terephthalic acid. The method of claim 61 or 62, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent selected from the group consisting of an alkyl group, an alcohol group, an alkoxyalkyl group, and an aldehyde group. The method of claim 61 or 62, wherein the precursor is selected from the group consisting of aromatic compounds having one substituent selected from the group consisting of alkyl, alcohol and alkoxyalkyl groups to 126160.doc 200827333 . The method of claim 61 or 62, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent selected from an alkyl group. The method of claim 61 or 62, wherein the precursor is selected from the group consisting of aromatic compounds having at least one substituent selected from the group consisting of Cw alkyl groups. 89. The method of claim 84, wherein the precursor is para-xylene. 90. An aromatic retardation acid produced by the method of any one of claims 61 to 89. 126160.doc