JP2022516354A - A method for producing a dicarboxylic acid using a cerium cocatalyst - Google Patents

Abstract

The method for oxidizing a dimethyl aromatic compound is a step of reacting the dimethyl aromatic compound and the oxidizing agent in a solvent in the presence of a catalyst and a co-catalyst to produce a reaction product containing an aromatic dicarboxylic acid. include. Catalysts include cobalt, manganese, and bromine. The weight ratio of cobalt to manganese is 1: 1 or more. The cocatalyst comprises at least one of cerium or iron. The cocatalyst is present in an amount in the range of 10 ppm to 200 ppm based on the total weight of the dimethyl aromatic compound and the solvent. The aromatic dicarboxylic acid is present in the reaction product in an amount of 70 wt% or more, or 90 wt% or more, based on the total weight of the solid in the reaction product.

Description

The present invention relates to a method for producing a dicarboxylic acid using a cerium cocatalyst.

(Mutual reference of related applications)
This international application claims priority to US Provisional Patent Application No. 62 / 789,583 (incorporated herein by reference) filed January 8, 2019.

Aromatic dicarboxylic acids (eg, terephthalic acid) can be produced by oxidation of dimethyl aromatic compounds (eg, para-xylene) in the presence of a catalyst. The reaction is usually carried out in the presence of a solvent such as acetic acid. Oxidation of dimethyl aromatics to the corresponding dicarboxylic acids proceeds through a number of intermediate steps. Inefficient catalytic and / or oxidation processes lead to the formation of intermediates as impurities in the product. Moreover, the oxidation process carried out at high pressure and high temperature leads to the formation of COx by the peroxidation of the final product (ie, aromatic dicarboxylic acid) and also by the combustion of the solvent, eg acetic acid. As a result of by-product formation and / or peroxidation, the consumption of dimethyl aromatic compounds and solvents increases unnecessarily.

US Pat. No. 5,453,538 discloses a process for the production of aromatic dicarboxylic acids using a low bromine to metal ratio, facilitated by the use of cerium with a cobalt-manganese catalyst.

U.S. Pat. No. 5,453,538

A method for producing a dicarboxylic acid using a cerium cocatalyst is provided.

The present invention is a method for oxidizing a dimethyl aromatic compound.
Including the step of reacting the dimethyl aromatic compound and the oxidizing agent in a solvent in the presence of a catalyst and a co-catalyst to produce a reaction product containing an aromatic dicarboxylic acid.
The catalyst contains cobalt, manganese, and bromine.
The weight ratio of cobalt to manganese is 1: 1 or greater, or 2: 1 or greater, preferably 3: 1 or greater.
The cocatalyst comprises at least one of cerium or iron, preferably cerium.
The cocatalyst is present in an amount ranging from 10 ppm to 200 ppm, or 20 ppm to 190 ppm, preferably 30 ppm to 180 ppm, based on the total weight of the dimethyl aromatic compound and the solvent.
Preferably, the aromatic dicarboxylic acid is 70 wt% or more, or 90 wt% or more, preferably 92 wt% or more, more preferably 94 wt% in the reaction product, based on the total weight of the solid in the reaction product. It is a method that exists in the above amount.

The figure below is an exemplary embodiment, in which similar elements are similarly numbered.

It is a process flow diagram of one Embodiment of the method for oxidizing para-xylene to obtain terephthalic acid. The mole percent of carbon monoxide and carbon dioxide (collectively "COx") formed as by-products, based on the total number of moles of reaction products in Comparative Example A and Example 1, and the implementation compared to Comparative Example A. It is a graph of the percent reduction of the number of moles of COx in Example 1. FIG. Graph of the percentage of moles of COx formed as a by-product based on the total number of moles of reaction products in Comparative Example B and Example 2, and the percentage reduction of the number of moles of COx in Example 2 compared to Comparative Example B. Is. Weight percent of _{C10 +} hydrocarbons formed as a by-product based on the total weight of reaction products in Comparative Examples AB and 1-2, and Comparative Examples B and 1 compared to Comparative Example A. It is a graph of the percent reduction of the amount of C _{10 +} hydrocarbon in -2.

The above and other features are exemplified by the following detailed description, examples, and claims.

It would be desirable to provide improved methods for oxidizing dimethyl aromatic compounds to selectively produce aromatic dicarboxylic acids, especially those that mitigate the disadvantages. Therefore, the present specification discloses a method for oxidizing an dimethyl aromatic compound to obtain an aromatic dicarboxylic acid. Desirably, the method consumes the dimethyl aromatic compound and solvent by oxidizing the dimethyl aromatic compound in the presence of a catalyst containing cobalt and manganese in a weight ratio of 1: 1 or greater, as well as a co-catalyst containing cerium. To reduce unwanted side reactions that form by-products. Previous methods for oxidizing dimethyl aromatic compounds are side reactions, such as carbon monoxide, carbon dioxide, or oxidation of solvents that form by-products such as _{C10 +} hydrocarbons (eg, intermediates or "heavy substances"). Or suffered from peroxidation of dimethyl aromatic compounds. These side reactions resulted in increased consumption of dimethyl aromatic compounds and solvents. For example, approximately 0.010 mol% more dimethyl aromatic compounds and approximately 0.016 mol% more solvent may be consumed by previous methods as compared to the methods of the present disclosure.

As used herein, the phrase "peroxidation" refers to the oxidation of terephthalic acid and acetic acid to COx.

In the methods of the present disclosure, the dimethyl aromatic compound is in the presence of a catalyst containing cobalt and manganese in a weight ratio of 1: 1 or greater, or 2: 1 or greater, preferably 3: 1 or greater, and a cocatalyst containing cerium. It is oxidized. Surprisingly, such catalysts and co-catalysts exclude the presence of such catalysts and co-catalysts (eg, containing less than 1: 1 weight ratio of cobalt to manganese, not cerium co-catalyst) dimethyl. Compared to previous methods for oxidizing aromatic compounds, it reduces the loss of reactants and catalysts, increases selectivity for aromatic dicarboxylic acids, and carbon monoxide, carbon dioxide, and C in the reaction products. It has been found to reduce the amount of at least one of the ₁₀₊ hydrocarbons as well as increase the purity of the aromatic dicarboxylic acid.

For example, the methods of the present disclosure can achieve at least one of the following: (i) reaction products obtained from methods for oxidizing dimethyl aromatic compounds excluding the presence of such catalysts and co-catalysts. Total number of moles of carbon dioxide and carbon monoxide formed, 5 mol% or more, or 10 mol% or more, preferably 15 mol% or more, compared to the total number of moles of carbon monoxide and carbon dioxide present in it. 10% by weight compared to the total amount of _{C10 +} hydrocarbons present in the reaction product obtained from the method for oxidizing dimethyl aromatic compounds excluding the presence of such catalysts and co-catalysts. (Wt%) or higher, or 20 wt% or higher, preferably 30 wt% or higher, a reduction in the amount of _C10 + hydrocarbons formed, and (iii) dimethyl aromatic compounds excluding the presence of such catalysts and co-catalysts. 0.5 mol% or more, or 1.0 mol% or more, preferably 1.5 mol, as compared to the number of moles of aromatic dicarboxylic acid present in the reaction product obtained from the previous method for oxidizing % Increase in the number of moles of aromatic dicarboxylic acid produced.

Moreover, surprisingly, it was found that the amount of catalyst could be reduced compared to the previous methods without the catalyst and co-catalyst described in this disclosure. For example, the method can reduce the amount of at least one of manganese and bromine used in the catalyst while maintaining the number of moles of aromatic dicarboxylic acid produced per milligram of catalyst. The reduction in the amount of manganese present is 25 wt% or more, or 50 wt%, compared to the number of moles of manganese present in previous methods for oxidizing dimethyl aromatic compounds excluding the presence of such catalysts and co-catalysts. It can be the above, or 75 wt% or more. Desirably, reducing the amount of bromine present can reduce, reduce, or avoid corrosion of the equipment used for oxidation, or allow the use of different constituent materials for the equipment. The reduction in the amount of bromine present is 25 wt% or more, or 50 wt%, compared to the number of moles of bromine present in previous methods for oxidizing dimethyl aromatic compounds excluding the presence of such catalysts and co-catalysts. It can be the above, or 75 wt% or more.

As mentioned above, the method for oxidizing a dimethyl aromatic compound is to react the dimethyl aromatic compound and the oxidizing agent in a solvent in the presence of a catalyst and a co-catalyst, and the reaction product containing an aromatic dicarboxylic acid. Can be included in the process of producing.

The dimethyl aromatic compound can include xylene (eg, at least one of para-xylene, meta-xylene, and ortho-xylene) and at least one of 2,6-dimethylnaphthalene, preferably para-xylene.

A catalyst is used to catalyze the oxidation of dimethyl aromatic compounds. The catalyst can include cobalt, manganese, and bromine. The catalyst can be unsupported, the sources of cobalt, manganese, and bromine can be combined and the catalyst is formed as a catalyst mixture. The sources of cobalt and manganese used for the catalyst include salts of cobalt (eg, cobalt acetate (II) tetrahydrate) and manganese (eg, manganese acetate (II) tetrahydrate), respectively. be able to. The bromine source can be hydrobromic acid, sodium bromide, ammonium bromide, tetrabromoethane, or a combination comprising at least one of the above. Other catalyst sources include metal bromides (eg, MnBr ₂ , CoBr ₂ , etc.) and metal nitrates. Desirably, the bromine can be at least one of the solids or can be dissolved in a solvent.

Desirably, the catalyst can contain a weight ratio of cobalt to manganese of 1: 1 or greater, or 2: 1 or greater, preferably 3: 1 or greater. The total amount of cobalt and manganese can be 1,000 parts per million (ppm) or less, or 900 ppm or less, preferably 800 ppm or less, based on the total weight of the reaction mixture containing dimethyl aromatics, acetic acid and water. ..

Bromine can be present in an amount of 800 ppm or less, or 400 ppm or less, preferably 200 ppm or less, based on the total weight of the reaction mixture containing dimethyl aromatics, acetic acid and water. The catalyst comprises a molar ratio of bromine pairs (cobalt and manganese) ranging from 0.3: 1 to 3: 1 or 0.3: 1 to 2: 1, preferably 0.3: 1 to 1: 1. be able to.

Desirably, in various embodiments, during the reaction, the reaction mixture, including, for example, dimethyl aromatic compounds, oxidants, catalysts, co-catalysts, and solvents, is ammonium acetate, meta-xylene, and bromide anions or iodides. It is substantially free of ionic liquids containing at least one of the anions and substantially free of ionic liquids containing ammonium acetate, meta-xylene, and bromide anions. As used herein, the phrase "substantially free" recognizes the presence of impurities in dimethyl aromatic compounds, oxidizing agents, catalysts, cocatalysts, and solvents. In other words, during the reaction, none of the ionic liquids containing ammonium acetate, meta-xylene, and at least one of the bromide anion and the iodide anion is present except for trace impurities. They are not intentionally added compounds.

In addition to the catalyst, the method uses a co-catalyst. Desirably, the cocatalyst comprises cerium. Cerium can be present in an amount ranging from 10 ppm to 200 ppm, or 20 ppm to 190 ppm, preferably 30 ppm to 180 ppm, based on the total weight of the dimethyl aromatic compound and solvent.

The solvent can include at least _one of the following: water, C1 _- C7 aliphatic carboxylic acid, aromatic acid, and supercritical CO ₂ , preferably acetic acid. The solvent can be an aqueous solution. Desirably, the weight ratio of the solvent to the dimethyl aromatic compound can be in the range of 15: 1 to 1: 1 or 10: 1 to 1: 1 and preferably 5: 1 to 1: 1.

To oxidize dimethyl aromatic compounds, the method uses an oxidant. Examples of the oxidizing agent include hydrogen peroxide, diatomic oxygen, ozone, anthraquinone, C _2-32 alkyl peroxide, C _2-32 alkyl hydroperoxide, C _2-32 ketone peroxide, C _2-32 diacyl peroxide, and C _3-22 . Diperoxy, Ketal, C _2-32 Peroxy Ester, C _2-32 Peroxy Dicarbonate, C _2-32 Peroxy Acid, C _6-32 Peroxy Acid, C _2-32 Peracid, Peryodinane, Periodic Acid, or the above. Combinations comprising at least one, preferably diatomic oxygen (eg, in the air), may be mentioned.

Desirably, the reaction of the dimethyl aromatic compound with the oxidizing agent can be carried out at a temperature in the range of 170 ° C to 200 ° C, or 180 ° C to 200 ° C, or 190 ° C to 200 ° C.

The reaction of the dimethyl aromatic compound with the oxidizing agent can be carried out at a pressure in the range of 1 megapascal (mPa) to 1.8 mPa, or 1 mPa to 1.7 mPa, preferably 1 mPa to 1.6 mPa.

The residence time of the reaction between the dimethyl aromatic compound and the oxidizing agent in the reactor can be in the range of 20 minutes to 200 minutes, or 40 minutes to 150 minutes, preferably 60 minutes to 100 minutes.

The reaction of dimethyl aromatic compounds can be carried out in any reactor capable of operating under the conditions described in the present disclosure, eg, batch reactors, continuous or semi-continuous reactors. The reactor is an inlet for continuously supplying at least one of a dimethyl aromatic compound, a solvent, a catalyst, and a cocatalyst for a period of time, and a sequence of reaction products for a period of time or at a particular time point (s). Can include an outlet for removal. Desirably, the reaction of the dimethyl aromatic compound with the oxidant can be carried out in a continuous stirring tank reactor.

Aromatic dicarboxylic acids are preferably 70 wt% or greater, or 90 wt% or greater, based on the total weight of the solid in the reaction product, eg, measured at ambient temperature by high performance liquid chromatography (HPLC). Can be present in an amount of 92 wt% or more, more preferably 94 wt% or more.

Desirably, by this method, C ₁₀₊ hydrocarbons are less than or equal to 1.5 wt% or 1.0 wt in the reaction product, based on the total weight of the solid in the reaction product as measured at ambient temperature, eg, by HPLC. The result is that it is present in an amount of% or less, preferably 0.5 wt% or less. The catalysts and co-catalysts described in the present disclosure can contribute to the prevention of the formation of C ₁₀₊ hydrocarbons. As used herein, "C 10 ₊ hydrocarbon" refers to a hydrocarbon containing 10 or more carbon atoms. A number of C 10 ₊ hydrocarbons, such as at least 5 different C 10 ₊ hydrocarbons, or at least 15 different C 10 ₊ hydrocarbons, or at least 20 different C 10 ₊ hydrocarbons can be present in the reaction product.

The method can further include separating the solvent, catalyst, and cocatalyst from the reaction product, and recycling the solvent, catalyst, and cocatalyst into a step of reacting the dimethyl aromatic compound. For example, the separation step can include the step of crystallizing the aromatic dicarboxylic acid to obtain an aromatic dicarboxylic acid crystal. The aromatic dicarboxylic acid crystals can then be separated from the solvent, catalyst, and co-catalyst. For example, the catalyst and co-catalyst may be dissolved in the solvent and the separation can be via filtration or any other solid-liquid separation method. The step of crystallizing the aromatic dicarboxylic acid can be at least one step, or at least two steps, preferably at least three steps.

The method can further include the step of reacting the reaction product with hydrogen in the presence of a hydrogenation catalyst. For example, the method can include the step of reacting an aromatic dicarboxylic acid crystal with hydrogen in the presence of a hydrogenation catalyst to purify the aromatic dicarboxylic acid crystal. The hydrogenation catalyst can include palladium, ruthenium, rhodium, osmium, iridium, platinum, or a combination comprising at least one of the above. The hydrogenation catalyst can be supported on a carrier such as silicon dioxide, diatomaceous earth, titanium dioxide, carbon, thorium oxide, zirconium oxide, silicon carbide, aluminum oxide, or a combination comprising at least one of the above. .. Desirably, the hydrogenation catalyst can be carbon carrier-supported palladium. Therefore, the purity of the aromatic dicarboxylic acid crystal and the yield of the aromatic dicarboxylic acid can be improved.

The reaction mixture for oxidation of the dimethyl aromatic compound by the above method can contain a dimethyl aromatic compound, an oxidizing agent, a catalyst, a co-catalyst, water, and a solvent.

The reaction product can be produced by the above method or by using the above reaction mixture.

A more complete understanding of the components, processes, and devices disclosed herein can be obtained by reference to the accompanying drawings. These figures (also referred to herein as "FIG.") Are merely schematic views based on the convenience and ease of explaining the present disclosure, and thus the device or its components. It is not intended to indicate the relative size and dimensions of and / or to define or limit the scope of the exemplary embodiments. For clarity, specific terms are used in the description below, but these terms are intended to indicate only the specific structure of the embodiment selected for illustration in the drawings and are intended to indicate the present disclosure. It is not intended to define or limit the scope. In the drawings and the description below, it should be understood that similar numerical representations indicate components of similar function.

As shown in FIG. 1, the terephthalic acid production facility can include a reactor 10. The reaction mixture 6 containing para-xylene, a solvent, a catalyst, and a co-catalyst can be delivered to the reactor 10. The oxidant 8 can also be delivered to the reactor 10. Upon reaction of para-xylene with the oxidant 8, the reaction product 12 containing terephthalic acid can be removed from the reactor 10. The reaction product 12 can be fed into the first crystallization apparatus 20 to generate the first crystallization stream 22. The first crystallization stream 22 can be sent to the second crystallization apparatus 30, and the second crystallization stream 32 is generated. The second crystallization stream (crystallyzer stream) 32 can be sent to the third crystallization apparatus 40 to generate a third crystallization stream 42 containing crystallization terephthalic acid. The solvent, catalyst, and cocatalyst stream 44 can be separated from the third crystallization stream 42 and recycled into the reaction mixture 6.

This disclosure is further illustrated by the following examples, which are non-limiting.

The following components listed in Table 1 were used in the examples. Unless explicitly stated otherwise, the amount of each component is expressed in weight percent based on the total weight of the composition in the examples below.

<Example 1-2 and Comparative Example AB>
In Examples 1-2 and Comparative Examples AB, para-xylene was oxidized in acetic acid in the presence of catalysts and co-catalysts of different compositions. The oxidation reaction was carried out in the presence of air in a semi-continuous flow stirring tank reactor. In Example 1-2, cerium was used in an amount of 50 ppm based on the total weight of para-xylene, water and acetic acid. In Comparative Examples AB, no cerium co-catalyst was used. In Example 2 and Comparative Example B, a smaller amount of catalyst was included than in Example 1 and Comparative Example A. Table 2 summarizes the amounts of the catalyst, co-catalyst, and solvent used, the weight ratio of solvent to para-xylene, and the reaction conditions in Examples and Comparative Examples.

As shown in FIG. 2A, a reduction in the total amount of carbon monoxide and carbon dioxide (COx) produced in about 10 mol% was seen in Example 1 compared to Comparative Example A. As shown in FIG. 2B, a reduction in the total amount of carbon monoxide and carbon dioxide (COx) produced in about 8 mol% was seen in Example 2 compared to Comparative Example B. Thus, the catalyst and cerium reduced the oxidation of the solvent and product terephthalic acid to carbon monoxide and carbon dioxide. Also, the presence of catalyst and cerium in the oxidation reaction does not significantly affect terephthalic acid selectivity, terephthalic acid selectivity can be measured by high performance liquid chromatography (HPLC) and only solid products (ie, ie). It can be calculated based on (not a gaseous product). For example, the methods of the present disclosure can achieve a purity of approximately 96.5 wt% terephthalic acid.

As can be seen in FIG. 3, the reduction in the amount of catalyst and the use of co-catalyst reduced the formation of C ₁₀₊ hydrocarbons. This reduction in C ₁₀₊ hydrocarbon production reduces para-xylene consumption.

In Example 3-27, para-xylene was oxidized in acetic acid in the presence of catalysts and co-catalysts of different compositions. The oxidation reaction was carried out in the presence of air in a semi-continuous flow stirring tank reactor. The amount of metal in the catalyst was based on the total weight of para-xylene, water and acetic acid. The reaction for Examples 3-10 was carried out at a temperature of 170 ° C. and for Examples 11-26 it was carried out at 190 ° C. All examples were carried out at a pressure of 1.3 mPa.

The composition of Co and Mn tested was two levels, 400: 400 Co: Mn and 300: 100 Co: Mn, with Br varying from 166 to 730 ppm. The results show the performance of the cocatalyst compared to the performance of the reaction without the cocatalyst (zero).

Initial experiments were performed on the p-xylene oxidation process at a temperature of 170 ° C. using 50 ppm of each Zr, Pd, Mo, Ce, or Ag as a cocatalyst. The results showed that the use of Ce as a co-catalyst reduced the amount of COx formed. Of all the metals, Zr provided a smaller amount of 4-CBA, but it provided a higher amount of Cox. 4-CBA is an unwanted impurity, which is about 4 wt% in the reaction carried out at 170 ° C. It was found that lower amounts of 4-CBA were produced in the reaction carried out at 190 ° C. Therefore, higher reaction temperatures are beneficial in reducing 4-CBA production.

As reported in Table 3, 50 ppm Fe, Ag, Ce and Cu were tested at 190 ° C. with Co-Mn-Br as co-metals. Among the different metals studied, experiments performed using copper as a co-catalyst showed incomplete oxidation, i.e., by product distribution analysis, more than the desired final product, terephthalic acid (TPA). , P-toluic acid and intermediate products such as 4-CBA are demonstrated.

Fe and Ce have been found to be promising candidates as co-catalysts for p-xylene oxidation, especially at 190 ° C. reaction temperature, in view of less COx formation. When these materials are used as co-catalysts:
Fe showed reduced COx and heaviness formation, but higher 4-CBA formation.
Ce showed reduced COx and 4-CBA formation, but higher heavy weight formation.

The role of cocatalyst in reduced amounts of Co, Mn, and Br was evaluated using Fe, Ce, Zr, and Ru. The combination of Fe + Ce and Fe + Zr was also studied for the distribution of p-xylene oxidation products at reduced amounts of Co-Mn-Br of 300-100-332, respectively. All the results showed that the presence of Fe and Ce was able to reduce COx and heavy matter formation. 4-CBA formation was reduced when Zr was used as a co-catalyst, but COx and heaviness formation was higher.

Therefore, the presence of a small amount of co-catalyst in the Co-Mn-Br catalyst showed a wide range of performance. For para-xylene oxidation, the improvement of consumption rate and the reduction of impurities by incorporating a co-catalyst into the Co-Mn-Br catalytic system are clearly shown. This study also demonstrates that reaction temperature has more effect on TPA quality and heavy weight formation. Cu as a co-catalyst showed an inhibitory role in the para-xylene oxidation process. Among the various cocatalysts tested, Fe and Ce showed promising performance by increasing product quality.

As shown in the examples, this method using a catalyst containing a weight ratio of 1: 1 or more, or 2: 1 or more, preferably 3: 1 or more of cobalt and manganese, and a co-catalyst containing cerium is such. Reduces the amount of reactants and solvents used, increases selectivity for aromatic dicarboxylic acids, and produces reactions compared to previous methods for oxidizing dimethyl aromatic compounds, excluding the presence of different catalysts and cocatalysts. It is possible to reduce the amount of at least one of carbon monoxide, carbon dioxide, and C ₁₀₊ hydrocarbons in the substance and increase the purity of the aromatic dicarboxylic acid. Moreover, the amount of catalyst, preferably the amount of bromine, can be reduced as compared to such previous methods.

This disclosure further includes the following aspects:

Aspect 1. A method for oxidizing a dimethyl aromatic compound, comprising the steps of reacting a dimethyl aromatic compound and an oxidizing agent in a solvent in the presence of a catalyst and a co-catalyst to produce a reaction product containing an aromatic dicarboxylic acid. The catalyst contains cobalt, manganese, and bromine, and the weight ratio of cobalt to manganese is 1: 1 or more, or 2: 1 or more, preferably 3: 1 or more, and the cocatalyst is at least cerium or iron. The cocatalyst is present in an amount ranging from 10 ppm to 200 ppm, or 20 ppm to 190 ppm, preferably 30 ppm to 180 ppm, based on the total weight of the dimethyl aromatic compound and the solvent, including one, preferably cerium, and the aromatic. The group dicarboxylic acid is present in the reaction product in an amount of 70 wt% or more, or 90 wt% or more, preferably 92 wt% or more, more preferably 94 wt% or more, based on the total weight of the solid in the reaction product. Method.

Aspect 2. The method of embodiment 1, wherein the dimethyl aromatic compound comprises para-xylene, meta-xylene, ortho-xylene, 2,6-dimethylnaphthalene, or a combination comprising at least one of the above, preferably para-xylene.

Aspect 3. The method of any one or more of the above embodiments, wherein the total amount of cobalt and manganese is 1,000 ppm or less, or 900 ppm or less, preferably 800 ppm or less, based on the total weight of the dimethyl aromatic compound and the solvent.

Aspect 4. The method of any one or more of the above embodiments, wherein the bromine is present in an amount of 800 ppm or less, or 600 ppm or less, preferably 400 ppm or less, based on the total weight of the dimethyl aromatic compound and the solvent.

Aspect 5. The method of any one or more of the above embodiments, wherein bromine comprises hydrobromic acid.

Aspect 6. The total number of moles of carbon monoxide and carbon dioxide present in the reaction product is the amount of carbon monoxide present in the reaction product obtained from the method for oxidizing dimethyl aromatic compounds excluding the presence of catalysts and co-catalysts. The method of any one or more of the aforementioned embodiments, wherein the total number of moles of carbon and carbon dioxide is reduced by 5 mol% or more, or 10 mol% or more, preferably 15 mol% or more.

Aspect 7. C ₁₀₊ hydrocarbons are present in the reaction product in an amount of 1.5 wt% or less, or 1.0 wt% or less, preferably 0.5 wt% or less, based on the total weight of the solids in the reaction product. One or more methods of any one of the embodiments.

Aspect 8. The method of any one or more of the above embodiments, wherein the oxidant comprises air.

Aspect 9. The method of any one or more of the above embodiments, wherein the solvent comprises water and at least _one of the C1 _- C7 aliphatic carboxylic acids, preferably acetic acid.

Aspect 10. One or more of the above embodiments, wherein the weight ratio of the solvent to the dimethyl aromatic compound is in the range of 15: 1 to 1: 1 or 10: 1 to 1: 1 and preferably 5: 1 to 1: 1. Method.

Aspect 11. Any of the above embodiments, the molar ratio of bromine to cobalt and manganese ranges from 0.3: 1 to 3: 1 or 0.3: 1 to 2: 1, preferably 0.3: 1 to 1: 1. Or one or more methods.

Aspect 12. The method of any one or more of the aforementioned embodiments, wherein the reaction is carried out at a temperature in the range of 170 ° C to 200 ° C, or 180 ° C to 200 ° C, preferably 190 ° C to 200 ° C.

Aspect 13. The reaction is carried out at a pressure in the range of 1 megapascal to 1.8 megapascal, or 1 megapascal to 1.7 megapascal, preferably 1 megapascal to 1.6 megapascal, any one of the above embodiments. More than one way.

Aspect 14. The method of any one or more of the aforementioned embodiments, wherein the reaction is carried out in a continuous stirring tank reactor and the residence time is in the range of 20 to 200 minutes, or 40 to 150 minutes, preferably 60 to 100 minutes.

Aspect 15. During the reaction, the reaction mixture containing a dimethyl aromatic compound, an oxidizing agent, a catalyst, a cocatalyst, and a solvent substantially contains an ionic liquid containing at least one of ammonium acetate, meta-xylene, and a bromide anion or an iodide anion. The reaction mixture is substantially free of ionic liquids containing ammonium acetate, meta-xylene, and bromide anions, and more preferably ions containing ammonium acetate, meta-xylene, and bromide anions. One or more of the above embodiments, comprising no bromide.

Aspect 16. The method of any one or more of the above embodiments, further comprising the step of crystallizing the reaction product.

Aspect 17. One or more of the methods described above, further comprising a step of separating the solvent, the catalyst, and the cocatalyst from the reaction product, and a step of recycling the solvent, the catalyst, and the cocatalyst into the reaction step.

Aspect 18. The method of any one or more of the above embodiments, further comprising the step of reacting the dimethyl aromatic compound and hydrogen in the presence of a hydrogenation catalyst.

Aspect 19. The reaction mixture (including dimethyl aromatic compounds, oxidants, catalysts, cocatalysts, and solvents) is a total amount of cobalt of 1,000 ppm or less, preferably 900 ppm or less, more preferably 800 ppm or less, based on the total weight of the reaction mixture. And one or more methods of any of the above embodiments comprising manganese.

Aspect 20. The catalyst has a molar ratio of bromine pairs (cobalt and manganese) ranging from 0.3: 1 to 3: 1, preferably 0.3: 1 to 2: 1, more preferably 0.3: 1 to 1: 1. One or more of the methods according to any of the above embodiments, including.

Aspect 21. The method according to any one or more of the above embodiments, wherein the catalyst does not contain Cu.

Aspect 22. A reaction mixture for oxidation of a dimethyl aromatic compound by any one or more of the above embodiments, comprising a dimethyl aromatic compound, an oxidizing agent, a catalyst, a cocatalyst, and a solvent.

Aspect 23. A reaction product produced by any one or more of the methods of aspects 1-21 or using the reaction mixture of aspects 22.

Aspect 24. A catalyst system for the oxidation of dimethyl aromatic compounds, the catalyst containing cobalt, manganese, and bromine, with a cobalt to manganese weight ratio of 1: 1 or greater, or 2: 1 or greater, preferably 3: 1. A catalyst system comprising one or more catalysts, as well as a co-catalyst comprising at least one of cerium or iron, preferably containing cerium.

Aspect 25. A reaction mixture for the oxidation of a dimethyl aromatic compound, comprising the catalytic system of embodiment 24, a dimethyl aromatic compound, an oxidant, and a solvent, the cocatalyst being based on the total weight of the dimethyl aromatic compound and the solvent. It is present in an amount ranging from 10 ppm to 200 ppm, or 20 ppm to 190 ppm, preferably 30 ppm to 180 ppm, and the total amount of cobalt and manganese is 1,000 ppm or less, or 900 ppm or less, based on the total weight of the dimethyl aromatic compound and solvent. It is preferably 800 ppm or less, and bromine is present in an amount of 800 ppm or less, or 600 ppm or less, preferably 400 ppm or less, based on the total weight of the dimethyl aromatic compound and the solvent, and the molar ratio of bromine to cobalt and manganese is 0. A reaction mixture in the range of 3: 1 to 3: 1, or 0.3: 1 to 2: 1, preferably 0.3: 1 to 1: 1.

The compositions, methods, and articles may optionally include, or may be essentially composed of, any suitable component or process disclosed herein. The composition, method, and article may or may not be added, or otherwise, a step, component, material, material component, adjuvant, or seed that is not necessary to achieve the function or purpose of the composition, method, and article. Can be formulated to lack or substantially not include.

The singular forms "one (a, an)" and "the" include a plurality of referents unless explicitly stated in the context. "Or" means "and / or" unless explicitly stated in the context. Terms such as "primary" and "secondary", such as "first" and "second", do not indicate any order, quantity, or materiality herein, but rather one element. Used to distinguish it from another element.

The endpoints of the entire range for the same component or characteristic are included and can be combined independently (eg, "25 wt% or less, or 5 wt% to 20 wt%" is the endpoint, and "5 wt% to 25 wt%". Includes all intermediate values in the range of, etc.). Disclosure of a narrower range or a more specific group in addition to a wider range does not deny a wider range or a larger group.

The subscript "(s)" is intended to include both the singular and the plural of the term it modifies, thus including at least one of the terms (eg, a colorant (s) at least. Includes one colorant). "Arbitrary" or "voluntary" means that the event or situation described thereafter may or may not occur, and that the description includes the case where the event occurs and the case where the event does not occur. means. Unless otherwise specified, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. "Combination" includes blends, mixtures, alloys, reaction products, and the like.

Although typical embodiments have been specified for illustration purposes, the above description should not be considered to limit the scope herein. Accordingly, various modifications, adaptations, and alternatives can be conceived by those of skill in the art without departing from the spirit and scope herein.

Claims (20)

A method for oxidizing dimethyl aromatic compounds,
Including the step of reacting the dimethyl aromatic compound and the oxidizing agent in a solvent in the presence of a catalyst and a co-catalyst to produce a reaction product containing an aromatic dicarboxylic acid.
The catalyst contains cobalt, manganese, and bromine.
The weight ratio of cobalt to manganese is 1: 1 or greater, or 2: 1 or greater, preferably 3: 1 or greater.
The cocatalyst comprises at least one of cerium or iron, preferably cerium.
The cocatalyst is present in an amount ranging from 10 ppm to 200 ppm, or 20 ppm to 190 ppm, preferably 30 ppm to 180 ppm, based on the total weight of the dimethyl aromatic compound and the solvent.
Preferably, the aromatic dicarboxylic acid is 70 wt% or more, or 90 wt% or more, preferably 92 wt% or more, more preferably 94 wt% in the reaction product, based on the total weight of the solid in the reaction product. A method that exists in more than the amount. The dimethyl aromatic compound according to claim 1, wherein the dimethyl aromatic compound contains para-xylene, meta-xylene, ortho-xylene, 2,6-dimethylnaphthalene, or a combination containing at least one of the above, preferably para-xylene. Method. The total amount of cobalt and manganese is 1,000 ppm or less, or 900 ppm or less, preferably 800 ppm or less, based on the total weight of the dimethyl aromatic compound and the solvent, and / or bromine is the dimethyl aromatic compound and The method according to claim 1 or 2, which is present in an amount of 800 ppm or less, or 600 ppm or less, preferably 400 ppm or less, based on the total weight of the solvent. The method according to any one of claims 1 to 3, wherein the co-catalyst contains cerium, preferably the co-catalyst is cerium. The method according to any one of claims 1 to 4, wherein the bromine contains hydrobromic acid. The total number of moles of carbon monoxide and carbon dioxide present in the reaction product is present in the reaction product obtained from the method for oxidizing the dimethyl aromatic compound excluding the presence of the catalyst and the co-catalyst. The invention according to any one of claims 1 to 5, wherein the total number of moles of carbon monoxide and carbon dioxide is reduced by 5 mol% or more, or 10 mol% or more, preferably 15 mol% or more. Method. C ₁₀₊ hydrocarbons are present in the reaction product in an amount of 1.5 wt% or less, or 1.0 wt% or less, preferably 0.5 wt% or less, based on the total weight of the solids in the reaction product. The method according to any one of claims 1 to 6. The method according to any one of claims 1 to 7, wherein the catalyst does not contain copper. The method according to any one of claims 1 to 8, wherein the solvent contains water and at least _one of C1 _- C7 aliphatic carboxylic acids, preferably acetic acid. Any of claims 1-9, wherein the weight ratio of the solvent to the dimethyl aromatic compound is in the range of 15: 1 to 1: 1 or 10: 1 to 1: 1, preferably 5: 1 to 1: 1. The method described in item 1. The molar ratio of bromine to cobalt and manganese is in the range of 0.3: 1 to 3: 1 or 0.3: 1 to 2: 1, preferably 0.3: 1 to 1: 1. The method according to any one of 10 to 10. The method according to any one of claims 1 to 11, wherein the reaction is carried out at a temperature in the range of 170 ° C to 200 ° C, or 180 ° C to 200 ° C, preferably 190 ° C to 200 ° C. The reaction is carried out at pressures ranging from 1 megapascal to 1.8 megapascals, or 1 megapascal to 1.7 megapascals, preferably 1 megapascals to 1.6 megapascals, claims 1-12. The method described in any one of the above. The reaction is carried out in a continuous stirring tank reactor, and the residence time is in the range of 20 minutes to 200 minutes, or 40 minutes to 150 minutes, preferably 60 minutes to 100 minutes, according to any one of claims 1 to 13. The method described in. During the reaction, the reaction mixture containing the dimethyl aromatic compound, the oxidizing agent, the catalyst, the cocatalyst, and the solvent contains an ionic liquid containing ammonium acetate, meta-xylene, and bromide anion and iodide anion. The method according to any one of claims 1 to 14, which is substantially not included. The method according to any one of claims 1 to 15, further comprising a step of crystallizing the reaction product. 13. The method described in item 1. The method according to any one of claims 1 to 17, further comprising a step of reacting the dimethyl aromatic compound and hydrogen in the presence of a hydrogenation catalyst. A catalytic system for the oxidation of dimethyl aromatic compounds,
It contains a catalyst containing cobalt, manganese, and bromine with a cobalt to manganese weight ratio of 1: 1 or greater, or 2: 1 or greater, preferably 3: 1 or greater, and preferably at least one of cerium or iron. A catalytic system containing a cocatalyst containing cerium. A reaction mixture for the oxidation of dimethyl aromatic compounds,
The catalyst system according to claim 19.
The dimethyl aromatic compound,
Contains oxidizers and solvents,
The cocatalyst is present in an amount ranging from 10 ppm to 200 ppm, or 20 ppm to 190 ppm, preferably 30 ppm to 180 ppm, based on the total weight of the dimethyl aromatic compound and the solvent.
The total amount of cobalt and manganese is 1,000 ppm or less, or 900 ppm or less, preferably 800 ppm or less, based on the total weight of the dimethyl aromatic compound and the solvent.
Bromine is present in an amount of 800 ppm or less, or 600 ppm or less, preferably 400 ppm or less, based on the total weight of the dimethyl aromatic compound and the solvent, and the molar ratio of bromine to cobalt and manganese is 0.3: 1. A reaction mixture ranging from 3: 1 or 0.3: 1 to 2: 1, preferably 0.3: 1 to 1: 1.

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