Processes for preparing aldaric, aldonic and uronic acids

Abstract

To provide processes for preparing glucaric acid and / or lactones thereof.SOLUTION: Various processes for preparing aldaric acids, aldonic acids, uronic acids, and / or lactones thereof are described. For example, processes for preparing a C2-C7 aldaric acid and / or lactones thereof by the catalytic oxidation of a C2-C7 aldonic acid and / or lactones thereof and / or a C2-C7 aldose are described.SELECTED DRAWING: None

Description

Technical Field

[0001]

[0001] Various methods for preparing aldonic acids, aldonolactones, uronic acids, and / or their lactones are described. For example, C 2 ~C 7 aldonic acids and / or their lactones and / or C 2 ~C 7 By catalytic oxidation of aldoses, C 2 ~C 7 Methods for preparing aldonic acids and / or their lactones are described.

Background Art

[0002]

[0002] For many years, there has been interest in using biorenewable materials as raw materials for manufacturing commercially useful chemicals. In particular, a significant body of research has focused on the oxidation of sugars obtained from these materials to aldonic acids, particularly the oxidation of glucose to glucaric acid. See, for example, U.S. Pat. Nos. 8,669,397 and 8,785,683, which are incorporated herein by reference. These products are useful not only as intermediates in the manufacture of monomers such as adipic acid, but also in the manufacture of compositions having commercial applications such as thawing fluids, acidulants, detergent builders, pH regulators, chelating agents, descaling agents, corrosion inhibitors, metal cleaning and finishing agents, and components of cement formulations.

[0003] [

[0003] ] Many catalysts and reaction conditions for these oxidation processes have been attempted. However, a consistently high yield of glucaric acid over long-term operation or at high reactor throughputs has not been demonstrated. For example, in Lee et al., “Pt catalysts for efficient aerobic oxidation of glucose to glucaric acid in water”, Green Chemistry 2016, 18(13), 3815 - 3822, a 74% glucaric acid yield was reported for the oxidation of a 5 wt% glucose feedstock with a 5 wt% Pt / C catalyst in a batch reactor for 10 hours at 80 °C and an O 2 partial pressure of about 200 psi. In U.S. Patent No. 9,770,705, a 70% glucaric acid yield was reported for an experiment in which 2.3 mL of a 10 wt% gluconic acid feedstock was contacted with 75 mg of catalyst at 112 - 126 °C for 2 - 5 hours. In particular, there is still a need for an efficient and cost-effective process for preparing aldaric acids such as glucaric acid, and intermediates thereof, from bioreproducible materials that exhibits improved and stable yields over long-term operation and at high reactor throughputs.

Summary of the Invention

Means for Solving the Problems

[0004] [

[0004] ] Various aspects of the present invention relate to methods for preparing aldaric acids (e.g., glucaric acid) and / or lactones thereof.

[0005] [

[0005] ] In one embodiment, a method for preparing an aldaric acid (e.g., glucaric acid) and / or lactone thereof is represented by formula (II): HOCH 2 (HCOH) x COOH (II) (wherein x is an integer from 0 to 10) of aldonic acid (e.g., gluconic acid) and / or its lactone is reacted in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing aldonic acid of formula (IV) and / or its lactone, wherein the first catalyst is different from the second catalyst, and the aldonic acid and / or its lactone has the formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer from 0 to 10).

[0006]

[0006] In a particular embodiment, a method for preparing aldonic acid (e.g., glucaric acid) is represented by formula (II): HOCH 2 (HCOH) x COOH (II) (wherein x is an integer from 0 to 10) of aldonic acid (e.g., gluconic acid) and / or its lactone is reacted in the first stage of the reaction zone in the presence of oxygen and a first catalyst containing platinum to form a first reaction mixture; and the first reaction mixture is contacted with oxygen and a second catalyst containing gold in the second stage of the reaction zone to form a second reaction mixture containing aldonic acid of formula (IV) and / or its lactone, wherein the first catalyst is different from the second catalyst, and the aldonic acid and / or its lactone has the formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer from 0 to 10).

[0007]

[0007] In a further embodiment, a method for preparing aldonic acid (e.g., glucaric acid) and / or its lactone is represented by formula (III): HOOC(HCOH) y CHO (III) (In the formula, y is an integer from 0 to 10) of uronic acid (for example, glucuronic acid) and / or its lactone is reacted in a reaction region in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing the aldic acid of formula (IV) and / or its lactone, where the first catalyst is different from the second catalyst, and the aldic acid and / or its lactone is of formula (IV): HOOC(HCOH) z COOH (IV) (In the formula, z is an integer from 0 to 10).

[0008]

[0008] In a further embodiment, the method for preparing an aldic acid (for example, glucaric acid) and / or its lactone is of formula (I): HOCH 2 (HCOH) w CHO (I) (In the formula, w is an integer from 0 to 10) of aldose (for example, glucose) and / or its lactone is reacted in a reaction region containing an oxidation catalyst, a first catalyst containing platinum, and a second catalyst containing gold in the presence of oxygen to form a reaction mixture containing the aldic acid of formula (IV) and / or its lactone, where the first catalyst is different from the second catalyst, and the aldic acid is of formula (IV): HOOC(HCOH) z COOH (IV) (In the formula, z is an integer from 0 to 10).

[0009]

[0009] A further aspect of the present invention relates to a method for preparing uronic acid (for example, glucuronic acid) and / or its lactone.

[0010]

[0010] In one embodiment, the method for preparing uronic acid (for example, glucuronic acid) and / or its lactone is of formula (I): HOCH 2 (HCOH) w CHO (I) (wherein, w is an integer from 0 to 10) of an aldose (for example, glucose) and / or its lactone is reacted in a reaction zone in the presence of oxygen, an oxidation catalyst, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing the uronic acid of formula (III) and / or its lactone, wherein the first catalyst is different from the second catalyst, and the uronic acid has the formula (III): HOOC(HCOH) y CHO (III) (wherein, y is an integer from 0 to 10).

[0011]

[0011] In another embodiment, a method for preparing a uronic acid (for example, guluronic acid) and / or its lactone is a compound of formula (II): HOCH 2 (HCOH) x COOH (II) (wherein, x is an integer from 0 to 10) of an aldonic acid (for example, gluconic acid) and / or its lactone is reacted in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing the uronic acid of formula (III) and / or its lactone, wherein the first catalyst is different from the second catalyst, and the uronic acid has the formula (III): HOOC(HCOH) y CHO (III) (wherein, y is an integer from 0 to 10).

[0012]

[0012] Another aspect of the present invention relates to a method for preparing an aldonic acid (for example, gluconic acid) and / or its lactone. In various embodiments, a method for preparing an aldonic acid (for example, gluconic acid) and / or its lactone is a compound of formula (I): HOCH 2 (HCOH) w CHO (I) An aldose (e.g., glucose) of (wherein, w is an integer from 0 to 10) and / or its lactone are reacted in the presence of oxygen and an oxidation catalyst to form a reaction mixture containing an aldonic acid of formula (II) and / or its lactone, wherein the aldonic acid has the formula (II): HOCH 2 (HCOH) x COOH (II) (wherein, x is an integer from 0 to 10).

[0013]

[0013] Other objects and features will become apparent in part and will be pointed out in part hereinafter.

Brief Description of the Drawings

[0014]

Figure 1

[0014] A diagram showing the steps of an oxidation process for preparing C2 - C7 aldonic acids and / or their lactones from C2 - C7 aldoses is shown.

Figure 2

[0015] A schematic diagram of a two - stage reaction zone is shown.

Figure 3

[0016] A schematic diagram of a two - stage reaction zone containing different catalyst mixtures is shown.

Figure 4

[0017] Glucose conversion rate, gluconic acid yield, and glucaric acid yield at an operating time of 16 - 1792 hours in an oxidation reaction using a 1 wt% Au / TiO2 catalyst are shown.

Figure 5

[0018] Glucose conversion rate, gluconic acid yield, and glucaric acid yield at an operating time of 2556 - 4640 hours in an oxidation reaction using a 1 wt% Au / TiO2 catalyst are shown.

Figure 6

[0019] Gluconic acid conversion rate, selectivity, and yields of glucaric acid, guluronic acid, 2 - keto - gluconate, and 5 - keto - gluconate achieved during oxidation reactions at various temperatures using a 4 wt% Pt / C catalyst are shown.

Figure 7

[0020] Shows the glucose conversion rate, on-path yield, and yields of glucaric acid, gluconic acid, 2-keto-gluconate, and 5-keto-gluconate in the oxidation of glucose using a Pt-Au / TiO₂ catalyst.

Figure 8

[0021] Shows the gluconic acid conversion rate and yields of glucaric acid, guluronic acid, 2-keto-gluconate, and 5-keto-gluconate in the oxidation of gluconic acid using a physical mixture of 4 wt% Pt / C and 1 wt% Au / TiO₂ catalyst.

Figure 9

[0022] Shows the gluconic acid conversion rate and yields of glucaric acid, guluronic acid, 2-keto-gluconate, and 5-keto-gluconate in the oxidation of gluconic acid using a staged reactor bed containing a physical mixture of Pt / C and Au / TiO₂ catalysts.

Figure 10

[0023] Shows the gluconic acid conversion rate, selectivity, and yields of glucaric acid, guluronic acid, 2-keto-gluconate, and 5-keto-gluconate in the oxidation of gluconic acid using a physical mixture of 4 wt% Pt / C and 1 wt% Au / TiO₂ catalyst.

Figure 11

[0024] Shows the results of the experiment in FIG. 10 conducted for a total operating time of 1468 hours.

Figure 12

[0025] Shows the arabinose conversion rate, arabinonic acid yield, and arabinalic acid yield measured in Example 7.

Figure 13

[0026] Shows the arabinonic acid conversion rate, arabinalic acid yield, tartaric acid yield, and glyceric acid yield measured in Example 8.

Figure 14

[0027] Shows the glyceric acid yield measured in Example 9.

Figure 15

[0028] Shows the glycolaldehyde conversion rate and glycolic acid yield measured in Example 11.

Mode for Carrying Out the Invention

[0015] Detailed Description

[0029] Embodiments of the present invention relate to various methods for preparing aldonic acids, aldonolactones, uronic acids, and / or lactones of any of these acids. For example, various embodiments relate to C 2 ~C 7 the catalytic oxidation of aldonic acids and / or their lactones (e.g., gluconic acid) to prepare C 2 ~C 7 aldonic acids and / or their lactones (e.g., glucaric acid). Other embodiments relate to C 2 ~C 7 the catalytic oxidation of aldonic acids and / or their lactones (e.g., gluconic acid) to prepare C 2 ~C 7 uronic acids and / or their lactones (e.g., guluronic acid). Further embodiments relate to the preparation of these various acids and / or their lactones from aldoses (e.g., glucose).

[0016]

[0030] Aldoses as referred to herein include various compounds having an aldehyde group and a hydroxyl group, which can be represented by formula (I): HOCH 2 (HCOH) w CHO (I) (wherein w can be, for example, an integer from 0 to 10, or in certain embodiments, from 0 to 5). In various embodiments, the aldose contains at least one C 2 ~C 7 aldose. In certain embodiments, the aldose contains at least one triose, tetrose, pentose, hexose, and / or heptose. Specific C 2 ~C 7Examples of aldoses include glycolaldehyde, glyceraldehyde, threose, erythrose, xylose, ribose, arabinose, glucose, galactose, mannose, glucoheptose, and L-glycero-D-mannoheptose. In various embodiments, the aldose includes hexoses such as glucose. In certain embodiments, the aldose includes pentoses such as xylose, ribose, and / or arabinose. The term "aldose" and any particular aldose described herein and defined by formula (I) also include the cyclic forms (hemiacetal forms) of these compounds.

[0017]

[0031] Aldoses can be obtained from various carbohydrate-containing sources, including conventional bio-renewable resources such as maize (corn) kernels, wheat, potatoes, cassava, and rice, as well as alternative sources such as energy crops, plant biomass, agricultural waste, forest residues, sugar processing residues, and plant-derived household waste. In various embodiments, the aldose (e.g., glucose) is obtained from cereal crops (e.g., maize, wheat, soybeans, rice, barley, rye, millet, sorghum, etc.). More generally, bio-renewable resources that can be used include any renewable organic matter containing a carbohydrate source, such as switchgrass, miscanthus, trees (hardwood and softwood), vegetation, and crop residues (e.g., bagasse and corn stover). Other sources include, for example, waste (e.g., used paper, green waste, municipal waste, etc.). Carbohydrates can be isolated from bio-renewable materials using known methods.

[0018]

[0032] The aldonic acids referred to herein have the formula (II): HOCH 2 (HCOH) x COOH (II) Examples of the monocarboxylic acid of (wherein x can be an integer from 0 to 10, and in certain embodiments, is from 0 to 5) include. In various embodiments, the aldonic acid has at least one C 2 ~C 7 aldonic acid. In certain embodiments, the aldonic acid includes at least one dionic acid, trionic acid, tetronic acid, pentonic acid, hexonic acid, and / or heptonic acid. Specific C 2 ~C 7 Examples of aldonic acids include glycolic acid, glyceric acid, threonic acid, erythronic acid, xylonic acid, ribonic acid, arabinonic acid, lyxonic acid, allonic acid, altroonic acid, mannonic acid, gluconic acid, galactonic acid, talonic acid, glucoheptonic acid, and the like. In various embodiments, C 2 ~C 7 aldonic acid includes hexonic acids such as gluconic acid. In certain embodiments, C 2 ~C 7 aldonic acid includes pentonic acid. For example, pentonic acid can be selected from the group consisting of xylonic acid, ribonic acid, arabinonic acid, and mixtures thereof. Lactones of various aldonic acids may also exist and can be formed by intramolecular cyclocondensation of the acid.

[0019]

[0033] Examples of the uronic acid when referred to herein include formula (III): HOOC(HCOH) y CHO (III) Examples of the monocarboxylic acid of (wherein y can be an integer from 0 to 10, and in certain embodiments, is from 0 to 5) include. In various embodiments, the uronic acid has at least one C 2 ~C 7It contains uronic acid. In certain embodiments, the uronic acid comprises at least one diuronic acid, triuronic acid, tetruronic acid, penturonic acid, hexuronic acid, and / or hepturonic acid. Specific C 2 ~C 7 Examples of uronic acids include glyoxylic acid, glyceruronic acid (tartronic aldehyde acid), treuronic acid, erythrulonic acid, xylouronic acid, ribouronic acid, arabinouronic acid, lyxonuronic acid, guluronic acid, glucuronic acid, galactouronic acid, mannouronic acid, alluronic acid, alturonic acid, iduronic acid, talonuronic acid, and glucoheptonuronic acid. In various embodiments, the uronic acid comprises a hexuronic acid such as guluronic acid. In certain embodiments, the uronic acid comprises a penturonic acid such as xylouronic acid, ribouronic acid, and / or arabinouronic acid. Lactones of various uronic acids may also exist and can be formed by intramolecular cyclocondensation of the acid. Also, the term "uronic acid" and any specific uronic acid described herein and defined by formula (III) include the cyclic forms (hemiacetal forms) of these compounds.

[0020]

[0034] Aldaric acids referred to herein include formula (IV): HOOC(HCOH) z COOH (IV) (wherein z can be, for example, an integer from 0 to 10, and in certain embodiments, from 0 to 5) of dicarboxylic acids. In various embodiments, the aldaric acid comprises at least one C 2 ~C 7It contains aldic acid. In certain embodiments, the aldic acid comprises at least one diaric acid, triaric acid, tetraric acid, pentaric acid, hexaric acid, and / or heptaric acid. Specific C 2 ~C 7 Examples of aldic acids include oxalic acid, tartronic acid, tartaric acid, xylaric acid, ribaric acid, arabinaric acid, lyxaric acid, allaric acid, altaric acid, glucaric acid, galactaric acid, mannaroic acid, gularoic acid, idaric acid, talaric acid, and glucoheptaric acid. In certain embodiments, C 2 ~C 7 The aldic acid contains hexaric acid and / or pentaric acid. In various embodiments, C 2 ~C 7 The aldic acid contains glucaric acid. In further embodiments, C 2 ~C 7 The aldic acid contains pentaric acid selected from the group consisting of xylaric acid, ribaric acid, arabinaric acid, and mixtures thereof. Lactones of various aldic acids may also exist and can be formed by intramolecular cyclocondensation of the acid. For example, lactones include glucarolactones such as D-glucaro-1,4-lactone, D-glucaro-6,3-lactone, and D-glucaro-1,4:6,3-dilactone.

[0021]

[0035] According to the present invention, the various methods described herein provide improved yields of uronic acids, aldonic acids, and aldaric acids, particularly improved yields of aldaric acids (e.g., improved yields of glucaric acid). Further, the various methods described herein provide stable product yields over long-term operation and / or at high reactor throughput. These methods can advantageously improve process economics by reducing the amount of off-path products that may require separation from the product mixture and / or by reducing the amount of on-path intermediates that require further processing.

[0022]

[0036] The preparation of aldaric acids and / or lactones and / or aldaric acids from aldonic acids and / or lactones and / or the corresponding aldoses is typically a multi-step synthesis that proceeds through various intermediates. For example, as shown in the following scheme, the oxidation of glucose to glucaric acid proceeds primarily through two intermediates: gluconic acid and glucuronic acid.

Chemical formula

[0023]

[0037] Previously reported glucaric acid yields (e.g., rarely exceeding 70% yield) can be limited by several factors. Some potential limiting factors include the formation of on-path or off-path products that significantly reduce catalyst effectiveness, over-conversion of glucaric acid, and leaching of the catalytically active metal. Also, without pH adjustment by the continuous introduction of a base during the oxidation reaction, the rate of glucaric acid formation decreases as the pH decreases. On the other hand, pH adjustment often causes the degradation of glucaric acid at C 2 ~C 5Excessive conversion to the sugar acid derivative results in a lower glucaric acid yield. Thus, several inhibitory factors, individually or in combination, can cause the overall yield to glucaric acid to be limited.

[0024]

[0038] In a method for preparing an aldaro acid and / or its lactone and / or its intermediate by catalytic oxidation of an aldose, an aldonic acid and / or its lactone, and / or a uronic acid and / or its lactone, it has surprisingly been found that using at least two different catalysts provides improved product yields (e.g., aldaro acid yield) even over long-term operation. It is theorized that using at least two different catalysts reduces or avoids some of the inhibitory factors that would be expected to limit the overall yield. In particular, a first catalyst containing platinum and a second catalyst containing gold are effective for the catalytic oxidation of C 2 ~C 7 aldose, C 2 ~C 7 uronic acid and / or its lactone, and C 2 ~C 7 to the corresponding aldaro acid and / or its lactone or its intermediate of an aldaro acid and / or its lactone.

[0025] Method for producing an aldaro acid and / or its lactone

[0039] As described above, embodiments of the present invention include an oxidation process for producing an aldaro acid and / or its lactone. Various methods include reacting an aldose of formula (I) with oxygen, a first catalyst containing platinum, and a second catalyst containing gold in the presence of an aldaro acid of formula (IV) and / or its lactone to form an aldaro acid and / or its lactone, where the first catalyst and the second catalyst are different. These methods can be represented by the following scheme (where w and z are as defined herein):

Chemical formula

[0026]

[0040] In one embodiment, C 2 ~C 7 reacting an aldose in a reaction zone containing an oxidation catalyst, a first catalyst containing platinum, and a second catalyst containing gold in the presence of oxygen to form a reaction mixture containing C 2 ~C 7 an aldonic acid and / or its lactone, C 2 ~C 7 relates to a method for preparing an aldonic acid and / or its lactone, wherein the first catalyst and the second catalyst are different. For example, if the method is a method for preparing glucaric acid and / or its lactone, the method may include reacting glucose in a reaction zone containing an oxidation catalyst, a first catalyst containing platinum, and a second catalyst containing gold in the presence of oxygen to form a reaction mixture containing glucaric acid and / or its lactone, wherein the first catalyst and the second catalyst are different. FIG. 1 shows C 2 ~C 7 from aldose to C 2 ~C 7 shows a diagram showing the steps of an oxidation method for preparing an aldonic acid and / or its lactone.

[0027]

[0041] Another method involves reacting an aldonic acid and / or its lactone of formula (II) in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form an aldonic acid and / or its lactone, including preparing an aldonic acid and / or its lactone of formula (IV), wherein the first catalyst and the second catalyst are different. These methods can be represented by the following scheme (where x and z are as defined herein): [Chemical formula] In one embodiment, C 2 ~C 7 The method for preparing an aldonic acid and / or its lactone is C 2 ~C 7 reacting an aldonic acid and / or its lactone in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form C 2~C 7 Forming a reaction mixture comprising an aldonic acid and / or its lactone, wherein the first catalyst and the second catalyst are different. For example, if the method relates to the preparation of glucaric acid and / or its lactone, the method may comprise reacting gluconic acid and / or its lactone in a reaction zone in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form a reaction mixture comprising glucaric acid and / or its lactone, wherein the first catalyst and the second catalyst are different.

[0028]

[0042] Embodiments of the invention also include a method for preparing an aldonic acid and / or its lactone of formula (IV), comprising reacting an uronic acid and / or its lactone of formula (III) in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form an aldonic acid and / or lactone, wherein the first catalyst and the second catalyst are different. These methods can be represented by the following scheme (where y and z are as defined herein):

Chemical formula

[0029] Method for producing uronic acid and / or its lactone

[0043] Embodiments of the present invention also include methods for producing uronic acid and / or lactone. Various methods include reacting an aldose of formula (I) in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form uronic acid and / or its lactone, including the preparation of uronic acid and / or its lactone of formula (III), where the first catalyst and the second catalyst are different. These methods can be represented by the following scheme (where w and y are as defined herein): [Chemical formula] In certain embodiments, C 2 ~C 7 A method for preparing uronic acid and / or its lactone is to react C 2 ~C 7 an aldose in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form C 2 ~C 7 a reaction mixture containing uronic acid and / or lactone, where the first catalyst and the second catalyst are different. For example, a method for preparing guluronic acid and / or its lactone may include reacting glucose in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing guluronic acid and / or lactone, where the first catalyst and the second catalyst are different.

[0030]

[0044] Embodiments of the present invention also include methods for preparing uronic acid and / or its lactone, which include reacting aldonic acid and / or its lactone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form uronic acid and / or its lactone, where the first catalyst and the second catalyst are different. These methods can be represented by the following scheme (where x and y are as defined herein): [Chemical formula] In one embodiment, C 2 ~C 7 A method for preparing uronic acid and / or its lactone is C 2 ~C 7 Reacting an aldonic acid and / or its lactone in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to C 2 ~C 7 Forming a reaction mixture containing uronic acid and / or lactone, where the first catalyst and the second catalyst are different. For example, a method for preparing guluronic acid and / or its lactone may include reacting gluconic acid and / or its lactone in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing guluronic acid and / or lactone, where the first catalyst and the second catalyst are different.

[0031] Method for producing aldonic acid and / or its lactone

[0045] Embodiments of the present invention also include a method for producing aldonic acid and / or lactone. Various methods include reacting an aldose of formula (I) in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to an aldonic acid of formula (II) and / or its lactone to form aldonic acid and / or its lactone, where the first catalyst and the second catalyst are different. These methods can be represented by the following scheme (where x and y are as defined herein):

Chemical formula

[0032]

[0046] The various methods described herein may further include reacting an aldose of formula (I) in the presence of oxygen and an oxidation catalyst to form an aldonic acid of formula (II) and / or its lactone. This further process step may be represented by the following scheme (where w and x are as defined herein):

Chemical formula

[0033] Further processes and process features

[0047] In the various methods described herein, the first catalyst and the second catalyst may be mixed. In other words, the reaction zone may contain a mixture (e.g., a physical mixture) of the first catalyst and the second catalyst.

[0034]

[0048] Further, in the various methods described herein, the first catalyst and the second catalyst can be stepwise, or can be in a combined state of being mixed and stepwise. For example, the reaction region can include a first stage containing the first catalyst and a second stage containing the second catalyst. See Figure 2, which is a schematic diagram of a two-stage reaction region. Various stepwise methods for preparing the aldonic acid of formula (IV) and / or its lactone by oxidizing the aldonic acid of formula (II) can be represented by the following scheme (where x, y, and z are as defined herein):

Chemical formula

[0035]

[0049] In various embodiments including the first stage and / or the second stage, the first stage may include a mixture of a first catalyst and a second catalyst. In certain embodiments, in the first stage, the weight or volume of the first catalyst may exceed the weight or volume of the second catalyst. For example, in various embodiments, the first stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the first catalyst to the second catalyst is about 2:1 or more, about 3:1 or more, or about 4:1 or more. In certain embodiments, the first stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the first catalyst to the second catalyst may be from about 2:1 to about 10:1, from about 2:1 to about 5:1, from about 3:1 to about 10:1, or from about 3:1 to about 5:1.

[0036]

[0050] In embodiments including the first stage and the second stage, the second stage may include a mixture of a first catalyst and a second catalyst. In certain embodiments, the weight or volume of the second catalyst may exceed the weight or volume of the first catalyst. For example, in various embodiments, the second stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the second catalyst to the first catalyst is about 2:1 or more, about 3:1 or more, or about 4:1 or more. For example, the second stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the second catalyst to the first catalyst may be from about 2:1 to about 10:1, from about 2:1 to about 5:1, from about 3:1 to about 10:1, or from about 3:1 to about 5:1.

[0037]

[0051] In various embodiments, the first stage and the second stage include a mixture of a first catalyst and a second catalyst. These stages may include different mixtures of the first and second catalysts including the mixtures described above. FIG. 3 shows a schematic diagram of a two-stage reaction zone including different catalyst mixtures.

[0038]

[0052] As described above, the various methods described herein may further include reacting an aldose in the presence of oxygen and an oxidation catalyst to form an aldonic acid and / or its lactone. In these embodiments, the oxidation catalyst, the first catalyst, and the second catalyst may be similarly staged. For example, in certain embodiments, the reaction zone may include an initial oxidation stage including an oxidation catalyst, a first stage including a first catalyst, and a second stage including a second catalyst.

[0039]

[0053] In the various methods described herein, the volume ratio of the total amount of the first catalyst to the second catalyst in the reaction zone is from about 1:10 to about 10:1, from about 1:5 to about 5:1, from about 1:3 to about 3:1, or about 1:1. In further embodiments, the weight or volume ratio of the total amount of the first catalyst to the second catalyst in the reaction zone is from about 1:10 to about 10:1, from about 1:5 to about 5:1, from about 1:3 to about 3:1, or about 1:1.

[0040]

[0054] In the various methods described herein, a raw material mixture (e.g., a raw material solution) can be supplied to the reaction zone. In certain embodiments, the concentration of aldose, aldonic acid and / or lactone, and / or uronic acid and / or its lactone in the raw material mixture is about 1 wt% or more, about 5 wt% or more, about 10 wt% or more, about 15 wt% or more, or about 20 wt% or more. In certain embodiments, the raw material mixture is supplied to the reaction zone, and the concentration of aldose, aldonic acid and / or lactone, and / or uronic acid and / or its lactone in the raw material mixture is from about 1 wt% to about 50 wt%, from about 1 wt% to about 30 wt%, from about 1 wt% to about 25 wt%, from about 5 wt% to about 50 wt%, from about 5 wt% to about 30 wt%, from about 5 wt% to about 25 wt%, from about 10 wt% to about 50 wt%, from about 10 wt% to about 30 wt%, from about 10 wt% to about 25 wt%, from about 15 wt% to about 50 wt%, from about 15 wt% to about 30 wt%, from about 15 wt% to about 25 wt%, from about 20 wt% to about 50 wt%, from about 20 wt% to about 30 wt%, or from about 20 wt% to about 25 wt%.

[0041]

[0055] In various embodiments, C in the raw material mixture 2~C 7 Aldose, C 2 ~C 7 Aldonic acid and / or lactone, and / or C 2 ~C 7 The concentration of uronic acid and / or its lactone is about 1 wt% or more, about 5 wt% or more, about 10 wt% or more, about 15 wt% or more, or about 20 wt% or more. In certain embodiments, the feed mixture is supplied to the reaction zone, and C in the feed mixture 2 ~C 7 Aldose, C 2 ~C 7 Aldonic acid, and / or lactone and C 2 ~C 7 The concentration of uronic acid and / or its lactone is about 1 wt% to about 50 wt%, about 1 wt% to about 30 wt%, about 1 wt% to about 25 wt%, about 5 wt% to about 50 wt%, about 5 wt% to about 30 wt%, about 5 wt% to about 25 wt%, about 10 wt% to about 50 wt%, about 10 wt% to about 30 wt%, about 10 wt% to about 25 wt%, about 15 wt% to about 50 wt%, about 15 wt% to about 30 wt%, about 15 wt% to about 25 wt%, about 20 wt% to about 50 wt%, about 20 wt% to about 30 wt%, or about 20 wt% to about 25 wt%.

[0042]

[0056] C 2 ~C 7In embodiments where the aldonic acid and / or lactone comprises gluconic acid and / or its lactone, the feed mixture can be supplied to the reaction zone, and the concentration of gluconic acid and / or lactone in the feed mixture can be about 1 wt% or more, about 5 wt% or more, about 10 wt% or more, about 15 wt% or more, or about 20 wt% or more. In certain embodiments, the feed mixture is supplied to the reaction zone, and the concentration of gluconic acid and / or lactone in the feed mixture is about 1 wt% to about 50 wt%, about 1 wt% to about 30 wt%, about 1 wt% to about 25 wt%, about 5 wt% to about 50 wt%, about 5 wt% to about 30 wt%, about 5 wt% to about 25 wt%, about 10 wt% to about 50 wt%, about 10 wt% to about 30 wt%, about 10 wt% to about 25 wt%, about 15 wt% to about 50 wt%, about 15 wt% to about 30 wt%, about 15 wt% to about 25 wt%, about 20 wt% to about 50 wt%, about 20 wt% to about 30 wt%, or about 20 wt% to about 25 wt%.

[0043]

[0057] As noted above, pH adjustment typically results in lower product yields due to over-conversion of the aldonic acid to other derivatives. Thus, in various embodiments, the methods described herein can be performed without adding a base. In further embodiments, processes can be performed in which the pH of the reaction mixture is not controlled or increased by the addition of a base. In certain embodiments, processes can be performed in which the reaction mixture does not contain or substantially does not contain salt-forming cations.

[0044]

[0058] In various embodiments, the pH of the reaction mixture of the methods described herein, as measured at 20 °C, is about 7 or less, about 6.5 or less, about 6 or less, about 5 or less, about 4 or less, about 3 or less, or about 2 or less. For example, the pH of the reaction mixture of the methods described herein, as measured at 20 °C, can be about 1 to about 7, about 1 to about 6, about 1 to about 5, about 1 to about 4, about 1.5 to about 7, about 1.5 to about 6, about 1.5 to about 5, about 1.5 to about 4, about 2 to about 7, about 2 to about 6, about 2 to about 5, or about 2 to about 4. In certain embodiments, the reaction mixture can reach a minimum pH, as measured at 20 °C, of about 4 or less, about 3 or less, or about 2 or less.

[0045]

[0059] In certain embodiments, the reaction zone is heated to a temperature of about 60 °C or greater, about 70 °C or greater, or about 80 °C or greater. For example, the reaction zone can be heated to a temperature of about 60 °C to about 150 °C, about 70 °C to about 150 °C, about 80 °C to about 150 °C, about 60 °C to about 125 °C, about 70 °C to about 125 °C, about 80 °C to about 125 °C, about 60 °C to about 100 °C, about 70 °C to about 100 °C, or about 80 °C to about 100 °C.

[0046]

[0060] In certain embodiments, oxygen is supplied to the reaction zone as an oxygen-containing gaseous mixture. For example, in some embodiments, oxygen is supplied to the reaction zone as air, oxygen-enriched air, a mixture containing oxygen, a mixture containing at least about 40 or 50 volume % oxygen, a mixture containing oxygen and nitrogen (e.g., a ~50:50 mixture on a volume basis), or substantially pure oxygen (at least 99 volume % oxygen). In various embodiments, oxygen is supplied to the reaction zone as a mixture having an oxygen concentration of about 0.5 volume % or greater, about 1 volume % or greater, about 5 volume % or greater, or about 10 volume % or greater. For example, in various embodiments, oxygen is supplied to the reaction zone as a mixture having an oxygen concentration of about 0.5 volume % to about 20 volume %, about 0.5 volume % to about 15 volume %, about 0.5 volume % to about 10 volume %, about 0.5 volume % to about 5 volume %, about 1 volume % to about 20 volume %, about 1 volume % to about 15 volume %, about 1 volume % to about 10 volume %, about 1 volume % to about 5 volume %, about 5 volume % to about 20 volume %, about 5 volume % to about 15 volume %, or about 5 volume % to about 10 volume %. In certain embodiments, oxygen is supplied to the reaction zone as a mixture having an oxygen concentration of about 10 volume % or less, about 5 volume % or less, about 4 volume % or less, about 3 volume % or less, about 2 volume % or less, about 1 volume % or less, or about 0.5 volume % or less. For example, it is about 10 volume % to about 0.5 volume %, about 5 volume % to about 0.5 volume %, about 4 volume % to about 0.5 volume %, about 3 volume % to about 0.5 volume %, about 2 volume % to about 0.5 volume %, or about 1 volume % to about 0.5 volume %.

[0047]

[0061] In various embodiments, the partial pressure of oxygen in the reaction zone is about 2 psig or greater, about 25 psig or greater, about 50 psig or greater, or about 100 psig or greater. For example, the partial pressure of oxygen in the reaction zone can be from about 2 psig to about 2000 psig, from about 50 psig to about 2000 psig, or from about 100 psig to about 2000 psig.

[0048]

[0062] Generally, the methods described herein are catalytic processes and do not require the application of an electric current. Thus, in various embodiments, the methods described herein are not electrochemical methods and / or do not include applying an electric current (e.g., via an electrode) to the reaction mixture.

[0049]

[0063] As noted above, the methods of the present invention can provide improved product yields. In certain embodiments, the yield of aldonic acid and / or its lactone, uronic acid and / or its lactone, and / or aldaric acid and / or its lactone is about 50% or greater, about 55% or greater, about 60% or greater, about 65% or greater, about 70% or greater, or about 75% or greater. For example, the yield of aldonic acid and / or its lactone, uronic acid and / or its lactone, and / or aldaric acid and / or its lactone can be from about 50% to about 85%, from about 50% to about 80%, from about 50% to about 75%, from about 50% to about 70%, from about 50% to about 65%, from about 60% to about 85%, from about 60% to about 80%, from about 60% to about 75%, from about 60% to about 70%, from about 65% to about 85%, from about 65% to about 80%, from about 65% to about 75%, or from about 65% to about 70%.

[0050]

[0064] In certain embodiments, C 2 ~C 7 aldonic acid and / or its lactone, C 2 ~C 7 uronic acid and / or its lactone, and / or C 2 ~C 7 aldaric acid and / or its lactone has a yield of about 50% or greater, about 55% or greater, about 60% or greater, about 65% or greater, about 70% or greater, or about 75% or greater. For example, C 2~C 7 Aldonic acid and / or its lactone, C 2 ~C 7 Uronic acid and / or its lactone, and / or C 2 ~C 7 The yield of aldic acid and / or its lactone can be about 50% to about 85%, about 50% to about 80%, about 50% to about 75%, about 50% to about 70%, about 50% to about 65%, about 60% to about 85%, about 60% to about 80%, about 60% to about 75%, about 60% to about 70%, about 65% to about 85%, about 65% to about 80%, about 65% to about 75%, or about 65% to about 70%.

[0051]

[0065] C 2 ~C 7 In embodiments where the aldic acid and / or lactone contains glucaric acid and / or its lactone, the yield of glucaric acid and / or its lactone can be about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more. In various embodiments, the yield of glucaric acid and / or its lactone can be about 50% to about 85%, about 50% to about 80%, about 50% to about 75%, about 50% to about 70%, about 50% to about 65%, about 60% to about 85%, about 60% to about 80%, about 60% to about 75%, about 60% to about 70%, about 65% to about 85%, about 65% to about 80%, about 65% to about 75%, or about 65% to about 70%.

[0052]

[0066] Further, the method of the present invention can provide a stable yield even at a high reactor throughput. In certain embodiments, the liquid hourly space velocity (LHSV) of the reaction zone is about 0.2 h -1 or more, about 0.5 h -1 or more, about 1 h -1 or more, about 1.5 h -1 or more, about 2 h -1 or more, about 5 h -1 or more, or about 10 h -1 or more. For example, the LHSV of the reaction zone is about 0.2 h -1 to about 50 h -1 , about 0.5 h -1 to about 50 h-1 and about 1 h -1 to about 50 h -1 and about 2 h -1 to about 50 h -1 and about 5 h -1 to about 50 h -1 and about 10 h -1 to about 50 h -1 and about 0.2 h -1 to about 10 h -1 and about 0.5 h -1 to about 10 h -1 and about 1 h -1 to about 10 h -1 and about 2 h -1 to about 10 h -1 or about 5 h -1 to about 10 h -1 and may be. In certain embodiments, at least about 60%, at least about 65%, at least about 70%, or at least about 75% product yield (e.g., C 2 ~C 7 aldaric acid, such as glucaric acid, and / or the yield of its lactone) can be achieved within or within the above LHSV range.

[0053]

[0067] The reaction mixture and / or feed mixture may contain a solvent. Suitable solvents for the oxidation reaction include, for example, water or an aqueous solution of a carboxylic acid (e.g., acetic acid).

[0054]

[0068] Generally, the reaction zone may include one or more batch, semi-batch, or continuous reactor designs using a fixed bed reactor, trickle bed reactors, slurry phase reactors, moving bed reactors, or any other design that allows for catalytic reactions, particularly heterogeneous catalytic reactions. Examples of reactors can be found in Chemical Process Equipment - Selection and Design, Couper et al., Elsevier 1990, which is incorporated herein by reference. In the various methods described herein, the reaction zone includes one or more trickle bed reactors. It should be understood that the reactants, oxygen, any solvent, and the catalyst can be introduced separately or in various combinations into a suitable reactor.

[0055]

[0069] Aldaric acids, aldonic acids, and uronic acids and / or their lactones produced according to the methods described herein can be converted into various other derivatives such as salts, esters, ketones, and lactones. Methods for converting carboxylic acids into such derivatives are known in the art and are described, for example, in Wade, Organic Chemistry 3 rd ed., Prentice Hall 1995.

[0056] Catalyst

[0070] As noted above, one catalyst effective in the oxidation processes described herein contains platinum (i.e., the first catalyst contains platinum). This catalyst has been found to be particularly useful for the oxidation of aldonic acids and / or their lactones (e.g., gluconic acid) to uronic acids and / or their lactones (e.g., guluronic acid).

[0057]

[0071] In certain embodiments, the first catalyst has a platinum loading of about 10 wt% or less, about 7.5 wt% or less, about 5 wt% or less, about 4 wt% or less, about 2 wt% or less, or about 1 wt% or less. In these and other embodiments, the first catalyst has a platinum loading of about 0.1 wt% or more, about 0.25 wt% or more, about 0.5 wt% or more, about 0.75 wt% or more, or about 1 wt% or more. For example, in various embodiments, the first catalyst has a platinum loading of about 0.1 wt% to about 10 wt%, about 0.1 wt% to about 7.5 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 4 wt%, about 0.5 wt% to about 10 wt%, about 0.5 wt% to about 7.5 wt%, about 0.5 wt% to about 5 wt%, about 0.5 wt% to about 4 wt%, about 1 wt% to about 10 wt%, about 1 wt% to about 7.5 wt%, about 1 wt% to about 5 wt%, about 1 wt% to about 4 wt%, or about 1 wt% to about 3 wt%.

[0058]

[0072] In various embodiments, the first catalyst includes a catalytically active phase, and platinum occupies a substantial portion of the catalytically active phase. For example, in certain embodiments, platinum occupies about 20 wt% or more, about 30 wt% or more, about 40 wt% or more, about 50 wt% or more, about 60 wt% or more, about 70 wt% or more, about 80 wt% or more, about 90 wt% or more, about 95 wt% or more, or about 99 wt% or more of the catalytically active phase of the first catalyst. In specific embodiments, platinum occupies from about 20 wt% to about 99 wt%, from about 30 wt% to about 99 wt%, from about 40 wt% to about 99 wt%, from about 50 wt% to about 99 wt%, from about 60 wt% to about 99 wt%, from about 70 wt% to about 99 wt%, from about 80 wt% to about 99 wt%, from about 90 wt% to about 99 wt%, from about 95 wt% to about 99 wt%, from about 20 wt% to about 95 wt%, from about 30 wt% to about 95 wt%, from about 40 wt% to about 95 wt%, from about 50 wt% to about 95 wt%, from about 60 wt% to about 95 wt%, from about 70 wt% to about 95 wt%, from about 80 wt% to about 95 wt%, from about 90 wt% to about 95 wt%, from about 20 wt% to about 90 wt%, from about 30 wt% to about 90 wt%, from about 40 wt% to about 90 wt%, from about 50 wt% to about 90 wt%, from about 60 wt% to about 90 wt%, from about 70 wt% to about 90 wt%, or from about 80 wt% to about 90 wt% of the catalytically active phase of the first catalyst.

[0059]

[0073] In various embodiments, the first catalyst is a heterogeneous catalyst. In certain embodiments, the first catalyst includes a catalyst support. For example, the support of the first catalyst can include a material selected from the group consisting of carbon, alumina, silica, ceria, titania, zirconia, niobia, zeolite, magnesia, clays, nickel, cobalt, copper, iron oxide, silicon carbide, aluminosilicate, montmorillonites, and combinations thereof. In particular embodiments, the support of the first catalyst includes carbon, titania, zirconia, and combinations thereof. In further embodiments, the support of the first catalyst includes at least one carbon material selected from the group consisting of graphite, carbon black, activated carbon, and combinations thereof. In certain embodiments, the support of the first catalyst includes carbon black. Various carbon supports and methods for preparing these supports and catalyst compositions are described in U.S. Patent No. 9,682,368 and U.S. Patent Application Publication Nos. 2017 / 0120223 and 2017 / 0120219, which are hereby incorporated by reference in their entireties.

[0060]

[0074] In various embodiments, the first catalyst has a BET specific surface area of at least about 5 m 2 / g, at least about 100 m 2 / g, at least about 200 m 2 / g, at least about 500 m 2 / g, at least about 1,000 m 2 / g, at least about 1,500 m 2 / g, or at least about 2,000 m 2 / g. For example, the first catalyst can have a BET specific surface area of from about 5 m 2 / g to about 2,500 m 2 / g, from about 5 m 2 / g to about 2,000 m 2 / g, from about 5 m 2 / g to about 1,500 m 2 / g, from about 5 m 2 / g to about 1,000 m 2 / g, from about 5 m 2 / g to about 500 m 2 / g, about 5 m 2 / g to about 200 m 2 / g, about 100 m 2 / g to about 2,500 m 2 / g, about 100 m 2 / g to about 2,000 m 2 / g, about 100 m 2 / g to about 1,500 m 2 / g, about 100 m 2 / g to about 1,000 m 2 / g, about 100 m 2 / g to about 500 m 2 / g, or about 100 m 2 / g to about 200 m 2 It may have a BET specific surface area of / g.

[0061]

[0075] As described above, a further catalyst effective for the methods described herein contains gold (i.e., the second catalyst contains gold). This catalyst has been found to be particularly useful for the oxidation of uronic acid and / or its lactone (e.g., guluronic acid) to aldonic acid and / or its lactone (e.g., glucaric acid).

[0062]

[0076] In certain embodiments, the second catalyst has a gold loading of about 10 wt% or less, about 7.5 wt% or less, about 5 wt% or less, about 4 wt% or less, about 2 wt% or less, or about 1 wt% or less. In these and other embodiments, the second catalyst has a gold loading of about 0.1 wt% or more, about 0.25 wt% or more, about 0.5 wt% or more, about 0.75 wt% or more, or about 1 wt% or more. For example, in various embodiments, the second catalyst has a gold loading of about 0.1 wt% to about 10 wt%, about 0.1 wt% to about 7.5 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 4 wt%, about 0.1 wt% to about 3 wt%, about 0.1 wt% to about 2 wt%, about 0.5 wt% to about 10 wt%, about 0.5 wt% to about 7.5 wt%, about 0.5 wt% to about 5 wt%, about 0.5 wt% to about 4 wt%, about 0.5 wt% to about 3 wt%, about 0.5 wt% to about 2 wt%, about 1 wt% to about 10 wt%, about 1 wt% to about 7.5 wt%, about 1 wt% to about 5 wt%, about 1 wt% to about 4 wt%, about 1 wt% to about 3 wt%, or about 1 wt% to about 2 wt%.

[0063]

[0077] In various embodiments, the second catalyst includes a catalytically active phase, and gold occupies a substantial portion of the catalytically active phase. For example, in one embodiment, gold occupies about 20 wt% or more, about 30 wt% or more, about 40 wt% or more, about 50 wt% or more, about 60 wt% or more, about 70 wt% or more, about 80 wt% or more, about 90 wt% or more, about 95 wt% or more, or about 99 wt% or more of the catalytically active phase of the second catalyst. In certain embodiments, gold occupies from about 20 wt% to about 99 wt%, from about 30 wt% to about 99 wt%, from about 40 wt% to about 99 wt%, from about 50 wt% to about 99 wt%, from about 60 wt% to about 99 wt%, from about 70 wt% to about 99 wt%, from about 80 wt% to about 99 wt%, from about 90 wt% to about 99 wt%, from about 95 wt% to about 99 wt%, from about 20 wt% to about 95 wt%, from about 30 wt% to about 95 wt%, from about 40 wt% to about 95 wt%, from about 50 wt% to about 95 wt%, from about 60 wt% to about 95 wt%, from about 70 wt% to about 95 wt%, from about 80 wt% to about 95 wt%, from about 90 wt% to about 95 wt%, from about 20 wt% to about 90 wt%, from about 30 wt% to about 90 wt%, from about 40 wt% to about 90 wt%, from about 50 wt% to about 90 wt%, from about 60 wt% to about 90 wt%, from about 70 wt% to about 90 wt%, or from about 80 wt% to about 90 wt% of the catalytically active phase of the second catalyst.

[0064]

[0078] In various embodiments, the second catalyst is a heterogeneous catalyst. In certain embodiments, the second catalyst may include a catalyst support. For example, the support of the second catalyst may include a material selected from the group consisting of carbon, alumina, silica, ceria, titania, zirconia, niobia, zeolite, magnesia, clay, nickel, cobalt, copper, iron oxide, silicon carbide, aluminosilicate, montmorillonite, and combinations thereof. In certain embodiments, the support of the second catalyst includes a material including carbon, alumina, silica, titania, zirconia, and combinations thereof. In a further embodiment, the support of the second catalyst includes at least one carbon material selected from the group consisting of graphite, carbon black, activated carbon, and combinations thereof (e.g., the carbon black supports shown herein). In a particular embodiment, the support of the second catalyst includes zirconia, doped zirconia, doped zirconia-metal composite, doped zirconia-metal oxide composite, titania, doped titania, doped titania-metal composite, doped titania-metal oxide composite, and mixtures thereof. In various embodiments, the support of the second catalyst includes titania. In a particular embodiment, the support of the second catalyst is not the same as the support of the first catalyst.

[0065]

[0079] In various embodiments, the second catalyst may have a BET specific surface area of at least about 5 m 2 / g, at least about 100 m 2 / g, at least about 200 m 2 / g, at least about 500 m 2 / g, at least about 1,000 m 2 / g, at least about 1,500 m 2 / g, or at least about 2,000 m 2 / g. For example, the second catalyst may have a BET specific surface area of from about 5 m 2 / g to about 2,500 m2 / g, about 5 m 2 / g to about 2,000 m 2 / g, about 5 m 2 / g to about 1,500 m 2 / g, about 5 m 2 / g to about 1,000 m 2 / g, about 5 m 2 / g to about 500 m 2 / g, about 5 m 2 / g to about 200 m 2 / g, about 100 m 2 / g to about 2,500 m 2 / g, about 100 m 2 / g to about 2,000 m 2 / g, about 100 m 2 / g to about 1,500 m 2 / g, about 100 m 2 / g to about 1,000 m 2 / g, about 100 m 2 / g to about 500 m 2 / g, or about 100 m 2 / g to about 200 m 2 may have a BET specific surface area of / g.

[0066]

[0080] As described above, the various methods of the present invention may further include reacting an aldose (e.g., glucose) in the presence of oxygen and an oxidation catalyst. In these embodiments, the oxidation catalyst may include, for example, the first catalyst or the second catalyst described herein or any combination thereof. In certain embodiments, the oxidation catalyst includes the second catalyst described herein.

[0067]

[0081] When a catalyst support is used, metals (e.g., platinum and gold) can be deposited on the catalyst support using procedures known in the art, including but not limited to incipient wetness, ion exchange, deposition-precipitation, and vacuum impregnation.

[0068]

[0082] Although the present invention has been described in detail, it will be apparent that modifications and variations can be made without departing from the scope of the invention as defined in the appended claims.

Example

[0069]

[0083] The following non-limiting examples are provided to further illustrate the present invention.

[0070] Example 1: 1 wt% Au / TiO 2 Gluconic acid from glucose using a catalyst

[0084] 1 wt% Au / TiO 2 The catalyst was sized to 40 / 80 mesh by grinding and sieving and approximately 27 g by weight (the amount was approximately 30 cm 3 resulting) was charged into a fixed packed bed reactor. An aqueous solution of 20 wt% glucose was fed to the reactor at a liquid hourly space velocity (LHSV) of 2.0 h -1 and a gas stream of 75% N 2 and 25% air was fed cocurrently at a flow rate of 1000 SCCM. The pressure inside the system was maintained at 750 psig. The reactor jacket temperature was set at 77°C. The space time yield (STY) (g[GA] / g[PGM] * h) was 43.

[0071]

[0085] The glucose conversion and gluconic acid production were stable over the observation period. The peak value of the internal temperature at the radial center of the catalyst bed was 88 - 89°C. The average yield of gluconic acid was approximately 94 mol% and the average yield of glucaric acid was less than approximately 0.5 mol%. Graphs plotting the glucose conversion, gluconic acid yield (mol%), and glucaric acid yield (mol%) are shown in FIGS. 4 and 5.

[0072]

[0086] This example is for 1 wt% Au / TiO 2The catalyst is suitable for forming gluconic acid, but it has been shown that it cannot convert the gluconic acid into an appreciable amount of glucaric acid.

[0073] Example 2: Oxidation of Gluconic Acid Using a Pt Catalyst

[0087] A 4 wt% Pt / C catalyst sized 40 / 80 mesh (30 cm 3 ) was filled into a packed fixed-bed reactor. An aqueous solution of 21.5 wt% gluconic acid was fed to the reactor at a liquid hourly space velocity (LHSV) of 1.0 h -1 , and an air gas stream was fed co-currently at a flow rate of 1000 SCCM. The pressure of the system was maintained at 750 psig. The reactor jacket temperature was varied between 60 and 90 °C.

[0074]

[0088] Figure 6 shows the various conversion rates, selectivities, and yields achieved by oxidation at various temperatures. The maximum yield of glucaric acid was found to be 65% at 90 °C, but it decreased to about 35% during the reaction at this temperature. During this reaction, it was found that guluronic acid was produced in a significant yield (about 10 - 30 mol%).

[0075]

[0089] Table 1 shows detailed data on the conversion rates and yields when using a 4 wt% Pt / C catalyst at various temperatures and air flow rates. For the data shown below, the pressure was maintained at 750 psig and the LHSV of the feed stream was maintained at 1.

[0076]

Table 1

[0077]

[0090] 4 wt% Pt / TiO 2Similarly, tests were conducted to determine the suitability for the conversion from gluconic acid to glucaric acid with respect to the catalyst. Similar to the case of using the Pt / C catalyst, the total yield of glucaric acid decreased with time. The range of the glucaric acid yield is shown in the following table, where the details of the maximum yield reached and the final yield observed are presented. A comparison of the results of these catalysts at 80 °C is shown in Table 2 below.

[0078]

Table 2

[0079]

[0091] This example shows that when gluconic acid is oxidized in the presence of only the 4 wt% Pt / C or 4 wt% Pt / TiO 2 catalyst, the stability is low and a significant decrease in the glucaric acid yield is observed.

[0080] Example 3: Pt - Au / TiO 2 The preparation of a platinum - gold catalyst for the conversion from glucose to glucaric acid using the

[0092] Au / TiO 2 catalyst was carried out by supporting platinum on the catalyst such that the final catalyst contained 1 wt% Pt and 1 wt% Au. The catalyst was filled into a packed - bed fixed - bed reactor. A raw material of a 10 wt% aqueous glucose solution was introduced into the reactor such that the initial LHSV was 1.0 h -1 and a gas stream of 25% air and 75% N 2 was introduced in parallel at a flow rate of 1000 SCCM. The initial temperature of the reactor was set at 60 °C and the initial oxygen partial pressure was maintained at 37.5 psig. The STY (g[glucaric acid] / g[PGM] * h) was 6.

[0081]

[0093] As shown in Figure 7, over a period of 2236 hours, the temperature was gradually increased from 60 °C to 90 °C in increments of 10 °C. After approximately 640 hours, while maintaining the total gas flow rate at 1000 SCCM, the gas composition was changed to 50% air and 50% N 2By changing to 50%, the partial pressure of oxygen was increased from 37.5 psig to 75 psig. After about 1232 hours, the LHSV of the feedstock with 10 wt% glucose was changed from 1.0 h -1 to LHSV 1.5 h -1 The operation was confirmed to be stable at 90 °C, total pressure 750 psig, and LHSV 1.5 h -1

[0082]

[0094] The experimental results are shown in Tables 3 and 4 below. The total pressure was maintained at 750 psig throughout

[0083]

Table 3

[0084]

Table 4

[0085] Example 4: Oxidation of gluconic acid using a physical mixture of 4 wt% Pt / C and 1 wt% Au / TiO 2

[0095] The catalyst of Example 1 (1 wt% Au / TiO 2 ) was physically mixed with the catalyst of Example 2 (4 wt% Pt / C) in a volume ratio of 1:1 to form a catalyst bed of 30 cm 3 . The mass ratio of the catalysts (Au / TiO 2 :Pt / C) was approximately 3:2

[0086]

[0096] A feedstock of 20 wt% aqueous gluconic acid solution was passed through the catalyst mixture at LHSV 0.5 h -1 , and a gas stream of 100% air was co-currently passed at a flow rate of 1000 SCCM. The pressure was maintained at 750 psig, and the LHSV of the feedstock stream was maintained at 0.5 h -1

[0087]

[0097] Figure 8 shows the gluconic acid conversion and various yields achieved during the reaction at temperatures from 70 °C to 90 °C. After 672 hours, at 90 °C, the gas stream was changed from 100% air to 50% air and N​​​2 It was changed to 50%. The total gas flow rate was maintained at 1000 SCCM.

[0088]

[0098] It was confirmed that the production of glucaric acid was stable at 80 °C and 90 °C (i.e., the yield exceeded about 60 mol%). This is because the yield of glucaric acid decreased to 44 - 29 mol% when Pt / C was used alone at 80 °C (Example 2), and 2 in contrast, the yield was 35 - 45 mol% when the catalyst containing Pt supported on it was used at 80 °C (Example 3). Whether Pt / C was used alone or Pt was supported on Au / TiO 2 and used, in either case, the desired yield was not reached or the maximum yield reached did not persist (for example, the yield of Pt / C decreased significantly with time at 90 °C).

[0089]

[0099] Table 5 shows detailed data on the conversion rate and yield when a mixture of Pt / C and Au / TiO 2 catalysts was used at various temperatures and air flow rates.

[0090]

Table 5

[0091] Example 5: Conversion of gluconic acid to glucaric acid using a staged reactor bed containing a physical mixture of catalysts

[0100] A mixture of Pt / C and Au / TiO 2 catalysts was used to convert gluconic acid to glucaric acid. A staged reactor bed containing two physical mixtures of catalysts was prepared. The upper stage was set to contain 4 wt% Pt / C and 1 wt% Au / TiO 2 in a ratio of 4:1 (vol). The lower stage was set to contain 4 wt% Pt / C and 1 wt% Au / TiO 2 in a ratio of 1:4 (vol). A raw material stream of 20 wt% aqueous gluconic acid solution was introduced at LHSV 1.0 h -1 . After about 624 hours, the reactor temperature was raised from 90 °C to 95 °C.

[0092]

[0101] As shown in Fig. 9, by increasing the temperature, the gluconic acid yield was significantly improved, and the yield reached 65 - 72 mol%. The average conversion rate of gluconic acid during the 808 - hour reaction exceeded 90%.

[0093]

[0102] Table 6 shows detailed data on the conversion rate and yield when a mixture of Pt / C and Au / TiO 2 catalysts was used at various temperatures and air flow rates.

[0094]

Table 6

[0095] Example 6: Oxidation of gluconic acid using a physical mixture of 4 wt% Pt / C catalyst and 1 wt% Au / TiO 2 catalyst

[0103] The experiment of Example 4 was modified to maintain the pressure at 1250 psig and the reactor jacket temperature at 85°C. A feedstock of 21.2 wt% aqueous gluconic acid solution was introduced at LHSV 0.5 h -1 and a gas stream (N 2 50% and air 50%) was supplied at a flow rate of 1000 SCCM.

[0096]

[0104] After about 1224 hours, while maintaining the gas stream and temperature described above, the supply of liquid gluconic acid was stopped and the supply of water was started to wash the catalyst. This was carried out at LHSV 1.0 h -1 for 4 hours. Then, the flow of the gluconic acid feedstock was restarted.

[0097]

[0105] Figs. 10 and Table 7 show the gluconic acid yields before and after the water - washing process. An increase in the gluconic acid yield was observed immediately after the washing process, which continued for about 75 hours and then decreased slightly. Fig. 11 shows the results from 1104 - 1468 hours.

[0098]

Table 7

[0099] Example 7: 1 wt% Au / TiO 2 Arabinonic acid from arabinose using a catalyst

[0106] 1 wt% Au / TiO 2 The catalyst was sized to 40 / 80 mesh by grinding and sieving and approximately 27 g by weight (the amount was approximately 30 cm 3 ) was charged into a packed fixed-bed reactor. An aqueous solution of 20.6 wt% arabinose was fed to the reactor at a liquid hourly space velocity (LHSV) of 1.0 h -1 and a gas stream of N 2 50% and air 50% was fed in parallel at a flow rate of 1000 SCCM. The pressure of the system was maintained at 750 psig. The reactor jacket temperature was set at 75 °C. Six data points were obtained during the total operation time of this experiment of 2716 - 2828 hours.

[0100]

[0107] Arabinose conversion and arabinonic acid production were stable over this observation period. Approximately 100% conversion was observed at each data point. The arabinonic acid yield was between approximately 84 - 86 mol% and the average value of the arabinalic acid yield was less than approximately 2.2 mol%. Figure 12 shows the arabinose conversion, arabinonic acid yield (mol%), and arabinalic acid yield (mol%) at each data point. A summary of the results is described in Table 8 below.

[0101]

Table 8

[0102] Example 8: Arabinalic acid from arabinonic acid using a staged reactor bed containing a physical mixture of catalysts

[0108] Pt / C and Au / TiO 2 Using a mixture of catalysts, arabinonic acid was converted to arabinalic acid. A staged reactor bed containing two physical mixtures of catalysts was prepared. The upper stage was taken to contain 4 wt% Pt / C and 1 wt% Au / TiO 2 in a ratio of 4:1 (vol). The lower stage was 4 wt% Pt / C and 1 wt% Au / TiO 2It was made to contain them in a ratio of 1:4 (vol). A raw material stream of a 19.4 wt% aqueous solution of arabinonic acid was introduced at LHSV 1.0 h -1 and introduced. A gas stream of 25% air and N 2 75% was introduced in parallel at a flow rate of 1000 SCCM. The initial pressure of the reactor was set at 1200 psig, and the initial temperature of the reactor was set at 100 °C. Six data points were acquired during the total operation time of this experiment of 856 to 938 hours.

[0103]

[0109] The arabinal acid yield reached 36 - 51 mol%, and the conversion rate of arabinonic acid was about 46 - 62%. Figure 13 shows the arabinonic acid conversion rate, arabinal acid yield (mol%), tartaric acid yield (mol%), and glyceric acid yield (mol%) for each measurement run. A summary of the results is described in Table 9 below.

[0104]

Table 9

[0105] Example 9: Au / TiO 2 catalyst was used to produce glyceric acid from glyceraldehyde

[0110] 1 wt% Au / TiO 2 catalyst was sized to 40 / 80 mesh by grinding and sieving, and a weight of about 27 g (the amount was about 30 cm 3 ) was filled into a fixed-bed reactor. An aqueous solution of 1.22 wt% glyceraldehyde was fed to the reactor at a liquid hourly space velocity (LHSV) of 1.0 h -1 and a gas stream of N 2 50% and air 50% was fed in parallel at a flow rate of 1000 SCCM. The pressure of the system was maintained at 750 psig. The reactor jacket temperature was set at 75 °C. Four data points were acquired during the total operation time of this experiment of 3000 to 3038 hours.

[0106]

[0111] The glyceraldehyde conversion rate and glyceric acid production were stable over this observation period. The glyceric acid yield was between about 100 - 105 mol%, and the average value of the tartronic acid yield was 0 mol%. The glyceric acid yield (mol%) is shown in Figure 14. A summary of the results is described in Table 10 below.

[0107]

Table 10

[0108] Example 10: Tartronic acid from glyceric acid using a staged reactor bed containing a physical mixture of catalysts

[0112] Pt / C and Au / TiO 2 Using a mixture of catalysts, glyceric acid was converted to tartronic acid. A staged reactor bed containing two physical mixtures of catalysts was prepared. The upper stage was assumed to contain 4 wt% Pt / C and 1 wt% Au / TiO 2 in a ratio of 4:1 (vol). The lower stage was assumed to contain 4 wt% Pt / C and 1 wt% Au / TiO 2 in a ratio of 1:4 (vol). A feed stream of 10.0 wt% aqueous glyceric acid solution was introduced at the LHSV described in Table 11 below. A gas stream of air and N 2 at the ratios described below was introduced cocurrently at a flow rate of 1000 SCCM. The initial pressure of the reactor was set at 750 psig and increased to 1250 psig during the experiment. Similarly, the initial temperature of the reactor was set at 95 °C and increased to 106 °C during the experiment.

[0109]

Table 11

[0110] Example 11: Glycolic acid from glycolaldehyde using various catalysts

[0113] Experiments were conducted to test the effects of various catalysts for oxidizing glycolaldehyde to glycolic acid. One experiment was conducted without using a catalyst. Other experiments were conducted with 1 wt% Au / TiO 2A catalyst, a 4 wt% Pt / C catalyst, or a physical mixture of a 4 wt% Pt / C catalyst and a 1 wt% Au / TiO 2 catalyst was used.

[0111]

[0114] 1 wt% Au / TiO 2 The catalyst and the 4 wt% Pt / C catalyst were pulverized and sieved to a size of 40 / 80 mesh. The total weight of the catalyst used in each experiment is shown in Table 12. The 4 wt% Pt / C catalyst and the 1 wt% Au / TiO 2 In the experiment containing a physical mixture of catalysts, the weight ratio of the catalysts was 1:1.

[0112]

[0115] In each experiment, the reactor was charged with the amount of catalyst described in Table 12 below in a batch reactor. A 6.1 wt% aqueous glycolaldehyde solution was charged into the batch reactor and pressurized to 1800 psig with 100% air. The reactor jacket temperature was set at 85 °C. The total volume of the liquid in the reactor in each experiment was 2.3 mL.

[0113]

Table 12

[0114]

[0116] The results of these experiments are shown in Figure 15. As expected, the results were not good when no catalyst was used. When the 1 wt% Au / TiO 2 catalyst was used, the conversion rate was high and the glycolic acid yield (mol%) was about 40%. The conversion rate when the 4 wt% Pt / C catalyst was used was lower than that when the 1 wt% Au / TiO 2 catalyst was used, but the glycolic acid yield was higher. The glycolic acid yield when a physical mixture of catalysts was used was higher than that when either catalyst was used alone.

[0115] Example 12: Oxalic acid from glycolic acid using a staged reactor bed containing a physical mixture of catalysts

[0117] Pt / C and Au / TiO 2Using the catalyst mixture, glycolic acid was converted to oxalic acid. A staged reactor bed containing two physical mixtures of catalysts was prepared. The upper stage was 4 wt% Pt / C and 1 wt% Au / TiO 2 in a ratio of 4:1 (vol). The lower stage was 4 wt% Pt / C and 1 wt% Au / TiO 2 in a ratio of 1:4 (vol). A feed stream of 10.3 wt% aqueous glycolic acid was introduced at the LHSV described below. The gas stream was introduced co-currently at about 1000 SCCM. Table 13 below shows the gas stream composition at various points during operation. The initial pressure of the reactor was 1250 psig, and the initial temperature of the reactor jacket was 75 °C and was varied as shown in Table 13 below. The results for an operating time of 1222 - 1280 hours are shown below.

[0116]

Table 13

[0117]

[0118] The reason for the low oxalic acid yield is thought to be the excessive conversion of the intermediates glyoxal and / or oxalic acid to CO 2 . This is supported by the fact that no glyoxal was detected in the reaction product and a high CO 2 amount was measured. By increasing the LHSV (i.e., operating times 1248 - 1280 hours), it appears that some of the oxalic acid is discharged from the reactor before excessive conversion occurs.

[0118]

[0119] When introducing elements of the present invention or preferred embodiments thereof, the articles "a", "an", "the", and "said" are intended to mean that there is one or more elements. The terms "comprising", "including", and "having" are intended to be inclusive and mean that there may be additional elements other than the recited elements.

[0119]

[0120] In view of the above, it will be appreciated that several objects of the present invention have been achieved and other advantageous results have been achieved.

[0120]

[0121] Since various changes can be made in the above method without departing from the scope of the present invention, all matters included in the above description and shown in the accompanying drawings are intended to be construed as illustrative and not in a limiting sense.

[0121]

[0122] As used herein, the term "comprising" is to be understood to include alternative examples in which the product / method / use in respect of which the term "comprising" is used may also consist only of the elements described thereafter.

[0122]

[0123] As used herein, the term "comprising" is to be understood to include alternative examples in which the product / method / use in respect of which the term "comprising" is used may also consist essentially of the elements described thereafter.

[0123]

[0124] Unless otherwise specified, it should be understood that all synthetic methods and parameter measurements were carried out at room temperature / ambient temperature, i.e., 21 ± 1 °C.

[0124] Item: 1. A method for preparing glucaric acid and / or its lactone, comprising: reacting gluconic acid and / or its lactone in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing glucaric acid and / or its lactone, wherein the first catalyst and the second catalyst are different.

[0125] 2. The method according to item 1, wherein the reaction zone contains a mixture of the first catalyst and the second catalyst.

[0126] 3. The method according to item 1 or 2, wherein the reaction zone comprises a first stage comprising a first catalyst and a second stage comprising a second catalyst.

[0127] 4. A method for preparing glucaric acid and / or its lactone, comprising: reacting gluconic acid and / or its lactone in a first stage of a reaction zone in the presence of a first catalyst comprising oxygen and platinum to form a first reaction mixture comprising guluronic acid and / or its lactone; and contacting the first reaction mixture comprising guluronic acid and / or its lactone with a second catalyst comprising oxygen and gold in a second stage of the reaction zone to form a second reaction mixture comprising glucaric acid and / or its lactone; wherein the first catalyst and the second catalyst are different.

[0128] 5. The method according to any one of items 1 to 4, wherein a raw material mixture is supplied to the reaction zone, and the concentration of gluconic acid and / or lactone in the raw material mixture is about 1 wt% or more, about 5 wt% or more, about 10 wt% or more, about 15 wt% or more, or about 20 wt% or more.

[0129] 6. The method according to any one of items 1 to 4, wherein a raw material mixture is supplied to the reaction zone, and the concentration of gluconic acid and / or lactone in the raw material mixture is about 1 wt% to about 50 wt%, about 1 wt% to about 30 wt%, about 1 wt% to about 25 wt%, about 5 wt% to about 50 wt%, about 5 wt% to about 30 wt%, about 5 wt% to about 25 wt%, about 10 wt% to about 50 wt%, about 10 wt% to about 30 wt%, about 10 wt% to about 25 wt%, about 15 wt% to about 50 wt%, about 15 wt% to about 30 wt%, about 15 wt% to about 25 wt%, about 20 wt% to about 50 wt%, about 20 wt% to about 30 wt%, or about 20 wt% to about 25 wt%.

[0130] 7. The method according to any one of items 1 to 6, wherein a raw material mixture is supplied to the reaction zone, and the concentration of gluconic acid and / or lactone in the raw material mixture is about 1 wt% to 25 wt%.

[0131] 8. The method according to any one of the preceding items, wherein a raw material mixture is supplied to a reaction zone, and the gluconic acid and / or lactone concentration of the raw material mixture is from about 5 wt% to 25 wt%.

[0132] 9. A method for preparing glucaric acid and / or its lactone, comprising: reacting glucuronic acid and / or its lactone in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing glucaric acid and / or lactone, wherein the first catalyst and the second catalyst are different.

[0133] 10. The method according to any one of items 1 to 9, wherein the yield of glucaric acid and / or its lactone is about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more.

[0134] 11. The method according to any one of items 1 to 9, wherein the yield of glucaric acid and / or its lactone is from about 50% to about 85%, from about 50% to about 80%, from about 50% to about 75%, from about 50% to about 70%, from about 50% to about 65%, from about 60% to about 85%, from about 60% to about 80%, from about 60% to about 75%, from about 60% to about 70%, from about 65% to about 85%, from about 65% to about 80%, from about 65% to about 75%, or from about 65% to about 70%.

[0135] 12. A method for preparing glucuronic acid and / or its lactone, comprising: reacting gluconic acid and / or its lactone in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing glucuronic acid and / or lactone, wherein the first catalyst and the second catalyst are different.

[0136] 13. The method according to any one of items 1 to 12, further comprising reacting glucose with oxygen in the presence of an oxidation catalyst to form gluconic acid and / or its lactone.

[0137] 14. The acid catalyst is the method according to item 13, which includes a second catalyst.

[0138] 15. A method for preparing glucuronic acid and / or its lactone, comprising: reacting glucose in a reaction zone in the presence of oxygen, an acid catalyst, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing glucuronic acid and / or lactone, wherein the first catalyst and the second catalyst are different.

[0139] 16. A method for preparing glucaric acid and / or its lactone, comprising: reacting glucose in a reaction zone containing an acid catalyst, a first catalyst containing platinum, and a second catalyst containing gold in the presence of oxygen to form a reaction mixture containing glucaric acid and / or its lactone, wherein the first catalyst and the second catalyst are different.

[0140] 17. The method according to item 16, wherein the yield of glucaric acid and / or its lactone is about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more.

[0141] 18. The method according to item 16, wherein the yield of glucaric acid and / or its lactone is about 50% to about 85%, about 50% to about 80%, about 50% to about 75%, about 50% to about 70%, about 50% to about 65%, about 60% to about 85%, about 60% to about 80%, about 60% to about 75%, about 60% to about 70%, about 65% to about 85%, about 65% to about 80%, about 65% to about 75%, or about 65% to about 70%.

[0142] 19. A method for preparing gluconic acid and / or its lactone, comprising: reacting glucose in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing gluconic acid and / or lactone, wherein the first catalyst and the second catalyst are different.

[0143] 20. A method according to any one of items 13 to 19, wherein glucose is obtained from a carbohydrate-containing source.

[0144] 21. A method according to any one of items 13 to 20, wherein glucose is obtained from cereal crops.

[0145] 22. A method for preparing an aldonic acid and / or its lactone, comprising: The uronic acid and / or its lactone of formula (III): HOOC(HCOH) y CHO (III) (wherein y is an integer from 0 to 10) is reacted in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing an aldonic acid and / or its lactone of formula (IV), wherein the first catalyst and the second catalyst are different, and the aldonic acid and / or its lactone is of formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer from 0 to 10), a method.

[0146] 23. The method according to item 22, wherein y and / or z is an integer from 0 to 5.

[0147] 24. The method according to item 23, wherein y = z and is an integer from 0 to 5.

[0148] 25. The method according to item 24, wherein y = z and is an integer from 2 to 5.

[0149] 26. The method according to item 25, wherein y = z and is an integer from 2 to 4.

[0150] 27. The method according to item 26, wherein y = z and is an integer from 3 to 4.

[0151] 28. A method for preparing an aldonic acid and / or its lactone, comprising: The aldonic acid and / or its lactone of formula (II): HOCH 2 (HCOH) x COOH (II) (wherein x is an integer from 0 to 10) is reacted in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing the aldic acid of formula (IV) and / or its lactone, wherein the first catalyst and the second catalyst are different, and the aldic acid and / or its lactone has the formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer from 0 to 10), a method.

[0152] 29. The method according to item 28, wherein x and / or z is an integer from 0 to 5.

[0153] 30. The method according to item 29, wherein x = z and is an integer from 0 to 5.

[0154] 31. The method according to item 30, wherein x = z and is an integer from 2 to 5.

[0155] 32. The method according to item 31, wherein x = z and is an integer from 2 to 4.

[0156] 33. The method according to item 32, wherein x = z and is an integer from 3 to 4.

[0157] 34. The method according to any one of items 22 to 33, wherein the reaction zone contains a mixture of the first catalyst and the second catalyst.

[0158] 35. The method according to any one of items 22 to 34, wherein the reaction zone includes a first stage containing the first catalyst and a second stage containing the second catalyst.

[0159] 36. A method for preparing an aldic acid and / or its lactone, comprising: The aldonic acid of formula (II) and / or its lactone: HOCH 2 (HCOH) x COOH (II) (wherein x is an integer from 0 to 10) is reacted in the first stage of the reaction zone in the presence of a first catalyst containing oxygen and platinum to form a first reaction mixture; and The first reaction mixture is contacted with a second catalyst containing oxygen and gold in the second stage of the reaction zone to form a second reaction mixture containing the aldic acid of formula (IV) and / or its lactone; comprising, wherein the first catalyst and the second catalyst are different, and the aldic acid and / or its lactone is of formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer from 0 to 10), a method.

[0160] 37. The method according to item 36, wherein x and / or z is an integer from 0 to 5.

[0161] 38. The method according to item 37, wherein x = z and is an integer from 0 to 5.

[0162] 39. The method according to item 38, wherein x = z and is an integer from 2 to 5.

[0163] 40. The method according to item 39, wherein x = z and is an integer from 2 to 4.

[0164] 41. The method according to item 40, wherein x = z and is an integer from 3 to 4.

[0165] 42. The method according to any one of items 28 to 41, wherein the raw material mixture is supplied to the reaction zone, and the concentration of the aldic acid and / or lactone of formula (II) in the raw material mixture is about 1 wt% or more, about 5 wt% or more, about 10 wt% or more, about 15 wt% or more, or about 20 wt% or more.

[0166] 43. The method according to any one of items 28 to 41, wherein a raw material mixture is supplied to a reaction zone, and the concentration of the aldonic acid and / or lactone of formula (II) in the raw material mixture is from about 1 wt% to about 50 wt%, from about 1 wt% to about 30 wt%, from about 1 wt% to about 25 wt%, from about 5 wt% to about 50 wt%, from about 5 wt% to about 30 wt%, from about 5 wt% to about 25 wt%, from about 10 wt% to about 50 wt%, from about 10 wt% to about 30 wt%, from about 10 wt% to about 25 wt%, from about 15 wt% to about 50 wt%, from about 15 wt% to about 30 wt%, from about 15 wt% to about 25 wt%, from about 20 wt% to about 50 wt%, from about 20 wt% to about 30 wt%, or from about 20 wt% to about 25 wt%.

[0167] 44. The method according to any one of items 28 to 43, wherein a raw material mixture is supplied to a reaction zone, and the gluconic acid and / or lactone concentration in the raw material mixture is from about 1 wt% to 25 wt%.

[0168] 45. The method according to any one of items 28 to 44, wherein a raw material mixture is supplied to a reaction zone, and the gluconic acid and / or lactone concentration in the raw material mixture is from about 5 wt% to 25 wt%.

[0169] 46. An aldose of formula (I) and / or its lactone: HOCH 2 (HCOH) w CHO (I) (wherein w is an integer from 0 to 10) is further reacted in the presence of oxygen and an oxidation catalyst to form an aldonic acid of formula (II) and / or its lactone, the method according to any one of items 28 to 45.

[0170] 47. The method according to item 46, wherein w is an integer from 0 to 5.

[0171] 48. The method according to item 47, wherein w is an integer from 2 to 5.

[0172] 49. The method according to item 48, wherein w is an integer from 2 to 4.

[0173] The method according to item 49, wherein 50.w is an integer from 3 to 4.

[0174] 51. The method according to any one of items 46 to 50, wherein the oxidation catalyst comprises a second catalyst.

[0175] 52. A method for preparing an aldic acid and / or its lactone, comprising: An aldose of formula (I) and / or its lactone: HOCH 2 (HCOH) w CHO (I) (wherein w is an integer from 0 to 10) is reacted in a reaction zone containing an oxidation catalyst, a first catalyst containing platinum, and a second catalyst containing gold in the presence of oxygen to form a reaction mixture containing an aldic acid of formula (IV) and / or its lactone, wherein the first catalyst and the second catalyst are different, and the aldic acid is of formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer from 0 to 10), the method.

[0176] 53. The method according to item 52, wherein w and / or z is an integer from 0 to 5.

[0177] 54. The method according to item 53, wherein w = z and is an integer from 0 to 5.

[0178] 55. The method according to item 54, wherein w = z and is an integer from 2 to 5.

[0179] 56. The method according to item 55, wherein w = z and is an integer from 2 to 4.

[0180] 57. The method according to item 56, wherein w = z and is an integer from 3 to 4.

[0181] 58. The method according to any one of items 52 to 57, wherein the reaction zone comprises an initial oxidation stage containing an oxidation catalyst, a first stage containing a first catalyst, and a second stage containing a second catalyst.

[0182] 59. The method according to any one of items 52 to 58, wherein the oxidation catalyst comprises a second catalyst.

[0183] 60. The method according to any one of items 52 to 59, wherein the yield of the alduronic acid of formula (IV) and / or its lactone is about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more.

[0184] 61. The method according to any one of items 52 to 59, wherein the yield of the alduronic acid of formula (IV) and / or its lactone is about 50% to about 85%, about 50% to about 80%, about 50% to about 75%, about 50% to about 70%, about 50% to about 65%, about 60% to about 85%, about 60% to about 80%, about 60% to about 75%, about 60% to about 70%, about 65% to about 85%, about 65% to about 80%, about 65% to about 75%, or about 65% to about 70%.

[0185] 62. A method for preparing uronic acid and / or its lactone, comprising: The aldose of formula (I) and / or its lactone: HOCH 2 (HCOH) w CHO (I) (wherein w is an integer from 0 to 10) is reacted in a reaction zone in the presence of oxygen, an oxidation catalyst, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing the uronic acid of formula (III) and / or its lactone, wherein the first catalyst and the second catalyst are different, and the uronic acid has the formula (III): HOOC(HCOH) y CHO (III) (wherein y is an integer from 0 to 10), the method.

[0186] 63. The method according to item 62, wherein w and / or y is an integer from 0 to 5.

[0187] 64. The method according to item 63, wherein w = y and is an integer from 0 to 5.

[0188] 65. The method according to item 64, wherein w = y and y is an integer from 2 to 5.

[0189] 66. The method according to item 65, wherein w = y and y is an integer from 2 to 4.

[0190] 67. The method according to item 66, wherein w = y and y is an integer from 3 to 4.

[0191] 68. A method for preparing an aldonic acid and / or its lactone, comprising: An aldose of formula (I) and / or its lactone: HOCH 2 (HCOH) w CHO (I) (wherein w is an integer from 0 to 10) is reacted in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing an aldonic acid of formula (II) and / or its lactone, wherein the first catalyst and the second catalyst are different, and the aldonic acid is of formula (II): HOCH 2 (HCOH) x COOH (II) (wherein x is an integer from 0 to 10), the method.

[0192] 69. The method according to item 68, wherein w and / or x is an integer from 0 to 5.

[0193] 70. The method according to item 69, wherein w = x and x is an integer from 0 to 5.

[0194] 71. The method according to item 70, wherein w = x and x is an integer from 2 to 5.

[0195] 72. The method according to item 71, wherein w = x and x is an integer from 2 to 4.

[0196] 73. The method according to item 72, wherein w = x and x is an integer from 3 to 4.

[0197] 74. The aldose has at least one C 2 ~C 7 The method according to any one of items 46 to 73, comprising an aldose.

[0198] 75. The method according to any one of items 46 to 74, wherein the aldose of formula (I) is obtained from a carbohydrate-containing source.

[0199] 76. The method according to any one of items 46 to 75, wherein the aldose of formula (I) is obtained from cereal crops.

[0200] 77. The method according to any one of items 46 to 76, wherein the aldose of formula (I) comprises triose, tetrose, pentose, hexose, heptose, and / or a mixture thereof.

[0201] 78. The method according to any one of items 46 to 77, wherein the aldose of formula (I) comprises glycolaldehyde, glyceraldehyde, erythrose, threose, xylose, ribose, arabinose, glucose, galactose, mannose, glucoheptose, L-glycero-D-mannoheptose, and / or a mixture thereof.

[0202] 79. The method according to any one of items 46 to 78, wherein the aldose of formula (I) comprises xylose, ribose, arabinose, glucose, and / or a mixture thereof.

[0203] 80. The method according to any one of items 46 to 79, wherein the aldose of formula (I) comprises glucose.

[0204] 81. A method for preparing uronic acid and / or its lactone, comprising: The aldonic acid of formula (II) and / or its lactone: HOCH 2 (HCOH) x COOH (II) (wherein x is an integer from 0 to 10) is reacted in a reaction zone in the presence of oxygen, a first catalyst containing platinum, and a second catalyst containing gold to form a reaction mixture containing the uronic acid of formula (III) and / or its lactone, wherein the first catalyst and the second catalyst are different, and the uronic acid is of formula (III): HOOC(HCOH) y CHO (III) (wherein y is an integer from 0 to 10), a method.

[0205] 82. The method according to item 81, wherein x and / or y is an integer from 0 to 5.

[0206] 83. The method according to item 82, wherein x = y and is an integer from 0 to 5.

[0207] 84. The method according to item 83, wherein x = y and is an integer from 2 to 5.

[0208] 85. The method according to item 84, wherein x = y and is an integer from 2 to 4.

[0209] 86. The method according to item 85, wherein x = y and is an integer from 3 to 4.

[0210] 87. The method according to any one of items 28 to 51 or 68 to 86, wherein the aldonic acid of formula (II) contains dionic acid, trionic acid, tetronic acid, pentonic acid, hexonic acid, heptonic acid, and / or a mixture thereof.

[0211] 88. The method according to any one of items 28 to 51 or 68 to 87, wherein the aldonic acid of formula (II) contains glycolic acid, glyceric acid, threonic acid, erythronic acid, xylonic acid, ribonic acid, arabinonic acid, gluconic acid, and / or a mixture thereof.

[0212] 89. The method according to any one of items 28 to 51 or 68 to 88, wherein the aldonic acid of formula (II) contains gluconic acid, xylonic acid, ribonic acid, arabinonic acid, and / or a mixture thereof.

[0213] 90. The method according to any one of items 28 to 51 or 68 to 89, wherein the aldonic acid of formula (II) comprises xylonic acid, ribonic acid, arabinonic acid, and / or a mixture thereof.

[0214] 91. The method according to any one of items 28 to 51 or 68 to 89, wherein the aldonic acid of formula (II) comprises gluconic acid.

[0215] 92. The uronic acid of formula (III) has at least one C 2 ~C 7 The method according to any one of items 22 to 27, 62 to 67, or 81 to 91, which comprises uronic acid.

[0216] 93. The method according to any one of items 22 to 27, 62 to 67, or 81 to 92, wherein the uronic acid of formula (III) comprises triuronic acid, tetrauronic acid, pentauronic acid, hexauronic acid, heptauronic acid, and / or a mixture thereof.

[0217] 94. The uronic acid of formula (III) comprises glyoxylic acid, glyceruronic acid (tartronaldehyde acid), threuronic acid, erythrulonic acid, xylouronic acid, ribouronic acid, arabinouronic acid, lyxouronic acid, guluronic acid, glucuronic acid, galacturonic acid, mannuronic acid, alluronic acid, alturonic acid, iduronic acid, talouronic acid, and glucoheptonicuronic acid, and / or a mixture thereof. The method according to any one of items 22 to 27, 62 to 67, or 81 to 93.

[0218] 95. The method according to any one of items 22 to 27, 62 to 67, or 81 to 94, wherein the uronic acid of formula (III) comprises guluronic acid, xylouronic acid, ribouronic acid, arabinouronic acid, and / or a mixture thereof.

[0219] 96. The method according to any one of items 22 to 27, 62 to 67, or 81 to 95, wherein the uronic acid of formula (III) comprises guluronic acid.

[0220] 97. The aldic acid of formula (IV) contains at least one C 2 ~C 7 The method according to any one of items 22 to 45 or 52 to 61, comprising an aldic acid.

[0221] 98. The method according to any one of items 22 to 45, 52 to 61, or 97, wherein the aldic acid of formula (IV) contains a trialic acid, a tetralic acid, a pentalic acid, a hexalic acid, a heptalic acid, and / or a mixture thereof.

[0222] 99. The method according to any one of items 22 to 45, 52 to 61, 97, or 98, wherein the aldic acid of formula (IV) contains oxalic acid, tartronic acid, tartaric acid, xylaric acid, ribaric acid, arabinaric acid, glucaric acid, galactaric acid, mannareic acid, and / or a mixture thereof.

[0223] 100. The method according to any one of items 22 to 45, 52 to 61, or 97 to 99, wherein the aldic acid of formula (IV) contains glucaric acid, xylaric acid, ribaric acid, arabinaric acid, and / or a mixture thereof.

[0224] 101. The method according to any one of items 22 to 45, 52 to 61, or 97 to 100, wherein the aldic acid of formula (IV) contains xylaric acid, ribaric acid, arabinaric acid, and / or a mixture thereof.

[0225] 102. The method according to any one of items 22 to 45, 52 to 61, or 97 to 101, wherein the aldic acid of formula (IV) contains glucaric acid.

[0226] 103. The reaction region includes a first stage, the first stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume of the first catalyst is greater than the weight or volume of the second catalyst. The method according to any one of items 1 to 102.

[0227] 104. The method according to any one of items 1 to 103, wherein the reaction zone includes a first stage, the first stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the first catalyst to the second catalyst is about 2:1 or more, about 3:1 or more, or about 4:1 or more.

[0228] 105. The method according to any one of items 1 to 104, wherein the reaction zone includes a first stage, the first stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the first catalyst to the second catalyst is about 2:1 to about 10:1, about 2:1 to about 5:1, about 3:1 to about 10:1, or about 3:1 to about 5:1.

[0229] 106. The method according to item 104 or 105, wherein the ratio of the first catalyst to the second catalyst mentioned is a volume ratio.

[0230] 107. The method according to any one of items 1 to 106, wherein the reaction zone includes a second stage, the second stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume of the second catalyst is greater than the weight or volume of the first catalyst.

[0231] 108. The method according to any one of items 1 to 107, wherein the reaction zone includes a second stage, the second stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the second catalyst to the first catalyst is about 2:1 or more, about 3:1 or more, or about 4:1 or more.

[0232] 109. The method according to any one of items 1 to 108, wherein the reaction zone includes a second stage, the second stage includes a mixture of a first catalyst and a second catalyst, and the weight or volume ratio of the second catalyst to the first catalyst is about 2:1 to about 10:1, about 2:1 to about 5:1, about 3:1 to about 10:1, or about 3:1 to about 5:1.

[0233] 110. The method according to item 108 or 109, wherein the ratio of the second catalyst to the first catalyst mentioned is a volume ratio.

[0234] 111. The reaction zone is (i) A first stage comprising a mixture of a first catalyst and a second catalyst, wherein the volume ratio of the first catalyst to the second catalyst is from about 3:1 to about 5:1; (ii) A second stage comprising a mixture of a first catalyst and a second catalyst, wherein the volume ratio of the second catalyst to the first catalyst is from about 3:1 to about 5:1; The method according to any one of the preceding items, comprising:

[0235] 112. In the first stage, the weight ratio of the first catalyst to the second catalyst is from about 3:1 to about 1:1; The method according to item 111, wherein in the second stage, the weight ratio of the second catalyst to the first catalyst is from about 4.5:1 to about 7.5:1.

[0236] 113. The method according to any one of items 1 to 112, wherein the volume ratio of the total amount of the first catalyst to the second catalyst in the reaction zone is from about 1:10 to about 10:1, from about 1:5 to about 5:1, from about 1:3 to about 3:1, or about 1:1.

[0237] 114. The method according to any one of items 1 to 113, wherein the first catalyst is a heterogeneous catalyst.

[0238] 115. The method according to any one of items 1 to 114, wherein the first catalyst comprises a catalyst support.

[0239] 116. The method according to item 115, wherein the support of the first catalyst comprises a material selected from the group consisting of carbon, alumina, silica, ceria, titania, zirconia, niobia, zeolite, magnesia, clay, nickel, cobalt, copper, iron oxide, silicon carbide, aluminosilicate, montmorillonite, and combinations thereof.

[0240] 117. The method according to item 115 or 116, wherein the support of the first catalyst comprises carbon, titania, zirconia, or a combination thereof.

[0241] The method according to any one of items 115 to 117, wherein the carrier of the first oxidation catalyst comprises at least one carbon material selected from the group consisting of graphite, carbon black, activated carbon, and combinations thereof.

[0242] 119. The method according to any one of items 115 to 118, wherein the carrier of the first catalyst comprises carbon black.

[0243] 120. The first catalyst and / or the second catalyst has a BET specific surface area of at least about 5 m 2 / g, at least about 100 m 2 / g, at least about 200 m 2 / g, at least about 500 m 2 / g, at least about 1,000 m 2 / g, at least about 1,500 m 2 / g, or at least about 2,000 m 2 / g, the method according to any one of items 1 to 119.

[0244] 121. The first catalyst and / or the second catalyst is about 5 m 2 / g to about 2,500 m 2 / g, about 5 m 2 / g to about 2,000 m 2 / g, about 5 m 2 / g to about 1,500 m 2 / g, about 5 m 2 / g to about 1,000 m 2 / g, about 5 m 2 / g to about 500 m 2 / g, about 5 m 2 / g to about 200 m 2 / g, about 100 m 2 / g to about 2,500 m 2 / g, about 100 m 2 / g to about 2,000 m 2 / g, about 100 m 2 / g to about 1,500 m 2 / g, about 100 m 2 / g to about 1,000 m 2 / g, about 100 m 2 / g to about 500 m 2 / g, or about 100 m2 / g to about 200 m 2 The method according to any one of items 1 to 119, having a BET specific surface area of / g.

[0245] 122. The first catalyst and / or the second catalyst has a BET specific surface area of about 100 m 2 / g to about 200 m 2 / g. The method according to any one of items 1 to 121.

[0246] 123. The first catalyst has a platinum loading of about 10 wt% or less, about 7.5 wt% or less, about 5 wt% or less, about 4 wt% or less, about 2 wt% or less, or about 1 wt% or less. The method according to any one of items 1 to 122.

[0247] 124. The first catalyst has a platinum loading of about 0.1 wt% or more, about 0.25 wt% or more, about 0.5 wt% or more, about 0.75 wt% or more, or about 1 wt% or more. The method according to any one of items 1 to 123.

[0248] 125. The first catalyst has a platinum loading of about 0.1 wt% to about 10 wt%, about 0.1 wt% to about 7.5 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 4 wt%, about 0.5 wt% to about 10 wt%, about 0.5 wt% to about 7.5 wt%, about 0.5 wt% to about 5 wt%, about 0.5 wt% to about 4 wt%, about 1 wt% to about 10 wt%, about 1 wt% to about 7.5 wt%, about 1 wt% to about 5 wt%, about 1 wt% to about 4 wt%, or about 1 wt% to about 3 wt%. The method according to any one of items 1 to 122.

[0249] 126. The first catalyst has a platinum loading of about 1 wt% to 5 wt%. The method according to any one of the preceding items.

[0250] 127. The first catalyst has a platinum loading of about 1 wt% to 4 wt%. The method according to any one of the preceding items.

[0251] 128. The second catalyst is a heterogeneous catalyst. The method according to any one of items 1 to 127.

[0252] 129. The method according to any one of items 1 to 128, wherein the second catalyst comprises a catalyst carrier.

[0253] 130. The method according to item 129, wherein the carrier of the first catalyst is not the same as the carrier of the second catalyst.

[0254] 131. The method according to item 129 or 130, wherein the carrier of the second catalyst comprises a material selected from the group consisting of carbon, alumina, silica, ceria, titania, zirconia, niobia, zeolite, magnesia, clay, nickel, cobalt, copper, iron oxide, silicon carbide, aluminosilicate, montmorillonite, and combinations thereof.

[0255] 132. The method according to any one of items 129 to 131, wherein the carrier of the second catalyst comprises a material comprising carbon, alumina, silica, titania, zirconia, or a combination thereof.

[0256] 133. The method according to any one of items 129 to 132, wherein the carrier of the second catalyst comprises at least one carbon material selected from the group consisting of graphite, carbon black, activated carbon, and combinations thereof.

[0257] 134. The method according to any one of items 129 to 133, wherein the carrier of the second catalyst comprises zirconia, doped zirconia, doped zirconia-metal composite, doped zirconia-metal oxide composite, titania, doped titania, doped titania-metal composite, doped titania-metal oxide composite, or a mixture thereof.

[0258] 135. The method according to any one of items 129 to 134, wherein the carrier of the second catalyst comprises titania.

[0259] 136. The method according to any one of items 1 to 135, wherein the second catalyst has a gold loading of about 10 wt% or less, about 7.5 wt% or less, about 5 wt% or less, about 4 wt% or less, about 2 wt% or less, or about 1 wt% or less.

[0260] 137. The method according to any one of items 1 to 136, wherein the second catalyst has a gold loading of about 0.1 wt% or more, about 0.25 wt% or more, about 0.5 wt% or more, about 0.75 wt% or more, or about 1 wt% or more.

[0261] 138. The method according to any one of items 1 to 135, wherein the second catalyst has a gold loading of about 0.1 wt% to about 10 wt%, about 0.1 wt% to about 7.5 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 4 wt%, about 0.1 wt% to about 3 wt%, about 0.1 wt% to about 2 wt%, about 0.5 wt% to about 10 wt%, about 0.5 wt% to about 7.5 wt%, about 0.5 wt% to about 5 wt%, about 0.5 wt% to about 4 wt%, about 0.5 wt% to about 3 wt%, about 0.5 wt% to about 2 wt%, about 1 wt% to about 10 wt%, about 1 wt% to about 7.5 wt%, about 1 wt% to about 5 wt%, about 1 wt% to about 4 wt%, about 1 wt% to about 3 wt%, or about 1 wt% to about 2 wt%.

[0262] 139. The method according to any one of the preceding items, wherein the second catalyst has a gold loading of about 0.1 wt% to about 10 wt%.

[0263] 140. The method according to any one of the preceding items, wherein the second catalyst has a gold loading of about 0.1 wt% to about 5 wt%.

[0264] 141. The method according to any one of the preceding items, wherein the second catalyst has a gold loading of about 0.1 wt% to about 2 wt%.

[0265] 142. The method according to any one of the preceding items, wherein the second catalyst has a gold loading of about 0.5 wt% to about 2 wt%.

[0266] 143. The method according to any one of the preceding items, wherein the second catalyst has a gold loading of about 1.0 wt% to about 2 wt%.

[0267] 144. The method according to any one of items 1 to 143, wherein the method is carried out without adding a base.

[0268] 145. The method according to any one of items 1 to 144, wherein the pH of the reaction mixture is not controlled or increased by the addition of a base.

[0269] 146. The method according to any one of items 1 to 145, wherein the base is not supplied to the reaction zone.

[0270] 147. The method according to any one of items 1 to 146, wherein the reaction mixture does not contain or substantially does not contain a salt-forming cation.

[0271] 148. The method according to any one of items 1 to 147, wherein the pH of the reaction mixture measured at 20 °C is about 7 or less, about 6.5 or less, about 6 or less, about 5 or less, about 4 or less, about 3 or less, or about 2 or less.

[0272] 149. The method according to any one of items 1 to 148, wherein the pH of the reaction mixture measured at 20 °C is about 1 to about 7, about 1 to about 6, about 1 to about 5, about 1 to about 4, about 1.5 to about 7, about 1.5 to about 6, about 1.5 to about 5, about 1.5 to about 4, about 2 to about 7, about 2 to about 6, about 2 to about 5, or about 2 to about 4.

[0273] 150. The method according to any one of items 1 to 149, wherein the reaction mixture reaches a minimum pH measured at 20 °C of about 4 or less, about 3 or less, or about 2 or less.

[0274] 151. The method according to any one of items 1 to 150, wherein the pH of the reaction mixture measured at 20 °C is about 1 to about 2.

[0275] 152. The method according to any one of items 1 to 151, wherein the reaction zone comprises one or more trickle bed reactors.

[0276] 153. The method according to any one of items 1 to 152, wherein the reaction zone comprises one or more fixed bed reactors.

[0277] 154. The liquid hourly space velocity (LHSV) of the reaction zone is about 0.2 h-1 for about 0.5 h or more -1 for about 1 h or more -1 for about 1.5 h or more -1 for about 2 h or more -1 for about 5 h or more -1 for about 10 h or more -1 The method according to any one of Items 1 to 153, which is for the above time or more.

[0278] 155. The LHSV of the reaction zone is from about 0.2 h -1 to about 50 h -1 from about 0.5 h -1 to about 50 h -1 from about 1 h -1 to about 50 h -1 from about 2 h -1 to about 50 h -1 from about 5 h -1 to about 50 h -1 from about 10 h -1 to about 50 h -1 from about 0.2 h -1 to about 10 h -1 from about 0.5 h -1 to about 10 h -1 from about 1 h -1 to about 10 h -1 from about 2 h -1 to about 10 h -1 from about 5 h -1 to about 10 h -1 The method according to any one of Items 1 to 153, which is in the above range.

[0279] 156. The LHSV of the reaction zone is from about 0.2 h -1 to about 5 h -1 The method according to any one of the preceding items, which is in the above range.

[0280] 157. The LHSV of the reaction zone is from about 0.2 h -1 to about 4 h -1 The method according to any one of the preceding items, which is in the above range.

[0281] 158. The LHSV of the reaction zone is from about 0.4 h -1 to about 2.5 h -1 The method according to any one of the preceding items, which is in the above range.

[0282] 159. The LHSV of the reaction zone is from about 0.5 h -1 to about 2 h -1 The method according to any one of the preceding items.

[0283] 160. The method according to any one of items 1 to 159, wherein the reaction zone is heated to a temperature of about 60 °C or higher, about 70 °C or higher, or about 80 °C or higher.

[0284] 161. The method according to any one of items 1 to 159, wherein the reaction zone is heated to a temperature of about 60 °C to about 150 °C, about 70 °C to about 150 °C, about 80 °C to about 150 °C, about 60 °C to about 125 °C, about 70 °C to about 125 °C, about 80 °C to about 125 °C, about 60 °C to about 100 °C, about 70 °C to about 100 °C, or about 80 °C to about 100 °C.

[0285] 162. The method according to any one of the preceding items, wherein the reaction zone is heated to a temperature of about 70 °C to about 110 °C.

[0286] 163. The method according to any one of the preceding items, wherein the reaction zone is heated to a temperature of about 75 °C to about 110 °C.

[0287] 164. The method according to any one of the preceding items, wherein the reaction zone is heated to a temperature of about 80 °C to about 110 °C.

[0288] 165. The method according to any one of the preceding items, wherein the reaction zone is heated to a temperature of about 80 °C to about 100 °C.

[0289] 166. The method according to any one of items 1 to 165, wherein the partial pressure of oxygen is in the range of about 2 psig or higher, about 25 psig or higher, about 50 psig or higher, or about 100 psig or higher, or about 2 psig to about 2000 psig, about 50 psig to about 2000 psig, or about 100 psig to about 2000 psig.

[0290] 167. The method according to any one of the preceding items, wherein the partial pressure of oxygen is about 2 psig to about 2000 psig.

[0291] 168. The method according to any one of the preceding items, wherein the partial pressure of oxygen is from about 50 psig to about 2000 psig.

[0292] 169. The method according to any one of the preceding items, wherein the partial pressure of oxygen is from about 75 psig to about 250 psig.

[0293] 170. The method according to any one of items 1 to 169, wherein oxygen is supplied to the reaction zone as an oxygen-containing gaseous mixture.

[0294] 171. The method according to any one of items 1 to 170, wherein oxygen is supplied to the reaction zone as air, oxygen-enriched air, a mixture containing at least about 40 or 50 volume % of oxygen, a mixture containing oxygen and nitrogen (e.g., about 50:50 mixture on a volume basis), or substantially pure oxygen (at least 99 volume % of oxygen).

[0295] 172. The method according to any one of items 1 to 169, wherein oxygen is supplied to the reaction zone as a mixture having an oxygen concentration of about 0.5 volume % or more, about 1 volume % or more, about 5 volume % or more, or about 10 volume % or more.

[0296] 173. The method according to any one of items 1 to 169, wherein oxygen is supplied to the reaction zone as a mixture having an oxygen concentration of from about 0.5 volume % to about 20 volume %, from about 0.5 volume % to about 15 volume %, from about 0.5 volume % to about 10 volume %, from about 0.5 volume % to about 5 volume %, from about 1 volume % to about 20 volume %, from about 1 volume % to about 15 volume %, from about 1 volume % to about 10 volume %, from about 1 volume % to about 5 volume %, from about 5 volume % to about 20 volume %, from about 5 volume % to about 15 volume %, or from about 5 volume % to about 10 volume %.

[0297] 174. The method according to any one of items 1 to 173, wherein oxygen is supplied to the reaction zone as a mixture having an oxygen concentration of from about 5 volume % to about 20 volume %.

[0298] 175. The method according to any one of items 1 to 174, wherein the first catalyst comprises a catalytically active phase, and platinum accounts for about 20 wt% or more, about 30 wt% or more, about 40 wt% or more, about 50 wt% or more, about 60 wt% or more, about 70 wt% or more, about 80 wt% or more, about 90 wt% or more, about 95 wt% or more, or about 99 wt% or more of the catalytically active phase.

[0299] 176. The method according to any one of items 1 to 175, wherein the first catalyst comprises a catalytically active phase, and platinum accounts for about 20 wt% to about 99 wt%, about 30 wt% to about 99 wt%, about 40 wt% to about 99 wt%, about 50 wt% to about 99 wt%, about 60 wt% to about 99 wt%, about 70 wt% to about 99 wt%, about 80 wt% to about 99 wt%, about 90 wt% to about 99 wt%, about 95 wt% to about 99 wt%, about 20 wt% to about 95 wt%, about 30 wt% to about 95 wt%, about 40 wt% to about 95 wt%, about 50 wt% to about 95 wt%, about 60 wt% to about 95 wt%, about 70 wt% to about 95 wt%, about 80 wt% to about 95 wt%, about 90 wt% to about 95 wt%, about 20 wt% to about 90 wt%, about 30 wt% to about 90 wt%, about 40 wt% to about 90 wt%, about 50 wt% to about 90 wt%, about 60 wt% to about 90 wt%, about 70 wt% to about 90 wt%, or about 80 wt% to about 90 wt% of the catalytically active phase.

[0300] 177. The method according to any one of items 1 to 176, wherein the second catalyst comprises a catalytically active phase, and gold accounts for about 20 wt% or more, about 30 wt% or more, about 40 wt% or more, about 50 wt% or more, about 60 wt% or more, about 70 wt% or more, about 80 wt% or more, about 90 wt% or more, about 95 wt% or more, or about 99 wt% or more of the catalytically active phase.

[0301] 178. The second catalyst contains a catalytic active phase, and gold accounts for about 20 wt% to about 99 wt%, about 30 wt% to about 99 wt%, about 40 wt% to about 99 wt%, about 50 wt% to about 99 wt%, about 60 wt% to about 99 wt%, about 70 wt% to about 99 wt%, about 80 wt% to about 99 wt%, about 90 wt% to about 99 wt%, about 95 wt% to about 99 wt%, about 20 wt% to about 95 wt%, about 30 wt% to about 95 wt%, about 40 wt% to about 95 wt%, about 50 wt% to about 95 wt%, about 60 wt% to about 95 wt%, about 70 wt% to about 95 wt%, about 80 wt% to about 95 wt%, about 90 wt% to about 95 wt%, about 20 wt% to about 90 wt%, about 30 wt% to about 90 wt%, about 40 wt% to about 90 wt%, about 50 wt% to about 90 wt%, about 60 wt% to about 90 wt%, about 70 wt% to about 90 wt%, or about 80 wt% to about 90 wt% of the catalytic active phase, and the method according to any one of items 1 to 177.

[0302] 179. The method according to any one of items 1 to 178, wherein the method is not an electrochemical method.

[0303] 180. The method according to any one of items 1 to 178, wherein the method does not include applying an electric current to the reaction mixture.

Claims

1. 1. A process for preparing an aldaric acid and / or lactone thereof, comprising: (i) An aldose and / or lactone thereof of formula (I): SO ２ ((HCOH) ｗ CHO (I) (wherein w is an integer from 0 to 10), or (ii) Aldonic acids and / or lactones thereof of formula (II): HOCH ２ (HCOH) ｘ COOH (II) where x is an integer from 0 to 10; or (iii) Uronic acids and / or lactones thereof of formula (III): HOOC(HCOH) ｙ CHO (III) (wherein y is an integer from 0 to 10), reacting in a reaction zone in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form a reaction mixture comprising an aldaric acid of formula (IV) and / or a lactone thereof, wherein said first catalyst and second catalyst are different; the first catalyst comprises a catalyst support; the second catalyst is a heterogeneous catalyst and comprises a catalyst support; The aldaric acid and / or lactone thereof has the formula (IV): HOOC(HCOH) ｚ COOH (IV) (wherein z is an integer from 0 to 10); The method of option (i), wherein the reaction zone further comprises an oxidation catalyst.

2. In option (i), w and / or z are integers from 0 to 5; In option (ii), x and / or z are integers from 0 to 5; In option (iii), y and / or z are integers from 0 to 5; The method of claim 1.

3. The aldaric acid of formula (IV) comprises at least one C ２ ~C ７ 3. The method of claim 1 or 2, comprising an aldaric acid.

4. 4. The method of any one of claims 1 to 3, wherein the aldaric acid of formula (IV) comprises a trialk acid, a tetral acid, a pentalic acid, a hexalic acid, a heptalic acid, and / or mixtures thereof.

5. 5. The method of any one of claims 1 to 4, wherein the aldaric acid of formula (IV) comprises oxalic acid, tartronic acid, tartaric acid, xylaric acid, ribalic acid, arabinaric acid, glucaric acid, galactaric acid, mannaric acid, and / or mixtures thereof.

6. 6. The method of any one of claims 1 to 5, wherein the aldaric acid of formula (IV) comprises glucaric acid, xylaric acid, ribalic acid, arabinaric acid, and / or mixtures thereof.

7. In option (i), the aldose of formula (I) is glucose and the aldaric acid of formula (IV) is glucaric acid; In option (ii), the aldonic acid of formula (II) is gluconic acid, and the aldaric acid of formula (IV) is glucaric acid; In option (iii), the uronic acid of formula (III) is guluronic acid and the aldaric acid of formula (IV) is glucaric acid; The method according to any one of claims 1 to 6.

8. 8. The method of any one of claims 1 to 7, wherein the reaction zone comprises a first stage, the first stage comprising a mixture of the first catalyst and the second catalyst, the weight or volume of the first catalyst being greater than the weight or volume of the second catalyst.

9. 9. The method of any one of claims 1 to 8, wherein the reaction zone comprises a second stage, the second stage comprising a mixture of the first catalyst and the second catalyst, the weight or volume of the second catalyst being greater than the weight or volume of the first catalyst.

10. 10. The method of any one of claims 1 to 9, wherein the first catalyst has a platinum loading of about 0.1 wt.% to about 10 wt.%, about 0.1 wt.% to about 7.5 wt.%, about 0.1 wt.% to about 5 wt.%, about 0.1 wt.% to about 4 wt.%, about 0.5 wt.% to about 10 wt.%, about 0.5 wt.% to about 7.5 wt.%, about 0.5 wt.% to about 5 wt.%, about 0.5 wt.% to about 4 wt.%, about 1 wt.% to about 10 wt.%, about 1 wt.% to about 7.5 wt.%, about 1 wt.% to about 5 wt.%, about 1 wt.% to about 4 wt.%, or about 1 wt.% to about 3 wt.%.

11. 11. The method of any one of claims 1 to 10, wherein the second catalyst has a gold loading of from about 0.1 wt.% to about 10 wt.%, from about 0.1 wt.% to about 7.5 wt.%, from about 0.1 wt.% to about 5 wt.%, from about 0.1 wt.% to about 4 wt.%, from about 0.1 wt.% to about 3 wt.%, from about 0.1 wt.% to about 2 wt.%, from about 0.5 wt.% to about 10 wt.%, from about 0.5 wt.% to about 7.5 wt.%, from about 0.5 wt.% to about 5 wt.%, from about 0.5 wt.% to about 4 wt.%, from about 0.5 wt.% to about 3 wt.%, from about 0.5 wt.% to about 2 wt.%, from about 1 wt.% to about 10 wt.%, from about 1 wt.% to about 7.5 wt.%, from about 1 wt.% to about 5 wt.%, from about 1 wt.% to about 4 wt.%, from about 1 wt.% to about 3 wt.%, or from about 1 wt.% to about 2 wt.%.

12. The LHSV of the reaction zone is about 0.2 h －１ ~About 50 hours －１ , about 0.5h －１ ~About 50 hours －１ , about 1 hour －１ ~About 50 hours －１ , about 2 hours －１ ~About 50 hours －１ , about 5 hours －１ ~About 50 hours －１ , about 10h －１ ~About 50 hours －１ , about 0.2h －１ ~about 10 hours －１ , about 0.5h －１ ~about 10 hours －１ , about 1 hour －１ ~about 10 hours －１ , about 2 hours －１ ~about 10 hours －１ , or about 5 hours －１ ~about 10 hours －１ The method according to any one of claims 1 to 11, wherein

13. 13. The method of any one of claims 1 to 12, wherein the reaction zone is heated to a temperature of about 60°C to about 150°C, about 70°C to about 150°C, about 80°C to about 150°C, about 60°C to about 125°C, about 70°C to about 125°C, about 80°C to about 125°C, about 60°C to about 100°C, about 70°C to about 100°C, or about 80°C to about 100°C.

14. 14. The method of any one of claims 1 to 13, wherein the partial pressure of oxygen ranges from about 2 psig to about 2000 psig, from about 50 psig to about 2000 psig, or from about 100 psig to about 2000 psig.

15. 15. The method of any one of claims 1 to 14, wherein the oxygen is supplied to the reaction zone as air, oxygen-enriched air, a mixture comprising at least about 40 or 50 volume percent oxygen, a mixture comprising oxygen and nitrogen, or substantially pure oxygen.

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