Process for preparing aldaric, aldonic, and uronic acids

Abstract

Various methods are described for preparing aldaric acids, aldonic acids, uronic acids, and / or lactones thereof, for example, by catalytic oxidation of C2-C7 aldonic acids and / or lactones thereof and / or C2-C7 aldoses.

Description

[Technical field]

[0001]

[0001] Various methods are described for preparing aldaric acids, aldonic acids, uronic acids, and / or lactones thereof, for example, by catalytic oxidation of C2-C7 aldonic acids and / or lactones thereof and / or C2-C7 aldoses. [Background technology]

[0002]

[0002] For many years there has been interest in using biorenewable materials as feedstocks for the production of commercially useful chemicals. In particular, a significant body of research has focused on the oxidation of sugars obtained from these materials to aldaric acids, in particular the oxidation of glucose to glucaric acid. See, for example, U.S. Patent Nos. 8,669,397 and 8,785,683, which are incorporated herein by reference. These products are useful not only as intermediates in the production of monomers such as adipic acid, but also in the manufacture of compositions having commercial applications such as thawing solutions, acidulants, detergent builders, pH adjusters, chelating agents, descalers, 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 tried. However, sustained high yields of glucaric acid over long periods of operation or at high reactor throughputs have 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 oxidation of 5 wt% glucose feedstock at 80°C and about 200 psi O2 partial pressure in a batch reactor for 10 hours, with 5 wt% Pt / C catalyst. In U.S. Patent No. 9,770,705, a 70% glucaric acid yield was reported for experiments in which 2.3 mL of 10 wt% gluconic acid feedstock was contacted with 75 mg of catalyst at 112-126°C for 2-5 hours. There remains a need for efficient and cost-effective processes for the preparation of aldaric acids, such as glucaric acid, and its intermediates from bio-renewable materials that exhibit improved and stable yields, especially over long periods of operation and at high reactor throughput. Summary of the Invention [Means for solving the problem]

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

[0005] In one embodiment, the method for preparing an aldaric acid (e.g., glucaric acid) and / or lactone thereof comprises reacting an aldaric acid having the formula (II): HOCH2(HCOH) x COOH (II) wherein x is an integer from 0 to 10, reacting an aldonic acid (e.g., gluconic acid) and / or lactone thereof 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 and / or lactone thereof having formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer of 0 to 10).

[0006]

[0006] In certain embodiments, a method for preparing an aldaric acid (e.g., glucaric acid) comprises preparing a compound of formula (II): HOCH2(HCOH) x COOH (II) wherein x is an integer between 0 and 10, reacting an aldonic acid (e.g., gluconic acid) and / or lactone thereof in the presence of oxygen and a first catalyst comprising platinum in a first stage of a reaction zone to form a first reaction mixture; and contacting the first reaction mixture in a second stage of the reaction zone with oxygen and a second catalyst comprising gold to form a second reaction mixture comprising an aldaric acid and / or lactone thereof of formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer of 0 to 10).

[0007] In a further embodiment, the process for preparing aldaric acids (e.g., glucaric acid) and / or lactones thereof comprises the step of preparing a compound of formula (III): HOOC(HCOH) y CHO (III) wherein y is an integer from 0 to 10, reacting a uronic acid (e.g., guluronic acid) and / or lactone thereof 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 and / or lactone thereof of formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer of 0 to 10).

[0008] In a further embodiment, the method for preparing aldaric acids (e.g., glucaric acid) and / or lactones thereof comprises reacting aldaric acids having the formula (I): HOCH2(HCOH) w CHO (I) wherein w is an integer from 0 to 10, reacting an aldose (e.g., glucose) and / or lactone thereof in the presence of oxygen in a reaction zone comprising an oxidation catalyst, 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 lactone thereof, wherein the first catalyst and the second catalyst are distinct and the aldaric acid has formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer of 0 to 10).

[0009] A further aspect of the invention relates to a method for preparing uronic acids (eg, guluronic acid) and / or lactones thereof.

[0010] In one embodiment, the method for preparing uronic acids (e.g., guluronic acid) and / or lactones thereof comprises reacting a compound of formula (I): HOCH2(HCOH) w CHO (I) wherein w is an integer from 0 to 10, reacting an aldose (e.g., glucose) and / or lactone thereof in a reaction zone in the presence of oxygen, an oxidation catalyst, a first catalyst comprising platinum, and a second catalyst comprising gold to form a reaction mixture comprising a uronic acid of formula (III) and / or lactone thereof, wherein the first catalyst and the second catalyst are distinct and the uronic acid has formula (III): HOOC(HCOH) y CHO (III) (wherein y is an integer of 0 to 10).

[0011] In another embodiment, the method for preparing a uronic acid (e.g., guluronic acid) and / or lactone thereof comprises reacting a compound of formula (II): HOCH2(HCOH) x COOH (II) wherein x is an integer between 0 and 10, reacting an aldonic acid (e.g., gluconic acid) and / or lactone thereof 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 a uronic acid of formula (III) and / or lactone thereof, wherein the first catalyst and the second catalyst are distinct and the uronic acid has formula (III): HOOC(HCOH) y CHO (III) (wherein y is an integer of 0 to 10).

[0012] Another aspect of the present invention relates to a method for preparing an aldonic acid (e.g., gluconic acid) and / or lactone thereof. In various embodiments, the method for preparing an aldonic acid (e.g., gluconic acid) and / or lactone thereof comprises the step of preparing an aldonic acid (e.g., gluconic acid) and / or lactone thereof comprising the steps of: HOCH2(HCOH) w CHO (I) wherein w is an integer from 0 to 10, in the presence of oxygen and an oxidation catalyst to form a reaction mixture comprising an aldose (e.g., glucose) of formula (II) and / or lactone thereof, wherein the aldonic acid has the formula (II): HOCH2(HCOH) x COOH (II) (wherein x is an integer of 0 to 10).

[0013]

[0013] Other objects and features will be in part apparent and in part pointed out hereinafter. [Brief description of the drawings]

[0014] [Figure 1]

[0014] FIG. 1 shows a diagram illustrating the steps of an oxidation process for preparing C2-C7 aldaric acids and / or lactones thereof from C2-C7 aldoses. [Diagram 2]

[0015] A schematic diagram of the two-stage reaction zone is shown. [Diagram 3]

[0016] FIG. 1 shows a schematic diagram of a two-stage reaction zone containing different catalyst mixtures. [Figure 4]

[0017] 8 shows the glucose conversion rate, gluconic acid yield, and glucaric acid yield for an oxidation reaction using a 1 wt % Au / TiO2 catalyst over an operation time of 16 to 1792 hours. [Diagram 5]

[0018] 4 shows the glucose conversion rate, gluconic acid yield, and glucaric acid yield for an oxidation reaction using a 1 wt % Au / TiO2 catalyst over an operation time of 2556 to 4640 hours. [Figure 6]

[0019] 4 shows the gluconic acid conversion, selectivity, and yields of glucaric acid, guluronic acid, 2-keto-gluconate, and 5-keto-gluconate achieved during the oxidation reaction at various temperatures using a 4 wt % Pt / C catalyst. [Figure 7]

[0020] FIG. 1 shows the glucose conversion, 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] 4 shows the gluconic acid conversion and the 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 / TiO 2 catalysts. [Figure 9]

[0022] FIG. 1 shows gluconic acid conversion 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 catalysts including Pt / C and Au / TiO2. [Figure 10]

[0023] 4 shows gluconic acid conversion, 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 catalysts. [Figure 11]

[0024] The results of the experiment in FIG. 10 conducted over a total operation time of 1,468 hours are shown. [Figure 12]

[0025] The arabinose conversion rate, arabinonic acid yield, and arabinaric acid yield measured in Example 7 are shown. [Figure 13]

[0026] The arabinonic acid conversion rate, arabinaric acid yield, tartaric acid yield, and glyceric acid yield measured in Example 8 are shown. [Figure 14]

[0027] 1 shows the glyceric acid yield measured in Example 9. [Figure 15]

[0028] 1 shows the glycoaldehyde conversion and glycolic acid yield measured in Example 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Detailed Description

[0029] Embodiments of the present invention relate to various methods for preparing aldaric acids, aldonic acids, uronic acids, and / or lactones of any of these acids. For example, various embodiments relate to methods for preparing C2-C7 aldaric acids and / or lactones thereof (e.g., glucaric acid) by catalytic oxidation of C2-C7 aldonic acids and / or lactones thereof (e.g., gluconic acid). Other embodiments relate to the preparation of C2-C7 uronic acids and / or lactones thereof (e.g., guluronic acid) by catalytic oxidation of C2-C7 aldonic acids and / or lactones thereof (e.g., gluconic acid). Further embodiments relate to the preparation of these various acids and / or lactones thereof from aldoses (e.g., glucose).

[0016]

[0030] Aldoses, as referred to herein, include a variety of compounds having an aldehyde group and a hydroxyl group, which can be represented by the formula (I): HOCH2(HCOH) w CHO (I) where w can be, for example, an integer from 0 to 10, or in some embodiments, 0 to 5. In various embodiments, the aldose comprises at least one C2-C7 aldose. In some embodiments, the aldose comprises at least one triose, tetrose, pentose, hexose, and / or heptose. Specific C2-C7 aldoses include, for example, glycolaldehyde, glyceraldehyde, threose, erythrose, xylose, ribose, arabinose, glucose, galactose, mannose, glucoheptose, and L-glycero-D-mannoheptose. In various embodiments, the aldose comprises a hexose, such as glucose. In some embodiments, the aldose comprises a pentose, such as xylose, ribose, and / or arabinose. The term "aldose" and any specific aldose described herein and defined by formula (I) also includes cyclic forms (hemiacetal forms) of these compounds.

[0017]

[0031] Aldoses can be obtained from a variety of carbohydrate-containing sources, including traditional biorenewable sources such as corn kernels (maize), wheat, potato, 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, aldoses (e.g., glucose) are obtained from cereal crops (e.g., corn, wheat, soybean, rice, barley, rye, millet, sorghum, etc.). More generally, biorenewable sources that can be used include any renewable organic matter that contains a carbohydrate source, such as, for example, switchgrass, miscanthus, trees (hardwoods and softwoods), vegetation, and crop residues (e.g., bagasse and corn stover). Other sources include, for example, waste materials (e.g., post-consumer paper, green waste, municipal waste, etc.). Carbohydrates can be isolated from biorenewable materials using known methods.

[0018]

[0032] Aldonic acids as referred to herein include those of formula (II): HOCH2(HCOH) x COOH (II) (wherein x can be, for example, an integer from 0 to 10, and in some embodiments, is 0 to 5). In various embodiments, the aldonic acid includes at least one C2-C7 aldonic acid. In some embodiments, the aldonic acid includes at least one dionic acid, trionic acid, tetronic acid, pentonic acid, hexonic acid, and / or heptonic acid. Specific C2-C7 aldonic acids include, for example, glycolic acid, glyceric acid, threonic acid, erythronic acid, xylonic acid, ribonic acid, arabinonic acid, lyxonic acid, allonic acid, altronic acid, mannonic acid, gulonic acid, idonic acid, galactonic acid, talonic acid, gluconic acid, and glucoheptonic acid. In various embodiments, the C2-C7 aldonic acid includes a hexonic acid, such as gluconic acid. In some embodiments, the C2-C7 aldonic acid comprises a pentonic acid. For example, the pentonic acid may be selected from the group consisting of xylonic acid, ribonic acid, arabinonic acid, and mixtures thereof. Lactones of various aldonic acids may also be present and may be formed by intramolecular cyclocondensation of the acids.

[0019]

[0033] As referred to herein, uronic acids include those of formula (III): HOOC(HCOH) y CHO (III) (wherein y can be, for example, an integer from 0 to 10, and in some embodiments, is 0 to 5). In various embodiments, the uronic acid comprises at least one C2 to C7 uronic acid. In some embodiments, the uronic acid comprises at least one diuronic acid, triuronic acid, tetrauronic acid, pentauronic acid, hexuronic acid, and / or heptauronic acid. Specific C2-C7 uronic acids include, for example, glyoxylic acid, glyceruronic acid (tartronaldehyde acid), treuronic acid, erythruronic acid, xylouronic acid, ribouronic acid, arabinuronic acid, lyxonuronic acid, guluronic acid, glucuronic acid, galactouronic acid, mannouronic acid, aruronic acid, altouronic 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 pentauronic acid, such as xylouronic acid, ribouronic acid, and / or arabinuronic acid. Lactones of the various uronic acids may also exist and may be formed by intramolecular cyclocondensation of the acids. The term "uronic acid" and any specific uronic acid described herein and defined by formula (III) also includes the cyclic forms (hemiacetal forms) of these compounds.

[0020]

[0034] Aldaric acids referred to herein include those of formula (IV): HOOC(HCOH) z COOH (IV) (wherein z can be, for example, an integer from 0 to 10, and in some embodiments, is 0 to 5). In various embodiments, the aldaric acid includes at least one C2-C7 aldaric acid. In some embodiments, the aldaric acid includes at least one dialic acid, triaric acid, tetraric acid, pentaric acid, hexaric acid, and / or heptaric acid. Specific C2-C7 aldaric acids include, for example, oxalic acid, tartronic acid, tartaric acid, xylaric acid, ribalic acid, arabinaric acid, lixaric acid, araric acid, altraric acid, glucaric acid, galactaric acid, mannaric acid, glular acid, idaric acid, talaric acid, and glucoheptaric acid. In certain embodiments, the C2-C7 aldaric acid includes hexalic acid and / or pentalic acid. In various embodiments, the C2-C7 aldaric acid includes glucaric acid. In further embodiments, the C2-C7 aldaric acid includes a pentalic acid selected from the group consisting of xylaric acid, ribalic acid, arabinaric acid, and mixtures thereof. Lactones of the various aldaric acids may also be present and may be formed by intramolecular cyclocondensation of the acids. 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] In accordance with the present invention, the various methods described herein provide improved yields of uronic acids, aldonic acids, and aldaric acids, particularly improved aldaric acid yields (e.g., improved glucaric acid yields). Furthermore, the various methods described herein provide stable product yields over long periods of 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 reducing the amount of on-path intermediates that require further processing.

[0022]

[0036] The preparation of aldaric acids and / or lactones from aldonic acids and / or lactones and / or the corresponding aldoses is typically a multi-step synthesis that proceeds via a variety of intermediates. For example, as shown in the following scheme, the oxidation of glucose to glucaric acid proceeds primarily via two intermediates: gluconic acid and guluronic acid. [ka] First, the carbonyl of glucose is oxidized to an acid to produce gluconic acid. Next, the terminal hydroxyl at the 6-position of gluconic acid is dehydrogenated to a carbonyl to produce guluronic acid. Finally, the carbonyl of guluronic acid is oxidized to an acid to produce glucaric acid.

[0023]

[0037] Previously reported glucaric acid yields (e.g., yields rarely exceed 70%) may be limited by several factors. Some potential limiting factors include the formation of on-pass or off-pass products that significantly reduce the catalyst effectiveness, overconversion of glucaric acid, and leaching of catalytically active metals. Also, without pH control by continuous base introduction during the oxidation reaction, the rate of glucaric acid production decreases as the pH decreases. On the other hand, pH adjustment often results in lower glucaric acid yields due to overconversion of glucaric acid to C2-C5 sugar acid derivatives. Thus, several inhibitors, individually or in combination, may be responsible for limiting the overall yield to glucaric acid.

[0024]

[0038] It has been surprisingly discovered that using at least two different catalysts in a process for preparing aldaric acids and / or lactones thereof and / or intermediates thereof by catalytic oxidation of aldoses, aldonic acids and / or lactones thereof, and / or uronic acids and / or lactones thereof provides improved product yields (e.g., aldaric acid yields), even over extended periods of operation. It is theorized that by using at least two different catalysts, some of the inhibitors expected to limit the overall yield are reduced or avoided. In particular, it has been discovered that a first catalyst comprising platinum and a second catalyst comprising gold are particularly effective in the catalytic oxidation of C2-C7 aldoses, C2-C7 uronic acids and / or lactones thereof, and C2-C7 aldonic acids and / or lactones thereof to the corresponding aldaric acids and / or lactones thereof or intermediates thereof.

[0025] Process for Producing Aldaric Acids and / or Lactones Thereof

[0039] As mentioned above, embodiments of the present invention include oxidation processes for producing aldaric acids and / or lactones thereof. Various methods include reacting an aldose of formula (I) to an aldaric acid of formula (IV) and / or lactones thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form an aldaric acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different. These methods may be represented by the following schemes (wherein w and z are as defined herein): [ka]

[0026]

[0040] An embodiment relates to a method for preparing C2-C7 aldaric acids and / or lactones thereof, comprising reacting a C2-C7 aldose in the presence of oxygen in a reaction zone comprising an oxidation catalyst, a first catalyst comprising platinum, and a second catalyst comprising gold to form a reaction mixture comprising C2-C7 aldaric acids and / or lactones thereof, where the first catalyst and the second catalyst are different. For example, when the method is a method for preparing glucaric acid and / or lactones thereof, the method may comprise reacting glucose in the presence of oxygen in a reaction zone comprising an oxidation catalyst, a first catalyst comprising platinum, and a second catalyst comprising gold to form a reaction mixture comprising glucaric acid and / or lactones thereof, where the first catalyst and the second catalyst are different. Figure 1 shows a diagram illustrating the steps of an oxidation method for preparing C2-C7 aldaric acids and / or lactones thereof from C2-C7 aldoses.

[0027]

[0041] Another method comprises preparing an aldaric acid and / or lactone thereof of formula (IV) comprising reacting an aldonic acid and / or lactone thereof of formula (II) in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form an aldaric acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different. These methods may be represented by the following schemes (wherein x and z are as defined herein): [ka] In certain embodiments, a method for preparing a C2-C7 aldaric acid and / or lactone thereof comprises reacting a C2-C7 aldonic acid and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising a C2-C7 aldaric acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different. For example, when the method is directed to preparing glucaric acid and / or lactone thereof, the method may comprise reacting gluconic acid and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising glucaric acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different.

[0028]

[0042]

[0013] Embodiments of the present invention also include methods for preparing aldaric acids and / or lactones thereof of formula (IV), comprising reacting a uronic acid and / or lactone thereof of formula (III) in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form an aldaric acid and / or lactone, wherein the first catalyst and the second catalyst are different. These methods may be represented by the following schemes (wherein y and z are as defined herein): [ka] In certain embodiments, a method for preparing a C2-C7 aldaric acid and / or lactone thereof comprises reacting a C2-C7 uronic acid and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising the C2-C7 aldaric acid and / or lactone, wherein the first catalyst and the second catalyst are different. For example, when the method is directed to preparing glucaric acid and / or lactone thereof, the method may comprise reacting a guluronic acid and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising the glucaric acid and / or lactone, wherein the first catalyst and the second catalyst are different.

[0029] Process for Producing Uronic Acids and / or Lactones Thereof

[0043]

[0023] Embodiments of the present invention also include methods for producing uronic acids and / or lactones. Various methods include the preparation of uronic acids and / or lactones thereof of formula (III) comprising reacting an aldose of formula (I) in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form the uronic acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different. These methods may be represented by the following schemes (wherein w and y are as defined herein): [ka] In certain embodiments, a method for preparing a C2-C7 uronic acid and / or lactone thereof may include reacting a C2-C7 aldose in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising the C2-C7 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 lactone thereof may include reacting glucose in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising the guluronic acid and / or lactone, where the first catalyst and the second catalyst are different.

[0030]

[0044]

[0013] Embodiments of the present invention also include methods for preparing uronic acids and / or lactones thereof, comprising reacting an aldonic acid and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form a uronic acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different. These methods may be represented by the following schemes (wherein x and y are as defined herein): [ka] In certain embodiments, a method for preparing a C2-C7 uronic acid and / or lactone thereof may include reacting a C2-C7 aldonic acid and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising the C2-C7 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 lactone thereof may include reacting gluconic acid and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold in a reaction zone to form a reaction mixture comprising the guluronic acid and / or lactone, where the first catalyst and the second catalyst are different.

[0031] Process for Producing Aldonic Acids and / or Lactones Thereof

[0045]

[0023] Embodiments of the present invention also include methods for producing aldonic acids and / or lactones. Various methods include reacting an aldose of formula (I) to an aldonic acid of formula (II) and / or lactone thereof in the presence of oxygen, a first catalyst comprising platinum, and a second catalyst comprising gold to form an aldonic acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different. These methods may be represented by the following schemes (wherein x and y are as defined herein): [ka] In certain embodiments, a method for preparing a C2-C7 aldonic acid and / or lactone thereof may include reacting a C2-C7 aldose 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 the C2-C7 aldonic acid and / or lactone, where the first catalyst and the second catalyst are different. For example, a method for preparing gluconic acid and / or lactone thereof may include reacting glucose 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 gluconic acid and / or lactone, where the first catalyst and the second catalyst are different.

[0032]

[0046] The various methods described herein may further comprise 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 a lactone thereof. This further process step may be represented by the following scheme (wherein w and x are as defined herein): [ka] In certain embodiments, various methods may further include reacting a C2-C7 aldose in the presence of oxygen and an oxidation catalyst to form a C2-C7 aldonic acid and / or lactone thereof. For example, in methods in which gluconic acid and / or lactones thereof are required, the methods may further include reacting glucose in the presence of oxygen and an oxidation catalyst to form gluconic acid and / or lactones thereof.

[0033] Further Process and Process Features

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

[0034]

[0048] Further, in various methods described herein, the first catalyst and the second catalyst can be stepwise or a combination of mixed and stepwise. For example, the reaction zone can include a first stage including a first catalyst and a second stage including a second catalyst. See FIG. 2, which is a schematic diagram of a two-stage reaction zone. Various stepwise methods for preparing aldaric acids of formula (IV) and / or lactones thereof by oxidizing aldonic acids of formula (II) can be represented by the following schemes (wherein x, y, and z are as defined herein): [ka] In certain embodiments, a method for preparing a C2-C7 aldaric acid and / or lactone may include reacting a C2-C7 aldonic acid and / or lactone thereof in the presence of a first catalyst comprising oxygen and platinum in a first stage of a reaction zone to form a first reaction mixture (e.g., a reaction mixture comprising a C2-C7 uronic acid); and contacting the first reaction mixture with a second catalyst comprising oxygen and gold in a second stage of the reaction zone to form a second reaction mixture comprising a C2-C7 aldaric acid and / or lactone thereof, wherein the first catalyst and the second catalyst are different. When the method is for preparing glucaric acid and / or its lactone, the method may comprise reacting gluconic acid and / or its lactone in the presence of oxygen and a first catalyst comprising platinum in a first stage of a reaction zone 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 oxygen and a second catalyst comprising gold in a second stage of a 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.

[0035]

[0049] In various embodiments including a first stage and / or a second stage, the first stage can include a mixture of a first catalyst and a second catalyst. In some embodiments, in the first stage, the weight or volume of the first catalyst can 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 some 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 can be 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.

[0036]

[0050] In embodiments that include a first stage and a second stage, the second stage can include a mixture of the first catalyst and the second catalyst. In some embodiments, the weight or volume of the second catalyst can exceed the weight or volume of the first catalyst. For example, in various embodiments, the second stage includes a mixture of the first catalyst and the 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 can include a mixture of the first catalyst and the second catalyst, and the weight or volume ratio of the second catalyst to the first catalyst can be 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.

[0037]

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

[0038]

[0052] As noted above, various methods described herein may further include reacting the aldose in the presence of oxygen and an oxidation catalyst to form an aldonic acid and / or lactone thereof. 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 various processes described herein, the weight or volume ratio of the first catalyst to the total amount of 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 first catalyst to the total amount of 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 various methods described herein, a feed mixture (e.g., a feed solution) can be fed to a reaction zone. In certain embodiments, the concentration of aldose, aldonic acid and / or lactone, and / or uronic acid and / or lactone thereof in the feed mixture is about 1% by weight or more, about 5% by weight or more, about 10% by weight or more, about 15% by weight or more, or about 20% by weight or more. In one embodiment, the raw material mixture is supplied to the reaction zone, and the concentration of the aldose, aldonic acid and / or lactone, and / or uronic acid and / or lactone thereof in the raw material mixture is about 1% by weight to about 50% by weight, about 1% by weight to about 30% by weight, about 1% by weight to about 25% by weight, about 5% by weight to about 50% by weight, about 5% by weight to about 30% by weight, about 5% by weight to about 25% by weight, about 10% by weight to about 50% by weight, about 10% by weight to about 30% by weight, about 10% by weight to about 25% by weight, about 15% by weight to about 50% by weight, about 15% by weight to about 30% by weight, about 15% by weight to about 25% by weight, about 20% by weight to about 50% by weight, about 20% by weight to about 30% by weight, or about 20% by weight to about 25% by weight.

[0041]

[0055] In various embodiments, the concentration of C2-C7 aldoses, C2-C7 aldonic acids and / or lactones, and / or C2-C7 uronic acids and / or lactones thereof in the feedstock mixture is about 1% by weight or more, about 5% by weight or more, about 10% by weight or more, about 15% by weight or more, or about 20% by weight or more. In one embodiment, the raw material mixture is supplied to the reaction zone, and the concentrations of the C2 to C7 aldoses, C2 to C7 aldonic acids and / or lactones, and C2 to C7 uronic acids and / or lactones thereof in the raw material mixture are about 1% by weight to about 50% by weight, about 1% by weight to about 30% by weight, about 1% by weight to about 25% by weight, about 5% by weight to about 50% by weight, about 5% by weight to about 30% by weight, about 5% by weight to about 25% by weight, about 10% by weight to about 50% by weight, about 10% by weight to about 30% by weight, about 10% by weight to about 25% by weight, about 15% by weight to about 50% by weight, about 15% by weight to about 30% by weight, about 15% by weight to about 25% by weight, about 20% by weight to about 50% by weight, about 20% by weight to about 30% by weight, or about 20% by weight to about 25% by weight.

[0042]

[0056] In embodiments in which the C2-C7 aldonic acid and / or lactone comprises gluconic acid and / or its lactone, a feed mixture can be provided 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 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% by weight to about 50% by weight, about 1% by weight to about 30% by weight, about 1% by weight to about 25% by weight, about 5% by weight to about 50% by weight, about 5% by weight to about 30% by weight, about 5% by weight to about 25% by weight, about 10% by weight to about 50% by weight, about 10% by weight to about 30% by weight, about 10% by weight to about 25% by weight, about 15% by weight to about 50% by weight, about 15% by weight to about 30% by weight, about 15% by weight to about 25% by weight, about 20% by weight to about 50% by weight, about 20% by weight to about 30% by weight, or about 20% by weight to about 25% by weight.

[0043]

[0057] As mentioned above, pH adjustment typically results in lower product yields due to overconversion of aldaric acid to other derivatives. Thus, in various embodiments, the methods described herein may be carried out without the addition of base. In further embodiments, processes may be carried out in which the pH of the reaction mixture is not controlled or increased by the addition of base. In certain embodiments, processes may be carried out in which the reaction mixture is free or substantially free of salt-forming cations.

[0044]

[0058] In various embodiments, the pH of the reaction mixture of the methods described herein, when 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, when 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, 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 region is heated to a temperature of about 60° C. or higher, about 70° C. or higher, or about 80° C. or higher. For example, the reaction region 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 certain embodiments, oxygen is supplied to the reaction zone as air, oxygen-enriched air, a mixture comprising oxygen, a mixture comprising at least about 40 or 50% oxygen by volume, a mixture comprising oxygen and nitrogen (e.g., about a 50:50 mixture by volume), or substantially pure oxygen (at least 99% oxygen by volume). In various embodiments, oxygen is supplied to the reaction zone as a mixture having an oxygen concentration of about 0.5% by volume or more, about 1% by volume or more, about 5% by volume or more, or about 10% by volume or more. For example, in various embodiments, oxygen is supplied to the reaction region as a mixture having an oxygen concentration of about 0.5% by volume to about 20% by volume, about 0.5% by volume to about 15% by volume, about 0.5% by volume to about 10% by volume, about 0.5% by volume to about 5% by volume, about 1% by volume to about 20% by volume, about 1% by volume to about 15% by volume, about 1% by volume to about 10% by volume, about 1% by volume to about 5% by volume, about 5% by volume to about 20% by volume, about 5% by volume to about 15% by volume, or about 5% by volume to about 10% by volume. In certain embodiments, oxygen is supplied to the reaction region as a mixture having an oxygen concentration of about 10% by volume or less, about 5% by volume or less, about 4% by volume or less, about 3% by volume or less, about 2% by volume or less, about 1% by volume or less, or about 0.5% by volume or less. For example, about 10 vol% to about 0.5 vol%, about 5 vol% to about 0.5 vol%, about 4 vol% to about 0.5 vol%, about 3 vol% to about 0.5 vol%, about 2 vol% to about 0.5 vol%, or about 1 vol% to about 0.5 vol%.

[0047]

[0061] In various embodiments, the partial pressure of oxygen in the reaction zone is about 2 psig or more, about 25 psig or more, about 50 psig or more, or about 100 psig or more. 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] In general, the methods described herein are catalytic processes, but do not require the application of an electric current. Thus, in various embodiments, the methods described herein are not electrochemical processes and / or do not involve the application of an electric current to the reaction mixture (e.g., via electrodes).

[0049]

[0063] As noted above, the methods of the present invention can provide improved product yields, in certain embodiments, the yield of aldonic acids and / or lactones thereof, uronic acids and / or lactones thereof, and / or aldaric acids and / or lactones thereof 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. For example, the yield of aldonic acid and / or lactone thereof, uronic acid and / or lactone thereof, and / or aldaric acid and / or lactone thereof 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%.

[0050]

[0064] In certain embodiments, the yield of C2 to C7 aldonic acids and / or lactones thereof, C2 to C7 uronic acids and / or lactones thereof, and / or C2 to C7 aldaric acids and / or lactones thereof 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. For example, the yield of C2 to C7 aldonic acids and / or lactones thereof, C2 to C7 uronic acids and / or lactones thereof, and / or C2 to C7 aldaric acids and / or lactones thereof 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] In embodiments in which the C2-C7 aldaric acid and / or lactone comprises glucaric acid and / or its lactone, the yield of glucaric acid and / or its lactone may 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 may 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] The method of the present invention can also provide stable yields even at high reactor throughput. In certain embodiments, the liquid hourly space velocity (LHSV) in the reaction zone is about 0.2 h -1 Over, about 0.5h -1 The above took about 1 hour. -1 More than 1.5 hours -1 More than that, about 2 hours -1 That's about 5 hours -1 or more, or about 10 hours -1For example, the LHSV of the reaction area is about 0.2h -1 ~About 50 hours -1 , about 0.5h -1 ~About 50 hours -1 , about 1h -1 ~About 50 hours -1 , about 2h -1 ~About 50 hours -1 , about 5h -1 ~About 50 hours -1 , about 10h -1 ~About 50 hours -1 , about 0.2h -1 ~about 10h -1 , about 0.5h -1 ~about 10h -1 , about 1h -1 ~about 10h -1 , about 2h -1 ~about 10h -1 , or about 5 hours -1 ~about 10h -1 In certain embodiments, a product yield (e.g., yield of C2-C7 aldaric acids, such as glucaric acid, and / or lactones thereof) of at least about 60%, at least about 65%, at least about 70%, or at least about 75% may be achieved at or within the LHSV ranges above.

[0053]

[0067] The reaction mixture and / or the raw material 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] In general, the reaction zone may include one or more batch, semi-batch, or continuous reactor designs using fixed bed reactors, 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 various processes described herein, the reaction zone includes one or more trickle bed reactors. It should be understood that the reactants, oxygen, optional solvent, and catalyst may be introduced into a suitable reactor separately or in various combinations.

[0055]

[0069] The aldaric, aldonic, and uronic acids and / or lactones thereof produced according to the methods described herein can be converted into a variety of 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 useful in the oxidation processes described herein comprises platinum (i.e., the first catalyst comprises platinum), which has been found to be particularly useful in the oxidation of aldonic acids and / or lactones thereof (e.g., gluconic acid) to uronic acids and / or lactones thereof (e.g., guluronic acid).

[0057]

[0071] In some embodiments, the first catalyst has a platinum loading of about 10% or less, about 7.5% or less, about 5% or less, about 4% or less, about 2% or less, or about 1% or less by weight. In these and other embodiments, the first catalyst has a platinum loading of about 0.1% or more, about 0.25% or more, about 0.5% or more, about 0.75% or more, or about 1% or more by weight. 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 comprises a catalytically active phase, and platinum comprises a significant portion of the catalytically active phase, for example, in certain embodiments, platinum comprises at least about 20% by weight, at least about 30% by weight, at least about 40% by weight, at least about 50% by weight, at least about 60% by weight, at least about 70% by weight, at least about 80% by weight, at least about 90% by weight, at least about 95% by weight, or at least about 99% by weight of the catalytically active phase of the first catalyst. In certain embodiments, platinum comprises from about 20% to about 99% by weight, from about 30% to about 99% by weight, from about 40% to about 99% by weight, from about 50% to about 99% by weight, from about 60% to about 99% by weight, from about 70% to about 99% by weight, from about 80% to about 99% by weight, from about 90% to about 99% by weight, from about 95% to about 99% by weight, from about 20% to about 95% by weight, from about 30% to about 95 ...50% to about 99% by weight, from about 50% to about 99% by weight, from about 50% to about 9 % to about 95% by weight, about 50% to about 95% by weight, about 60% to about 95% by weight, about 70% to about 95% by weight, about 80% to about 95% by weight, about 90% to about 95% by weight, about 20% to about 90% by weight, about 30% to about 90% by weight, about 40% to about 90% by weight, about 50% to about 90% by weight, about 60% to about 90% by weight, about 70% to about 90% by weight, or about 80% to about 90% by weight.

[0059]

[0073] In various embodiments, the first catalyst is a heterogeneous catalyst. In some embodiments, the first catalyst comprises a catalyst support. For example, the support of the first catalyst may comprise a material selected from the group consisting of carbon, alumina, silica, ceria, titania, zirconia, niobia, zeolites, magnesia, clays, nickel, cobalt, copper, iron oxide, silicon carbide, aluminosilicates, montmorillonites, and combinations thereof. In certain embodiments, the support of the first catalyst comprises carbon, titania, zirconia, and combinations thereof. In further embodiments, the support of the first catalyst comprises 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 comprises carbon black. Various carbon supports and methods of preparing these supports and catalyst compositions are described in U.S. Pat. No. 9,682,368 and U.S. Patent Application Publication Nos. 2017 / 0120223 and 2017 / 0120219, each of which is incorporated herein by reference.

[0060]

[0074] In various embodiments, the first catalyst is at least about 5 m 2 / g, at least about 100m 2 / g, at least about 200m 2 / g, at least about 500m 2 / g, at least about 1,000m 2 / g, at least about 1,500m 2 / g, or at least about 2,000 m 2 For example, the first catalyst may have a BET specific surface area of ​​about 5 m 2 / g ~ approx. 2,500m 2 / g, approx. 5m 2 / g ~ approx. 2,000m 2 / g, approx. 5m 2 / g ~ approx. 1,500m 2 / g, approx. 5m 2 / g ~ approx. 1,000m 2 / g, approx. 5m 2 / g~about 500m 2 / g, approx. 5m 2 / g~about 200m 2 / g, about 100m 2 / g ~ approx. 2,500m 2 / g, about 100m 2 / g ~ approx. 2,000m 2 / g, about 100m 2 / g ~ approx. 1,500m 2 / g, about 100m 2 / g ~ approx. 1,000m 2 / g, about 100m 2 / g~about 500m 2 / g, or about 100m 2 / g~about 200m 2 / g.

[0061]

[0075] As noted above, an additional catalyst useful in the methods described herein comprises gold (i.e., the second catalyst comprises gold), which has been found to be particularly useful for the oxidation of uronic acids and / or lactones thereof (e.g., guluronic acid) to aldaric acids and / or lactones thereof (e.g., glucaric acid).

[0062]

[0076] In some embodiments, the second catalyst has a gold loading of about 10% or less, about 7.5% or less, about 5% or less, about 4% or less, about 2% or less, or about 1% or less by weight. In these and other embodiments, the second catalyst has a gold loading of about 0.1% or more, about 0.25% or more, about 0.5% or more, about 0.75% or more, or about 1% or more by weight. 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 comprises a catalytically active phase and gold comprises a significant portion of the catalytically active phase, for example, in certain embodiments, gold comprises at least about 20% by weight, at least about 30% by weight, at least about 40% by weight, at least about 50% by weight, at least about 60% by weight, at least about 70% by weight, at least about 80% by weight, at least about 90% by weight, at least about 95% by weight, or at least about 99% by weight of the catalytically active phase of the second catalyst. In certain embodiments, gold comprises about 20% to about 99% by weight, about 30% to about 99% by weight, about 40% to about 99% by weight, about 50% to about 99% by weight, about 60% to about 99% by weight, about 70% to about 99% by weight, about 80% to about 99% by weight, about 90% to about 99% by weight, about 95% to about 99% by weight, about 20% to about 95% by weight, about 30% to about 95 ... % to about 95% by weight, about 50% to about 95% by weight, about 60% to about 95% by weight, about 70% to about 95% by weight, about 80% to about 95% by weight, about 90% to about 95% by weight, about 20% to about 90% by weight, about 30% to about 90% by weight, about 40% to about 90% by weight, about 50% to about 90% by weight, about 60% to about 90% by weight, about 70% to about 90% by weight, or about 80% to about 90% by weight.

[0064]

[0078] In various embodiments, the second catalyst is a heterogeneous catalyst. In some 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 some embodiments, the support of the second catalyst includes a material including carbon, alumina, silica, titania, zirconia, and combinations thereof. In further embodiments, 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 support shown herein). In certain embodiments, the support 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, and mixtures thereof. In various embodiments, the support of the second catalyst comprises titania. In certain embodiments, 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 is at least about 5 m 2 / g, at least about 100m 2 / g, at least about 200m 2 / g, at least about 500m 2 / g, at least about 1,000m 2 / g, at least about 1,500m 2 / g, or at least about 2,000 m 2 For example, the second catalyst may have a BET specific surface area of ​​about 5 m 2 / g ~ approx. 2,500m2 / g, approx. 5m 2 / g ~ approx. 2,000m 2 / g, approx. 5m 2 / g ~ approx. 1,500m 2 / g, approx. 5m 2 / g ~ approx. 1,000m 2 / g, approx. 5m 2 / g~about 500m 2 / g, approx. 5m 2 / g~about 200m 2 / g, about 100m 2 / g ~ approx. 2,500m 2 / g, about 100m 2 / g ~ approx. 2,000m 2 / g, about 100m 2 / g ~ approx. 1,500m 2 / g, about 100m 2 / g ~ approx. 1,000m 2 / g, about 100m 2 / g~about 500m 2 / g, or about 100m 2 / g~about 200m 2 / g.

[0066]

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

[0067]

[0081] If a catalyst support is used, the 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] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention as defined in the appended claims. EXAMPLES

[0069]

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

[0070] Example 1: Glucose to gluconic acid using 1 wt% Au / TiO2 catalyst

[0084] The 1 wt% Au / TiO catalyst was crushed and sieved to a size of 40 / 80 mesh, weighing about 27 g (volume: about 30 cm 3 A 20% by weight aqueous solution of glucose was added to the packed bed reactor for 2.0 h. -1 The reactor was fed with a liquid hourly space velocity (LHSV) of 1000 psi and a gas stream of 75% N2 and 25% air was fed cocurrently at a flow rate of 1000 SCCM. The pressure in the system was maintained at 750 psig. The reactor jacket temperature was set at 77°C. 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 internal temperature at the radial center of the catalyst bed was 88-89°C. The average yield of gluconic acid was about 94 mol%, and the average yield of glucaric acid was less than about 0.5 mol%. Graphs plotting the glucose conversion, gluconic acid yield (mol%), and glucaric acid yield (mol%) are shown in Figures 4 and 5.

[0072]

[0086] This example shows that the 1 wt. % Au / TiO2 catalyst is suitable for forming gluconic acid, but is unable to convert said gluconic acid to an appreciable amount of glucaric acid.

[0073] Example 2: Oxidation of gluconic acid using Pt catalyst

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

[0074]

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

[0075]

[0089] Detailed conversion and yield data using 4 wt% Pt / C catalyst at various temperatures and air flow rates are provided in Table 1. For the data presented below, the pressure was maintained at 750 psig and the LHSV of the feed stream was maintained at 1.

[0076] [Table 1]

[0077]

[0090] A 4 wt% Pt / TiO2 catalyst was also tested to determine its suitability for the conversion of gluconic acid to glucaric acid. As with the Pt / C catalyst, the overall yield of glucaric acid decreased over time. The range of glucaric acid yields is shown in the table below, which details the maximum yields achieved and the final yields observed. 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 oxidation of gluconic acid in the presence of 4 wt % Pt / C or 4 wt % Pt / TiO2 catalyst alone results in poor stability and a significant decrease in glucaric acid yield.

[0080] Example 3: Glucose to glucaric acid using Pt-Au / TiO2 catalyst

[0092] A platinum-gold catalyst was prepared by supporting platinum on the Au / TiO2 catalyst such that the final catalyst contained 1 wt% Pt and 1 wt% Au. The catalyst was packed into a packed fixed-bed reactor. A 10 wt% glucose aqueous solution was added as a feedstock with an initial LHSV of 1.0 h. -1 The reactor was charged with 25% air and 75% N2 at a flow rate of 1000 SCCM, and a gas flow of 25% air and 75% N2 was introduced in parallel at a flow rate of 1000 SCCM. The initial temperature of the reactor was 60°C, and the initial oxygen partial pressure was maintained at 37.5 psig. STY (g [glucaric acid] / g [PGM] * h) was 6.

[0081]

[0093] As shown in Figure 7, the temperature was gradually increased from 60°C to 90°C in 10°C increments over a period of 2236 hours. After approximately 640 hours, the oxygen partial pressure was increased from 37.5 psig to 75 psig by changing the gas composition to 50% air and 50% N2 while maintaining the total gas flow at 1000 SCCM. After approximately 1232 hours, the LHSV of the 10 wt% glucose feedstock was increased to 1.0 h. -1 From LHSV1.5h -1 90°C, total pressure 750 psig, and LHSV 1.5h -1 It was confirmed that the operation was stable.

[0082]

[0094] The experimental results are shown below in Tables 3 and 4. 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 / TiO2 catalysts

[0095] The catalyst of Example 1 (1 wt. % Au / TiO2) was physically mixed with the catalyst of Example 2 (4 wt. % Pt / C) in a 1:1 volume ratio and poured into a 30 cm 3 The mass ratio of the catalyst (Au / TiO2:Pt / C) was about 3:2.

[0086]

[0096] 20% by weight of gluconic acid aqueous solution was used as raw material at LHSV 0.5h. -1 The catalyst mixture was passed through the reactor at 1000 psi and a co-flowing gas stream of 100% air was run at 1000 SCCM. The pressure was maintained at 750 psig and the LHSV of the feed stream was 0.5 h. -1 maintained.

[0087]

[0097] Figure 8 shows the gluconic acid conversion and various yields achieved during the reaction at temperatures between 70°C and 90°C. After 672 hours at 90°C, the gas flow was changed from 100% air to 50% air and 50% N2. The total gas flow was maintained at 1000 SCCM.

[0088]

[0098] It was observed that the production of glucaric acid stabilized (i.e., the yield was greater than about 60 mol%) at 80° C. and 90° C. This is in contrast to the yield of glucaric acid, which dropped to 44-29 mol% when Pt / C was used alone at 80° C. (Example 2), and the yield of 35-45 mol% when a catalyst including Pt supported on Au / TiO2 was used at 80° C. (Example 3). When Pt / C was used alone or with Pt supported on Au / TiO2, the desired yield was not reached or the maximum yield reached was not sustained (e.g., the yield of Pt / C dropped significantly with time at 90° C.).

[0089]

[0099] Table 5 shows detailed data on conversion and yield using mixtures of Pt / C and Au / TiO2 catalysts at various temperatures and air flow rates.

[0090] [Table 5]

[0091] Example 5: Gluconic Acid to Glucaric Acid Using a Staged Reactor Bed Containing a Physical Mixture of Catalysts

[0100] Gluconic acid was converted to glucaric acid using a mixture of Pt / C and Au / TiO2 catalysts. A staged reactor bed containing two physical mixtures of catalysts was prepared. The top bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a ratio of 4:1 (vol). The bottom bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a ratio of 1:4 (vol). A feed stream of 20 wt% aqueous gluconic acid was fed to the reactor at an LHSV of 1.0 h. -1 After about 624 hours, the reactor temperature was increased from 90°C to 95°C.

[0092]

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

[0093]

[0102] Table 6 shows detailed data on conversion and yield using mixtures of Pt / C and Au / TiO2 catalysts 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 and 1 wt. % Au / TiO2 catalysts

[0103] The experiment of Example 4 was modified to maintain the pressure at 1250 psig and the reactor jacket temperature at 85° C. A 21.2 wt % aqueous gluconic acid feed was added at an LHSV of 0.5 h. -1 and the gas flow (50% N2 and 50% air) was supplied at a flow rate of 1000 SCCM.

[0096]

[0104] After about 1224 hours, the catalyst was washed by stopping the liquid gluconic acid feed and starting the water feed while maintaining the gas flows and temperatures described above. -1 The gluconic acid feedstock flow was then resumed.

[0097]

[0105] Figure 10 and Table 7 show the glucaric acid yield before and after the water washing step. An increase in the glucaric acid yield was observed immediately after the washing step, which continued for about 75 hours and then slightly decreased. Figure 11 shows the results from 1104 to 1468 hours.

[0098] [Table 7]

[0099] Example 7: Arabinone acid from arabinose using 1 wt% Au / TiO2 catalyst

[0106] The 1 wt% Au / TiO catalyst was crushed and sieved to a size of 40 / 80 mesh, weighing about 27 g (volume: about 30 cm 3 ) was packed into a packed fixed-bed reactor. An aqueous solution of 20.6 wt. % arabinose was added to the reactor at a liquid hourly space velocity (LHSV) of 1.0 h -1 and a gas flow of 50% N2 and 50% air was fed cocurrently at a rate of 1000 SCCM. The system pressure was maintained at 750 psig. The reactor jacket temperature was set at 75° C. Six data points were acquired during the total run time of this experiment, ranging from 2716 to 2828 hours.

[0100]

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

[0101] [Table 8]

[0102] Example 8: Arabinonic Acid to Arabinaric Acid Using Staged Reactor Beds Containing a Physical Mixture of Catalysts

[0108] Arabinonic acid was converted to arabinaric acid using a mixture of Pt / C and Au / TiO2 catalysts. Staged reactor beds containing two physical mixtures of catalysts were prepared. The top bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a ratio of 4:1 (vol). The bottom bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a ratio of 1:4 (vol). A feed stream of 19.4 wt% arabinonic acid in water was fed to the reactor at an LHSV of 1.0 h. -1 The reactor was run for 6 hours at 100° C. A gas stream of 25% air and 75% N2 was run cocurrently at a rate of 1000 SCCM. The initial reactor pressure was 1200 psig and the initial reactor temperature was 100° C. Six data points were acquired over a total run time of 856 to 938 hours for this experiment.

[0103]

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

[0104] [Table 9]

[0105] Example 9: Glyceraldehyde to glyceric acid using Au / TiO2 catalyst

[0110] The 1 wt% Au / TiO catalyst was crushed and sieved to a size of 40 / 80 mesh, weighing about 27 g (volume: about 30 cm 3 ) was packed in a fixed-bed reactor. An aqueous solution of 1.22 wt. % glyceraldehyde was added to the reactor at a liquid hourly space velocity (LHSV) of 1.0 h -1 and a gas flow of 50% N2 and 50% air was fed cocurrently at a rate of 1000 SCCM. The system pressure was maintained at 750 psig. The reactor jacket temperature was set at 75°C. Four data points were acquired over a total run time of 3000-3038 hours for this experiment.

[0106]

[0111] Glyceraldehyde conversion and glyceric acid production were stable over the observation period. Glyceric acid yields ranged from about 100-105 mol%, and the average tartronic acid yield was 0 mol%. Glyceric acid yields (mol%) are shown in Figure 14. A summary of the results is given in Table 10 below.

[0107] [Table 10]

[0108] Example 10: Tartronic Acid from Glyceric Acid Using Staged Reactor Beds Containing a Physical Mixture of Catalysts

[0112] Glyceric acid was converted to tartronic acid using a mixture of Pt / C and Au / TiO2 catalysts. A staged reactor bed was prepared containing two physical mixtures of catalysts. The top bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a ratio of 4:1 (vol). The bottom bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a ratio of 1:4 (vol). A feed stream of 10.0 wt% glyceric acid in water was introduced at the LHSV listed in Table 11 below. A gas stream of air and N2 in the ratios listed below was introduced cocurrently at a flow rate of 1000 SCCM. The reactor pressure was initially 750 psig and was increased to 1250 psig during the experiment. Similarly, the reactor temperature was initially 95°C and was increased to 106°C during the experiment.

[0109] [Table 11]

[0110] Example 11: Glycolic Acid from Glycoaldehyde Using Various Catalysts

[0113] Experiments were conducted to test the effectiveness of various catalysts in oxidizing glycoaldehyde to glycolic acid. One experiment was conducted without a catalyst. Other experiments used a 1 wt% Au / TiO2 catalyst, a 4 wt% Pt / C catalyst, or a physical mixture of a 4 wt% Pt / C catalyst and a 1 wt% Au / TiO2 catalyst.

[0111]

[0114] The 1 wt% Au / TiO2 and 4 wt% Pt / C catalysts were crushed and sieved to 40 / 80 mesh size. The total weight of catalyst used for each experiment is shown in Table 12. For experiments involving a physical mixture of 4 wt% Pt / C and 1 wt% Au / TiO2 catalysts, the catalysts were in a 1:1 weight ratio.

[0112]

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

[0113] [Table 12]

[0114]

[0116] The results of these experiments are shown in Figure 15. As expected, the results were poor when no catalyst was used. The conversion was high with the 1 wt% Au / TiO2 catalyst, with a glycolic acid yield (mol%) of about 40%. The conversion was lower with the 4 wt% Pt / C catalyst than with the 1 wt% Au / TiO2 catalyst, but the glycolic acid yield was higher. The glycolic acid yield was higher with the physical mixture of catalysts than with either catalyst alone.

[0115] Example 12: Oxalic Acid from Glycolic Acid Using a Staged Reactor Bed Containing a Physical Mixture of Catalysts

[0117] Glycolic acid was converted to oxalic acid using a catalyst mixture of Pt / C and Au / TiO2. A staged reactor bed was prepared containing two physical mixtures of catalysts. The top bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a 4:1 (vol) ratio. The bottom bed contained 4 wt% Pt / C and 1 wt% Au / TiO2 in a 1:4 (vol) ratio. A feed stream of 10.3 wt% glycolic acid in water was introduced at the LHSV listed below. A gas stream was introduced cocurrently at about 1000 SCCM. Table 13 below shows the gas stream composition at various times during the run. The initial reactor pressure was 1250 psig and the initial reactor jacket temperature was 75°C and varied as shown in Table 13 below. Results from run times 1222 to 1280 hours are shown below.

[0116] [Table 13]

[0117]

[0118] The low oxalic acid yield is likely due to overconversion of the intermediates glyoxal and / or oxalic acid to CO2. This is supported by the absence of glyoxal in the reaction products and the high measured amounts of CO2. By using a higher LHSV (i.e., run times between 1248 and 1280 hours), it appears that some oxalic acid is vented from the reactor before it is overconverted.

[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 are 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 listed elements.

[0119]

[0120] In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

[0120]

[0121] Since various changes may be made in the above methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0121]

[0122] As used herein, the term "comprising" is to be understood to encompass the alternative that the product / method / use in relation to which the term "comprising" is used may also "consist only of" the elements listed thereafter.

[0122]

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

[0123]

[0124] It should be understood that unless otherwise noted, all synthetic procedures and parameter measurements were conducted at room / ambient temperature, i.e., 21±1° C.

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

[0125] 2. The method of claim 1, wherein the reaction zone comprises a mixture of a first catalyst and a second catalyst.

[0126] 3. The process according to claim 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 process for preparing glucaric acid and / or its lactones comprising: reacting gluconic acid and / or lactones thereof in a first stage of a reaction zone in the presence of oxygen and a first catalyst comprising platinum to form a first reaction mixture comprising guluronic acid and / or lactones thereof; and contacting the first reaction mixture comprising guluronic acid and / or lactones thereof 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 lactones thereof; wherein the first catalyst and the second catalyst are different.

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

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

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

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

[0132] 9. A process for preparing glucaric acid and / or its lactones comprising: The method includes reacting guluronic 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 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 a lactone thereof 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%.

[0135] 12. A process for preparing guluronic acid and / or its lactones comprising: The method includes 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 guluronic 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 a lactone thereof.

[0137] 14. The method of claim 13, wherein the oxidation catalyst comprises a second catalyst.

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

[0139] 16. A process for preparing glucaric acid and / or its lactones comprising: 1. A method comprising reacting glucose in the presence of oxygen in a reaction zone comprising an oxidation catalyst, a first catalyst comprising platinum, and a second catalyst comprising gold to form a reaction mixture comprising glucaric acid and / or lactones thereof, 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 a lactone thereof 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 process for preparing gluconic acid and / or its lactones comprising: 1. The method of claim 1, comprising reacting glucose 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 gluconic acid and / or lactone, wherein the first catalyst and the second catalyst are different.

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

[0144] 21. The method according to any one of items 13 to 20, wherein the glucose is obtained from a cereal crop.

[0145] 22. A process for preparing an aldaric acid and / or a lactone thereof comprising: Uronic acids and / or lactones thereof of formula (III): HOOC(HCOH) y CHO (III) wherein y is an integer from 0 to 10, 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 and / or lactone thereof of formula (IV): HOOC(HCOH)z COOH (IV) (wherein z is an integer of 0 to 10).

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

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

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

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

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

[0151] 28. A process for preparing an aldaric acid and / or a lactone thereof comprising: Aldonic acids and / or lactones thereof of formula (II): HOCH2(HCOH) x COOH (II) wherein x is an integer from 0 to 10, 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 and / or lactone thereof of formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer of 0 to 10).

[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 is an integer of 0 to 5.

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

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

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

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

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

[0159] 36. A process for preparing an aldaric acid and / or a lactone thereof comprising: Aldonic acids and / or lactones thereof of formula (II): HOCH2(HCOH) x COOH (II) wherein x is an integer from 0 to 10, in the presence of oxygen and a first catalyst comprising platinum in a first stage of a reaction zone to form a first reaction mixture; and contacting the first reaction mixture in a second stage of the reaction zone with a second catalyst comprising oxygen and gold to form a second reaction mixture comprising an aldaric acid of formula (IV) and / or a lactone thereof; wherein the first catalyst and the second catalyst are different and the aldaric acid and / or lactone thereof has formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer of 0 to 10).

[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 is an integer of 0 to 5.

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

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

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

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

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

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

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

[0169] 46. ​​Aldoses and / or lactones thereof of formula (I): HOCH2(HCOH) w CHO (I) (wherein w is an integer from 0 to 10) in the presence of oxygen and an oxidation catalyst to form an aldonic acid of formula (II) and / or a lactone thereof.

[0170] 47. The method according to item 46, wherein w is an integer of 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] 50. The method according to item 49, wherein w is an integer of 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 process for preparing an aldaric acid and / or a lactone thereof comprising: Aldoses and / or lactones thereof of formula (I): HOCH2(HCOH) w CHO (I) wherein w is an integer from 0 to 10, in the presence of oxygen in a reaction zone comprising an oxidation catalyst, 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 the first catalyst and the second catalyst are different, and the aldaric acid has formula (IV): HOOC(HCOH) z COOH (IV) (wherein z is an integer of 0 to 10).

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

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

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

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

[0180] 57. The method according to item 56, wherein w=z is an integer of 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 comprising an oxidation catalyst, a first stage comprising a first catalyst, and a second stage comprising 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 aldaric 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 aldaric acid of formula (IV) and / or lactone thereof 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 process for preparing uronic acids and / or lactones thereof comprising: Aldoses and / or lactones thereof of formula (I): HOCH2(HCOH) w CHO (I) wherein w is an integer from 0 to 10, in a reaction zone in the presence of oxygen, an oxidation catalyst, a first catalyst comprising platinum, and a second catalyst comprising gold to form a reaction mixture comprising a uronic acid of formula (III) and / or lactone thereof, 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 of 0 to 10).

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

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

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

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

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

[0191] 68. A process for preparing aldonic acids and / or lactones thereof comprising: Aldoses and / or lactones thereof of formula (I): HOCH2(HCOH) w CHO (I) wherein w is an integer from 0 to 10, 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 aldonic acid of formula (II) and / or a lactone thereof, wherein the first catalyst and the second catalyst are different, and the aldonic acid has the formula (II): HOCH2(HCOH) x COOH (II) (wherein x is an integer of 0 to 10).

[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 is an integer of 0 to 5.

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

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

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

[0197] 74. The method according to any one of items 46 to 73, wherein the aldose comprises at least one C2 to C7 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 a cereal crop.

[0200] 77. The method according to any one of items 46 to 76, wherein the aldose of formula (I) comprises a triose, a tetrose, a pentose, a hexose, a heptose, and / or mixtures 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 mixtures 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 mixtures 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 process for preparing uronic acids and / or lactones thereof comprising: Aldonic acids and / or lactones thereof of formula (II): HOCH2(HCOH) x COOH (II) wherein x is an integer from 0 to 10, 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 a uronic acid of formula (III) and / or lactone thereof, 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 of 0 to 10).

[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 is an integer of 0 to 5.

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

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

[0209] 86. The method according to item 85, wherein x=y is an integer between 3 and 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) comprises a dionic acid, a trionic acid, a tetronic acid, a pentonic acid, a hexonic acid, a heptonic acid, and / or mixtures 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) comprises glycolic acid, glyceric acid, threonic acid, erythronic acid, xylonic acid, ribonic acid, arabinonic acid, gluconic acid, and / or mixtures 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) comprises gluconic acid, xylonic acid, ribonic acid, arabinonic acid, and / or mixtures 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 mixtures 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 method according to any one of items 22 to 27, 62 to 67, or 81 to 91, wherein the uronic acid of formula (III) comprises at least one C2 to C7 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, hexuronic acid, heptauronic acid, and / or mixtures thereof.

[0217] 94. The method according to any one of items 22 to 27, 62 to 67, or 81 to 93, wherein the uronic acid of formula (III) comprises glyoxylic acid, glyceruronic acid (tartronaldehyde acid), treuronic acid, erythruronic acid, xylouronic acid, ribouronic acid, arabinuronic acid, lyxonuronic acid, guluronic acid, glucuronic acid, galacturonic acid, mannouronic acid, aruronic acid, altluronic acid, iduronic acid, talonuronic acid, and glucoheptonuronic acid, and / or mixtures thereof.

[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, arabinuronic acid, and / or mixtures 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 method according to any one of items 22 to 45 or 52 to 61, wherein the aldaric acid of formula (IV) comprises at least one C2 to C7 aldaric acid.

[0221] 98. The method according to any one of items 22 to 45, 52 to 61, or 97, 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.

[0222] 99. The method according to any one of items 22 to 45, 52 to 61, 97 or 98, 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.

[0223] 100. The method according to any one of items 22 to 45, 52 to 61, or 97 to 99, wherein the aldaric acid of formula (IV) comprises glucaric acid, xylaric acid, ribalic acid, arabinaric acid, and / or mixtures thereof.

[0224] 101. The method according to any one of items 22 to 45, 52 to 61, or 97 to 100, wherein the aldaric acid of formula (IV) comprises xylaric acid, ribalic acid, arabinaric acid, and / or mixtures thereof.

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

[0226] 103. The method according to any one of items 1 to 102, wherein the reaction zone comprises a first stage, the first stage comprising 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.

[0227] 104. The method of any one of items 1 to 103, wherein the reaction zone comprises a first stage, the first stage comprising 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 of any one of items 1 to 104, wherein the reaction zone comprises a first stage, the first stage comprising 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 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.

[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 comprises a second stage, the second stage comprising 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 of any one of items 1 to 107, wherein the reaction zone comprises a second stage, the second stage comprising a mixture of the first catalyst and the 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 comprises a second stage, the second stage comprising a mixture of the first catalyst and the second catalyst, and the weight or volume ratio of the second catalyst to the first catalyst is 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.

[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 area is (i) a first stage comprising a mixture of a first catalyst and a second catalyst, the volume ratio of the first catalyst to the second catalyst being from about 3:1 to about 5:1; (ii) a second stage comprising a mixture of the first catalyst and the second catalyst, the volume ratio of the second catalyst to the first catalyst being from about 3:1 to about 5:1; 3. The method of any one of the preceding items, comprising:

[0235] 112. the weight ratio of the first catalyst to the second catalyst in the first stage is from about 3:1 to about 1:1; Item 112. The method of claim 111, wherein the weight ratio of the second catalyst to the first catalyst in the second stage 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 of any one of items 1 to 114, wherein the first catalyst comprises a catalyst support.

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

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

[0241] 118. The method according to any one of items 115 to 117, wherein the support 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 support of the first catalyst comprises carbon black.

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

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

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

[0246] 123. The method of any one of items 1 to 122, wherein 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.

[0247] 124. The method of any one of items 1 to 123, wherein 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.

[0248] 125. The method of any one of items 1 to 122, 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.%.

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

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

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

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

[0253] 130. The method of claim 129, wherein the support of the first catalyst is not the same as the support of the second catalyst.

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

[0255] 132. The method according to any one of items 129 to 131, wherein the support 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 support 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 support 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 of any one of items 129 to 134, wherein the support of the second catalyst comprises titania.

[0259] 136. The method of 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 of 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 of 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 of any one of the preceding items, wherein the second catalyst has a gold loading of about 0.1% to about 10% by weight.

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

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

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

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

[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 no base is provided to the reaction region.

[0270] 147. The method according to any one of items 1 to 146, wherein the reaction mixture is free or substantially free of salt-forming cations.

[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 from about 1 to about 7, from about 1 to about 6, from about 1 to about 5, from about 1 to about 4, from about 1.5 to about 7, from about 1.5 to about 6, from about 1.5 to about 5, from about 1.5 to about 4, from about 2 to about 7, from about 2 to about 6, from about 2 to about 5, or from 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 from 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 process 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) in the reaction zone is about 0.2 h -1 Over, about 0.5h -1 The above took about 1 hour. -1 More than 1.5 hours -1 More than that, about 2 hours -1 That's about 5 hours -1 or more, or about 10 hours -1 The method according to any one of items 1 to 153, wherein

[0278] 155. The LHSV of the reaction zone is about 0.2h -1 ~About 50 hours -1 , about 0.5h -1 ~About 50 hours -1 , about 1h -1 ~About 50 hours -1 , about 2h -1 ~About 50 hours -1 , about 5h -1 ~About 50 hours -1 , about 10h -1 ~About 50 hours -1, about 0.2h -1 ~about 10h -1 , about 0.5h -1 ~about 10h -1 , about 1h -1 ~about 10h -1 , about 2h -1 ~about 10h -1 , or about 5 hours -1 ~about 10h -1 The method according to any one of items 1 to 153, wherein

[0279] 156. The LHSV of the reaction zone is about 0.2h -1 ~about 5h -1 Item 11. The method of any one of the preceding items, wherein

[0280] 157. The LHSV of the reaction zone is about 0.2h -1 ~about 4 hours -1 Item 11. The method of any one of the preceding items, wherein

[0281] 158. The LHSV of the reaction area is about 0.4h -1 ~about 2.5h -1 Item 11. The method of any one of the preceding items, wherein

[0282] 159. The LHSV of the reaction area is about 0.5h -1 ~about 2h -1 Item 11. The method of any one of the preceding items, wherein

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

[0284] 161. The method according to any one of items 1 to 159, wherein the reaction region 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 of 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 of 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 of 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 of 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 about 2 psig or more, about 25 psig or more, about 50 psig or more, or about 100 psig or more, or in the range of 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 of any one of the preceding items, wherein the partial pressure of oxygen is from about 2 psig to about 2000 psig.

[0291] 168. The method of 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 of 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 of 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% oxygen by volume, a mixture containing oxygen and nitrogen (e.g., about a 50:50 mixture by volume), or substantially pure oxygen (at least 99% oxygen by volume).

[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% by volume or more, about 1% by volume or more, about 5% by volume or more, or about 10% by 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 about 0.5% by volume to about 20% by volume, about 0.5% by volume to about 15% by volume, about 0.5% by volume to about 10% by volume, about 0.5% by volume to about 5% by volume, about 1% by volume to about 20% by volume, about 1% by volume to about 15% by volume, about 1% by volume to about 10% by volume, about 1% by volume to about 5% by volume, about 5% by volume to about 20% by volume, about 5% by volume to about 15% by volume, or about 5% by volume to about 10% by 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 about 5% by volume to about 20% by volume.

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

[0299] 176. The first catalyst includes a catalytically active phase, and platinum is about 20% by weight to about 99% by weight, about 30% by weight to about 99% by weight, about 40% by weight to about 99% by weight, about 50% by weight to about 99% by weight, about 60% by weight to about 99% by weight, about 70% by weight to about 99% by weight, about 80% by weight to about 99% by weight, about 90% by weight to about 99% by weight, about 95% by weight to about 99% by weight, about 20% by weight to about 95% by weight, about 30% by weight to about 95% by weight, about 40% by weight to about 95 ... %, about 50% to about 95% by weight, about 60% to about 95% by weight, about 70% to about 95% by weight, about 80% to about 95% by weight, about 90% to about 95% by weight, about 20% to about 90% by weight, about 30% to about 90% by weight, about 40% to about 90% by weight, about 50% to about 90% by weight, about 60% to about 90% by weight, about 70% to about 90% by weight, or about 80% to about 90% by weight.

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

[0301] 178. The second catalyst includes a catalytically active phase, and gold is about 20% to about 99% by weight, about 30% to about 99% by weight, about 40% to about 99% by weight, about 50% to about 99% by weight, about 60% to about 99% by weight, about 70% to about 99% by weight, about 80% to about 99% by weight, about 90% to about 99% by weight, about 95% to about 99% by weight, about 20% to about 95% by weight, about 30% to about 95% by weight, or about 40% to about 95% by weight of the catalytically active phase. , about 50% by weight to about 95% by weight, about 60% by weight to about 95% by weight, about 70% by weight to about 95% by weight, about 80% by weight to about 95% by weight, about 90% by weight to about 95% by weight, about 20% by weight to about 90% by weight, about 30% by weight to about 90% by weight, about 40% by weight to about 90% by weight, about 50% by weight to about 90% by weight, about 60% by weight to about 90% by weight, about 70% by weight to about 90% by weight, or about 80% by weight to about 90% by weight.

[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; the first catalyst comprises a catalyst support; the second catalyst is a heterogeneous catalyst and comprises a catalyst support; the catalyst support of the first catalyst is different from the catalyst support of the second catalyst; 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).

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. The method of any one of claims 1 to 9, wherein the first catalyst has a platinum loading of 0.1% to 10% by weight.

11. The method of any one of claims 1 to 10, wherein the second catalyst has a gold loading of 0.1% to 10% by weight.

12. The LHSV of the reaction zone is 0.2 h －１ ~50h －１ The method according to any one of claims 1 to 11, wherein

13. A process according to any one of claims 1 to 12, wherein the reaction zone is heated to a temperature of from 60°C to 150°C.

14. The method of any one of claims 1 to 13, wherein the partial pressure of oxygen ranges from 2 psig to 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 40% by volume oxygen, a mixture comprising oxygen and nitrogen, or substantially pure oxygen.

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