JPH0892156A - Production of tartronic acid - Google Patents

Abstract

PURPOSE: To readily, industrially and advantageously obtain tartronic acid useful as a builder for detergents, a neutralizing agent, etc., by catalytically oxidizing glycerol or glyceric acid in the presence of a supported catalyst composition with an oxidizing agent. CONSTITUTION: This method for producing tartronic acid is to catalytically oxidize glycerol (glyceric acid) in the presence of a supported catalyst composition, comprising (A) platinum, (B) one or more elements selected from tin, lead, antimony, bismuth, selenium and tellurium and (C) one or more elements selected from rare earths as respective components and prepared by supporting (i) the components (A) and (B), (ii) the components (A) and (C), (iii) the components (A), (B) and (C) and (iv) the component (A) alone on a carrier (e.g. active carbon or silica) with an oxidizing agent at pH<=6.9. Furthermore, the compositional ratio of the catalyst composition (i) is preferably 0.01-2 molar ratio of the components (B)/(A) and that of the catalyst composition (ii) is preferably 0.01-5 molar ratio of the components (C)/(A). The compositional ratio of the catalyst composition (iii) preferably satisfies the molar ratios simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing tartronic acid, which comprises producing glycerin or glyceric acid, which is important as a detergent builder, a neutralizing agent, or a polymer raw material.

[0002]

2. Description of the Related Art There are few reports on the chemical synthesis method of tartronic acid, for example, "Acta. Chem. Scand., 15 , 260-270 (1961)" describes diethyl malonate and tert-butylacetic acid. Although a method of synthesizing it as a diethyl ester is described, the yield is as low as 27%, and it is not industrially satisfactory because it reacts in an organic solvent.

On the other hand, as a structurally most advantageous method, a method for producing tartaronic acid salt (oxymalonate) by catalytically oxidizing glycerin is described in JP-A-52-116415. However, the publication discloses that commercially available 5% Pd / C
(Palladium-supported activated carbon catalyst) was used as a catalyst, and the yield of tartronate was at most 20%. This is because not only is the activity of further oxidizing the glycerate salt, which is an intermediate oxide, low, but most of the generated tartronate salt is decarboxylated and decomposed into glycolate salt.
In order to produce tartronic acid from tartronic acid salt, acid decomposition with acid, ion exchange method, etc. are applied.
The former requires desalting by electrodialysis and the latter requires regeneration of the ion exchange resin. Therefore, when tartronic acid is produced as its salt, the above-mentioned additional steps are required. Therefore, a method of directly producing tartronic acid itself is desired, but the method of the above publication is not industrially satisfactory.

An object of the present invention is to provide an industrially advantageous method for producing tartronic acid by a simple method in order to solve such a problem.

[0005]

The present inventors have developed a catalyst to efficiently catalytically oxidize two primary hydroxyl groups of glycerin to convert it into tartronic acid in a high yield. The present invention has been completed based on the above findings. That is, when glycerin is catalytically oxidized with a commercially available 5% Pd / C catalyst, palladium is the main catalyst element, so oxidation of primary hydroxyl groups to carboxylic acids is efficient unless basic atmosphere (pH 8 or higher). It is necessary to carry out the reaction by adding an alkaline agent such as sodium hydroxide in order to prevent the reduction of the oxidation rate that does not proceed and is usually caused by the reduction of pH due to the formation of a carboxyl group. In this case, the produced tartronic acid is inevitably a salt thereof, and in order to produce tartronic acid as a free carboxylic acid, the above-mentioned acid decomposition, ion exchange, etc. are necessary, and in order to avoid this, acidic It was necessary to allow the oxidation reaction to proceed in the atmosphere. Then, they have found that the main catalyst element must be platinum for that purpose.

That is, the gist of the present invention is (1) a method for producing tartronic acid, which comprises catalytically oxidizing glycerin or glyceric acid with an oxidizing agent at a pH of 6.9 or less in the presence of the following catalyst composition, Catalyst composition: platinum as the catalyst first component, one or more elements selected from the group consisting of tin, lead, antimony, bismuth, selenium and tellurium as the catalyst second component, and one or more selected from the group consisting of rare earth elements As the catalyst third component, (a) catalyst first component and catalyst second component, (b) catalyst first component and catalyst third component, and (c) catalyst first component, catalyst second component and catalyst third component ,
Alternatively, (d) a supported catalyst in which any one of the catalyst first component is supported on a carrier. (2) In the catalyst composition, the composition ratio R1 (second component / first component) of the catalyst first component and the catalyst second component in (a) catalyst composition (a) is 0.01 to 2 in molar ratio. some stuff,
(B) A catalyst composition having a composition ratio R2 (third component / first component) of the catalyst first component and the catalyst third component of 0.01 to 5 in the catalyst composition (b), and (c) a catalyst composition. R of the composition ratio of the catalyst first component and the catalyst second component in the product (C) is (A)
1, R of the composition ratio of the catalyst first component and the catalyst third component is (b)
2. The production method according to (1) above, which is any one of the following items: (3) The catalyst loading amount of the catalyst first component in the catalyst composition is:
The manufacturing method according to (1) or (2), which is 1 to 10% by weight, (4) The oxidant is air, oxygen, or a mixed gas of oxygen and nitrogen, (1) to (3) The production method according to any one of (1) to (4) above, wherein the carrier is activated carbon, carbon black, alumina or silica.

The catalyst composition in the present invention has the following (a)
4 modes of (d) can be mentioned. That is, platinum is used as the catalyst first component, one or more elements selected from the group consisting of tin, lead, antimony, bismuth, selenium and tellurium are used as the catalyst second component, and one or more elements selected from the group consisting of rare earth elements. As a catalyst third component, (a) a catalyst composition in which a catalyst first component and a catalyst second component are combined, (b) a catalyst composition in which a catalyst first component and a catalyst third component are combined, (C) A catalyst composition in which a catalyst first component, a catalyst second component and a catalyst third component are combined,
Alternatively, (d) a catalyst composition in which the catalyst first component alone is supported on a carrier. Hereinafter, they will be described in order.

In the catalyst composition (a) in which the catalyst first component and the catalyst second component are combined, when platinum alone is used as the catalyst first component, self-poisoning by oxygen is observed.
It is a preferable catalyst composition from the viewpoint of suppressing the decrease in catalytic activity due to this oxygen poisoning. The second component of the catalyst includes tin, lead, antimony, bismuth, selenium and tellurium, and is not particularly limited, but antimony, tellurium and lead are particularly effective. For example, by complexing platinum and tellurium, oxygen poisoning can be avoided and the oxidation reaction rate can be greatly improved. The composition ratio R1 (second component / platinum) of the catalyst second component to platinum, which is the catalyst first component, is 0.01 to 2, preferably 0.
It is 05 to 1. When the molar ratio is less than 0.01, the composite effect of the catalyst second component is low, and when it is more than 2, the catalyst second component may act as a catalyst poison. As described above, the catalyst second component (Bi, Te, Se, etc.) has an optimum supported amount, and excessive support becomes a catalyst poison and the oxidation reaction cannot be efficiently carried out.

In order to more completely suppress the decrease in catalytic activity due to oxygen poisoning, it is preferable to combine the second component of the catalyst. When a plurality of catalyst second components are used, the composition ratio of each catalyst second component to platinum, which is the catalyst first component (each second component / platinum), is 0.01-molar.
2, preferably 0.05 to 1.

The catalyst composition (b) in which the catalyst first component and the catalyst third component are combined is a combination of the catalyst third component from the viewpoint of achieving high-speed reactivity. Lanthanum, cerium, praseodymium, neobidium and the like are effective as the rare earth element. This is because basicity is imparted on the catalyst surface, resulting in fast reactivity. When supporting a rare earth element at the time of catalyst preparation, a water-soluble salt of a rare earth element, such as chloride, nitrate, sulfate, etc., is usually used, but these are usually alkaline agents (sodium hydroxide, When converted to hydroxide using potassium hydroxide), basicity is imparted and catalytic activity is improved. Furthermore, by baking in a nitrogen stream to convert the hydroxide into an oxide, higher basicity can be imparted to the surface of the catalyst, and the catalytic activity can be further improved. The composition ratio R2 (third component / platinum) of the catalyst third component to platinum as the catalyst first component is 0.01 in terms of molar ratio.
-5, preferably 0.05-3. Molar ratio 0.0
If it is less than 1, the compounding effect is low, and if it is more than 5, the catalytic activity may decrease.

The catalyst third component can also be compounded by using a plurality of catalyst third components as in the case of the catalyst second component in the catalyst composition (a). In this case, the composition ratio of the catalyst third component to platinum which is the catalyst first component (the third component
The total amount of components / platinum) is 0.01 to 5, preferably 0.05 to 3, in molar ratio.

First catalyst component, second catalyst component and third catalyst component
The catalyst composition (C) in which the components are combined is the above (A).
It is a composition having both the properties of the catalyst composition of (2) and (2), and it is possible to obtain the effect of suppressing the decrease in catalyst activity due to oxygen poisoning and achieving high-speed reactivity. Such a catalyst composition is not particularly limited, but for example, Pt.Te
-Ce is illustrated. In this case, the composition ratio of the catalyst second component and the catalyst third component to platinum, which is the catalyst first component, is the same as that of R1 and R2, respectively. Further, the composite of the respective catalyst components is also the same as the above (a) and (b).

The amount of platinum supported on the catalyst composition (d) consisting of the catalyst first component alone is not particularly limited, but is preferably 1 to 10% by weight, more preferably 2 to 7% by weight in the catalyst composition.
% By weight. If the supported amount is less than 1% by weight, the reaction cannot proceed efficiently, and if it exceeds 10% by weight, there is a cost problem.

In the catalyst composition of the present invention, platinum may be used alone, as shown in the catalyst composition (d), but it is preferable to use platinum in combination with the catalyst second component. )), By combining with the catalyst third component (catalyst composition (b)), and further by combining with the catalyst second component and the catalyst third component (catalyst composition (c)), the catalyst activity and selectivity can be improved. Can be improved. The amount of platinum supported as the catalyst first component is preferably 1 to 10% by weight when used in combination with the catalyst second component and the catalyst third component in the same manner as in the case of using them alone as described above. 2 to 7% by weight is more preferable. If it is less than 1% by weight, the reaction rate is slow, and if it exceeds 10% by weight, byproducts increase, which is not preferable. Therefore, 5% Pt
Even in the case of the / C catalyst, the activity and selectivity of the catalyst can be improved by combining the catalyst components.

The catalyst composition according to the present invention is obtained by loading the catalyst component on the catalyst carrier in water by a conventional impregnation method, co-impregnation method, dipping method or co-precipitation method to form formalin, hydrazine, sodium borohydride, hydrogen, Lower alcohol (methanol, ethanol, glycerin, ethylene glycol, etc.)
It can be easily prepared by carrying out a reduction treatment such as. At this time, the amount of the catalyst supported on all the catalyst components is preferably 1 to 30% by weight, and more preferably 2 to 15% by weight in the catalyst composition.

Examples of the catalyst carrier include activated carbon, carbon black, silica, alumina, molecular sieve, asbestos, etc., but activated carbon, carbon black, alumina and silica having a high surface area are more preferable. Of these, activated carbon is particularly effective. The preferred physical properties when using activated carbon or carbon black as the carrier are as follows. (A) The specific surface area of activated carbon and carbon black is 200 m
² / g or more (b) Activated carbon and carbon black have a bulk density of 100 to 8
00g / liter or less (c) Pore volume of activated carbon and carbon black is 0.1m
l / g or more

That is, since the specific surface area of the carrier has a great influence on the high dispersibility of the catalyst component, it is preferably 200 m ² / g or more, and if it is less than 200 m ² / g, the reaction in the present invention cannot proceed efficiently. It is more preferably 500 m ² / g or more, and particularly preferably 1000 m ² / g or more. The bulk density of the carrier is an important item, and is preferably 100 to 800 g / liter. Outside this range, the reaction efficiency per unit weight of the catalyst component decreases. More preferably 150 to 600 g /
It is a liter.

When activated carbon or carbon black is used in the present invention, its properties are (a) to (a) above.
It is preferable to have at least one physical property selected from (c), and it is not necessary to satisfy all the physical property requirements. However, it is more effective to use those satisfying the requirements of these physical properties as much as possible.

The activated carbon as the catalyst carrier used in the present invention may be derived from any raw material such as coconut shell, wood-based, coal-based, beet carbon-based or petroleum pitch-based materials.
In particular, coconut shells, woods and petroleum pitches having a low ignition residue or low ash content are effective. The activated carbon may be activated by either steam activation or chemical activation, but the steam activated product may be more effective as a carrier. The activated carbon as the catalyst carrier used in the present invention may be a commercially available product as it is, but may be used after a suitable pretreatment such as acid treatment to adjust the pore distribution or reduce the ash content. . As the commercially available granular and powdered activated carbon used in the present invention, those for general water treatment and water-soluble food refining are used, for example, granular Shirasagi series (WH, Sx, KL) and carborafine manufactured by Takeda Pharmaceutical Co., Ltd. Powdered activated carbon represented by Norit and granular activated carbon (RO
X, RAX, DARCO, C, ELORIT, etc.) and powder products (AZO
, PN, ZN, etc.), beaded activated carbon (BAC) manufactured by Kureha Chemical Co., Ltd.
Is mentioned.

The activated carbon is JIS K 1474-19.
A basic one having a pH of more than 7 under the condition of 91 is preferable, and examples thereof include Shirasagi C manufactured by Takeda Pharmaceutical. The use of this basic carrier promotes the oxidation of glyceric acid to tartronic acid.

Further, commercially available carbon black is also effective as a catalyst carrier when carrying out the reaction in the present invention,
For example, carbon black manufactured by Cavrac Co., Ltd. may be mentioned. However, the activated carbon and carbon black used in the present invention are not particularly limited to these activated carbon and carbon black. Further, the silica is also effective as a catalyst support specific surface area 100~800m ² / g is more preferable preferably 500~800m ² / g. Alumina is also effective as a catalyst carrier, and specifically, γ-
Alumina having a specific surface area of 50 to 300 m ² / g is preferable.

In the reaction of the present invention, the catalyst composition is preferably added to the aqueous solution of glycerin and glyceric acid in an amount of preferably 1 to 20% by weight, more preferably 5 to 15% by weight, and usually 20% by weight.
The oxidation reaction is carried out at a reaction temperature of ˜90 ° C. under stirring and at a pH of 6.9 or less while supplying an oxidizing agent such as air or oxygen-containing gas. As the reaction progresses, the pH of the reaction mixture becomes 3.0 or less due to the formation of tartronic acid. The progress of the reaction can be monitored by high performance liquid chromatography (HPLC). The reaction in the present invention is as follows:
It looks like this:

[0023]

[Chemical 1]

The raw materials glycerin and glyceric acid are
Usually, it is used as an aqueous solution, and its concentration is 5 to 80% by weight, preferably 10 to 50% by weight. Since the effect of mass transfer is great, it is necessary to perform sufficient stirring when using a high-concentration aqueous solution of glycerin or glyceric acid exceeding 50% by weight.

The reaction temperature is usually 20 to 9 as described above in consideration of the oxygen solubility and the reaction rate and side reaction rate.
The temperature is 0 ° C, preferably 30 to 60 ° C. If the temperature is lower than 20 ° C, the reaction rate is slow, and if it is higher than 90 ° C, side reactions increase. The reaction time varies depending on the reaction temperature, but is usually 2
~ 40 hours.

The pH during the oxidation reaction in the present invention is 6.9 or less as described above, and if it exceeds 6.9, the amount of salt increases. Further, as the oxidizer during the oxidation reaction, air, oxygen, or a mixed gas of oxygen and nitrogen gas can be used, but it is preferable to use air from the economical viewpoint. From the viewpoint of suppressing oxidative poisoning, it is preferable to supply the oxidizing agent so that the oxidation reaction proceeds at a rate-determining rate. The reaction pressure is usually from atmospheric pressure to 10 atm, preferably atmospheric pressure. If the reaction rate is low under reduced pressure and is higher than 10 atm, the catalyst poisoning by oxygen becomes large and the reaction rate decreases.

The manufacturing method of the present invention can be applied to both a batch system and a continuous system. The reactor may be of a stirred tank type, an injector type, a fluidized bed type, a fixed bed type or the like. The shape of the catalyst composition is not particularly limited,
Powder, granules, molded products, etc. may be used depending on the type of reactor. When the catalyst composition of the present invention is applied to a fixed bed reactor, a high-concentration reaction becomes possible, and the concentration of glycerin and glyceric acid can be increased up to 50% by weight for mass production. Is a highly productive method. When applied to a fixed bed reactor,
Since the catalyst separation step can be omitted, the productivity is high in this respect as well.

After completion of the reaction, the tartronic acid-containing oxidation reaction product can be dehydrated by distillation or the like and further purified by recrystallization or the like.

[0029]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following examples,% means% by weight. The raw material conversion rate represents the ratio of the weight of the raw material consumed in the oxidation reaction to the charged raw material.

The HPLC measurement conditions are as follows. High performance liquid chromatography: D-2500 / L-60
00 type Hitachi Ltd. detector: L-3300 type (RI monitor) Column: C-61OS Eluent: 0.5% phosphoric acid aqueous solution, 0.5 ml / min Pressure: 10 Kg / cm ² Temperature: 50 ° C. Sample Concentration: 0.1% aqueous solution

Example 1 1 g of chloroplatinic acid (platinum content 37.5% by weight) dissolved in 20 ml of ion-exchanged water in carborafine (activated carbon manufactured by Takeda Pharmaceutical Co., Ltd.) dispersed in 100 ml of ion-exchanged water. Was added dropwise, and the supporting treatment was carried out at room temperature for 5 hours. After that, adjust the pH to 13 or higher with an aqueous solution of sodium hydroxide,
40% 12% sodium borohydride manufactured by Monton
% Aqueous sodium hydroxide solution (0.6 g) was added and reduction treatment was performed at room temperature for 30 minutes with stirring. After that, 15 g of 5% Pt / C catalyst having a water content of 50% is obtained by washing with water and filtering.
Obtained. This catalyst was used in the reaction without drying. A 0.5 liter reactor equipped with a stirrer, a thermometer, a gas introduction line and a waste gas line was charged with 300 g of a 10% glycerin aqueous solution and 30 g of the above catalyst in terms of dry product, and the reaction temperature was 40 ° C. and the air was 5 per hour. It was introduced in liter for 18 hours to carry out the oxidation reaction. The results are shown in the table.

Example 2 5% Pt / C was prepared in the same manner as in Example 1 except that Shirasagi, a basic activated carbon (pH 12) manufactured by Takeda Pharmaceutical Co., Ltd., was used. The oxidation reaction was carried out under the reaction conditions. The results are shown in the table.

Example 3 1 g of cerium chloride (CeCl ₃ .7H ₂ O) was used as a catalyst second.
A catalyst was prepared under the same conditions as in Example 1 except that they were added as components, and the oxidation reaction was carried out under the same catalyst addition amount and the same reaction conditions as in Example 1 (R1 = 1.0). The results are shown in the table.

Example 4 The oxidation reaction was carried out under the same catalyst addition amount and the same reaction conditions as in Example 1 except that the catalyst of Example 3 was used and 10% glyceric acid was used. The results are shown in the table.

Example 5 A catalyst was prepared under the same conditions as in Example 1 except that γ-alumina was used instead of carborafine, and the oxidation reaction was carried out under the same catalyst addition amount and reaction conditions as in Example 1. I went. The results are shown in the table.

[0036]

[Table 1]

[0037]

According to the method for producing tartronic acid of the present invention, tartronic acid can be industrially advantageously produced by a simple method by using a specific supported metal catalyst. Further, the productivity is greatly improved by applying the fixed bed reactor.

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Claims (5)

[Claims] 1. A method for producing tartronic acid, which comprises catalytically oxidizing glycerin or glyceric acid with an oxidizing agent in the presence of the following catalyst composition at a pH of 6.9 or less. Catalyst composition: platinum as the catalyst first component, one or more elements selected from the group consisting of tin, lead, antimony, bismuth, selenium and tellurium as the catalyst second component, and one or more selected from the group consisting of rare earth elements As the catalyst third component, (a) catalyst first component and catalyst second component, (b) catalyst first component and catalyst third component, and (c) catalyst first component, catalyst second component and catalyst third component ,
Alternatively, (d) a supported catalyst in which any one of the catalyst first component is supported on a carrier. 2. The catalyst composition comprises: (a) a composition ratio R1 (second component / first component) of the catalyst first component and the catalyst second component in the catalyst composition (a) of 0.01 to molar ratio. 2), (b) a catalyst composition (b) in which the composition ratio R2 of the catalyst first component and the catalyst third component (third component / first component) is 0.01 to 5 in molar ratio, (C) In the catalyst composition (c), the composition ratio of the catalyst first component and the catalyst second component is R1 and the composition ratio of the catalyst first component and the catalyst third component is R2 (b). The manufacturing method according to claim 1, which is any one of the following: 3. The production method according to claim 1, wherein the catalyst-supported amount of the catalyst first component is 1 to 10% by weight in the catalyst composition. 4. The production method according to claim 1, wherein the oxidant is air, oxygen, or a mixed gas of oxygen and nitrogen. 5. The method according to claim 1, wherein the carrier is activated carbon, carbon black, alumina or silica.