KR102364554B1 - Catalyst for preparation of ethylene carbonate and ethylene glycol, method for preparing the catalyst, method and apparatus for preparing ethylene glycol using thereof - Google Patents

Abstract

As a catalyst for the production of ethylene carbonate and ethylene glycol, a carbonyl group (-C=O); And halide, an amine group (-NH ₂ ), a catalyst containing a hydroxyl group (-OH), a method for preparing the same, and an aqueous solution of ethylene oxide and carbon dioxide using the catalyst to react with ethylene through carbonate reaction and hydrolysis reaction Methods and apparatus for preparing glycols are disclosed. The catalyst can obtain ethylene carbonate and/or ethylene glycol at a low cost and high yield compared to the existing catalyst.

Description

Catalyst for preparing ethylene carbonate and ethylene glycol, a method for preparing the same, and a method and apparatus for preparing ethylene glycol using the catalyst

The present invention relates to a catalyst for preparing ethylene carbonate and ethylene glycol, a method for preparing the same, and a method and apparatus for preparing ethylene glycol using the catalyst.

Ethylene glycol is a useful industrial compound widely used as a starting material for the production of polyester fibers and polyethylene terephthalate (PET) resins. In addition, it is applied to automobile antifreeze and hydraulic brake fluid, aircraft deicing agent and pharmaceutical field.

Ethylene glycol is usually produced through two steps. In the first step, ethylene oxide is reacted with carbon dioxide in the presence of a catalyst to produce ethylene carbonate, and in the second step, ethylene carbonate is hydrolyzed to produce ethylene glycol.

The reaction via ethylene carbonate is known to have high selectivity for conversion of ethylene oxide to ethylene glycol.

However, since the process for producing ethylene glycol requires a reaction under high temperature and high pressure, there is a problem of decomposition or polymerization of ethylene oxide, a raw material, to generate a large amount of by-products, and there is also a risk of explosion.

In order to solve these problems, research has been conducted to develop various catalysts to convert them from low temperature low pressure to high efficiency. For example, Patent Document 1 describes a method using a quaternary phosphonium halide such as tributylmethylphosphonium iodide or a quaternary ammonium halide as a catalyst.

However, since conventional catalysts are ionic liquids and are very expensive, there is still a need for a relatively inexpensive and high-efficiency catalyst with improved performance.

International Patent Application Publication No. WO2011-065528

In exemplary embodiments of the present invention, in one aspect, ethylene carbonate and ethylene glycol are produced at a low cost and high yield compared to conventional catalysts in the reaction between ethylene oxide and carbon dioxide (carbonation reaction), which is the first step in preparing ethylene glycol. An object of the present invention is to provide a catalyst that can be produced, a method for producing the same, and a method and apparatus for producing ethylene glycol using the catalyst.

In exemplary embodiments of the present invention, as a catalyst for preparing ethylene carbonate and ethylene glycol, a carbonyl group (-C=O); And halide, an amine group (-NH ₂ ), and provides a catalyst including all of the hydroxyl group (-OH).

In exemplary embodiments of the present invention, as the method for preparing the catalyst, reacting a compound containing a halide, an amine group, and a hydroxyl group with a carboxylic acid precursor (or an ester precursor); A method for preparing a catalyst for preparing ethylene carbonate comprising; provides

In exemplary embodiments of the present invention, further, in the presence of a catalyst, a first step of reacting an aqueous solution of ethylene oxide with carbon dioxide to prepare a product comprising ethylene carbonate and ethylene glycol; and a second step of hydrolyzing the ethylene carbonate of the product; provides a method and apparatus for producing ethylene glycol comprising.

According to exemplary embodiments of the present invention, by accelerating the reaction of ethylene oxide aqueous solution and carbon dioxide in the first step of ethylene glycol production, it is inexpensive compared to existing phosphoric acid catalysts, etc. A product comprising ethylene carbonate and ethylene glycol can be obtained in yield. In addition, ethylene glycol can be obtained in high yield in the second step by hydrolyzing the ethylene carbonate of the product obtained in the first step.

1 is an FT-IR measurement result of a catalyst prepared in Examples 1-3 of the present invention.

In the present specification, the catalyst for preparing ethylene carbonate and ethylene glycol refers to a catalyst used in a reaction in which an aqueous ethylene oxide solution and carbon dioxide are used as reactants and ethylene carbonate and ethylene glycol are produced.

Since the reaction is a carbonate reaction, the catalyst may also be referred to as a carbonate catalyst. In addition, in that the products of the reaction are ethylene carbonate and ethylene glycol, the catalyst may be referred to as a catalyst for preparing ethylene carbonate or as a catalyst for preparing ethylene glycol.

Exemplary embodiments of the present invention are described in detail below.

When a high concentration of ethylene oxide is used to prepare ethylene carbonate by reacting ethylene oxide with carbon dioxide, pure ethylene carbonate is obtained, whereas when an aqueous solution of ethylene oxide with a low concentration diluted with water is used, ethylene glycol is produced as a product other than ethylene carbonate. In addition, diethylene glycol and triethylene glycol are also produced.

The present inventors have found that, when reacting an aqueous solution of alkylene oxide diluted with water and carbon dioxide, using the catalyst of exemplary embodiments of the present invention, only ethylene carbonate and ethylene glycol can be produced with high selectivity without other by-products, and further, the ethylene Since ethylene glycol is produced when carbonate is hydrolyzed, it was confirmed that ethylene glycol can be obtained in high yield. It will be detailed below.

Catalyst and method for preparing the same

In exemplary embodiments of the present invention, as a catalyst for preparing ethylene carbonate and/or ethylene glycol, a carbonyl group (-C=O-); and an amine group (—NH ₂ ), a hydroxyl group (—OH), and a halide component.

In this catalyst, the carbonyl group (-C=O) serves to strengthen one or more chemical bonds among an amine group, a hydroxyl group, and a halide. amine groups, hydroxy groups, and halide substances are present.

The catalyst promotes carbon dioxide absorption as a carbonation reaction (the first step reaction of ethylene glycol production), and opens an O-ring in ethylene oxide to facilitate the carbon dioxide addition reaction (ie, ethylene oxide + carbon dioxide → ethylene carbonate).

For reference, the catalyst not only shows a high yield of ethylene in the first step of preparing ethylene glycol of the present invention, but also can exhibit a high yield even when the alkylene carbonate is obtained by reacting the alkylene carbonate with carbon dioxide.

In an exemplary embodiment, the catalyst may be a catalyst represented by the following [Formula 1] or [Formula 2] or [Formula 3].

[Formula 1]

[Formula 2]

[Formula 3]

In [Formula 1] to [Formula 3], n is each a repeating unit, and may be an integer of 1 to 10.

As shown in the above [Formula 1] to [Formula 3], the catalyst includes a carbonyl group (-C=O), and also includes an amine group, a hydroxyl group (-OH), and a halide component.

In the [Formula 1] to [Formula 3], the halide is F, Cl, Br or I, and is preferably Br or I or Cl in terms of the large effect of the epoxide O ring opening and carbon dioxide addition reaction.

In exemplary embodiments of the present invention, in another aspect, as a method for preparing the catalyst described above, reacting a catalyst compound including all of halide, amine group, and hydroxyl group with a carboxylic acid precursor, which is a polycondensation reaction precursor; It provides a method for preparing a catalyst comprising.

In an exemplary embodiment, the method includes: generating a catalyst compound including a halide, an amine group, and a hydroxyl group from an amine precursor, an aldehyde precursor, and a halide precursor; and reacting the catalyst compound with a carboxylic acid precursor to generate a carbonyl group or an ester group in the catalyst compound.

In an exemplary embodiment, the amine precursor is urea, melamine, dicyandiamide, cyanamide, guanidine, biguanidine, guanylurea) , one or more substances including polycyclic guanidine may be used.

In an exemplary embodiment, the aldehyde precursor includes formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, benzaldehyde, glutaraldehyde, glyoxal, malondialdehyde, succindialdehyde ), one or more substances known as aldehydes such as phthalaldehyde may be used.

In an exemplary embodiment, the halide may be one or more selected from, for example, KI, KBr, KCl, HI, HBr, HCl, NH ₄ I, NH ₄ Br, NH ₄ Cl, and the like.

In an exemplary embodiment, the carboxylic acid precursor is formic acid, acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, polyacrylic acid (PAA), It may be at least one selected from a material containing a carboxyl group, such as graphene oxide and alginic acid.

Ethylene glycol manufacturing method and apparatus

On the other hand, in exemplary embodiments of the present invention, also, in the presence of a catalyst, a first step of reacting an aqueous solution of ethylene oxide with carbon dioxide to prepare a product containing ethylene carbonate and ethylene glycol; and a second step of hydrolyzing the ethylene carbonate of the product; provides a method for producing ethylene glycol comprising.

That is, in the first step under the catalyst, an ethylene oxide aqueous solution and carbon dioxide are reacted to prepare a mixture of ethylene carbonate and ethylene glycol, and in the second step, ethylene glycol produced through a hydrolysis reaction is prepared. It will be further detailed below.

(1) First Step: Carbonation Reaction

In an exemplary embodiment, when a mixture of ethylene oxide and water is used as a raw material in an aqueous ethylene oxide solution as a reactant, the molar ratio of supply of water to ethylene oxide is typically 10 (converted to ethylene oxide concentration, about 20% by weight) or less, preferably 0.5-5.0 (in terms of ethylene oxide concentration, about 1 to 10% by weight).

The amount of the catalyst used is preferably 0.0001-20 parts by weight, more preferably 0.05-5 parts by weight based on 100 parts by weight of ethylene oxide. If it is less than 0.0001 parts by weight, the reaction rate may be too slow, and if it is more than 20 parts by weight, the reaction rate and selectivity may not be improved any more, so there may be no economic benefit.

In an exemplary embodiment, the reaction temperature of the reaction may be 40 ~ 150 ℃ or 80 ~ 150 ℃. If the reaction temperature is too low, the reaction rate may be slowed, and if the reaction temperature is too high, ethylene oxide will self-polymerize, and thus the reaction selectivity may be reduced.

In an exemplary embodiment, the carbon dioxide reaction pressure of the reaction is 10 to 30 atmospheres. When the reaction pressure is less than 10 atmospheres, the reaction rate may be slowed, and if the reaction pressure is more than 30 atmospheres, there is no effect of improving the reaction rate, whereas the equipment cost may be excessive.

In an exemplary embodiment, the ethylene carbonate (EC) yield of the first step reaction may be 5 to 15%.

In an exemplary embodiment, the reaction time of the reaction may be 1 to 4 hours. If the reaction time is less than 1 hour, the reaction may not occur, and if the reaction time exceeds 4 hours, the generated EGs may react with each other to produce diethylene glycol (DEG) or triethylene glycol (TEG) as a by-product.

(2) Second step: hydrolysis reaction

On the other hand, the second step reaction for preparing ethylrel glycol is a hydrolysis reaction, and the ethylene carbonate of the product produced in the first step is converted into ethylene glycol in high yield through a hydrolysis reaction with water (that is, ethylene carbonate) + water → ethylene glycol + carbon dioxide). However, after the first step, not only ethylene carbonate is separated from ethylene carbonate and ethylene glycol, but the product itself including ethylene glycol and ethylene carbonate is provided for the hydrolysis reaction.

In a non-limiting example, the reaction in the hydrolysis step is advantageous in terms of reaction rate to be carried out at a high temperature, but if the temperature is too high, a side reaction may occur and the purity of ethylene glycol may decrease, so it is usually 100 to 180 ° C. It is preferable to carry out in The reaction pressure is arbitrary as long as it is in the range up to the boiling point of the liquid, but it is usually preferable to carry out the reaction at normal pressure to 30 atm.

As a result of the carbonation reaction in the first step as described above, in the presence of a catalyst, carbon dioxide and an aqueous ethylene oxide solution are reacted to obtain a mixture of ethylene carbonate and ethylene carbonate, and in the second step, additional water is added to the mixture to obtain ethylene carbonate. Through the process of converting to ethylene glycol, it is possible to obtain ethylene glycol in high yield using a low-cost catalyst. In this case, the amount of water added in the second step is preferably about 2-3 times that of ethylene carbonate by weight.

Hereinafter, specific examples according to embodiments of the present invention will be described in more detail. However, the present invention is not limited to the following examples, and various types of embodiments can be embodied within the scope of the appended claims, and only the following examples are provided to ensure that the disclosure of the present invention is complete and at the same time as common in the art. It will be understood that the intention is to facilitate practice of the invention to those skilled in the art.

[New catalyst preparation example]

Preparation of novel catalyst Example 1

5 g of biguanidine, 2.2 g of potassium iodide and 5.2 g of 50% glutaraldehyde were put into a 3-neck flask equipped with a thermometer, a reflux condenser and a dropper, and stirred at a reaction temperature of 75° C., pH 3 for 1 hour. 5.2 g of 50% glutaraldehyde is additionally added through a dropper, and the pH is adjusted to 4.0 with 20% hydrochloric acid, followed by reaction for 12 hours.

1.5 g of the catalyst precursor synthesized by the above method, 50 g of distilled water, and 0.5 g of polyacrylic acid were charged into a 100 mL two-neck flask equipped with a reflux device, and the reaction was carried out for 2 hours while stirring at 60°C.

After the reaction, water was removed under reduced pressure using a rotary evaporator, and a novel catalyst powder ([Formula 1]) containing a carbonyl group was synthesized.

Preparation of novel catalyst Example 2

Put urea 3.6g, ammonium iodide 2.2g, glyoxal 3.8g, and diethylenetriamine 0.05g into a 3-neck flask equipped with a thermometer, reflux condenser and dropping device, and stir at a reaction temperature of 75℃, pH 3 for 1 hour. . 3.8 g of glyoxal was additionally added through a dropping device, and the pH was adjusted to 4.0 with a 20% hydrochloric acid solution, followed by reaction for 12 hours.

1.5 g of the catalyst precursor synthesized by the above method, 50 g of distilled water, and 0.5 g of graphene oxide were charged in a 100 mL two-necked flask equipped with a reflux device, and the reaction was carried out for 2 hours while stirring at 60°C.

After the reaction, water was removed under reduced pressure using a rotary evaporator, and a novel catalyst powder ([Formula 2]) containing a carbonyl group was synthesized.

Preparation of novel catalyst Example 3

In a three-neck flask equipped with a thermometer, reflux condenser and dropping device, 2.8 g of dicyandiamide, 1.9 g of ammonium bromide, 4.5 g of succindialdehyde, and 0.05 g of diethylenetriamine were placed at a reaction temperature of 75°C, pH 3, and 1 time to stir. 4.5 g of succindialdehyde was further added through a dropper, adjusted to pH 4.0 with 20% hydrochloric acid, and reacted for 12 hours.

1.5 g of the catalyst precursor synthesized by the above method, 50 g of distilled water, and 0.5 g of propionic acid were charged in a 100 mL two-neck flask equipped with a reflux device, and the reaction was carried out for 2 hours while stirring at 60°C.

After the reaction, water was removed under reduced pressure using a rotary evaporator, and a novel catalyst powder ([Formula 3]) containing a carbonyl group was synthesized.

[Alkylene glycol production example]

(1) Preparation of carbonation reaction (ethylene carbonate and ethylene glycol mixture)

Ethylene carbonate and ethylene glycol were produced by reacting 3 wt% of the new catalyst exemplified in the first reactor at 100 °C with a residence time of 4 hours pressurized to 20 atmospheres with carbon dioxide, and an aqueous raw material ethylene oxide solution (60 wt% ethylene oxide). The carbonated reaction liquid containing was obtained.

(2) hydrolysis reaction (production of ethylene glycol)

Ethylene carbonate was converted to ethylene glycol by hydrolysis of the carbonate reaction solution at 150° C., residence time of 2 hours, and nitrogen pressure of 20 atm. GC/MS was used to analyze reactant concentration, conversion, and yield.

The reaction results in each preparation step are shown in Table 1 below. In Table 1, EC represents ethylene carbonate and EG represents ethylene glycol.

Step 1 Carbonation Reaction Result
(100 degrees, 20 atmospheres, 4 hours, catalyst amount 3wt%) 2nd step hydrolysis reaction result
(150 degrees, 5 atmospheres, 2 hours) EC EG EG Catalyst Preparation Example 1 13% 84% 97% Catalyst Preparation Example 2 15% 82% 97% Catalyst Preparation Example 3 5% 90% 95% Comparative example phosphonium iodine 39% 56% 94%

As can be seen from Table 1 above, it can be seen that the produced EC was converted to EG faster than the commercial catalyst phosphonium iodine, which is a comparative example, in all of the catalyst preparation Examples 1, 2, and 3 catalysts, so that the generated EC was converted to EG more quickly, the second step It can be seen that the final EG yield is higher than that of a commercial catalyst even in the hydrolysis reaction of

Claims (14)

delete A catalyst for the production of ethylene carbonate and ethylene glycol, comprising:
The catalyst is a catalyst, characterized in that represented by any one of the following [Formula 1] to [Formula 3].
[Formula 1]

[Formula 2]

[Formula 3]

(In [Formula 1] to [Formula 3], n is an integer of 1 to 10 as a repeating unit, respectively)
3. The method of claim 2,
[Formula 1] to [Formula 3] halide (halide) is a catalyst, characterized in that Br or I or Cl.
A method for preparing the catalyst of claim 2 or 3, comprising:
A method for preparing a catalyst comprising: reacting a catalyst compound containing a halide, an amine group, and a hydroxyl group with a carboxylic acid precursor.
A first step of preparing a product comprising ethylene carbonate and ethylene glycol by reacting an aqueous ethylene oxide solution with carbon dioxide under the catalyst of claim 2 or 3; and
A method for producing ethylene glycol comprising a; a second step of hydrolyzing the ethylene carbonate of the product.
6. The method of claim 5,
The ethylene oxide aqueous solution is characterized in that the molar ratio of water to ethylene oxide is 10 or less.
6. The method of claim 5,
The amount of the catalyst used is 0.0001-20 parts by weight based on 100 parts by weight of ethylene oxide.
6. The method of claim 5,
The reaction temperature of the first step reaction is a method, characterized in that 40 ~ 150 ℃.
6. The method of claim 5,
Method, characterized in that the reaction pressure of the first step reaction is 10 to 30 atmospheres.
6. The method of claim 5,
A method, characterized in that in the first step, a product comprising ethylene carbonate and ethylene glycol is obtained, and in the second step, hydrolysis is performed by mixing the product with water.
6. The method of claim 5,
Method characterized in that the hydrolysis reaction of the second step is carried out at 100 ~ 180 ℃.
6. The method of claim 5,
The method characterized in that the hydrolysis reaction of the second step is carried out at atmospheric pressure to 30 atmospheres.
An apparatus for producing at least one of ethylene carbonate and ethylene glycol, comprising:
Device characterized in that it comprises the catalyst of claim 2 or 3 .
14. The method of claim 13,
The apparatus comprises: a first reactor in which an aqueous ethylene oxide solution and carbon dioxide are provided, and when the catalyst is included, producing a product comprising ethylene carbonate and ethylene glycol; and
and a second reactor in which the product of the first reaction device and water are provided, and the ethylene carbonate of the product is hydrolyzed to ethylene glycol.

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