CN115108887A - A kind of preparation method of ethylene glycol - Google Patents

Abstract

The invention provides a preparation method of ethylene glycol, which comprises the following steps: and (2) carrying out hydrogenation reaction on glycolaldehyde and a solvent under the action of a metal nickel catalyst to obtain the ethylene glycol. In the process of preparing the ethylene glycol, the glycolaldehyde is used as a raw material, the metal nickel catalyst is adopted, and the ethylene glycol is prepared by hydrogenation, so that the catalyst is low in cost, mild in catalytic reaction conditions, simple in product separation, and has the advantages of high selectivity and high yield of the ethylene glycol.

Description

A kind of preparation method of ethylene glycol

technical field

The present invention relates to the technical field of ethylene glycol, in particular to a preparation method of ethylene glycol.

Background technique

Ethylene glycol, also known as glycol, 1,2-ethylene glycol; chemical formula (CH ₂ OH) ₂ , is the simplest glycol. Ethylene glycol is a colorless, odorless, sweet liquid with low toxicity to animals, and is miscible with water and acetone, but less soluble in ethers. Ethylene glycol is a very important basic organic chemical raw material, which is widely used and can be used to synthesize various chemical products, such as polyester fibers, unsaturated polyester resins, plasticizers, hygroscopic agents, non-ionic surfactants, cosmetics, antifreeze agents and lubricants.

The method of industrial production of ethylene glycol is mainly from petroleum to ethylene, ethylene oxidation to ethylene oxide, and ethylene oxide is further obtained by direct hydration. In recent years, due to the increasing demand for energy and the increasing scarcity of petroleum resources, researchers have developed a process route for preparing ethylene glycol from cheap and resource-rich coal or natural gas, that is, using coal to first prepare syngas (CO, H ₂ ), the intermediate product dimethyl oxalate is prepared through synthesis gas, and then ethylene glycol is prepared by direct hydrogenation of dimethyl oxalate. According to the current energy situation of “rich coal and lean oil” in China, the process route of coal-to-ethylene glycol is more suitable for my country, but this process has a big disadvantage. There are many impurities in the product, which will affect the downstream industry of ethylene glycol. , mainly including polyethylene succinate and polyethylene terephthalate produced by ethylene glycol polymerization. In addition, coal-based ethylene glycol also has insufficient chromaticity and ultraviolet transmittance. Based on this, the future development of the process route for preparing ethylene glycol from dimethyl oxalate in my country will be greatly restricted.

The preparation of ethylene glycol based on coal as a raw material can be achieved not only by dimethyl oxalate, but also by the process route of preparing methanol from coal-methanol to prepare formaldehyde-formaldehyde to prepare glycolaldehyde-glycolaldehyde to prepare ethylene glycol. CN105085211 B has a detailed introduction. In the patent CN 105085211 B, a case of glycolaldehyde hydrogenation to ethylene glycol is provided. In the autoclave, diphenyl ether (Ph ₂ O) is used as the solvent, and the temperature is 120 ° C and the pressure is 2 MPa. , using the mixed composition of HRuCl(CO)(PPh ₃ ) ₃ and HRh(CO)(PPh ₃ ) ₃ as the catalyst to react for 5h, the conversion rate of glycolaldehyde was 93%, the selectivity of ethylene glycol was 97%, and the The yield of alcohol is about 90%. In the patent CN 108368014 A, a high-pressure reactor is used, TiO ₂ -ZrO ₂ supports 0.4% Ru or Si-doped ZrO ₂ supports 0.4% Ru as the catalyst, water is used as the solvent, the reaction temperature is 195 ° C, and the reaction pressure is 10 MPa , the reaction was carried out at a stirring speed of 1450 rpm for 75 min, and the yield of ethylene glycol after the reaction was over 80%. In patent CN 106470965A, the gas phase composition of C1-3 oxygen-containing compounds (formaldehyde, glycolaldehyde, glyoxal, glyoxal, acetol) is used in the presence of a catalyst, using Ru/C as a catalyst, at 80 ° C, Under the condition of 9MPa, the conversion rate of C2 oxygenates is 100%, and the yield of ethylene glycol is over 90%. In patent WO 2017137355 A1, glycolaldehyde and glucose mixture are used as raw materials, and ethylene glycol can be obtained through two hydrogenation reactors; the temperature of the first hydrogenation reaction is 160-270° C. The compound or complex of tungsten or molybdenum is reacted for about 5 minutes. After the reaction is completed, it is cooled and hydrogenated; the reaction temperature of the second hydrogenation is 150 ° C. The catalyst adopts Raney nickel or Raney ruthenium, and the reaction is performed for 90 minutes, that is Ethylene glycol can be obtained, and the selectivity of ethylene glycol reaches about 90%.

In summary, the preparation of ethylene glycol by the hydrogenation of glycolaldehyde is a feasible process route. However, the catalysts currently used are mostly noble metal materials, and the preparation cost of the catalyst is expensive and the reaction conditions are relatively harsh, which limits the industrial application of the direct hydrogenation of glycolaldehyde to prepare ethylene glycol.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is to provide a preparation method of ethylene glycol. The preparation method provided by the present application has the advantages of low catalyst preparation cost, mild catalytic reaction conditions, and simple separation of subsequent products.

In view of this, the application provides a kind of preparation method of ethylene glycol, comprising:

Glycolaldehyde and solvent are hydrogenated under the action of metal nickel catalyst to obtain ethylene glycol.

Preferably, the solvent is selected from water, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, glycerol, n-butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, hexanol, octanol, Isooctanol, polyethylene glycol, acetone, butanone, cyclopentanone, cyclohexanone, ethylene glycol dimethyl ether, N,N-dimethylformamide, N,N-dimethylacetamide, N - one or more of methylpyrrolidone, 2-methylpyrrolidone, dioxane, dioxane, tetrahydrofuran, acetonitrile and dimethyl sulfoxide.

Preferably, the metal nickel catalyst is selected from supported metal nickel or Raney metal nickel.

Preferably, the supported metal in the supported metal nickel is selected from the combination of one or more of Cu, Mo, Al, Fe, Co and Zn and Ni, and the support is selected from alumina, activated carbon or dioxide silicon.

Preferably, the mesh number of the Raney-type metallic nickel is 20-50 mesh.

Preferably, the temperature of the hydrogenation reaction is 20-200°C.

Preferably, the pressure of the hydrogenation reaction is 0.1-20 MPa.

Preferably, the liquid hourly space velocity of the glycolaldehyde is 0.1-10 h ^-1 .

Preferably, in the hydrogenation reaction, the molar ratio of hydrogen to glycolaldehyde is (1-100):1.

Preferably, the hydrogenation reaction is carried out in a solid bed.

The present application provides a method for preparing ethylene glycol, which includes: hydrogenating glycolaldehyde and a solvent under the action of a metal nickel catalyst to obtain ethylene glycol. In the process of preparing ethylene glycol, the present application uses glycolaldehyde as a raw material, adopts a metal nickel catalyst, and hydrogenates to prepare ethylene glycol. Therefore, the catalyst has low cost, mild catalytic reaction conditions, simple product separation, and has the advantages of ethylene glycol. Advantages of high selectivity and high yield.

Detailed ways

In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with the examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

Aiming at the problems of expensive catalyst preparation cost and high catalytic reaction conditions temperature and pressure in the process of preparing ethylene glycol by hydrogenation of glycolaldehyde, a new method for preparing ethylene glycol by hydrogenating glycolaldehyde is provided. The method has the advantages of low catalyst preparation cost, mild catalytic reaction conditions, and simple separation of subsequent products, and has a good industrial application background. Specifically, the embodiment of the present invention discloses a preparation method of ethylene glycol, comprising:

Glycolaldehyde and solvent are hydrogenated under the action of metal nickel catalyst to obtain ethylene glycol.

In the process of preparing ethylene glycol in the present application, the solvent is selected from water, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, glycerol, n-butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol Alcohol, hexanol, octanol, isooctanol, polyethylene glycol, acetone, butanone, cyclopentanone, cyclohexanone, ethylene glycol dimethyl ether, N,N-dimethylformamide, N,N - one or more of dimethylacetamide, N-methylpyrrolidone, 2-methylpyrrolidone, dioxane, dioxane, tetrahydrofuran, acetonitrile and dimethyl sulfoxide; the metal nickel The catalyst is selected from supported metal nickel or Raney metal nickel, and the supported metal in the supported metal nickel is selected from the combination of one or more of Cu, Mo, Al, Fe, Co and Zn and Ni, so The carrier is selected from alumina, activated carbon or silica; the mesh number of the Raney metal nickel is 20-50 mesh.

In the process of hydrogenation reaction, the temperature of the hydrogenation reaction is 20～200 ℃, the pressure is 0.1～20MPa; the liquid hourly space velocity of the glycolaldehyde is 0.1～10h ⁻¹ ; the molar ratio of hydrogen and glycolaldehyde is (1 to 100): 1. The hydrogenation reactions described herein are carried out in a solid bed.

It can be seen from the technical scheme provided by the present invention that the use of glycolaldehyde to prepare ethylene glycol has the characteristics of low catalyst preparation cost, mild catalytic reaction operating conditions and simple product separation, and has good industrial application value.

In order to further understand the present invention, the preparation method of ethylene glycol provided by the present invention is described in detail below with reference to the examples, and the protection scope of the present invention is not limited by the following examples.

Example 1

The present embodiment provides a method for preparing ethylene glycol by hydrogenating glycolaldehyde, which includes: in a fixed bed reactor, a supported nickel and copper catalyst is used, the carrier is alumina, and the reaction solution is a 10wt% glycolaldehyde aqueous solution. The catalytic reaction is carried out under the conditions of ℃, 3MPa, liquid hourly space velocity of 2h ^-1 , and the molar ratio of hydrogen to glycolaldehyde of 10:1, and the reaction product is detected by gas chromatography. The obtained reaction results were: the conversion rate of glycolaldehyde was 67.25%, the selectivity of ethylene glycol was 26.52%, and the yield of ethylene glycol was 17.83%.

Example 2

Compared with Example 1, this example uses a supported nickel catalyst, the carrier is alumina, and a fixed-bed reactor is used. Through the catalytic reaction, the obtained reaction results are: was 41.66%, and the yield of ethylene glycol was 19.48%.

Example 3

Compared with examples 1 and 2, this example adopts supported nickel and zinc catalysts, adopts a fixed bed reactor, and through catalytic reaction, the obtained reaction results are: the conversion rate of glycolaldehyde is 71.89%, and the selectivity of ethylene glycol is 71.89%. 7.49%, the yield of ethylene glycol is 5.38%.

Example 4

Compared with examples 1, 2 and 3, this example adopts Raney nickel catalyst, adopts fixed bed reactor, and through catalytic reaction, the obtained reaction results are: the conversion rate of glycolaldehyde is 95.76%, and the selectivity of ethylene glycol is 95.76%. was 72.29%, and the yield of ethylene glycol was 69.22%.

Example 5

Compared with Example 4, this example uses methanol as a solvent, adopts a fixed-bed reactor, and through catalytic reaction, the obtained reaction results are: the conversion rate of glycolaldehyde is 79.01%, the selectivity of ethylene glycol is 70.28%, and the The yield of diol was 55.53%.

Example 6

Compared with examples 4 and 5, this example uses isopropanol as a solvent, adopts a fixed-bed reactor, and through catalytic reaction, the obtained reaction results are: the conversion rate of glycolaldehyde is 97.92%, and the selectivity of ethylene glycol is 97.92%. 96.04%, the yield of ethylene glycol is 94.04%.

Example 7

Compared with Examples 4, 5 and 6, this example uses N,N-dimethylacetamide as a solvent, adopts a fixed bed reactor, and through catalytic reaction, the obtained reaction result is: the conversion rate of glycolaldehyde is 96.51% , the selectivity of ethylene glycol is 93.78%, and the yield of ethylene glycol is 90.51%.

Example 8

Compared with Example 7, the reaction temperature of this example is 110°C, and a fixed bed reactor is used. Through catalytic reaction, the obtained reaction results are: the conversion rate of glycolaldehyde is 96.76%, and the selectivity of ethylene glycol is 85.56%. , the yield of ethylene glycol was 82.79%.

Example 9

Compared with Examples 7 and 8, the reaction temperature of this example is 70°C, and a fixed-bed reactor is used. Through the catalytic reaction, the obtained reaction results are: the conversion rate of glycolaldehyde is 48.68%, and the selectivity of ethylene glycol is 48.68%. 76.68%, the yield of ethylene glycol is 37.33%.

Example 10

Compared with Example 7, the reaction pressure of this example is 1MPa, and a fixed-bed reactor is used. Through catalytic reaction, the obtained reaction results are: the conversion rate of glycolaldehyde is 86.42%, the selectivity of ethylene glycol is 94.51%, The yield of ethylene glycol was 81.68%.

Example 11

Compared with examples 7 and 10, the reaction pressure of this example is 5MPa, a fixed bed reactor is used, and the reaction results obtained through catalytic reaction are: the conversion rate of glycolaldehyde is 95.92%, and the selectivity of ethylene glycol is 93.62%. %, the yield of ethylene glycol was 89.80%.

Example 12

Compared with Example 7, the liquid hourly space velocity of glycolaldehyde in this example is 1h ^-1 , and a fixed bed reactor is used to conduct catalytic reaction, and the obtained reaction results are: the conversion rate of glycolaldehyde is 96.21%, and the The property was 90.41%, and the yield of ethylene glycol was 86.99%.

Example 13

Compared with Examples 7 and 13, the liquid hourly space velocity of glycolaldehyde in this example is 4h ^-1 , and a fixed bed reactor is used to conduct catalytic reaction. The obtained reaction results are: the conversion rate of glycolaldehyde is 82.34%, the The selectivity was 94.18% and the yield of ethylene glycol was 77.55%.

Example 14

Compared with Example 7, the molar ratio of hydrogen to glycolaldehyde in this example is 20:1, using a fixed-bed reactor, through catalytic reaction, the obtained reaction result is: the conversion rate of glycolaldehyde is 96.57%, the conversion of ethylene glycol The selectivity was 93.79% and the yield of ethylene glycol was 90.57%.

The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a preparation method of ethylene glycol, comprising: Glycolaldehyde and solvent are hydrogenated under the action of metal nickel catalyst to obtain ethylene glycol. 2. preparation method according to claim 1 is characterized in that, described solvent is selected from water, methyl alcohol, ethanol, ethylene glycol, isopropanol, propylene glycol, glycerol, n-butanol, n-amyl alcohol, isopropyl alcohol Amyl alcohol, tert-amyl alcohol, hexanol, octanol, isooctanol, polyethylene glycol, acetone, butanone, cyclopentanone, cyclohexanone, ethylene glycol dimethyl ether, N,N-dimethylmethyl One or more of amide, N,N-dimethylacetamide, N-methylpyrrolidone, 2-methylpyrrolidone, dioxane, dioxane, tetrahydrofuran, acetonitrile and dimethyl sulfoxide . 3 . The preparation method according to claim 1 , wherein the metal nickel catalyst is selected from supported metal nickel or Raney metal nickel. 4 . 4. The preparation method according to claim 3, wherein the supported metal in the supported metal nickel is selected from the combination of one or more of Cu, Mo, Al, Fe, Co and Zn and Ni , the carrier is selected from alumina, activated carbon or silica. 5 . The preparation method according to claim 3 , wherein the mesh number of the Raney-type metallic nickel is 20-50 meshes. 6 . 6 . The preparation method according to claim 1 , wherein the temperature of the hydrogenation reaction is 20-200° C. 7 . 7 . The preparation method according to claim 1 , wherein the pressure of the hydrogenation reaction is 0.1-20 MPa. 8 . 8 . The preparation method according to claim 1 , wherein the liquid hourly space velocity of the glycolaldehyde is 0.1˜10 h ⁻¹ . 9 . The preparation method according to claim 1 , wherein, in the hydrogenation reaction, the molar ratio of hydrogen to glycolaldehyde is (1-100):1. 10 . 10 . The preparation method according to claim 1 , wherein the hydrogenation reaction is carried out in a solid bed. 11 .