A catalyst for synthesizing propylene glycol dimethyl ether and its preparation method and application

Abstract

The application discloses a catalyst for synthesizing propylene glycol dimethyl ether and a preparation method and application thereof. The catalyst is a composite oxide catalyst, which is composed of a carrier and an active component supported on the carrier. The carrier is CeO2 and ZrO2, and the active component is an oxide of metal M, wherein the metal M is at least two of Cu, Zn, Al, Cr, Fe, Co, Ni and Mn. According to 100% by weight, the proportion of the active component is 10-50%, and the rest is the carrier. The catalyst can be used for synthesizing propylene glycol dimethyl ether from synthesis gas and methylal, belongs to a coal-based route, has a simple flow, is economic and environmental, has low cost, has a by-product of water, conforms to the development concept of green chemistry, and is easy to separate and purify, and has low energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of preparing propylene glycol dimethyl ether, and particularly relates to a catalyst for synthesizing propylene glycol dimethyl ether, a preparation method and application thereof. Background Art

[0002] Propylene glycol dimethyl ether, chemically known as 1,2-dimethoxypropane, has the structural formula: CH₃OCH₂CH(CH₃)OCH₃. As a new, low-toxic, aprotic polar solvent that readily solvates cationic substances, propylene glycol dimethyl ether is used in chemical processes such as electrochemistry, polar organic reactions, anionic polymerization, and coordination ion polymerization; in physical processing such as extraction and stabilization; and in industrial products such as lubricants, textiles, pharmaceuticals, and pesticides. It is also widely used as a cleaning agent, extractant, stabilizer, cosolvent, organic synthesis reaction solvent, additive, and wetting solvent.

[0003] According to the classic etherification synthesis method, there are currently three main methods for the synthesis of propylene glycol dimethyl ether: (1) Intermolecular dehydration of propylene glycol methyl ether and methanol. In this reaction, intermolecular dehydration is also likely to occur, generating a series of by-product ethers, which affects the purity of the product; (2) Ring-opening reaction of propylene oxide and methyl ether. This reaction is carried out under pressure. When the epoxy bond is opened, propylene oxide is likely to polymerize, forming a series of higher molecular weight homologous compounds; (3) Williamson etherification synthesis method. The traditional Williamson etherification synthesis method is to first react propylene glycol methyl ether with metallic sodium (or NaNH4) to generate sodium propylene glycol methyl ether, and then react with methyl halide to generate propylene glycol dimethyl ether: During this reaction, gas is generated and discharged, causing the reaction equilibrium to proceed to the right, which is beneficial to the formation of propylene glycol dimethyl ether. However, due to the use of metallic sodium, the safety of the reaction is poor. CN1241888C discloses a method for synthesizing propylene glycol dimethyl ether. The method uses propylene glycol methyl ether, a base, and an alkylating agent as raw materials, uses a polyalkylene dialkyl ether as a catalyst, and conducts a reaction at a reaction temperature of 40°C to 90°C to produce the propylene glycol dimethyl ether product. Although this route has mild reaction conditions, it requires the addition of an additional base source and an alkylating agent, making separation of the target product difficult, increasing energy consumption, and causing serious environmental pollution, which is not in line with the development concept of green chemistry. Summary of the Invention

[0004] In view of the defects of the prior art, the present invention provides a catalyst for synthesizing propylene glycol dimethyl ether and a preparation method thereof. At the same time, the present invention also provides a method for preparing propylene glycol dimethyl ether using synthesis gas and methylal as raw materials under the action of the catalyst. The process flow is simple, economical and environmentally friendly.

[0005] A catalyst for synthesizing propylene glycol dimethyl ether is a composite oxide catalyst composed of a carrier and an active component supported on the carrier, wherein the carrier is CeO2 and ZrO2, and the active component is an oxide of a metal M, wherein the metal M is at least two of Cu, Zn, Al, Cr, Fe, Co, Ni, and Mn. Based on a weight ratio of 100%, the active component accounts for 10-50% of the catalyst, and the remainder is the carrier.

[0006] Preferably, in the carrier, the ratio of CeO2 to ZrO2 is 1:1.

[0007] Preferably, in the active component, the weight ratio of any one metal oxide to the active component is N, 10%≤N≤90%.

[0008] The preparation method of the catalyst for synthesizing propylene glycol dimethyl ether comprises the following steps:

[0009] (1) Dissolve the water-soluble salts of metals M, Ce, and Zr and the precipitant in water, control the pH to 8-9, and stir at 35-45°C to form an aqueous solution;

[0010] (2) The aqueous solution is heated to 90-150°C, stirred and reacted for 6-15 hours, cooled, filtered and washed until neutral, dried, and calcined.

[0011] Preferably, in step (2), the temperature is raised to 90-150°C at a rate of 2-5°C / min.

[0012] Preferably, in step (2), the stirring speed is 20-60 rpm.

[0013] Preferably, the drying condition is 80-120° C. for 12 h-20 h; the calcination condition is heating to 450° C.-600° C. at a rate of 1-5° C. / min and calcining for 5-10 h.

[0014] Preferably, the precipitant is one of ammonia water, urea, sodium carbonate and sodium bicarbonate.

[0015] The method for synthesizing propylene glycol dimethyl ether is as follows: using synthesis gas and methylal as raw materials, loading a catalyst into a fixed bed reactor, injecting the synthesis gas through a high-pressure gas cylinder, and the methylal entering a gasifier through a horizontal flow pump for gasification and then entering the fixed bed reactor. The reaction temperature is 120-200° C., the reaction pressure is 1-4 MPa, and the reaction product is liquefied and collected through a condenser. The catalyst is the catalyst for synthesizing propylene glycol dimethyl ether of the present invention.

[0016] Preferably, the flow rate of the synthesis gas is 20-100 mL / min, and the liquid space velocity of methylal is 1-10 h -1, the carbon-hydrogen ratio of synthesis gas is 2-6.

[0017] The principle of synthesizing propylene glycol dimethyl ether of the present invention is as follows: .

[0018] Advantages of the present invention:

[0019] (1) The catalyst provided by the present invention can catalyze the synthesis of propylene glycol dimethyl ether from synthesis gas and methylal. The process belongs to the coal-based route, has a simple process, is economical and environmentally friendly, has low cost, and produces water as a by-product, which is in line with the development concept of green chemistry. At the same time, the product is easy to separate and purify, and the energy consumption is low;

[0020] (2) When the catalyst is used to catalyze the preparation of propylene glycol dimethyl ether, a fixed bed reactor is used, which has the advantages of high product selectivity and long catalyst life, and provides a new method for preparing propylene glycol dimethyl ether using synthesis gas and methylal as raw materials;

[0021] (3) The catalyst preparation method is simple, the raw materials are widely available, the cost is low, and it is suitable for mass production. At the same time, the reaction conditions are mild, and it has good industrial application prospects. DETAILED DESCRIPTION

[0022] Example 1

[0023] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the weight ratio of the catalyst is 100%, the active component accounts for 10%, and the rest is a support; the support is equal in weight of CeO2 and ZrO2, the active components are equal in weight of CuO and ZnO; the catalyst is marked as 10% 5.0 CuO- 5.0 ZnO / CeO2-ZrO2.

[0024] 2. The method for preparing the catalyst for synthesizing propylene glycol dimethyl ether comprises the following steps:

[0025] (1) Dissolve copper nitrate, zinc nitrate, cerium nitrate, zirconium nitrate and urea in water, control the pH to 8-9, and stir at 40°C to form an aqueous solution;

[0026] (2) The aqueous solution was heated to 90°C at a rate of 2°C / min, stirred at a speed of 20 rpm for 15 h, cooled, filtered and washed until neutral, dried at 80°C for 20 h, and then heated to 450°C in a muffle furnace at a rate of 1°C / min and calcined for 10 h to obtain the catalyst.

[0027] 3. A method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is as follows: Synthesis gas and methylal are used as raw materials, the catalyst is loaded into a fixed-bed reactor, the synthesis gas is sampled through a high-pressure gas cylinder, and the methylal is gasified by a horizontal flow pump into a gasifier and then enters the fixed-bed reactor. The reaction temperature is 120°C and the reaction pressure is 4 MPa. The reaction product is liquefied and collected through a condenser and quantitatively analyzed by gas chromatography. The results are shown in Table 1. The flow rate of the synthesis gas is 20 mL / min, and the liquid space velocity of the methylal is 1 h / min. -1 , the carbon-hydrogen ratio of the synthesis gas is 2.

[0028] Example 2

[0029] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the weight ratio of the catalyst is 100%, the active component accounts for 10%, and the rest is a support; the support is equal in mass to CeO2 and ZrO2, the active components are CuO and ZnO in a mass ratio of 9:1; the catalyst is marked as 10% 9.0 CuO- 1.0 ZnO / CeO2-ZrO2.

[0030] 2. The preparation method of the catalyst for synthesizing propylene glycol dimethyl ether is the same as that in Example 1.

[0031] 3. The method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is the same as that in Example 1. The results are shown in Table 1.

[0032] Example 3

[0033] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the weight ratio of the catalyst is 100%, the active component accounts for 10%, and the rest is a support; the support is equal in mass to CeO2 and ZrO2, the active components are CuO and ZnO in a mass ratio of 1:9; the catalyst is marked as 10% 1.0 CuO- 9.0 ZnO / CeO2-ZrO2.

[0034] 2. The preparation method of the catalyst for synthesizing propylene glycol dimethyl ether is the same as that in Example 1.

[0035] 3. The method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is the same as that in Example 1. The results are shown in Table 1.

[0036] Example 4

[0037] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the weight ratio of the catalyst is 100%, the active component accounts for 50%, and the rest is a support; the support is equal in weight of CeO2 and ZrO2, the active component is equal in weight of CuO and ZnO; the catalyst is marked as 50% 5.0 CuO- 5.0 ZnO / CeO2-ZrO2.

[0038] 2. The preparation method of the catalyst for synthesizing propylene glycol dimethyl ether is the same as that in Example 1.

[0039] 3. The method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is the same as that in Example 1. The results are shown in Table 1.

[0040] Example 5

[0041] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the weight ratio of the catalyst is 100%, the active component accounts for 10%, and the rest is a support; the support is equal in weight of CeO2 and ZrO2, the active components are equal in weight of CuO and ZnO; the catalyst is marked as 10% 5.0 CuO- 5.0 ZnO / CeO2-ZrO2.

[0042] 2. The method for preparing the catalyst for synthesizing propylene glycol dimethyl ether comprises the following steps:

[0043] (1) Dissolve copper nitrate, zinc nitrate, cerium nitrate, zirconium nitrate and urea in water, control the pH to 8-9, and stir at 45°C to form an aqueous solution;

[0044] (2) The aqueous solution was heated to 150°C at a rate of 5°C / min, stirred at a speed of 60 rpm for 6 hours, cooled, filtered and washed until neutral, dried at 120°C for 12 hours, and then heated to 600°C in a muffle furnace at a rate of 5°C / min and calcined for 5 hours to obtain the catalyst.

[0045] 3. The method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is the same as that in Example 1. The results are shown in Table 1.

[0046] Example 6

[0047] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the weight ratio of the catalyst is 100%, the active component accounts for 10%, and the rest is a support; the support is equal in weight of CeO2 and ZrO2, the active components are equal in weight of CuO and ZnO; the catalyst is marked as 10%5.0 CuO- 5.0 ZnO / CeO2-ZrO2.

[0048] 2. The preparation method of the catalyst for synthesizing propylene glycol dimethyl ether is the same as that in Example 5.

[0049] 3. A method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is as follows: Synthesis gas and methylal are used as raw materials, the catalyst is loaded into a fixed-bed reactor, the synthesis gas is sampled through a high-pressure gas cylinder, the methylal is fed into a gasifier through a horizontal flow pump, and then enters the fixed-bed reactor for gasification. The reaction temperature is 200°C and the reaction pressure is 1 MPa. The reaction product is liquefied and collected through a condenser and quantitatively analyzed by gas chromatography. The flow rate of the synthesis gas is 100 mL / min, and the liquid space velocity of the methylal is 10 h / min. -1 , the carbon-hydrogen ratio of the synthesis gas is 6, and the results are shown in Table 1.

[0050] Example 7

[0051] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the weight ratio of the catalyst is 100%, the active component accounts for 30%, and the rest is a support; the support is equal in weight of CeO2 and ZrO2, the active component is equal in weight of CuO and ZnO; the catalyst is marked as 30% 5.0 CuO- 5.0 ZnO / CeO2-ZrO2.

[0052] 2. The method for preparing the catalyst for synthesizing propylene glycol dimethyl ether comprises the following steps:

[0053] (1) Dissolve copper nitrate, zinc nitrate, cerium nitrate, zirconium nitrate and urea in water, control the pH to 8-9, and stir at 35°C to form an aqueous solution;

[0054] (2) The aqueous solution was heated to 120°C at a rate of 3°C / min, stirred at a speed of 30 rpm for 10 hours, cooled, filtered and washed until neutral, dried at 110°C for 15 hours, and then heated to 550°C in a muffle furnace at a rate of 2°C / min and calcined for 6 hours to obtain the catalyst.

[0055] 3. A method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is as follows: Synthesis gas and methylal are used as raw materials, the catalyst is loaded into a fixed-bed reactor, the synthesis gas is sampled through a high-pressure gas cylinder, the methylal is gasified in a gasifier via a horizontal flow pump, and then enters the fixed-bed reactor. The reaction temperature is 180°C and the reaction pressure is 4 MPa. The reaction product is liquefied and collected through a condenser and quantitatively analyzed by gas chromatography. The flow rate of the synthesis gas is 50 mL / min, and the liquid space velocity of the methylal is 4 h / min.-1 , the carbon-hydrogen ratio of the synthesis gas is 4, and the results are shown in Table 1.

[0056] Example 8

[0057] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, the catalyst having an active component accounting for 30% by weight based on 100%, and the rest being a carrier; the carrier being equal mass of CeO2 and ZrO2, and the active component being CuO, ZnO and Al2O3 in a mass ratio of 3:2:5; the catalyst being labeled as 30%. 3.0 CuO- 2.0 ZnO- 5.0 Al2O3 / CeO2-ZrO2.

[0058] 2. A preparation method of the catalyst for synthesizing propylene glycol dimethyl ether, comprising the following steps:

[0059] (1) dissolving copper nitrate, zinc nitrate, aluminum nitrate, cerium nitrate, zirconium nitrate and sodium bicarbonate in water, controlling the pH to be 8-9, and stirring at 40°C to form an aqueous solution;

[0060] (2) heating the aqueous solution to 120°C at a rate of 3°C / min, stirring at a speed of 30 rpm for 10 h, after cooling, filtering and washing to neutral, drying at 110°C for 15 h, then heating to 550°C at a rate of 2°C / min in a muffle furnace, and calcining for 6 h to obtain the catalyst.

[0061] 3. A method for synthesizing propylene glycol dimethyl ether by using the catalyst prepared in this example, the results being shown in Table 1.

[0062] Example 9

[0063] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, the catalyst having an active component accounting for 30% by weight based on 100%, and the rest being a carrier; the carrier being equal mass of CeO2 and ZrO2, and the active component being CuO, ZnO and MnO in a mass ratio of 1:1:8; the catalyst being labeled as 30%. 1.0 CuO- 1.0 ZnO- 8.0 MnO / CeO2-ZrO2.

[0064] 2. A preparation method of the catalyst for synthesizing propylene glycol dimethyl ether, comprising the following steps:

[0065] (1) dissolving copper nitrate, zinc nitrate, manganese nitrate, cerium nitrate, zirconium nitrate and sodium carbonate in water, controlling the pH to be 8-9, and stirring at 40°C to form an aqueous solution;

[0066] (2) The aqueous solution was heated to 120°C at a rate of 3°C / min, stirred at a speed of 30 rpm for 10 hours, cooled, filtered and washed until neutral, dried at 110°C for 15 hours, and then heated to 550°C in a muffle furnace at a rate of 2°C / min and calcined for 6 hours to obtain the catalyst.

[0067] 3. A method for synthesizing propylene glycol dimethyl ether using the catalyst prepared in this example is as follows: Synthesis gas and methylal are used as raw materials, the catalyst is loaded into a fixed-bed reactor, the synthesis gas is sampled through a high-pressure gas cylinder, the methylal is gasified in a gasifier via a horizontal flow pump, and then enters the fixed-bed reactor. The reaction temperature is 150°C and the reaction pressure is 3 MPa. The reaction product is liquefied and collected through a condenser and quantitatively analyzed by gas chromatography. The flow rate of the synthesis gas is 60 mL / min, and the liquid space velocity of the methylal is 6 h / min. -1 , the carbon-hydrogen ratio of the synthesis gas is 3, and the results are shown in Table 1.

[0068] Example 10

[0069] 1. A catalyst for synthesizing propylene glycol dimethyl ether, the catalyst being a composite oxide catalyst, wherein the active component accounts for 40% of the catalyst by weight, and the remainder is a support; the support is equal in mass to CeO2 and ZrO2, and the active components are Fe2O3, CoO, and NiO in a mass ratio of 4:3:3; the catalyst is marked as 40% 4.0 Fe2O3- 3.0 CoO- 3.0 NiO / CeO2-ZrO2.

[0070] 2. The method for preparing the catalyst for synthesizing propylene glycol dimethyl ether comprises the following steps:

[0071] (1) Dissolve ferric nitrate, cobalt nitrate, nickel nitrate, cerium nitrate, zirconium nitrate and ammonia water in water, control the pH to 8-9, and stir at 40°C to form an aqueous solution;

[0072] (2) The aqueous solution was heated to 120°C at a rate of 3°C / min, stirred at a speed of 30 rpm for 10 hours, cooled, filtered and washed until neutral, dried at 110°C for 15 hours, and then heated to 550°C in a muffle furnace at a rate of 2°C / min and calcined for 6 hours to obtain the catalyst.

[0073] 3. The method for synthesizing propylene glycol dimethyl ether by using the catalyst prepared in the embodiment, specifically as follows: taking the synthesis gas and methylal as raw materials, the catalyst is loaded into a fixed bed reactor, the synthesis gas is sampled through a high-pressure gas cylinder, the methylal is gasified through a flat flow pump into a gasification furnace and then into the fixed bed reactor, the reaction temperature is 150°C, the reaction pressure is 3 MPa, the reaction product is liquefied through a condenser tube and collected, and is quantitatively analyzed by gas chromatography; wherein the flow of the synthesis gas is 60 mL / min, the liquid space velocity of the methylal is 6 h -1 , the carbon-hydrogen ratio of the synthesis gas is 3, and the results are shown in Table 1.

[0074] Table 1. Reaction results

[0075] .

Claims

1. A catalyst for synthesizing propylene glycol dimethyl ether, characterized in that: The catalyst is a composite oxide catalyst, which consists of a carrier and an active component supported on the carrier, wherein the carrier is CeO2 and ZrO2, and the active component is an oxide of a metal M, wherein the metal M is at least two of Cu, Zn, Al, Cr, Fe, Co, Ni, and Mn; the active component accounts for 10-50% of the catalyst based on a weight ratio of 100%, and the rest is the carrier; the catalyst can catalyze the synthesis of propylene glycol dimethyl ether from synthesis gas and methylal.

2. The catalyst for synthesizing propylene glycol dimethyl ether according to claim 1, wherein: In the carrier, the ratio of CeO2 to ZrO2 is 1:

1.

3. The catalyst for synthesizing propylene glycol dimethyl ether according to claim 2, wherein: In the active component, the weight ratio of any one metal oxide to the active component is N, 10%≤N≤90%.

4. The method for preparing a catalyst for synthesizing propylene glycol dimethyl ether according to any one of claims 1 to 3, wherein: The following steps are involved: (1) Dissolve the water-soluble salts of metals M, Ce, and Zr and the precipitant in water, control the pH to 8-9, and stir at 35-45°C to form an aqueous solution; (2) The aqueous solution is heated to 90-150°C, stirred and reacted for 6-15 hours, cooled, filtered and washed until neutral, dried, and calcined.

5. The method for preparing a catalyst for synthesizing propylene glycol dimethyl ether according to claim 4, wherein: In step (2), the temperature is raised to 90-150°C at a rate of 2-5°C / min.

6. The method for preparing a catalyst for synthesizing propylene glycol dimethyl ether according to claim 5, wherein: In step (2), the stirring speed is 20-60 rpm.

7. The method for preparing a catalyst for synthesizing propylene glycol dimethyl ether according to claim 6, wherein: The drying conditions are as follows: drying at 80-120° C. for 12 h-20 h; and the calcining conditions are heating to 450° C.-600° C. at a rate of 1-5° C. / min and calcining for 5-10 h.

8. The method for preparing a catalyst for synthesizing propylene glycol dimethyl ether according to claim 7, wherein: The precipitant is one of ammonia water, urea, sodium carbonate and sodium bicarbonate.

9. A method for synthesizing propylene glycol dimethyl ether, characterized in that: The method is as follows: using synthesis gas and methylal as raw materials, loading a catalyst into a fixed bed reactor, injecting the synthesis gas through a high-pressure gas cylinder, and the methylal entering a gasifier through a horizontal flow pump for gasification and then entering the fixed bed reactor. The reaction temperature is 120-200° C., the reaction pressure is 1-4 MPa, and the reaction product is liquefied and collected through a condenser. The catalyst is the catalyst according to any one of claims 1 to 3.

10. The method for synthesizing propylene glycol dimethyl ether according to claim 9, wherein: The flow rate of the synthesis gas is 20-100 mL / min, and the liquid space velocity of methylal is 1-10 h -1 , the carbon-hydrogen ratio of synthesis gas is 2-6.