Multi-component composite catalyst for the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol and its preparation method

Abstract

This invention relates to a multi-component composite catalyst for the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol and its preparation method, mainly addressing the problems of low catalyst activity, low selectivity for the main product 1,3-propanediol, and poor stability in this type of catalyst. The catalyst for the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol according to this invention is prepared by hydrolysis precipitation. The catalyst comprises the following components: (a) CuO as the main component; (b) vanadium, a group VB element, as a structural aid; (c) Zn as an electronic aid; and (d) SiO2 as its support and pore-expanding agent. Under the action of the catalyst of this invention, the composite active phase formed by the structural aid, electronic aid, and main component CuO easily generates active sites for the conversion of 1,3-propanediol, and these active sites are more stable and less prone to agglomeration and deactivation, exhibiting good stability.

Description

Technical Field

[0001] This invention relates to a highly stable multi-component composite catalyst for the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol and its preparation method. Background Technology

[0002] PTT fiber is short for polypropylene terephthalate, which is produced by esterification and polycondensation of terephthalic acid (PTA) and 1,3-propanediol (1,3-PDO) to obtain polyester, which is then melt-spun into fiber. It belongs to the polyester fiber family, along with polyethylene terephthalate (PET) fiber and polybutylene terephthalate (PBT) fiber. PTT fiber combines the advantages of various fibers, including the stain resistance and stability of polyester (PET), the softness and abrasion resistance of nylon (PA), and the bulkiness of acrylic fiber (PAN). It also features wrinkle resistance, easy dyeing, good weather resistance, and low processing and finishing costs, making it an essential choice for high-end textile fabrics.

[0003] 1,3-PDO, as a bifunctional organic compound, is used in synthetic reactions, particularly as a monomer in polycondensation reactions to produce polyethers, polyurethanes, and polyesters. Polyethers are used in adhesives, elastomers, and flexible foams; polyurethanes are used in the textile industry, paints, and coatings. The largest application of 1,3-PDO is as a monomer in the production of polypropylene terephthalate (PTT). High-performance PTT fibers combine the properties of polyethylene terephthalate (PET) with the good resilience and stain resistance of nylon, making them widely used in carpets, engineering plastics, and clothing fabrics. As PTT has become a hot topic in international synthetic fiber development, its demand is constantly increasing, thus promoting the market growth of 1,3-PDO. Therefore, the production of 1,3-PDO has become a cornerstone of the PTT industry's development.

[0004] Currently, the main methods for preparing 1,3-propanediol are divided into two types: chemical synthesis and bio-fermentation. Among these, the chemical synthesis methods for 1,3-propanediol preparation include the EO method and the acrolein hydration method. The EO method, also known as the ethylene oxide carbonyl synthesis method, mainly consists of two process routes: ethylene oxide hydroformylation and ethylene oxide hydrogen esterification. The ethylene oxide hydrogen esterification method has lower raw material costs and is easier to scale up for large-scale production. Furthermore, the intermediate product in this method is stable methyl 3-hydroxypropionate, avoiding the formation of the unstable intermediate aldehyde, which can increase reactant concentration, simplify product separation processes, and improve product quality.

[0005] In recent years, copper-based catalysts have become the preferred choice for the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol due to their low production cost and the advantages of high activity, high selectivity, mild reaction conditions, and good resistance to toxicity when combined with other active agents. Existing patents and literature mainly focus on improving the conversion rate and selectivity of copper-based catalysts. Patent CN101993352A discloses a multi-metal oxide catalyst of Cu, Mn, and Zr prepared by co-precipitation, which can suppress dehydration side reactions and improve product conversion and selectivity. Patent CN106179361A reports the preparation of a silica-supported Cu, Zr, and Zn composite catalyst by precipitation, which features mild reaction conditions, a simple preparation process, high product conversion, high product selectivity, and high yield. Patent CN103721734A discloses a multi-component copper-based catalyst that uses silica as a catalyst support and adds Mn, Mo, and P as active additives. This catalyst can still maintain a high product conversion rate and selectivity in the hydrogenation reaction of high concentration of methyl 3-hydroxypropionate to produce 1,3-propanediol.

[0006] However, when using supported copper catalysts, the high free energy of copper atoms on the particle surface leads to Ostward ripening or particle migration during the hydrogenation of 3-HPM (methyl 3-hydroxypropionate). This results in copper particles easily agglomerating into large particles, reducing reactivity and stability. This invention utilizes vanadium as a structural aid, zinc as an electronic aid, and CuO as the main component to form a composite active phase. This facilitates the generation of active sites for the conversion of 1,3-propanediol, and the active sites are more stable, less prone to agglomeration and deactivation, and exhibit good stability. Summary of the Invention

[0007] One of the technical problems to be solved by this invention is the low catalyst activity, low selectivity of the main product 1,3-propanediol, and poor stability.

[0008] The second technical problem to be solved by the present invention is to provide a method for preparing the catalyst described in one of the above-mentioned technical problems.

[0009] The third technical problem to be solved by the present invention is to provide a method for the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol using the catalyst described in one of the above technical problems.

[0010] To solve one of the above-mentioned technical problems, the present invention provides a hydrogenation catalyst for preparing 1,3-propanediol. The technical solution of the present invention is as follows: A hydrogenation catalyst for preparing 1,3-propanediol, comprising the following components:

[0011] (a) The main component is CuO;

[0012] (b) The structural additive is a group VB element, vanadium;

[0013] (c) The electronic additive is zinc;

[0014] (d) SiO2 serves as its carrier and pore-expanding agent.

[0015] In the above technical solution, the main component is CuO, with a content of 30-50%.

[0016] In the above technical solution, the structural aid is a group VB element: vanadium, and the content of the active aid is 1-3% (based on the mass of oxides).

[0017] In the above technical solution, the electronic additive is zinc, and the content of the active additive is 0.5-2% (based on the mass of oxides).

[0018] In the above technical solution, the carrier and pore-expanding agent are SiO2 with a content of 45%-68.5%.

[0019] In the above technical solution, the sum of the weight percentages of the above components satisfies 100%.

[0020] To solve the second technical problem mentioned above, the present invention provides a hydrogenation catalyst for preparing 1,3-propanediol. The technical solution of the present invention is as follows: A hydrogenation catalyst for preparing 1,3-propanediol includes the following steps:

[0021] (1) Weigh a certain amount of copper source and zinc source and dissolve them in a certain amount of deionized water, and continue stirring until a transparent solution is obtained;

[0022] (2) Then add a certain amount of ammonium metavanadate powder to the solution obtained in step (1), disperse it by ultrasound, and then stir it thoroughly for 2 hours.

[0023] (3) Then add a certain amount of a well-mixed solution of tetraethyl orthosilicate and anhydrous ethanol to the solution obtained in step (2), disperse it by ultrasound, and then stir it thoroughly for 1 hour.

[0024] (4) Then, using the co-dropping method, the mixed solution prepared in step (3) and a certain amount of ammonium carbonate solution were added dropwise to the beaker simultaneously, and stirred thoroughly for 2 hours;

[0025] (5) Transfer the mixture obtained in step (4) to a three-necked flask, seal and age it at 80°C for 16-24 hours, during which water and ethanol are added to maintain the pH at 7-7.5;

[0026] (6) Filter the precipitate obtained in step (5), wash it until the residual liquid is neutral, and dry it in an oven at 80-150℃ for 12-36 hours;

[0027] (7) The solid obtained in step (6) is calcined at 650-750℃ for 4-8 hours;

[0028] (8) Grind the solid obtained in step (7), compress it into tablets, crush it, and sieve it to obtain the catalyst.

[0029] In the above technical solution, the copper source in step (1) is one or more of copper nitrate, copper sulfate, copper acetate, copper acetylacetone, and copper chloride, preferably copper nitrate.

[0030] In the above technical solution, the structural additive in step (2) is a group VB element: vanadium, and its precursor is ammonium metavanadate.

[0031] In the above technical solution, the zinc source in step (1) is one or more of zinc nitrate, zinc sulfate, zinc acetate, and zinc chloride, preferably zinc nitrate.

[0032] In the above technical solution, the ultrasonic dispersion time in steps (2) and (3) is 15-60 min.

[0033] In the above technical solution, in the mixed solution of tetraethyl orthosilicate and anhydrous ethanol in step (3), the molar ratio of tetraethyl orthosilicate to anhydrous ethanol is 1:17.

[0034] In the above technical solution, the molar amount of ammonium carbonate in step (4) is 1.6 times the total molar amount of copper salt and zinc salt.

[0035] In the above technical solution, the aging time in step (5) is 16-24 hours.

[0036] In the above technical solution, the drying in step (6) is vacuum drying or atmospheric pressure drying.

[0037] In the above technical solution, the roasting atmosphere in step (7) is air.

[0038] In the above technical solution, the catalyst sieved in step (8) is 20-40 mesh.

[0039] The third technical problem to be solved by the present invention is to provide a method for the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol using the catalyst described in one of the above technical problems.

[0040] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0041] This invention uses a methanol solution of methyl 3-hydroxypropionate as the reactant to evaluate the performance of the catalyst described in any of the above technical solutions in a high-pressure fixed-bed reactor. The catalyst loading is 10.0 ml. Before feeding, the catalyst is reduced with hydrogen to ensure that the active component exists in elemental form. The reduction conditions are: temperature 200~450℃, pressure 0.1~8.0 MPa, hydrogen flow rate 10~200 ml / min, and time 6~36 h. During the reaction, methyl 3-hydroxypropionate is diluted with methanol to a mass concentration of 5-20%, temperature 130-170℃, pressure 3-8 MPa, and feed volume hourly space velocity (VHSV) 0.01~3.0 h. -1 The hydrogen-to-ester ratio is 500-900.

[0042] Qualitative and quantitative analyses of the raw materials and hydrogenated products were performed using a GC-MC system to calculate the conversion rate of methyl 3-hydroxypropionate hydrogenation and the selectivity of 1,3-propanediol.

[0043]

[0044]

[0045] Compared with the prior art, the significant feature of this invention is that it utilizes vanadium as a structural aid, zinc as an electronic aid, and CuO as the main component to form a composite active phase, which easily generates active sites for the conversion of 1,3-propanediol. Moreover, these active sites are more stable and less prone to agglomeration and deactivation, thus the catalyst exhibits good activity and stability. Attached Figure Description

[0046] Figure 1 This is a graph showing the long-cycle reaction performance of the catalyst;

[0047] Figure 2 The XRD pattern of the catalyst before reaction in this invention;

[0048] Figure 3 XRD patterns of the catalyst after reduction were prepared according to the present invention;

[0049] Figure 4 The XRD pattern of the catalyst after reaction is shown in the present invention. Detailed Implementation

[0050] The present invention will be further illustrated below by way of examples, but these examples are not intended to limit the scope of the present invention.

[0051]

Example 1

[0052] Weigh 18.22 g of copper nitrate trihydrate and 0.685 g of zinc nitrate hexahydrate and dissolve them in 300 ml of deionized water, stirring continuously until a clear solution is obtained. Then, slowly add a mixed solution of 30.56 g of tetraethyl orthosilicate and 114.88 g of anhydrous ethanol, sonicate for 30 min, and stir thoroughly for 1 hour. Then, co-drop the above mixture with ammonium carbonate solution (8.085 g of ammonium carbonate dissolved in 200 ml of deionized water) into a beaker using a co-dropping method, stirring thoroughly for 2 hours. Subsequently, transfer it to a three-necked flask and age it in a sealed container at 80 °C for 18 h, adding water and ethanol during the process, and testing the pH to maintain 7-7.5. Filter the obtained precipitate, wash until the residue is neutral, and dry it in an oven at 120 °C for 12 hours. Calcine the resulting solid at 700 °C for 6 hours to obtain catalyst 40CuO-1.25ZnO / SiO2.

[0053] The 40CuO-1.25ZnO / SiO2 catalyst was compacted and then crushed and sieved into 20-40 mesh particles for catalytic performance testing.

[0054] 2. Catalyst Evaluation

[0055] The performance of the catalyst was evaluated in a high-pressure fixed-bed reactor using a methanol solution of methyl 3-hydroxypropionate as the reactant. The catalyst loading was 10.0 ml. The catalyst was reduced with hydrogen before feeding under the following conditions: temperature 320 °C, pressure 7 MPa, hydrogen flow rate 100 ml / min, and time 10 h. The reaction conditions were: methyl 3-hydroxypropionate diluted with methanol (methyl 3-hydroxypropionate mass concentration 5%), temperature 150 °C, pressure 7 MPa, and feed space velocity 0.21 h⁻¹. -1 The hydrogen-to-ester ratio is 500.

[0056] Long-term operation tests were conducted to examine the catalyst's conversion rate, selectivity, and stability. After the reaction temperature and pressure stabilized, a solution of methyl 3-hydroxypropionate was introduced as the reactant. The sample penetrated the catalyst bed. After the thermal high-resolution analyzer reached a liquid level, the product from the high-resolution condenser after the reactor was collected every 12 hours. GC-MC was used for quantitative and qualitative analysis of the reactant and the hydrogenated product. The conversion rate of methyl 3-hydroxypropionate hydrogenation and the selectivity of 1,3-propanediol were calculated. The physicochemical properties of the catalyst are shown in Table 1, and the reaction results are as follows: Figure 1 .

[0057] [Comparative Example 1] 40CuO / SiO2

[0058] 18.22 g of copper nitrate trihydrate was weighed and dissolved in 300 ml of deionized water, and stirred continuously until a clear solution was obtained. Then, a mixed solution of 31.21 g of tetraethyl orthosilicate and 117.32 g of anhydrous ethanol was slowly added dropwise, and the mixture was ultrasonically dispersed for 30 min and stirred thoroughly for 1 hour. Next, the mixture was co-dropped with ammonium carbonate solution (7.73 g of ammonium carbonate dissolved in 200 ml of deionized water) into a beaker using a co-dropping method, and stirred thoroughly for 2 hours. The mixture was then transferred to a three-necked flask and aged under sealed conditions at 80 °C for 18 h, during which water and ethanol were added, and the pH was maintained between 7 and 7.5. The resulting precipitate was filtered, washed until the residual liquid was neutral, and dried in an oven at 120 °C for 12 hours. The resulting solid was calcined at 700 °C for 6 hours to obtain catalyst 40CuO / SiO2.

[0059] The 40CuO / SiO2 catalyst was compacted and then crushed and sieved into 20-40 mesh particles for catalytic performance testing.

[0060] 2. Catalyst Evaluation

[0061] The catalytic performance of this catalyst in the hydrogenation of methyl 3-hydroxypropionate was evaluated using the same method as in Example 1. The physicochemical properties of the catalyst are shown in Table 1, and the reaction results are shown in [Table 1]. Figure 1 .

[0062] [Example 2] 40CuO-2V2O5 / SiO2

[0063] 18.22 g of copper nitrate trihydrate was weighed and dissolved in 300 ml of deionized water, and stirred continuously until a clear solution was obtained. Then, 0.193 g of ammonium metavanadate powder was added, and the mixture was ultrasonically dispersed for 30 min, followed by thorough stirring for 2 hours. Next, a mixed solution of 30.17 g of tetraethyl orthosilicate and 113.41 g of anhydrous ethanol was slowly added dropwise, ultrasonically dispersed for 30 min, and stirred thoroughly for 1 hour. Then, the mixture was co-dropped with ammonium carbonate solution (8.364 g of ammonium carbonate dissolved in 200 ml of deionized water) into a beaker, and stirred thoroughly for 2 hours. The mixture was then transferred to a three-necked flask and aged under sealed conditions at 80 °C for 18 h, during which water and ethanol were added, and the pH was maintained between 7 and 7.5. The resulting precipitate was filtered, washed until the residue was neutral, and dried in an oven at 120 °C for 12 hours. The resulting solid was calcined at 700 °C for 6 hours to obtain catalyst 40CuO-2V2O5 / SiO2.

[0064] The 40CuO-2V2O5 / SiO2 catalyst was compacted and then crushed and sieved into 20-40 mesh particles for catalytic performance testing.

[0065] 2. Catalyst Evaluation

[0066] The catalytic performance of this catalyst in the hydrogenation of methyl 3-hydroxypropionate was evaluated using the same method as in Example 1. The physicochemical properties of the catalyst are shown in Table 1, and the reaction results are shown in [Table 1]. Figure 1 .

[0067]

Example 3

[0068] Weigh 18.22 g of copper nitrate trihydrate and 0.685 g of zinc nitrate hexahydrate and dissolve them in 300 ml of deionized water, stirring continuously until a clear solution is obtained. Then add 0.193 g of ammonium metavanadate powder, disperse by ultrasonication for 30 min, and then stir thoroughly for 2 hours. Next, slowly add a mixed solution of 29.52 g of tetraethyl orthosilicate and 110.97 g of anhydrous ethanol, disperse by ultrasonication for 30 min, and stir thoroughly for 1 hour. Then, co-drop the above mixture with ammonium carbonate solution (8.718 g of ammonium carbonate dissolved in 200 ml of deionized water) into a beaker using the co-dropping method, stirring thoroughly for 2 hours. Then, transfer it to a three-necked flask, seal and age the precipitate at 80 °C for 18 h, adding water and ethanol during the process, and testing the pH to be between 7 and 7.5. Filter the obtained precipitate, wash until the residual liquid is neutral, and dry it in an oven at 120 °C for 12 hours. The resulting solid was calcined at 700℃ for 6 hours to obtain catalyst 40CuO-1.25ZnO-2V2O5 / SiO2.

[0069] The 40CuO-1.25ZnO-2V2O5 / SiO2 catalyst was compacted and then crushed and sieved into 20-40 mesh particles for catalytic performance testing.

[0070] 2. Catalyst Evaluation

[0071] The catalytic performance of this catalyst in the hydrogenation reaction of methyl 3-hydroxypropionate was evaluated using the same method as in Example 1. The physicochemical and characterization properties of the catalyst are shown in Table 1, and the reaction results are shown in [Table 1]. Figure 1 .

[0072] Table 1. Physicochemical Properties of Catalysts

[0073]

[0074] The comparison of the physicochemical properties of Examples 1, 2, 3 and Comparative Example 1 shows that the addition of metal additives vanadium or zinc can increase the specific surface area and pore volume of the catalyst, enhance the dispersibility of Cu species, generate more active sites, and thus improve the activity of the catalyst.

[0075] Comparison of XRD patterns from different stages of Examples 1, 2, 3, and Comparative Example 1 shows that the addition of vanadium as a structural aid and zinc as an electronic aid is beneficial to improving Cu 0 With Cu +The proportion of Cu species affects the catalytic activity; and the interfacial effect between the structural promoter vanadium, the electronic promoter zinc and Cu species enhances the interaction between the three, thus effectively inhibiting the migration of Cu species and forming a stable reactive phase, making it difficult for Cu species to aggregate.

[0076] The comparison of the reaction performance of Examples 1, 2, 3 and Comparative Example 1 shows that the addition of the structural additive vanadium and the electronic additive zinc is beneficial to maintaining the formation of Cu during the reaction. 0 / Cu + The active valence state of the catalyst enhances the adsorption of ester groups on the catalyst, thereby improving the conversion rate and selectivity of the hydrogenation reaction of methyl 3-hydroxypropionate to 1,3-propanediol. On the other hand, the composite active phase formed by the structural auxiliary vanadium, the electronic auxiliary zinc and the main component CuO is more stable and less prone to agglomeration and deactivation, which is consistent with the XRD characterization results. Therefore, the catalyst of the present invention exhibits good stability.

[0077] A comparison of the performance and characterization data of Example 3 and Example 1 shows that the introduction of the structural additive vanadium can further promote the interfacial effect (alloy formation) between Cu and Zn species, further enhancing the interaction between the active species Cu and the additive Zn. This effect increases the specific surface area of ​​the catalyst, promotes the dispersion of Cu active species, and effectively inhibits the migration of Cu species, improving the stability of Cu species and making it less prone to agglomeration (the change in Cu particle size before and after the reaction is not significant), thereby further improving the stability of the catalyst.

[0078] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. The application of a multi-component composite catalyst in the hydrogenation of methyl 3-hydroxypropionate to 1,3-propanediol, characterized in that: The multi-component composite catalyst comprises the following components: (a) The main component is CuO; (b) The structural additive is a group VB element, vanadium; (c) The electronic additive is zinc; (d) SiO2 serves as both the carrier and the pore-expanding agent; The main component CuO content is 30-50wt%; the structural additive vanadium content is 1-3wt% (based on oxide mass); the electronic additive zinc content is 0.5-2wt% (based on oxide mass); the carrier and pore expander SiO2 content is 45%-68.5wt%; and the sum of the weight percentages of all components satisfies 100%.

2. The application according to claim 1, characterized in that: The preparation method of the multi-component composite catalyst specifically includes the following steps: (1) Weigh a certain amount of copper source and zinc source and dissolve them in a certain amount of deionized water, and continue stirring until a transparent solution is obtained; (2) Then add a certain amount of ammonium metavanadate powder to the solution obtained in step (1), disperse it by ultrasound, and then stir it thoroughly for 2 hours. (3) Then add a certain amount of a well-mixed solution of tetraethyl orthosilicate and anhydrous ethanol to the solution obtained in step (2), disperse it by ultrasound, and then stir it thoroughly for 1 hour. (4) Then, using the co-dropping method, the mixed solution prepared in step (3) and a certain amount of ammonium carbonate solution were added dropwise to the beaker simultaneously, and stirred thoroughly for 2 hours; (5) Transfer the mixture obtained in step (4) to a three-necked flask, seal and age it at 80°C for 16-24 hours, during which water and ethanol are added to maintain the pH at 7-7.5; (6) Filter the precipitate obtained in step (5), wash it until the residual liquid is neutral, and dry it in an oven at 80-150℃ for 12-36 hours; (7) The solid obtained in step (6) is calcined at 650-750℃ for 4-8 hours; (8) Grind the solid obtained in step (7), compress it into tablets, crush it, and sieve it to obtain the catalyst.

3. The application according to claim 2, characterized in that: The copper source in step (1) is one or more of copper nitrate, copper sulfate, copper acetate, copper acetylacetone, and copper chloride.

4. The application according to claim 2, characterized in that: The zinc source in step (1) is one or more of zinc nitrate, zinc sulfate, zinc acetate, and zinc chloride.

5. The application according to claim 2, characterized in that: The ultrasonic dispersion time in steps (2) and (3) is 15-60 min.

6. The application according to claim 2, characterized in that: In step (3), the molar ratio of tetraethyl orthosilicate to anhydrous ethanol in the mixed solution is 1:

17.

7. The application according to claim 2, characterized in that: The molar amount of ammonium carbonate used in step (4) is 1.6 times the total molar amount of copper and zinc salts.

8. The application according to claim 2, characterized in that: The roasting atmosphere in step (7) is air; the catalyst sieved in step (8) is 20-40 mesh.

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