Catalyst for preparing 1, 3-propylene glycol through hydrogenation of beta-propiolactone as well as preparation method and application of catalyst

Abstract

The invention relates to a catalyst for preparing 1, 3-propylene glycol through hydrogenation of beta-propiolactone and a preparation method and application thereof.The catalyst comprises an active component, a structural auxiliary agent, an electronic auxiliary agent and a carrier, the active component of the catalyst is Cu metal, the structural auxiliary agent comprises one or more of Al, Zr, Zn, graphite and carbon nitride, the electronic auxiliary agent comprises one or more of Mn, P, La and Ce, and the carrier is a carrier. The carrier is SiO2, and in the catalyst, the content of Cu metal is 20-40 wt%, the content of the structural auxiliary agent is 0.1-20 wt%, and the content of the electronic auxiliary agent is 0.1-2 wt%. Compared with the prior art, the method has the advantages that the raw material beta-propiolactone is high in thermal stability and activity, side reactions in the hydrogenation process can be effectively reduced, the copper catalyst is high in hydrogenation activity and selectivity, the process is simple and efficient, the production continuity degree is high, subsequent separation and purification are simple, the product purity is high, and the method is suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry and environmental protection, and in particular to a catalyst for preparing 1,3-propylene glycol by hydrogenating beta-propiolactone, and a preparation method and application thereof. Background Art

[0002] 1,3-Propanediol (1,3-PDO) is an important organic chemical raw material, often used as a raw material for synthesizing plasticizers, detergents, preservatives, emulsifiers, etc., and its most important use is as a monomer for synthesizing polytrimethylene terephthalate (PTT). PTT is a new type of polyester fiber with excellent performance. It is made by polycondensation of terephthalic acid (PTA) and 1,3-propylene glycol. It combines the softness of nylon, the fluffiness of acrylic fiber, the stain resistance and good tensile resilience of polyester, and has the characteristics of being able to be dyed at low temperature and normal pressure. At present, affected by the price, PTT is mainly used in clothing and carpets, and its application in the fields of engineering plastics and film materials is limited. The current output growth rate of my country's PTT fiber industry is slower than the demand growth rate. The main reason is the restriction of 1,3-propylene glycol. On the one hand, the production technology of 1,3-propylene glycol was monopolized by foreign countries before 2014, which led to a late start in my country. On the other hand, the current mainstream biological method is too expensive, resulting in high prices for 1,3-propylene glycol, which limits its application.

[0003] At present, the main industrial method for synthesizing 1,3-propylene glycol is the one-step hydroformylation of ethylene oxide, that is, ethylene oxide, carbon monoxide and hydrogen are used as raw materials to directly synthesize 1,3-propylene glycol. The reaction temperature used is 90°C, the reaction pressure is 10MPa, and the catalyst is a cobalt / ruthenium / phosphine catalyst. However, under this process route, the conversion rate of EO is only 21-34%, and 3-hydroxypropionaldehyde (3-HPA) that is easily condensed or polymerized will inevitably be produced during the hydroformylation process. Even if there is a trace amount of 3-HPA in the product, it will affect the viscosity and color of the downstream PTT product.

[0004] The method for synthesizing 1,3-propylene glycol reported so far also includes the acrolein route, which also has the problem that the 3-HPA produced is easy to polymerize, and the raw material acrolein is relatively expensive, and acrolein itself is also easy to condense with 3-HPA. In addition, the hydration catalyst used in this process route is complicated to prepare and has a short life. CN116239445A discloses a method for synthesizing 1,3-propylene glycol by ring-opening hydrogenation of propiolactone, which uses β-propiolactone as a raw material, and reacts β-propiolactone and alcohol continuously under the catalysis of a strong alkaline resin and an auxiliary agent to open the ring to obtain 3-hydroxypropionic ester, and the 3-hydroxypropionic ester is continuously hydrogenated under the action of a hydrogenation catalyst to obtain 1,3-propylene glycol. The hydrogenation reaction is carried out in an autoclave, and the reaction process is complicated and the catalyst separation is difficult.

[0005] In addition to chemical synthesis, another method reported for synthesizing 1,3-propylene glycol is the bioengineering route. There have been many studies on this route abroad. Compared with chemical synthesis, the bioengineering method has the advantages of mild conditions, simple operation, and green environmental protection. However, the cost of the bioengineering method is very high, and the industrial production scale is usually small.

[0006] Therefore, there is an urgent need to develop a safe, environmentally friendly, green and economical method for synthesizing 1,3-propylene glycol. Summary of the invention

[0007] The purpose of the present invention is to provide a catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone in order to overcome the defects of the above-mentioned prior art, and a preparation method and application thereof. The catalyst used includes an active component, a structural additive, an electronic additive and a carrier, has a ring-opening active center and a hydrogenation active center, can catalyze the hydrogenation of β-propiolactone to prepare 1,3-propylene glycol, the hydrogenation process has high hydrogenation activity and high selectivity, the process is simple and efficient, the production is highly continuous, the subsequent separation and purification are simple, the product purity is high, and it is suitable for large-scale production.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] The first object of the present invention is to provide a catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, the catalyst comprising an active component, a structural additive, an electronic additive and a carrier; the active component is Cu metal; the structural additive comprises one or more of Al, Zr, Zn, graphite, and carbon nitride; the electronic additive comprises one or more of Mn, P, Sb, Ge, Bi, La, and Ce; the carrier is SiO2; in the catalyst, the content of Cu metal is 20-40wt%, the content of the structural additive is 0.1-20wt%, and the content of the electronic additive is 0.1-2wt%.

[0010] Further preferably, the catalyst is CuZnMnSi.

[0011] Furthermore, in the catalyst, the content of Cu metal is 20-40wt%. Within this content range, the particle size of Cu metal is small, and the catalyst has high hydrogenation activity and selectivity for 1,3-propylene glycol.

[0012] Furthermore, the content of the structural additive is 0.1-20wt%. Within this content range, the addition of the structural additive can effectively improve the dispersion and catalytic activity of Cu, and improve the stability and service life of the catalyst.

[0013] Furthermore, the content of the electronic auxiliary agent is 0.1-2wt%. Within this content range, the addition of the electronic auxiliary agent can regulate and stabilize the Cu 0 and Cu+ The ratio of electronic additives and Cu + It can effectively promote the ring opening of β-propiolactone, thereby regulating the activity and selectivity of the catalyst, inhibiting side reactions, and improving the selectivity of 1,3-propylene glycol.

[0014] The second object of the present invention is to provide a method for preparing a catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, wherein the preparation of the catalyst can be achieved by the following method:

[0015] The precursor of the active component, the precursor of the structural auxiliary agent, the precursor of the electronic auxiliary agent and the precursor of the carrier are dissolved in the first solvent to obtain a mixed solution, which is neutralized and treated with an alkaline solution to obtain a precipitate, and then dried, calcined, formed and reduced to obtain a catalyst for hydrogenating β-propiolactone to prepare 1,3-propylene glycol.

[0016] Furthermore, the calcination temperature of the catalyst is 450-650° C., which can ensure the full decomposition of the active component precursor and the interaction between copper, the additive and the carrier, thereby improving the stability and activity of the catalyst.

[0017] Furthermore, the reduction temperature of the catalyst is 250-350°C. The appropriate reduction temperature can not only effectively reduce Cu metal, but also quickly create a reasonable Cu / Cu ratio in the active center. + ratio, thereby effectively promoting the ring-opening hydrogenation of propiolactone, reducing the catalyst induction period, and improving the catalyst activity and 1,3-propylene glycol selectivity.

[0018] Furthermore, the precursor of the active component includes Cu(NO3)2·3H2O; the precursor of the structural auxiliary agent includes Zn(NO3)2·6H2O; the precursor of the electronic auxiliary agent includes Mn(NO3)2; the precursor of the carrier includes silica sol; and the first solvent includes deionized water.

[0019] Furthermore, the preparation method specifically comprises the following steps:

[0020] The precursor of the active component, the precursor of the structural auxiliary agent and the precursor of the electronic auxiliary agent are dissolved in the first solvent and stirred to obtain a solution. The precursor of the carrier is dropped into the solution under stirring. After the dropwise addition is completed, sodium carbonate solution is dropped under stirring and 70°C for precipitation. After the dropwise addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a hydrogenation reactor using a H2 / N2 mixed gas.

[0021] The third object of the present invention is to provide an application of a catalyst for hydrogenating β-propiolactone to prepare 1,3-propylene glycol, using the catalyst for hydrogenating β-propiolactone to prepare 1,3-propylene glycol, and to provide a method for hydrogenating β-propiolactone to prepare 1,3-propylene glycol.

[0022] Furthermore, a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone comprises the following steps: loading a catalyst into a hydrogenation reactor, wherein the catalyst is the above catalyst or a catalyst prepared by the above preparation method; preheating the β-propiolactone and a second solvent in a preheater to obtain a preheated material, subjecting the preheated material to a catalytic hydrogenation reaction in a hydrogenation reactor to generate 1,3-propylene glycol to obtain a reacted material, wherein the reacted material enters a gas-liquid separator, hydrogen is extracted from the top for reflux, and the bottom stream enters a hydrogenation delightening tower, and the by-product propanol is extracted from the top of the hydrogenation delightening tower, and the bottom stream of the hydrogenation delightening tower enters a refining tower, and the unreacted material is extracted from the top of the refining tower, which is circulated into the hydrogenation reactor, and high-purity 1,3-propylene glycol is extracted from the bottom of the refining tower.

[0023] Furthermore, the second solvent is one of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, diethylene glycol dimethyl ether, or a mixture of several of them.

[0024] Further, the temperature of the preheater is 60-140°C and the pressure is 2.0-6.0MPa;

[0025] The temperature of the hydrogenation reactor is 140-180° C., and the pressure is 2.0-6.0 MPa.

[0026] Furthermore, the molar ratio of β-propiolactone to hydrogen in the catalytic hydrogenation reaction is 1:20-1:200.

[0027] Furthermore, the operating pressure of the gas-liquid separator is 2.0-6.0 MPa, and the operating temperature of the gas-liquid separator is -30-30°C.

[0028] Furthermore, the space velocity of the catalytic hydrogenation reaction is 0.05-0.5h -1 .

[0029] Furthermore, the operating pressure of the hydrogenation and lightness removal tower is reduced pressure or normal pressure, and the operating temperature is 30-200°C; the operating pressure of the refining tower is reduced pressure or normal pressure, and the operating temperature is 60-200°C.

[0030] The present invention further provides a system for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, which is used to realize the method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone. The system comprises a preheater, a hydrogenation reactor, a gas-liquid separator, a hydrogenation-dehydrogenation tower, and a refining tower; the preheater is connected to the hydrogenation reactor, the hydrogenation reactor is connected to the gas-liquid separator, the gas-liquid separator is connected to the hydrogenation-dehydrogenation tower, the hydrogenation-dehydrogenation tower is connected to the hydrogenation reactor, the hydrogenation-dehydrogenation tower is connected to the refining tower, and the refining tower is connected to the hydrogenation reactor.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) The present invention uses β-propiolactone as a raw material, has high thermal stability, can effectively reduce side reactions in the hydrogenation process, has high copper catalyst hydrogenation activity and high selectivity, has a simple and efficient process, has a high degree of production continuity, is simple to subsequently separate and purify, has a high product purity, and is suitable for large-scale production.

[0033] 2) The method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone of the present invention can obtain 1,3-propylene glycol with a purity of 99.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a system schematic diagram of the method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone in the examples and comparative examples of the present invention.

[0035] in:

[0036] R101, preheater; R102, hydrogenation reactor; V101, gas-liquid separator; T101, hydrogenation and delightening tower; T102, refining tower. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with specific embodiments, which are only used to illustrate the present invention and are not used to limit the scope of protection of the present invention. The features such as component models, material names, connection structures, control methods, etc. that are not clearly described in this technical solution are regarded as common technical features disclosed in the prior art.

[0038] refer to Figure 1 The present invention provides a catalyst and method for synthesizing 1,3-propylene glycol. The catalyst comprises an active component, a structural additive, an electronic additive and a carrier, wherein the active component of the catalyst is Cu metal, the structural additive comprises one or more of Al, Zr, Zn, graphite and carbon nitride, the electronic additive comprises one or more of Mn, P, La and Ce, the carrier is SiO2, and in the catalyst, the content of Cu metal is 20-40wt%, the content of the structural additive is 0.1-20wt%, and the content of the electronic additive is 0.1-2wt%.

[0039] The precursors of copper, an auxiliary agent and a carrier are dissolved to obtain a mixed solution, which is neutralized and treated with an alkaline solution to obtain a precipitate, and then dried, calcined, formed and reduced to obtain a catalyst for hydrogenating β-propiolactone to prepare 1,3-propylene glycol.

[0040] The calcination temperature of the catalyst is 450-650°C, and the reduction temperature of the catalyst is 250-350°C.

[0041] The method for synthesizing 1,3-propylene glycol specifically comprises the following steps: β-propiolactone and a solvent are preheated in a preheater, the preheated materials undergo a catalytic hydrogenation reaction in a fixed bed reactor to generate 1,3-propylene glycol, the materials after the reaction enter a gas-liquid separation tank, hydrogen is extracted from the top for reflux, the bottom logistics enters a hydrogenation and light removal tower, by-product propanol and the like are extracted from the top of the hydrogenation and light removal tower, the bottom logistics enters a refining tower, unreacted materials are extracted from the top of the refining tower, circulated into a hydrogenation reactor, and high-purity 1,3-propylene glycol is extracted from the bottom of the refining tower.

[0042] Furthermore, the solvent is one or a mixture of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, and diethylene glycol dimethyl ether.

[0043] refer to Figure 1 In an embodiment of the present invention, the preheater R101 is connected to the hydrogenation reactor R102, the hydrogenation reactor R102 is connected to the gas-liquid separator V101, the gas-liquid separator V101 is connected to the hydrogenation dehydrogenation tower T101, the hydrogenation dehydrogenation tower T101 is connected to the hydrogenation reactor R102, the hydrogenation dehydrogenation tower T101 is connected to the refining tower T102, and the refining tower T102 is connected to the hydrogenation reactor R102.

[0044] The hydrogenation reactor R102 is a fixed bed reactor.

[0045] In the following examples, silica sol was purchased from MacLean's Reagent.

[0046] Example 1

[0047] This embodiment provides a method for preparing a CuZnMnSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, comprising the following steps:

[0048] In a beaker, dissolve the measured Cu(NO3)2·3H2O, Zn(NO3)2·6H2O, and Mn(NO3)2·6H2O in deionized water and stir to obtain a uniform and transparent solution. 2+The concentration is 0.5 mol / L, and silica sol is slowly added to the solution under stirring. After the addition is completed, 1 mol / L sodium carbonate solution is added under stirring and 70°C for precipitation. After the addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a hydrogenation reactor R102 with 2% H2 / N2 mixed gas to obtain a CuZnMnSi catalyst, in which the content of Cu is 40wt%, the content of Zn is 0.5wt%, and the content of Mn is 0.5wt%.

[0049] Comparative Example 1

[0050] This comparative example provides a method for preparing a CuSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, comprising the following steps:

[0051] In a beaker, dissolve the measured amount of Cu(NO3)2·3H2O in deionized water solution and stir to obtain a uniform and transparent solution. 2+ The concentration is 0.5 mol / L. Silica sol is slowly added to the solution under stirring. After the addition is completed, 1 mol / L sodium carbonate solution is added under stirring and 70°C for precipitation. After the addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ in the hydrogenation reactor R102 with 2% H2 / N2 mixed gas at 300°C for 10 hours to obtain a CuSi catalyst with a Cu content of 40wt%.

[0052] Comparative Example 2

[0053] This comparative example provides a method for preparing a CuZnSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, comprising the following steps:

[0054] In a beaker, dissolve the measured Cu(NO3)2·3H2O and Zn(NO3)2·6H2O in deionized water solution and stir to obtain a uniform and transparent solution. 2+The concentration is 0.5 mol / L. Silica sol is slowly added to the solution under stirring. After the addition is completed, 1 mol / L sodium carbonate solution is added under stirring and 70°C for precipitation. After the addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a hydrogenation reactor R102 with 2% H2 / N2 mixed gas. The content of Cu is 40wt% and the content of Zn is 0.5wt%.

[0055] Comparative Example 3

[0056] This comparative example provides a method for preparing a CuMnSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, comprising the following steps:

[0057] In a beaker, dissolve the measured Cu(NO3)2·3H2O and Mn(NO3)2 in deionized water solution and stir to obtain a uniform and transparent solution. 2+ The concentration is 0.5 mol / L. Silica sol is slowly added to the solution under stirring. After the addition is completed, 1 mol / L sodium carbonate solution is added under stirring and 70°C for precipitation. After the addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a solid hydrogenation reactor R102 with 2% H2 / N2 mixed gas. The content of Cu is 40wt% and the content of Mn is 0.5wt%.

[0058] Comparative Example 4

[0059] This comparative example provides a method for preparing a CuMnSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, comprising the following steps:

[0060] In a beaker, dissolve the measured Cu(NO3)2·3H2O, Zn(NO3)2·6H2O, and Mn(NO3)2·6H2O in deionized water and stir to obtain a uniform and transparent solution. 2+The concentration is 0.5 mol / L, and silica sol is slowly added to the solution under stirring. After the addition is completed, 1 mol / L sodium carbonate solution is added under stirring and 70°C for precipitation. After the addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a hydrogenation reactor R102 with 2% H2 / N2 mixed gas to obtain a CuZnMnSi catalyst, in which the content of Cu is 50wt%, the content of Zn is 0.5wt%, and the content of Mn is 0.5wt%.

[0061] Comparative Example 5

[0062] This comparative example provides a method for preparing a CuMnSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, comprising the following steps:

[0063] In a beaker, dissolve the measured Cu(NO3)2·3H2O, Zn(NO3)2·6H2O, and Mn(NO3)2·6H2O in deionized water and stir to obtain a uniform and transparent solution. 2+ The concentration is 0.5 mol / L, and silica sol is slowly added to the solution under stirring. After the addition is completed, 1 mol / L sodium carbonate solution is added under stirring and 70°C for precipitation. After the addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a hydrogenation reactor R102 with 2% H2 / N2 mixed gas to obtain a CuZnMnSi catalyst, in which the content of Cu is 40wt%, the content of Zn is 30wt%, and the content of Mn is 0.5wt%.

[0064] Comparative Example 6

[0065] This comparative example provides a method for preparing a CuMnSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, comprising the following steps:

[0066] In a beaker, dissolve the measured Cu(NO3)2·3H2O, Zn(NO3)2·6H2O, and Mn(NO3)2·6H2O in deionized water and stir to obtain a uniform and transparent solution. 2+The concentration is 0.5 mol / L, and silica sol is slowly added to the solution under stirring. After the addition is completed, 1 mol / L sodium carbonate solution is added under stirring and 70°C for precipitation. After the addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, it is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a hydrogenation reactor R102 with 2% H2 / N2 mixed gas to obtain a CuZnMnSi catalyst, in which the content of Cu is 40wt%, the content of Zn is 0.5wt%, and the content of Mn is 5wt%.

[0067] Example 2

[0068] This embodiment provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuZnMnSi catalyst prepared in Example 1 as a catalyst. The method comprises the following steps:

[0069] β-Propiolactone and the second solvent methanol enter the preheater R101 at a volume ratio of 1:10 for preheating to obtain the preheated material. The preheated material undergoes catalytic hydrogenation reaction with hydrogen in the hydrogenation reactor R102 at a reaction space velocity of 0.2h -1 , 1,3-propylene glycol is generated, and the reacted material is obtained. The reacted material enters the gas-liquid separator V101, and the hydrogen is refluxed from the top. The bottom logistics enters the hydrogenation and lightness removal tower T101, and the by-product propanol is taken from the top of the hydrogenation and lightness removal tower T101. The bottom logistics of the hydrogenation and lightness removal tower T101 enters the refining tower T102, and the unreacted material is taken from the top of the refining tower T102, and circulated into the hydrogenation reactor R102, and high-purity 1,3-propylene glycol is taken from the bottom of the refining tower T102. Among them, the temperature of the preheater R101 is 80°C and the pressure is 6.0MPa.

[0070] The temperature of the hydrogenation reactor R102 (fixed bed reactor) is 160° C. and the pressure is 60 bar.

[0071] Among them, the temperature of the gas-liquid separator V101 is 30°C and the pressure is 6MPa; the top temperature of the hydrodelightening tower T101 is 90°C, the bottom temperature is 210°C, and the pressure is 1bar; the top temperature of the refining tower T102 is 162°C, the bottom temperature is 214°C, and the pressure is 1bar.

[0072] Comparative Example 7

[0073] This comparative example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuSi catalyst prepared in comparative example 1 as a catalyst. The steps of the method are the same as those of example 2 (different catalysts), and high-purity 1,3-propylene glycol is extracted at the bottom of the refining tower T102.

[0074] Comparative Example 8

[0075] This comparative example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuZnSi catalyst prepared in comparative example 2 as a catalyst. The steps of the method are the same as those of example 2 (different catalysts), and high-purity 1,3-propylene glycol is produced at the bottom of the refining tower T102.

[0076] Comparative Example 9

[0077] This comparative example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuMnSi catalyst prepared in comparative example 3 as a catalyst. The steps of the method are the same as those of example 2 (different catalysts), and high-purity 1,3-propylene glycol is produced at the bottom of the refining tower T102.

[0078] Comparative Example 10

[0079] This comparative example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuMnSi catalyst prepared in comparative example 4 as a catalyst. The steps of the method are the same as those of example 2 (different catalysts), and high-purity 1,3-propylene glycol is produced at the bottom of the refining tower T102.

[0080] Comparative Example 11

[0081] This comparative example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuMnSi catalyst prepared in comparative example 5 as a catalyst. The steps of the method are the same as those of Example 2 (different catalysts), and high-purity 1,3-propylene glycol is produced at the bottom of the refining tower T102.

[0082] Comparative Example 12

[0083] This comparative example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuMnSi catalyst prepared in comparative example 6 as a catalyst. The steps of the method are the same as those of Example 2 (different catalysts), and high-purity 1,3-propylene glycol is produced at the bottom of the refining tower T102.

[0084] System reference for hydrogenation of β-propiolactone to 1,3-propylene glycol Figure 1 , Example 2 and Comparative Examples 4 to 6 are all methods for synthesizing 1,3-propylene glycol. The specific process conditions of Example 2 and Comparative Examples 4 to 6 are shown in Table 1.

[0085] Table 1. Effect of catalyst on hydrogenation performance of β-propiolactone

[0086]

[0087] In Example 2 and Comparative Examples 7 to 12, doping with Zn can effectively improve the conversion rate of β-propiolactone, doping with Mn can effectively improve the selectivity of 1,3-propylene glycol, and doping with Zn and Mn at the same time can simultaneously improve the hydrogenation activity of β-propiolactone and the selectivity of 1,3-propylene glycol, and the purity of 1,3-propylene glycol after separation and purification can reach 99.9%. However, when the content of Cu metal is greater than 40wt%, the content of structural additives is greater than 20wt%, and the content of electronic additives is greater than 2wt%, the conversion rate of β-propiolactone and / or the selectivity of 1,3-propylene glycol will be affected, and the conversion rate of β-propiolactone and / or the selectivity of 1,3-propylene glycol will be reduced.

[0088] Embodiments 3 to 8

[0089] This embodiment provides a method for preparing a CuZnMnSi catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, which is different from Embodiment 1 in that the calcination temperature and the reduction temperature are different.

[0090] This example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, using the CuZnMnSi catalyst prepared in Example 1 as a catalyst. The steps of the method are the same as those of Example 2 (with a different catalyst), and high-purity 1,3-propylene glycol is extracted at the bottom of the refining tower T102.

[0091] System reference for hydrogenation of β-propiolactone to 1,3-propylene glycol Figure 1 , Examples 3 to 8 are all methods for synthesizing 1,3-propylene glycol, and the specific process conditions of Examples 3 to 8 are shown in Table 2.

[0092] Table 2. Effects of calcination temperature and reduction temperature of catalyst on catalyst activity and selectivity

[0093]

[0094] In Examples 3 to 8, as the calcination temperature increases, the conversion rate of β-propiolactone and the selectivity of 1,3-propylene glycol both show a trend of first increasing and then decreasing. As the reduction temperature increases, the conversion rate of β-propiolactone shows an increasing trend, but the selectivity of 1,3-propylene glycol shows a trend of first increasing and then decreasing. The purity of 1,3-propylene glycol after separation and purification can reach 99.9%.

[0095] Embodiments 9 to 15

[0096] This example provides a method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, wherein the CuZnMnSi catalyst prepared in Example 1 and the CuSi catalyst prepared in Comparative Example 1 are used as catalysts respectively. The steps of the method are substantially the same as those of Example 2, except that the reaction time is different, and high-purity 1,3-propylene glycol is extracted at the bottom of the refining tower T102.

[0097] System reference for hydrogenation of β-propiolactone to 1,3-propylene glycol Figure 1 , Examples 3 to 8 are all methods for synthesizing 1,3-propylene glycol, and the specific process conditions of Examples 9 to 15 are shown in Table 3.

[0098] Table 3. Effect of additives on the stability of β-propiolactone hydrogenation catalyst

[0099]

[0100]

[0101] In Examples 9 to 15, as the catalyst evaluation time increases, the activity and selectivity of the CuSi catalyst gradually decrease, which may be due to coking on the catalyst surface or the loss of active components. The activity and selectivity of the CuZnMnSi catalyst remain basically stable, and the purity of 1,3-propylene glycol after separation and purification can reach 99.9%.

[0102] In Examples 15-21, as the catalyst evaluation time increases, the activity and selectivity of the CuSi catalyst gradually decrease, which may be due to coking on the catalyst surface or the loss of active components. The activity and selectivity of the CuZnMnSi catalyst remain basically stable, and the purity of 1,3-propylene glycol after separation and purification can reach 99.9%.

[0103] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, characterized in that: The catalyst comprises an active component, a structural auxiliary agent, an electronic auxiliary agent and a carrier; The active component is Cu metal; The structural additive includes one or more of Al, Zr, Zn, graphite, and carbon nitride; The electronic auxiliary agent includes one or more of Mn, P, Sb, Ge, Bi, La, and Ce; The carrier is SiO2; In the catalyst, the content of Cu metal is 20-40wt%, the content of structural auxiliary agent is 0.1-20wt%, and the content of electronic auxiliary agent is 0.1-2wt%.

2. A method for preparing a catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone as claimed in claim 1, characterized in that: The preparation method comprises the following steps: The precursor of the active component, the precursor of the structural auxiliary agent, the precursor of the electronic auxiliary agent and the precursor of the carrier are dissolved in the first solvent to obtain a mixed solution, which is neutralized and treated with an alkaline solution to obtain a precipitate, and then dried, calcined, formed and reduced to obtain a catalyst for hydrogenating β-propiolactone to prepare 1,3-propylene glycol.

3. The method for preparing a catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone according to claim 2, characterized in that: The calcination temperature of the catalyst is 450-650°C, and the reduction temperature of the catalyst is 250-350°C.

4. The method for preparing a catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone according to claim 2, characterized in that: The precursor of the active component includes Cu(NO3)2·3H2O; The precursor of the structural auxiliary agent includes Zn(NO3)2·6H2O; The precursor of the electronic auxiliary agent includes Mn(NO3)2; The precursor of the carrier includes silica sol; The first solvent includes deionized water.

5. The method for preparing a catalyst for preparing 1,3-propylene glycol by hydrogenating β-propiolactone according to claim 2, characterized in that: The preparation method specifically comprises the following steps: The precursor of the active component, the precursor of the structural auxiliary agent and the precursor of the electronic auxiliary agent are dissolved in the first solvent and stirred to obtain a solution. The precursor of the carrier is dropped into the solution under stirring. After the dropwise addition is completed, sodium carbonate solution is dropped under stirring and 70°C for precipitation. After the dropwise addition is completed, the stirring is stopped after aging at this temperature for 4 hours. After cooling to room temperature, the solid is filtered and washed. The obtained solid is dried at 120°C for 12 hours and calcined at 550°C for 4 hours. Before the reaction, the catalyst is reduced in situ at 300°C for 10 hours in a hydrogenation reactor (R102) with a H2 / N2 mixed gas.

6. A method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone, characterized in that: The method comprises the following steps: Filling a catalyst into a hydrogenation reactor (R102), wherein the catalyst is the catalyst according to claim 1 or a catalyst prepared by the preparation method according to any one of claims 2 to 5; β-Propiolactone and the second solvent are preheated in a preheater (R101) to obtain a preheated material. The preheated material undergoes a catalytic hydrogenation reaction in a hydrogenation reactor (R102) to generate 1,3-propylene glycol to obtain a reacted material. The reacted material enters a gas-liquid separator (V101), hydrogen is withdrawn from the top for reflux, and the bottom stream enters a hydrogenation delightening tower (T101), and the by-product propanol is withdrawn from the top of the hydrogenation delightening tower (T101). The bottom stream of the hydrogenation delightening tower (T101) enters a refining tower (T102), and the incompletely reacted material is withdrawn from the top of the refining tower (T102), circulated into the hydrogenation reactor (R102), and high-purity 1,3-propylene glycol is withdrawn from the bottom of the refining tower (T102).

7. The method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone according to claim 6, characterized in that: The second solvent is one of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, diethylene glycol dimethyl ether, or a mixture of several of them.

8. The method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone according to claim 6, characterized in that: The temperature of the preheater (R101) is 60-140°C and the pressure is 2.0-6.0MPa; The temperature of the hydrogenation reactor (R102) is 140-180°C and the pressure is 2.0-6.0 MPa.

9. The method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone according to claim 6, characterized in that: The molar ratio of β-propiolactone to hydrogen in the catalytic hydrogenation reaction is 1:20-1:

200.

10. The method for preparing 1,3-propylene glycol by hydrogenating β-propiolactone according to claim 6, characterized in that: The operating pressure of the gas-liquid separator (V101) is 2.0-6.0 MPa, and the operating temperature of the gas-liquid separator (V101) is -30-30°C; The operating pressure of the hydrogenation and light removal tower (T101) is reduced pressure or normal pressure, and the operating temperature is 30-200°C; The operating pressure of the refining tower (T102) is reduced pressure or normal pressure, and the operating temperature is 60-200°C.

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