A method for directly preparing 1,3-propanediol from acrolein in one step

Abstract

The application discloses a method for directly preparing 1,3-propanediol from propenal in one step, wherein a hydration hydrogenation catalyst is filled in a constant temperature zone of a hydration hydrogenation reactor, quartz sand is filled at both ends of the hydration hydrogenation catalyst, liquid-phase raw materials and gas-phase raw materials are uniformly mixed, and then the mixture is fed into the hydration hydrogenation reactor to perform hydration hydrogenation reaction, and the reaction product is fed into a rectifying tower for separation, and high-purity 1,3-propanediol is obtained through the separation. The preparation method is short in process, simple in operation, and low in cost, the conversion rate of propenal is greater than 94%, the selectivity of 1,3-propanediol is greater than 89%, and industrialized production can be easily realized.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals, specifically relating to a method for the one-step direct preparation of 1,3-propanediol from acrolein. Background Technology

[0002] 1,3-Propanediol, abbreviated as 1,3-PDO, is an important chemical raw material. It is mainly used in the synthesis of plasticizers, detergents, preservatives, and emulsifiers. It can also be used in the food, cosmetics, and pharmaceutical industries. Its main use is to replace ethylene glycol and butanediol as a monomer in the synthesis of polypropylene terephthalate (PTT), which is used to manufacture new polyester fibers with excellent performance.

[0003] Currently, the synthesis methods for 1,3-propanediol are divided into two types: chemical synthesis and bioconversion. Chemical synthesis is mainly represented by Shell's ethylene oxide process and Degussa's acrolein route. Bioconversion, represented by DuPont in the United States, uses renewable resources such as corn starch as raw materials for microbial fermentation. Relatively speaking, chemical synthesis has readily available raw materials and lower production costs.

[0004] Patent CN 110386856 A uses N-alkyl amino acids as a homogeneous catalyst to react acrolein with water to prepare 3-hydroxypropanal. The hydrated reaction solution is extracted to recover unreacted acrolein and N-alkyl amino acids, which are then reused in the hydration reaction. The aqueous phase, a 3-hydroxypropanal aqueous solution, is directly hydrogenated to prepare 1,3-propanediol. Patent CN 110204422 A prepares 3-hydroxypropanal from acrolein hydration, followed by separation and hydrogenation reactions to prepare 1,3-propanediol. Patent CN 115745740 A uses propylene as its raw material. Under the action of a catalyst, propylene undergoes a selective oxidation reaction to obtain acrolein and acrylic acid. Then, under the action of a hydration catalyst, a hydration reaction occurs to obtain 3-hydroxypropanal and 3-hydroxypropionic acid. These are then separated to obtain 3-hydroxypropanal and 3-hydroxypropionic acid, respectively. The 3-hydroxypropionic acid undergoes an esterification reaction to obtain 3-hydroxypropionate. The 3-hydroxypropionate is mixed with 3-hydroxypropanal, and the mixture is subjected to catalytic hydrogenation to obtain 1,3-propanediol and alcohols. Finally, 1,3-propanediol is separated. All of the above patents involve the hydration of acrolein to obtain 3-hydroxypropanal, which is then hydrogenated to obtain 1,3-propanediol. This results in a complex process, high energy consumption, and high production costs for 1,3-propanediol.

[0005] Currently, the technology for synthesizing 1,3-propanediol from acrolein is monopolized by Degussa, and there are no reports of large-scale industrial production in China. Therefore, there is a great need to explore a method that is short in process, simple in operation, low in cost, and fills the gap in domestic industrialization. Summary of the Invention

[0006] This invention is proposed to overcome the shortcomings of the prior art, and its purpose is to provide a method for preparing 1,3-propanediol by hydrogenation hydrolysis of 1,3-propanediol byproducts.

[0007] This invention is achieved through the following technical solution:

[0008] A method for one-step direct preparation of 1,3-propanediol from acrolein involves loading a hydration hydrogenation catalyst into the isothermal zone of a hydration hydrogenation reactor. Quartz sand is packed at both ends of the hydration hydrogenation catalyst. Liquid and gaseous raw materials are mixed evenly and then fed into the hydration hydrogenation reactor for hydration hydrogenation reaction. The reaction product is then separated in a distillation column to obtain high-purity 1,3-propanediol.

[0009] In the above technical solution, the liquid phase raw material includes a main liquid phase raw material, which includes acrolein and water. Acrolein accounts for 5% to 30% of the weight of the liquid phase raw material, and water accounts for 40% to 90% of the weight of the liquid phase raw material. The gas phase raw material is hydrogen. The inlet volume of the gas phase raw material per unit time is 10 to 200 times the volume of the liquid phase raw material.

[0010] In the above technical solution, the liquid phase raw material also includes a secondary liquid phase raw material, which is any one or more of propionaldehyde, propanol or propionic acid; the secondary liquid phase raw material accounts for 5% to 30% of the weight of the liquid phase raw material.

[0011] In the above technical solution, the reaction temperature of the hydration hydrogenation reaction is 30℃~90℃, the pressure is 2.0MPa~6.0MPa, and the mass hourly space velocity of acrolein is 0.2~4.0h. -1 .

[0012] In the above technical solution, the hydrated hydrogenation catalyst is a supported catalyst with a loading of 0.1% to 10%; the catalyst support is any one or more of resin, molecular sieve, or alumina; and the catalyst loading is any one or more of Group VIII.

[0013] In the above technical solution, the Group VIII metal is any one or more of ruthenium, palladium, or platinum; the catalyst support is a sulfonic acid type polystyrene cation exchange resin or a chelating ion exchange resin in which the benzene ring of styrene-divinylbenzene copolymer spheres has an imine diacetic acid group [-N-(CH2COOH)2].

[0014] In the above technical solution, the preparation method of the hydrated hydrogenation catalyst is as follows: according to the saturated water absorption of the catalyst support, the catalyst support is immersed in a Group VIII metal salt solution with a saturated water absorption of 1 to 10 times its saturated water absorption for 0.5 h to 8.0 h, the immersion solution is drained, and the support is rinsed with water until the pH of the wash water is 4.0 to 6.5. The support is then dried to constant weight in a vacuum drying oven at 60 °C to 65 °C, and then reduced at 60 °C to 100 °C under a hydrogen atmosphere of 1.0 MPa to 8.0 MPa for 5 h to 10 h to obtain the hydrated hydrogenation catalyst.

[0015] The beneficial effects of this invention are:

[0016] This invention provides a one-step method for the direct preparation of 1,3-propanediol from acrolein. The method is short, simple, and low-cost, achieving an acrolein conversion rate greater than 94% and a 1,3-propanediol selectivity greater than 89%, making it easy to implement for industrial production. The liquid-phase feedstock contains propional and propanol, which can suppress the side reaction of direct hydrogenation of acrolein to propional or propanol. Simultaneously, the liquid-phase feedstock contains propionic acid, and the H+ ions from propionic acid ionization further favor the initial hydration reaction of acrolein. The catalyst prepared by this invention possesses dual functions of hydration and hydrogenation, enabling the simultaneous hydration of acrolein to 3-hydroxypropional and the hydrogenation of 3-hydroxypropional to 1,3-propanediol. The catalyst support provides acidic sites, catalyzing the hydration of the double bonds in the acrolein molecule to obtain 3-hydroxypropional. The metal supported on the catalyst provides hydrogenation sites, catalyzing the hydrogenation of 3-hydroxypropional to 1,3-propanediol. Attached Figure Description

[0017] Figure 1 This is a flowchart of the method of the present invention (1 represents the hydration hydrogenation reactor; 2 represents the distillation column).

[0018] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below through specific embodiments.

[0020] The method flow of the present invention is as follows: Figure 1 As shown, the material composition of each embodiment was analyzed using an Agilent 7890B gas chromatograph.

[0021] The calculation methods for acrolein conversion rate and 1,3-propanediol selectivity in the embodiments of the present invention are as follows:

[0022] Acrolein conversion rate = 100% * (Amount of acrolein in the reaction feed - Amount of acrolein at the reactor outlet) / Amount of acrolein in the reaction feed

[0023] 1,3-Propanediol selectivity = 100% * amount of acrolein consumed corresponding to 1,3-propanediol at reactor outlet / (amount of acrolein in the reaction feedstock - amount of acrolein at reactor outlet)

[0024] Example 1

[0025] (1) Preparation of reaction raw materials

[0026] Weigh 6000g acrolein, 4000g propanol, 1600g propionaldehyde, 400g propionic acid and 28000g deionized water, mix them evenly to prepare a liquid phase raw material; use 99.99% pure hydrogen from a steel cylinder as a gaseous phase raw material.

[0027] (2) Preparation of hydrated hydrogenation catalyst

[0028] Take 490g of sulfonic acid-type polystyrene cation exchange resin (dry basis) and pour it into 2000ml of ruthenium nitrate aqueous solution containing 10g of ruthenium. Soak for 6 hours, drain the soaking solution, rinse the resin with water until the pH of the wash water is 6.0, dry in a vacuum drying oven to constant weight, and then reduce the ion-exchanged metal resin at 80℃ under a 5.0MPa hydrogen atmosphere to obtain a catalyst with a ruthenium content of 2%.

[0029] (3) Preparation of 1,3-propanediol

[0030] The hydration-hydrogenation reaction was carried out in a fixed-bed reactor with a 30 ml isothermal zone. 10 ml of the aforementioned hydration-hydrogenation catalyst was loaded into the isothermal zone of the reactor. Quartz sand was packed at both ends of the catalyst; 20 ml of quartz sand was packed at the top of the catalyst, and 30 ml at the bottom. A Riva pump delivered the liquid feed at a flow rate of 30 ml / h. A mass flow meter controlled the gaseous feed at a flow rate of 1 L / h. After the liquid and gaseous feeds were thoroughly mixed, they entered the hydration-hydrogenation reactor. The reaction temperature was 80 °C, and the reaction pressure was 4.0 MPa. The reaction product was separated in a distillation column to obtain high-purity 1,3-propanediol.

[0031] The product composition was analyzed by gas chromatography at the reactor outlet, and the conversion rate and selectivity of the reaction were calculated. The results are shown in Table 1.

[0032] Example 2

[0033] (1) Preparation of reaction raw materials

[0034] Weigh 6000g acrolein, 1600g propanol, 4000g propionaldehyde, 400g propionic acid and 28000g deionized water, mix them evenly to prepare a liquid phase raw material; use 99.99% pure hydrogen from a steel cylinder as a gaseous phase raw material.

[0035] (2) Preparation of hydrated hydrogenation catalyst

[0036] Take 490g of chelated ion exchange resin (dry basis) and pour it into 1500ml of a palladium nitrate aqueous solution containing 10g of palladium. Soak for 6 hours, drain the soaking solution, rinse the resin with water until the pH of the wash water is 5.5, dry in a vacuum drying oven to constant weight, and then reduce the ion-exchanged metal resin at 80℃ under a 5.0MPa hydrogen atmosphere to obtain a catalyst with a palladium content of 2%.

[0037] (3) Preparation of 1,3-propanediol

[0038] The hydration-hydrogenation reaction was carried out in a fixed-bed reactor with a 30 ml isothermal zone. 10 ml of the aforementioned hydration-hydrogenation catalyst was loaded into the isothermal zone of the reactor, with quartz sand packed at both ends. A Riva pump delivered the liquid feed at a flow rate of 40 ml / h. A mass flow meter controlled the gaseous feed at a flow rate of 1 L / h. After the liquid and gaseous feeds were thoroughly mixed, they entered the hydration-hydrogenation reactor. The reaction temperature was 60 °C, and the reaction pressure was 3.0 MPa. The reaction product was separated in a distillation column to obtain high-purity 1,3-propanediol.

[0039] The product composition was analyzed by gas chromatography at the reactor outlet, and the conversion rate and selectivity of the reaction were calculated. The results are shown in Table 1.

[0040] Example 3

[0041] (1) Preparation of reaction raw materials

[0042] Weigh 6000g acrolein, 2800g propanol, 2800g propionaldehyde, 400g propionic acid and 28000g deionized water, mix them evenly to prepare a liquid phase raw material; use 99.99% high-purity hydrogen from a steel cylinder as a gaseous phase raw material.

[0043] (2) Preparation of hydrated hydrogenation catalyst

[0044] Take 490g of chelated ion exchange resin (dry basis) and pour it into 2000ml of a platinum nitrate aqueous solution containing 10g of platinum. Soak for 6 hours, drain the soaking solution, rinse the resin with water until the pH of the wash water is 5.5, dry in a vacuum drying oven to constant weight, and then reduce the ion-exchanged metal resin at 80℃ under a 5.0MPa hydrogen atmosphere to obtain a catalyst with a platinum content of 2%.

[0045] (3) Preparation of 1,3-propanediol

[0046] The hydration-hydrogenation reaction was carried out in a fixed-bed reactor with a 30 ml isothermal zone. 10 ml of the aforementioned hydration-hydrogenation catalyst was loaded into the isothermal zone of the reactor, with quartz sand packed at both ends. A Riva pump delivered the liquid feed at a flow rate of 20 ml / h. A mass flow meter controlled the gaseous feed at a flow rate of 1 L / h. After homogenization, the liquid and gaseous feeds entered the hydration-hydrogenation reactor. The reaction temperature was 90 °C, and the reaction pressure was 5.0 MPa. The reaction product was separated in a distillation column to obtain high-purity 1,3-propanediol.

[0047] The product composition was analyzed by gas chromatography at the reactor outlet, and the conversion rate and selectivity of the reaction were calculated. The results are shown in Table 1.

[0048] Comparative Example 1

[0049] (1) Preparation of reaction raw materials

[0050] Weigh 6000g of acrolein and 34000g of deionized water, mix thoroughly, and prepare a liquid-phase feedstock. High-purity hydrogen (99.99%) from a steel cylinder is used as the gaseous-phase feedstock.

[0051] (2) Preparation of hydrated hydrogenation catalyst

[0052] Take 490g of sulfonic acid-type polystyrene cation exchange resin (dry basis) and pour it into 2000ml of ruthenium nitrate aqueous solution containing 10g of ruthenium. Soak for 6 hours, drain the soaking solution, rinse the resin with water until the pH of the wash water is 6.0, dry in a vacuum drying oven to constant weight, and then reduce the ion-exchanged metal resin at 80℃ under a 5.0MPa hydrogen atmosphere to obtain a catalyst with a ruthenium content of 2%.

[0053] (3) Preparation of 1,3-propanediol

[0054] The hydration-hydrogenation reaction was carried out in a fixed-bed reactor with a 30 ml isothermal zone. 10 ml of the aforementioned hydration-hydrogenation catalyst was loaded into the isothermal zone of the reactor, with quartz sand packed at both ends. A Riva pump delivered the liquid feed at a flow rate of 30 ml / h. A mass flow meter controlled the gaseous feed at a flow rate of 1 L / h. After the liquid and gaseous feeds were thoroughly mixed, they entered the hydration-hydrogenation reactor. The reaction temperature was 80 °C, and the reaction pressure was 4.0 MPa. The reaction product was separated in a distillation column to obtain high-purity 1,3-propanediol.

[0055] The product composition was analyzed by gas chromatography at the reactor outlet, and the conversion rate and selectivity of the reaction were calculated. The results are shown in Table 1.

[0056] Comparative Example 2

[0057] (1) Preparation of reaction raw materials

[0058] Weigh out 6000g acrolein, 4000g propanol, 1600g propionaldehyde, 400g propionic acid, and 28000g deionized water, mix thoroughly, and prepare a liquid-phase raw material. High-purity hydrogen gas (99.99% purity) from a steel cylinder is used as the gaseous-phase raw material.

[0059] (2) Preparation of hydrated hydrogenation catalyst

[0060] Use 500g of sulfonic acid-type polystyrene cation exchange resin (dry basis) as a hydration-hydrogenation catalyst.

[0061] (3) Preparation of 1,3-propanediol

[0062] The hydration-hydrogenation reaction was carried out in a fixed-bed reactor with a 30 ml isothermal zone. 10 ml of the aforementioned hydration-hydrogenation catalyst was loaded into the isothermal zone of the reactor, with quartz sand packed at both ends. A Riva pump delivered the liquid feed at a flow rate of 30 ml / h. A mass flow meter controlled the gaseous feed at a flow rate of 1 L / h. After the liquid and gaseous feeds were thoroughly mixed, they entered the hydration-hydrogenation reactor. The reaction temperature was 80 °C, and the reaction pressure was 4.0 MPa. The reaction product was separated in a distillation column to obtain high-purity 1,3-propanediol.

[0063] The product composition was analyzed by gas chromatography at the reactor outlet, and the conversion rate and selectivity of the reaction were calculated. The results are shown in Table 1.

[0064] Table 1. Results under different raw material compositions and catalysts.

[0065]

[0066] As can be seen from the table above, in Comparative Example 1, when propanol, propionaldehyde, and propionic acid were not added to the raw materials, although acrolein could react completely, the selectivity for 1,3PDO was low, indicating that acrolein directly hydrogenated to produce propionaldehyde or propanol as byproducts. In Comparative Example 2, propanol, propionaldehyde, and propionic acid were added to the raw materials, but the resin used did not contain ruthenium, palladium, or platinum, causing acrolein to only undergo hydration. The 3-hydroxypropionaldehyde produced by hydration was difficult to convert to 1,3-propanediol.

[0067] As can be seen from the table above, only when the raw materials contain the main reactants acrolein and water, and propanol and propionaldehyde are added to inhibit the direct hydrogenation of acrolein, and propionic acid is added to promote the initial hydration of acrolein to form 3-hydroxypropionaldehyde, and resins containing ruthenium, palladium, or platinum are used, can the 3-hydroxypropionaldehyde formed by the hydration of acrolein be further hydrogenated to 1,3-propanediol. Therefore, the acrolein conversion rate of Examples 1, 2, and 3 is greater than 94%, and the 1,3-propanediol selectivity is greater than 89%, demonstrating good catalytic performance.

Claims

1. A method for the one-step direct preparation of 1,3-propanediol from acrolein, characterized in that: Specifically, the hydration hydrogenation catalyst is loaded into the constant temperature zone of the hydration hydrogenation reactor, and quartz sand is loaded at both ends of the hydration hydrogenation catalyst. After the liquid phase raw material and the gas phase raw material are mixed evenly, they are fed into the hydration hydrogenation reactor for hydration hydrogenation reaction. The reaction product is separated to obtain 1,3-propanediol. The liquid phase raw material includes a main liquid phase raw material, which includes acrolein and water. Acrolein accounts for 5% to 30% of the weight of the liquid phase raw material, and water accounts for 40% to 90% of the weight of the liquid phase raw material. The gas phase raw material is hydrogen. The inlet volume of the gas phase raw material per unit time is 10 to 200 times the volume of the liquid phase raw material. The liquid phase feedstock also includes a secondary liquid phase feedstock, which is any one or more of propionaldehyde, propanol, or propionic acid; the secondary liquid phase feedstock accounts for 5% to 30% of the weight of the liquid phase feedstock. The hydration hydrogenation catalyst is a supported catalyst with a loading of 0.1% to 10%; the catalyst support is any one or more of ruthenium, palladium, or platinum; the catalyst support is any one or more of sulfonic acid type polystyrene cation exchange resin or chelated ion exchange resin with imine diacetic acid groups on the benzene ring of styrene-divinylbenzene copolymer spheres.

2. The method for one-step direct preparation of 1,3-propanediol from acrolein according to claim 1, characterized in that: The hydration hydrogenation reaction is carried out at a temperature of 30℃ to 90℃, a pressure of 2.0 MPa to 6.0 MPa, and a mass hourly space velocity (WHSV) of acrolein of 0.2 to 4.0 h⁻¹. -1 .

3. The method for one-step direct preparation of 1,3-propanediol from acrolein according to claim 1, characterized in that: The preparation method of the hydrated hydrogenation catalyst is as follows: the catalyst support is immersed in a loaded salt solution, the immersion solution is drained, and then the catalyst is obtained by washing, drying and reduction.

4. The method for one-step direct preparation of 1,3-propanediol from acrolein according to claim 3, characterized in that: The volume of the loaded salt solution is 1 to 10 times the saturated water absorption capacity of the catalyst support, and the soaking time is 0.5 h to 8.0 h.

5. The method for one-step direct preparation of 1,3-propanediol from acrolein according to claim 3, characterized in that: The cleaning method involves rinsing the carrier with water until the pH of the wash water is 4.0~6.5; the drying method involves drying in a vacuum drying oven to constant weight at a drying temperature of 60℃~65℃.

6. The method for one-step direct preparation of 1,3-propanediol from acrolein according to claim 3, characterized in that: The reduction method is to reduce the hydrogen atmosphere at 1.0MPa~8.0MPa and at 60℃~100℃ for 5h~10h.

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