Method for preparing 1, 5-pentanediol by hydrating and hydrogenating 2, 3-dihydropyran
By coupling 2,3-dihydropyranyl hydration and hydrogenation into one process, the production of 1,5-pentanediol in a reactor is solved, and the problems of cumbersome and high cost in the prior art are realized. High yield and low cost 1,5-pentanediol production.
Patent Information
- Application Number
- CN202411736097.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-02-07
AI Technical Summary
In the prior art, there are problems such as cumbersome operation, cumbersome steps and the need to make a specific catalyst in the production process of 1,5-pentanediol, and it needs to be carried out under the protection of an inert gas in the hydration reaction, which increases the cost and operation difficulty.
Coupling 2,3-dihydropyran hydration and hydrogenation into a process to achieve 2,3-dihydropyran hydrogen hydration to make 1,5-pentanediol in a reactor, simplifying the operation process and reducing the Investment and operating costs are improved, and thermal management is optimized to reduce energy consumption.
High yield production of 1,5-pentanediol is achieved, simplified process flow, reduced costs, and improved process operability and industrial application prospects.
Abstract
Description
Technical Field
[0001] The invention relates to a continuous synthesis method of 1,5-pentanediol, and belongs to the technical field of fine chemicals. Background Art
[0002] 1,5-pentanediol is an important chemical intermediate used to synthesize polyester, polyurethane and other products. It can also be used as a green solvent for chemical synthesis. At present, 1,5-pentanediol is mainly derived from glutaric acid and its derivatives, while glutaric acid is a by-product of the production process of adipic acid. The source of raw materials such as glutaric acid limits the production and application scale of 1,5-pentanediol. Biomass resources have the advantages of wide distribution, large reserves, green environmental protection, economic availability and renewable. The biomass-derived chemical furfural is a C5 platform molecule that has been industrialized and mass-produced. Furfural can be produced through a series of chemical transformations to produce furfuryl alcohol, tetrahydrofurfuryl alcohol and 2,3-dihydropyran. Using these downstream products as raw materials to produce 1,5-pentanediol can solve the shortage of C5 components in petrochemical raw materials. The invention of producing 1,5-pentanediol using tetrahydrofurfuryl alcohol as raw material disclosed in Chinese patent CN108368015 involves hydration of 2,3-dihydropyran to obtain 2-hydroxytetrahydropyran, and then hydrogenation of 2-hydroxytetrahydrofuran as raw material to produce 1,5-pentanediol. The two-step reaction is isolated, the steps are cumbersome, and a homemade specific catalyst is required. The synthesis method of 5-amino-1-pentanol disclosed in Chinese patent CN108947851 involves hydration of 2,3-dihydropyran to 2-hydroxytetrahydropyran. The reaction needs to be carried out under the protection of inert gas, which is not conducive to operation, and the use of inert gas increases the cost. These patents all have the problems of cumbersome operation and difficulty in amplification. In response to these problems, the present invention couples hydration and hydrogenation of 2,3-dihydropyran into one process, and realizes hydration of 2,3-dihydropyran to produce 1,5-pentanediol in one reactor. The simple process is conducive to reducing investment and operating costs. At the same time, the use of a single reactor is conducive to optimizing heat management and reducing energy consumption. Summary of the invention
[0003] The present invention discloses a method for preparing 1,5-pentanediol with high yield by direct one-step hydrogenation and hydrogenation using 2,3-dihydropyran as raw material. The specific content of the invention is as follows:
[0004] A method for preparing 1,5-pentanediol by hydration and hydrogenation of 2,3-dihydropyran. In a hydrogen atmosphere, raw materials 2,3-dihydropyran and water are respectively introduced into a fixed bed reactor, a hydration catalyst and a hydrogenation catalyst are respectively loaded into the reactor, 2,3-dihydropyran, water and hydrogen flow through the hydration catalyst and hydrogenation catalyst beds simultaneously and in sequence, and hydration-hydrogenation continuous reaction is carried out under reaction conditions of 80-160° C. and 0.5-20 MPa to produce 1,5-pentanediol; wherein the molar ratio of 2,3-dihydropyran to water is 1:1-1:10, and the mass space velocity of 2,3-dihydropyran (calculated based on the hydration catalyst) is 0.2-10 h -1 .
[0005] In a preferred embodiment, the reaction temperature is 80-160°C, preferably 90-155°C, more preferably 100-150°C, most preferably 120-150°C.
[0006] In a preferred embodiment, the reaction pressure is 0.5 to 20 MPa, preferably 1 to 16 MPa, more preferably 1.5 to 12 MPa, and most preferably 2 to 8 MPa.
[0007] In a preferred embodiment, the molar ratio of the 2,3-dihydropyran to water is 1:1 to 1:10, preferably 1:2 to 1:9, more preferably 1:2 to 1:8, and most preferably 1:3 to 1:6.
[0008] In a preferred embodiment, the mass space velocity of the 2,3-dihydropyran (calculated as hydrated catalyst) is 0.2 to 10 h -1 , preferably 0.4 to 8 hours -1 , more preferably 0.5 to 6 hours -1 , the most preferred time is 0.5 to 4 hours -1 .
[0009] In a preferred embodiment, the molar ratio of hydrogen to 2,3-dihydropyran is 5-100, preferably 10-80, more preferably 12-60, most preferably 15-40.
[0010] In a preferred embodiment, the hydration catalyst is ZSM-5.
[0011] In a preferred embodiment, the hydrogenation catalyst is Raney nickel, and the mass ratio of the hydrogenation catalyst to the hydration catalyst is 1:0.1-8, preferably 1:0.2-4, more preferably 1:0.3-3, and most preferably 1:0.5-2.
[0012] In a preferred embodiment, when the upper layer of the reactor is filled with a hydration catalyst and the lower layer is filled with a hydrogenation catalyst, the feedstock enters the reactor from the top of the reactor and the product flows out from the bottom of the reactor.
[0013] In a preferred embodiment, when the upper layer of the reactor is filled with a hydrogenation catalyst and the lower layer is filled with a hydration catalyst, the feedstock enters the reactor from the bottom of the reactor and the product flows out from the top of the reactor.
[0014] This method does not require the separation of intermediate products, has a simple process, high raw material and heat utilization, and has good industrial application prospects. DETAILED DESCRIPTION
[0015] The method of the present invention is implemented according to the above steps, and is described in detail below through examples.
[0016] Example 1
[0017] A stainless steel fixed bed reactor with a length of 400 mm and an inner diameter of 10 mm was selected, and an electric heating furnace was used as the heat source. The height of the constant temperature section of the reactor exceeded 50 mm. The catalyst was loaded in the constant temperature section of the reactor. The upper layer was loaded with 2 grams of 20-40 mesh ZSM-5 (silicon-aluminum ratio 100, Nankai University Catalyst Factory) catalyst, and the lower layer was loaded with 1 gram of block Raney nickel catalyst (Shanghai Xunkai New Materials Technology Co., Ltd., FAMC-1900). 2,3-Dihydropyran was injected into the reactor from the top of the fixed bed at a rate of 0.018 ml / min and deionized water was injected at a rate of 0.011 ml / min respectively, and hydrogen was introduced into the reactor from the top of the reactor at a rate of 66 ml / min (the mass space velocity of 2,3-dihydropyran was 0.5h -1 , the molar ratio of 2,3-dihydropyran to water was 1:3, and the molar ratio of hydrogen to 2,3-dihydropyran was 15). The continuous hydration reaction was carried out under the reaction conditions of 120°C and 8MPa, and the samples were taken for analysis after 12 hours of reaction. The conversion rate of 2,3-dihydropyran was 95%, and the yield of 1,5-pentanediol was 93%.
[0018] Example 2
[0019] Except that the upper hydration catalyst was replaced with ZSM-5 (silicon-aluminum ratio 25, catalyst plant of Nankai University), other conditions (and processes, the same below) were the same as in Example 1. The conversion rate of 2,3-dihydropyran was 100%, and the yield of 1,5-pentanediol was 97%.
[0020] Example 3
[0021] Except that the upper hydration catalyst was replaced with ZSM-5 (silicon-aluminum ratio 25, catalyst plant of Nankai University) and the reaction pressure was changed to 2 MPa, other conditions were the same as in Example 1. The conversion rate of 2,3-dihydropyran was 97%, and the yield of 1,5-pentanediol was 93%.
[0022] Example 4
[0023] The reaction equipment is the same as that in Example 1. 2 g of blocky Raney nickel catalyst (FAMC-1900, Shanghai Xunkai New Material Technology Co., Ltd.) was loaded on the upper layer of the constant temperature section of the reactor, and 1 g of 20-40 mesh ZSM-5 (silicon-aluminum ratio 100, Nankai University Catalyst Factory) catalyst was loaded on the lower layer. 2,3-Dihydropyran was injected into the reactor from the bottom of the fixed bed at a rate of 0.072 ml / min and deionized water was injected at a rate of 0.085 ml / min, respectively. Hydrogen was introduced into the reactor from the bottom of the reactor at a rate of 355 ml / min (the mass space velocity of 2,3-dihydropyran was 4.0 h / min). -1 , the molar ratio of 2,3-dihydropyran to water was 1:6, and the molar ratio of hydrogen to 2,3-dihydropyran was 20). The continuous hydration reaction was carried out under the reaction conditions of 150°C and 8MPa, and the samples were taken for analysis after 12 hours of reaction. The conversion rate of 2,3-dihydropyran was 97%, and the yield of 1,5-pentanediol was 90%.
[0024] Example 5
[0025] Except that the loading amount of the ZSM-5 catalyst in the lower layer was changed to 2 g, other conditions were the same as those in Example 4. The conversion rate of 2,3-dihydropyran was 99%, and the yield of 1,5-pentanediol was 96%.
[0026] Example 6
[0027] Except that the loading order of ZSM-5 and Raney nickel catalyst was changed and 2,3-dihydropyran, water and hydrogen were introduced from the top of the reactor, other conditions were the same as those in Example 4. The conversion rate of 2,3-dihydropyran was 97%, and the yield of 1,5-pentanediol was 95%.
[0028] Example 7
[0029] Except that the reaction pressure was changed to 5 MPa, other conditions were the same as those in Example 4. The conversion rate of 2,3-dihydropyran was 96%, and the yield of 1,5-pentanediol was 88%.
[0030] Example 8
[0031] Except that the reaction temperature was changed to 120° C., other conditions were the same as those in Example 4. The conversion rate of 2,3-dihydropyran was 93%, and the yield of 1,5-pentanediol was 90%.
[0032] Example 9
[0033] Except that the loading order of ZSM-5 and Raney nickel catalyst was changed, 2,3-dihydropyran, water and hydrogen were introduced from the bottom of the reactor, and the reaction temperature was changed to 140° C., other conditions were the same as in Example 1. The conversion rate of 2,3-dihydropyran was 99%, and the yield of 1,5-pentanediol was 96%.
[0034] Example 10
[0035] Except that the hydrogen flow rate was changed to 710 ml / min (the molar ratio of hydrogen to 2,3-dihydropyran was 40), other conditions were the same as those in Example 4. The conversion rate of 2,3-dihydropyran was 95%, and the yield of 1,5-pentanediol was 89%.
[0036] Comparative Example 1
[0037] The reaction equipment is the same as that in Example 1. 2 g of 20-40 mesh ZSM-5 (silicon-aluminum ratio 100, Nankai University Catalyst Factory) catalyst and 1 g of block Raney nickel catalyst (Shanghai Xunkai New Material Technology Co., Ltd., FAMC-1900) were mixed evenly and then loaded into the constant temperature section of the reactor. 2,3-Dihydropyran was injected into the reactor from the top of the fixed bed at a rate of 0.018 ml / min and deionized water was injected into the reactor at a rate of 0.011 ml / min, respectively. Hydrogen was introduced into the reactor from the top of the reactor at a rate of 66 ml / min (the mass space velocity of 2,3-dihydropyran was 0.5 h -1 , the molar ratio of 2,3-dihydropyran to water was 1:3, and the molar ratio of hydrogen to 2,3-dihydropyran was 15). The continuous hydration reaction was carried out under the reaction conditions of 120°C and 8MPa, and the samples were taken for analysis after 12 hours of reaction. The conversion rate of 2,3-dihydropyran was 99%, and the yield of 1,5-pentanediol was 37%.
[0038] Comparative Example 2
[0039] The reaction equipment is the same as that in Example 1. 2 g of 20-40 mesh ZSM-5 (silicon-aluminum ratio 100, Nankai University Catalyst Factory) catalyst is loaded into the constant temperature section of the reactor. 2,3-Dihydropyran is injected into the reactor from the top of the fixed bed at a rate of 0.018 ml / min and deionized water is injected into the reactor at a rate of 0.011 ml / min, respectively. Hydrogen is introduced into the reactor from the top of the reactor at a rate of 66 ml / min (the mass space velocity of 2,3-dihydropyran is 0.5 h -1 , the molar ratio of 2,3-dihydropyran to water was 1:3, and the molar ratio of hydrogen to 2,3-dihydropyran was 15). The continuous hydration reaction was carried out under the reaction conditions of 120°C and 8MPa, and the samples were taken for analysis after 12 hours of reaction. The conversion rate of 2,3-dihydropyran was 93%, and there was no 1,5-pentanediol in the product.
[0040] Comparative Example 3
[0041] The reaction equipment is the same as that in Example 1. 1 gram of block Raney nickel catalyst (Shanghai Xunkai New Materials Technology Co., Ltd., FAMC-1900) is loaded in the constant temperature section of the reactor. 2,3-Dihydropyran is injected into the reactor from the top of the fixed bed at a rate of 0.018 ml / min and deionized water is injected into the reactor at a rate of 0.011 ml / min, respectively, and hydrogen is introduced into the reactor from the top of the reactor at a rate of 66 ml / min (the molar ratio of 2,3-Dihydropyran to water is 1:3, and the molar ratio of hydrogen to 2,3-Dihydropyran is 15). Continuous hydration reaction is carried out under the reaction conditions of 120°C and 8MPa, and sampling and analysis are performed after 12 hours of reaction. The conversion rate of 2,3-Dihydropyran is 100%, and the yield of 1,5-pentanediol is 10%.
[0042] As can be seen from Examples 1-6, the method provided by the present invention can achieve the continuous production of 1,5-pentanediol by one-step hydration and hydrogenation of 2,3-dihydropyran in the presence of hydrogen, and obtain a 1,5-pentanediol yield of more than 88%. As can be seen from Example 1 and Comparative Examples 1-3, the loading method and selection of the catalyst have a significant impact on the reaction. The hydration-hydrogenation sequential reaction of the present invention ensures that 2,3-dihydropyran reacts with water under hydrogen conditions to obtain 1,5-pentanediol in high yield. The method of the present invention can use commercial catalysts, and the reaction conditions are mild and the operating window is large, which is easy to scale up and has considerable industrial application prospects.
Claims
1. A method for preparing 1,5-pentanediol by hydration and hydrogenation of 2,3-dihydropyran, characterized in that: In a hydrogen atmosphere, raw materials 2,3-dihydropyran and water are respectively introduced into a fixed bed reactor, a hydration catalyst and a hydrogenation catalyst are respectively loaded into the reactor, 2,3-dihydropyran, water and hydrogen flow through the hydration catalyst and hydrogenation catalyst beds in sequence at the same time, and a hydration-hydrogenation continuous reaction is carried out under the reaction conditions of 80-160° C. and 0.5-20 MPa to produce 1,5-pentanediol; wherein the molar ratio of 2,3-dihydropyran to water is 1:1-1:10, and the mass space velocity of 2,3-dihydropyran (calculated based on the hydration catalyst) is 0.2-10 h -1 , the molar ratio of hydrogen to 2,3-dihydropyran is 5-100.
2. The method according to claim 1, characterized in that: The reaction temperature is 80-160°C, preferably 90-155°C, more preferably 100-150°C, most preferably 120-150°C.
3. The method according to claim 1, characterized in that: The reaction pressure is 0.5 to 20 MPa, preferably 1 to 16 MPa, more preferably 1.5 to 12 MPa, and most preferably 2 to 8 MPa.
4. The method according to claim 1, characterized in that: The molar ratio of the 2,3-dihydropyran to water is 1:1 to 1:10, preferably 1:2 to 1:9, more preferably 1:2 to 1:8, and most preferably 1:3 to 1:
6.
5. The method according to claim 1, characterized in that: The mass space velocity of the 2,3-dihydropyran (calculated as hydrated catalyst) is 0.2 to 10 h -1 , preferably 0.4 to 8 hours -1 , more preferably 0.5 to 6 hours -1 , the most preferred time is 0.5 to 4 hours -1 .
6. The method according to claim 1, characterized in that: The molar ratio of hydrogen to 2,3-dihydropyran is 5-100, preferably 10-80, more preferably 12-60, and most preferably 15-40.
7. The method according to claim 1, characterized in that: The hydration catalyst is ZSM-5.
8. The method according to claim 1, characterized in that: The hydrogenation catalyst is Raney nickel, and the mass ratio of the hydrogenation catalyst to the hydration catalyst is 1:0.1-8, preferably 1:0.2-4, more preferably 1:0.3-3, and most preferably 1:0.5-2.
9. The method according to claim 1, characterized in that: When the upper layer of the reactor is filled with a hydration catalyst and the lower layer is filled with a hydrogenation catalyst, the raw materials enter the reactor from the top of the reactor and the products flow out from the bottom of the reactor.
10. The method according to claim 1, characterized in that: When the upper layer of the reactor is filled with a hydrogenation catalyst and the lower layer is filled with a hydration catalyst, the raw materials enter the reactor from the bottom of the reactor and the products flow out from the top of the reactor.