Method for producing 1, 5-pentanediol through hydrogen conversion of tetrahydrofurfuryl alcohol

Abstract

The invention discloses a method for continuously producing 1, 5-pentanediol from tetrahydrofurfuryl alcohol through hydroconversion. According to the invention, tetrahydrofurfuryl alcohol, water and hydrogen raw materials simultaneously and sequentially pass through a fixed bed filled with an acid catalyst, a fixed bed filled with a rectification filler and a fixed bed reactor filled with a solid hydrogenation catalyst, and the materials flow out of the reactors and are condensed and collected to produce 1, 5-pentanediol, according to the method, raw materials enter a starting reactor at the same time, and 1, 5-pentanediol is directly produced without intermediate product separation between the reactors. The method is simple in process, high energy consumption and high material consumption caused by separation of intermediate products are avoided, the utilization rate of raw materials and heat is high, and the method has good industrial application prospects.

Description

Technical Field

[0001] The invention relates to a method for producing 1,5-pentanediol by hydrogenation conversion of tetrahydrofurfuryl alcohol, belonging to the technical field of fine chemical industry. 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. Furfural, a biomass-derived chemical, is a C5 platform molecule that has been industrialized and mass-produced. Furfural can be produced into tetrahydrofurfuryl alcohol through a series of chemical transformations. The production of 1,5-pentanediol using tetrahydrofurfuryl alcohol as raw material can solve the problem of shortage of C5 components in petrochemical raw materials. At present, most studies focus on the one-step hydrogenolysis of tetrahydrofurfuryl alcohol to produce 1,5-pentanediol. The one-step process product contains both 1,5-pentanediol and 1,2-pentanediol, which are difficult to separate and difficult to obtain 1,5-pentanediol that meets the requirements of polyester. Chinese patent CN108368015 discloses a method for producing 1,5-pentanediol using tetrahydrofurfuryl alcohol as a raw material. Tetrahydrofurfuryl alcohol is first dehydrated to obtain 2,3-dihydropyran, 2,3-dihydropyran and water are subjected to an addition reaction at a high ratio of water to 2,3-dihydropyran to obtain 2-hydroxytetrahydropyran, and then 2-hydroxytetrahydropyran is used as a raw material for hydrogenation to produce 1,5-pentanediol. This step-by-step reaction process requires intermediate product refining, which on the one hand brings about large separation energy consumption, and on the other hand is not conducive to the thermal coupling utilization between reaction systems. In addition, the aqueous phase component obtained by dehydrating tetrahydrofurfuryl alcohol in this process is wasted, which on the one hand causes an increase in subsequent water consumption and increases the difficulty of wastewater treatment. On the other hand, the tetrahydrofurfuryl alcohol, a small amount of 2,3-dihydropyran and 2-hydroxytetrahydropyran remaining in the water are wasted, resulting in a decrease in raw material utilization. In view of these problems, the present invention discloses a method for producing 1,5-pentanediol by continuous series reaction under hydrogen conditions using tetrahydrofurfuryl alcohol, water and hydrogen as raw materials, without setting a separation device between the series reactions, thus avoiding problems such as waste of raw materials and high separation energy consumption. At the same time, the series process is conducive to heat coupling inside the reaction system. Summary of the invention

[0003] The present invention discloses a method for producing 1,5-pentanediol by hydrogenation of tetrahydrofurfuryl alcohol. The present invention can use tetrahydrofurfuryl alcohol, water and hydrogen as raw materials to continuously produce 1,5-pentanediol through a series reaction process without separation. The specific content of the invention is as follows:

[0004] A method for producing 1,5-pentanediol by hydrogenation of tetrahydrofurfuryl alcohol, wherein tetrahydrofurfuryl alcohol, water and hydrogen raw materials are simultaneously and sequentially passed through a fixed bed (reactor A) equipped with an acid catalyst, a fixed bed (reactor B) filled with fillers and a fixed bed reactor (reactor C) equipped with a solid hydrogenation catalyst; after the materials flow out of the reactor C, they are condensed and collected to produce 1,5-pentanediol.

[0005] In a preferred embodiment, the molar ratio of water to tetrahydrofurfuryl alcohol is 1:1 to 10:1, preferably 2:1 to 9:1, more preferably 2:1 to 7:1, and most preferably 3:1 to 6:1.

[0006] In a preferred embodiment, the molar ratio of hydrogen to tetrahydrofurfuryl alcohol is 2:1 to 200:1, preferably 5:1 to 150:1, more preferably 10:1 to 100:1, and most preferably 15:1 to 60:1.

[0007] In a preferred embodiment, the acidic catalyst is γ-Al2O3, H3O 40 PW 12 5-40wt% H3O 40 PW 12 / SiO2 catalyst, H4Si(W3O 10 )4H4Si(W3O 10 ) one or more of 4 / SiO2 catalysts; the volume space velocity of the tetrahydrofurfuryl alcohol based on the acid catalyst is 0.1 to 10 h -1 .

[0008] In a preferred embodiment, the filler is one or more of Raschig rings, spiral rings, ceramic rings, ceramic corrugated fillers, metal corrugated fillers, wire mesh fillers, saddle-shaped fillers or glass springs; the volume space velocity of tetrahydrofurfuryl alcohol based on the filler is 0.1 to 10 h -1 .

[0009] In a preferred embodiment, the hydrogenation catalyst is one or more of Raney nickel, Ni / AC with a Ni content of 1-50%, Pd / AC with a Pd content of 0.1-20%, or Ru-Pd / AC with a Ru content of 0.1-20% and a Pd content of 0.1-20%. The volume space velocity of tetrahydrofurfuryl alcohol based on the hydrogenation catalyst is 0.1 to 5 h -1 In a preferred embodiment, the reaction temperature of the reactor A is 200-400°C, preferably 230-350°C, more preferably 230-330°C, most preferably 250-330°C.

[0010] In a preferred embodiment, the reaction temperature of reactor B is 70-200°C, preferably 80-180°C, more preferably 90-160°C, most preferably 100-140°C.

[0011] In a preferred embodiment, the reaction temperature of the reactor C is 50-200°C, preferably 70-180°C, more preferably 90-160°C, most preferably 100-150°C.

[0012] In a preferred embodiment, there is no intermediate product separation device between reactors A and B, and there is no intermediate product separation device between reactors B and C; after the material flows out of reactor C, it is condensed and collected to produce 1,5-pentanediol.

[0013] The raw materials of the method enter the starting reactor at the same time and the intermediate product separation between the reactors is not required to directly produce 1,5-pentanediol. The method is simple in process, avoids the high energy and material consumption caused by the separation of intermediate products, has high utilization rate of raw materials and heat, and has good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the process of the present invention.

[0015] Tetrahydrofurfuryl alcohol, water and hydrogen raw materials are simultaneously and sequentially passed through a fixed bed (reactor A) filled with an acid catalyst, a fixed bed (reactor B) filled with fillers and a fixed bed reactor (reactor C) filled with a solid hydrogenation catalyst. After the materials flow out of reactor C, they are condensed and collected in a liquid collection tank to produce 1,5-pentanediol, wherein the hydrogen in the liquid collection tank can be recycled as a raw material to be passed into reactor A for use. DETAILED DESCRIPTION

[0016] The method of the present invention is implemented according to the above steps, and is described in detail below through examples.

[0017] Example 1

[0018] Reactor A is filled with 10 grams of γ-Al2O3, reactor B is filled with 40 milliliters of Raschig rings, and reactor C is filled with 5 grams of block Raney nickel. The temperature of reactor A is 330°C, the temperature of reactor B is 140°C, and the temperature of reactor C is 150°C. Deionized water is injected into the top of reactor A at 0.088 ml / min and tetrahydrofurfuryl alcohol is injected into the top of reactor A at 0.079 ml / min, and hydrogen is introduced into the top of reactor A at a rate of 274 ml / min (the molar ratio of water to tetrahydrofurfuryl alcohol is 6:1, and the molar ratio of hydrogen to tetrahydrofurfuryl alcohol is 15:1). The pressure of the reactor system is maintained at 0.5 MPa. After 5 hours of continuous feeding reaction, sampling analysis and calculation show that the conversion rate of tetrahydrofurfuryl alcohol is greater than 99%, and the selectivity of 1,5-pentanediol is 96%.

[0019] Example 2

[0020] Reactor A is filled with 10 grams of γ-Al2O3, reactor B is filled with 40 milliliters of Raschig rings, and reactor C is filled with 5 grams of block Raney nickel. The temperature of reactor A is 300°C, the temperature of reactor B is 100°C, and the temperature of reactor C is 120°C. Deionized water is injected into the top of reactor A at 0.088 ml / min and tetrahydrofurfuryl alcohol is injected into the top of reactor A at 0.079 ml / min, and hydrogen is introduced into the top of reactor A at a rate of 274 ml / min (the molar ratio of water to tetrahydrofurfuryl alcohol is 6:1, and the molar ratio of hydrogen to tetrahydrofurfuryl alcohol is 15:1). The pressure of the reactor system is maintained at 0.5 MPa. After 5 hours of continuous feeding reaction, sampling analysis and calculation show that the conversion rate of tetrahydrofurfuryl alcohol is 96% and the selectivity of 1,5-pentanediol is 94%.

[0021] Example 3

[0022] Reactor A is filled with 10 g of γ-Al2O3, reactor B is filled with 40 ml of glass spring, and reactor C is filled with 3 g of Pd with a mass content of 5% Pd / AC. The temperature of reactor A is 300°C, the temperature of reactor B is 120°C, and the temperature of reactor C is 100°C. Deionized water is injected into the top of reactor A at 0.088 ml / min and tetrahydrofurfuryl alcohol is injected into the top of reactor A at 0.079 ml / min, and hydrogen is introduced into the top of reactor A at a rate of 274 ml / min (the molar ratio of water to tetrahydrofurfuryl alcohol is 6:1, and the molar ratio of hydrogen to tetrahydrofurfuryl alcohol is 15:1). The pressure of the reactor system is maintained at 0.5 MPa. After 5 hours of continuous feeding reaction, sampling analysis and calculation show that the conversion rate of tetrahydrofurfuryl alcohol is 95% and the selectivity of 1,5-pentanediol is 98%.

[0023] Example 4

[0024] Reactor A was filled with 10 g H4Si(W3O 10 )4 mass content 30wt% H4Si(W3O 10 )4 / SiO2 catalyst, the catalyst was prepared by impregnation method, 30g H4Si(W3O 10)4 was dissolved in 50ml of deionized water, 70g of silicon dioxide was added and mixed evenly, and the mixture was rotary evaporated to obtain a solid, dried at 120°C for 12 hours, and calcined at 300°C for 3 hours to obtain a catalyst. 40ml of glass spring was filled in reactor B, and 3g of 5% Pd / AC was filled in reactor C. The temperature of reactor A was 250°C, the temperature of reactor B was 120°C, and the temperature of reactor C was 100°C. Deionized water was injected into the top of reactor A at 0.088ml / min and tetrahydrofurfuryl alcohol at 0.079ml / min, and hydrogen was introduced into the top of reactor A at a rate of 274ml / min (the molar ratio of water to tetrahydrofurfuryl alcohol was 6:1, and the molar ratio of hydrogen to tetrahydrofurfuryl alcohol was 15:1). The pressure of the reactor system was maintained at 0.5MPa. After 5 hours of continuous feeding reaction, sampling and analysis were performed, and the conversion rate of tetrahydrofurfuryl alcohol was 96%, and the selectivity of 1,5-pentanediol was 96%.

[0025] Example 5

[0026] Except that the catalyst loaded in reactor A was changed to 10 g H3O 40 PW 12 Mass content 30wt% H3O 40 PW 12 / SiO2 catalyst, the catalyst was prepared by impregnation method, 30g H3O 40 PW 12 Dissolve in 30 ml of deionized water, add 70 g of silicon dioxide and mix evenly, rotary evaporate to obtain solid, dry at 120° C. for 12 hours, and calcine at 300° C. for 3 hours to obtain a catalyst. Other conditions are the same as in Example 4. The conversion rate of tetrahydrofurfuryl alcohol is greater than 93%, and the selectivity of 1,5-pentanediol is 95%.

[0027] Example 6

[0028] Except that the hydrogen flow rate was changed to 1097 ml / min (the molar ratio of hydrogen to tetrahydrofurfuryl alcohol was 60:1), other conditions (and processes) were the same as those in Example 1. The conversion rate of tetrahydrofurfuryl alcohol was greater than 92%, and the selectivity of 1,5-pentanediol was 96%.

[0029] Example 7

[0030] Except that the flow rate of deionized water was changed to 0.044 ml / min (the molar ratio of water to tetrahydrofurfuryl alcohol was 3:1), other conditions (and processes) were the same as those in Example 1. The conversion rate of tetrahydrofurfuryl alcohol was greater than 94%, and the selectivity of 1,5-pentanediol was 90%.

[0031] Example 8

[0032] Except that the temperature of reactor A is 280° C., the temperature of reactor B is 140° C., and the temperature of reactor C is 150° C., other conditions (and processes) are the same as those in Example 4. The conversion rate of tetrahydrofurfuryl alcohol is greater than 99%, and the selectivity of 1,5-pentanediol is 94%.

[0033] Example 9

[0034] Except that the temperature of reactor A is 300° C., the temperature of reactor B is 110° C., and the temperature of reactor C is 150° C., other conditions (and processes) are the same as those in Example 1. The conversion rate of tetrahydrofurfuryl alcohol is greater than 96%, and the selectivity of 1,5-pentanediol is 97%.

[0035] Example 10

[0036] Except that 40 ml of the spiral ring was filled in the reactor B, the other conditions (and process) were the same as those in Example 1. The conversion of tetrahydrofurfuryl alcohol was greater than 97%, and the selectivity of 1,5-pentanediol was 95%.

[0037] As can be seen from Examples 1-10, the method provided by the present invention can realize the production of 1,5-pentanediol by continuous reaction without separation using tetrahydrofurfuryl alcohol, water and hydrogen as raw materials, with a tetrahydrofurfuryl alcohol conversion rate higher than 90% and a 1,5-pentanediol selectivity higher than 90%. In addition, the operating window of the present invention is relatively wide, the non-separation reaction process reduces separation energy consumption, is conducive to heat integrated management, is easy to scale up, and has considerable industrial application prospects.

Claims

1. A method for producing 1,5-pentanediol by hydrogenation of tetrahydrofurfuryl alcohol, characterized in that: Tetrahydrofurfuryl alcohol, water and hydrogen raw materials are simultaneously and sequentially passed through a fixed bed (reactor A) filled with an acidic catalyst, a fixed bed (reactor B) filled with fillers and a fixed bed reactor (reactor C) filled with a solid hydrogenation catalyst. After the materials flow out of reactor C, they are condensed and collected to produce 1,5-pentanediol.

2. The method according to claim 1, characterized in that: The molar ratio of water to tetrahydrofurfuryl alcohol is 1:1 to 10:1, preferably 2:1 to 9:1, more preferably 2:1 to 7:1, and most preferably 3:1 to 6:

1.

3. The method according to claim 1, characterized in that: The molar ratio of hydrogen to tetrahydrofurfuryl alcohol is 2:1 to 200:1, preferably 5:1 to 150:1, more preferably 10:1 to 100:1, and most preferably 15:1 to 60:

1.

4. The method according to claim 1, characterized in that: The acidic catalyst is γ-Al2O3, H3O 40 PW 12 5-40wt% H3O 40 PW 12 / SiO2 catalyst, H4Si(W3O 10 )4H4Si(W3O 10 ) one or more of 4 / SiO2 catalysts; the volume space velocity of the tetrahydrofurfuryl alcohol based on the acid catalyst is 0.1 to 10 h -1 .

5. The method according to claim 1, characterized in that: The filler is one or more of Raschig rings, spiral rings, ceramic rings, ceramic corrugated fillers, metal corrugated fillers, metal mesh fillers, saddle-shaped fillers or glass springs; the volume space velocity of tetrahydrofurfuryl alcohol based on the filler is 0.1 to 10 h -1 .

6. The method according to claim 1, characterized in that: The hydrogenation catalyst is one or more of Raney nickel, Ni / AC with a Ni content of 1-50%, Pd / AC with a Pd content of 0.1-20%, or Ru-Pd / AC with a Ru content of 0.1-20% and a Pd content of 0.1-20%. The volume space velocity of tetrahydrofurfuryl alcohol based on the hydrogenation catalyst is 0.1-5h -1 .

7. The method according to claim 1, characterized in that: The reaction temperature of the reactor A is 200-400°C, preferably 230-350°C, more preferably 230-330°C, most preferably 250-330°C.

8. The method according to claim 1, characterized in that: The reaction temperature of the reactor B is 70 to 200°C, preferably 80 to 180°C, more preferably 90 to 160°C, and most preferably 100 to 140°C.

9. The method according to claim 1, characterized in that: The reaction temperature of the reactor C is 50 to 200°C, preferably 70 to 180°C, more preferably 90 to 160°C, and most preferably 100 to 150°C.

10. The method according to claim 1, characterized in that: There is no intermediate product separation device between reactors A and B, and there is no intermediate product separation device between reactors B and C; after the material flows out of reactor C, it is condensed and collected to produce 1,5-pentanediol.

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