A method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material

Abstract

The present invention relates to a method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material. The method comprises the following steps: After hydrogen and the raw material liquid are preheated to 20-150 °C in a preheater, they are simultaneously introduced into a fixed-bed reactor equipped with two sections of catalysts, and reacted at 30-150 °C and a reaction pressure of 0.1-8 MPa to obtain 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine; the first catalyst is a metal catalyst supported on graphitic carbon nitride; the active metal of the second catalyst is one, two, or more of Ru, Pt, Rh, Cu, Co, and Ni; the carrier of the second catalyst is γ-Al2O3, TiO2, SiO2, ZrO2, CeO2, ZSM-5, cerium-zirconium solid solution, or activated carbon. The present invention solves the problem of poor selectivity in the process of generating 1,5-pentanediamine, and the product distribution can be changed by changing the catalyst.

Description

Technical Field

[0001] The present invention relates to a method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material, belonging to the field of fine chemical industry. Background Art

[0002] Furfural is the only biomass platform compound molecule that has achieved industrial production. Due to the limitation of the development of downstream products, the production capacity of furfural is in large-scale overproduction. 5-Amino-1-pentanol is the starting material for the production of the alkaloid manheimin. 1-Amino-2-pentanol is a high-value-added amino alcohol and is used in the synthesis of pesticides and pharmaceuticals. 1,5-Pentanediamine is the raw material for synthesizing high-grade polyamides nylon 56 and nylon 510.

[0003] Chinese Patent CN109678732A discloses a method for continuously performing reductive amination reaction in a fixed-bed reactor on a mixed reaction system containing dihydropyran hydrate, ammonia water, and a supported nickel-based catalyst in a hydrogen atmosphere to prepare 5-amino-1-pentanol. This method uses dihydropyran as a raw material, and dihydropyran, as a derivative of furfural, needs to be prepared through multiple steps of hydrogenation and dehydration.

[0004] For example, using the hydrogenolysis of furfurylamine, the amination product of furfural, to prepare 5-amino-1-pentanol will shorten the reaction steps and reduce the operation process. Chinese Patent CN114805098A discloses a method for synthesizing 5-amino-1-pentanol using furfural as the initial raw material. Among them, the hydrogenolysis of furfurylamine is used to prepare 5-amino-1-pentanol. However, this method uses a batch autoclave reactor, and the reaction product needs to be separated from the catalyst by centrifugation or filtration, resulting in low production efficiency.

[0005] Chinese Patents CN115646488A, CN115216498A, and CN115197954A report the decarboxylation of L-lysine catalyzed by an enzyme to produce 1,5-pentanediamine. Many problems are faced during the production process, such as low raw material concentration and poor enzyme recycling performance, which will increase the production cost. In the process of preparing 1,5-pentanediamine by amination of 1,5-pentanediol and 5-amino-1-pentanolamine, since cyclization to form piperidine is more thermodynamically favorable, the main product is piperidine, and the selectivity of 1,5-pentanediamine is very low (Catalysts, 2023, 13(3): 528). Obviously, the existing technical methods at present have problems such as high production cost, unclean and inefficient production process, and low yield of the target product, which are not conducive to large-scale industrial production. Summary of the Invention

[0006] The object of the present invention is to address the deficiencies in the current methods for producing 5-amino-1-pentanol and 1,5-pentanediamine, and to propose a method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material. This method employs a reaction system in which two catalysts are filled in sections in the same reactor, and consists of three parts: continuously preparing 5-amino-1-pentanol using furfural as a raw material, continuously preparing 1-amino-2-pentanol using furfural as a raw material, and continuously preparing 1,5-pentanediamine using furfural as a raw material. Continuously preparing 5-amino-1-pentanol using furfural as a raw material solves the problem that the current production of 5-amino-1-pentanol requires many steps. Literature reports that there is a phenomenon of enol intermediate converting to ketone during the hydrogenolysis of the furan ring, and the amination conditions for aldehydes and ketones are relatively mild. Under mild conditions, 1,5-pentanediamine and 5-amino-1-pentanol are not easily cyclized to form piperidine. The present invention solves the problem of poor selectivity during the production of 1,5-pentanediamine, and by changing the catalyst, the product distribution can be changed.

[0007] The technical solution of the present invention is as follows:

[0008] A method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material, which comprises the following steps:

[0009] After hydrogen and the raw material liquid are preheated to 20 - 150 °C in a preheater, they are simultaneously introduced into a fixed-bed reactor filled with two sections of catalyst, and 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine are obtained through reaction at 30 - 150 °C and a reaction pressure of 0.1 - 8 MPa;

[0010] wherein, the hydrogen space velocity is 900 - 3500 h -1 , the liquid hourly space velocity is 3 - 20 h -1 , and the raw material liquid is a mixed liquid of furfural, ammonia water, and a solvent; the molar ratio is ammonia water:furfural = 10:1 - 1000:1; for every 1 mmol of furfural, 2 - 15 mL of solvent is added in terms of the material ratio;

[0011] The fixed-bed tubular reactor is a tubular reactor, and two catalysts are filled in sections inside the tube. The first catalyst is filled near the feed port end, and the second catalyst is filled at the far end from the feed port end; the length ratio of the first catalyst bed layer to the second catalyst bed layer is 1:1 - 1:25; the part outside the catalyst bed layer is filled with quartz sand;

[0012] The solvent is one or more of water, methanol, ethanol, isopropanol, tetrahydrofuran, and 1,4-dioxane.

[0013] The temperature of the preheater is preferably 40 - 80 °C.

[0014] The temperature of the reactor is preferably 60 to 120 °C.

[0015] The reaction pressure is preferably 1 to 3 MPa.

[0016] The concentration of the ammonia water is 20 to 40 wt%.

[0017] When the target product is 5-amino-1-pentanol or 1-amino-2-pentanol, the molar ratio is preferably ammonia water: furfural

[0018] = 10:1 to 50:1; when the target product is 1,5-pentanediamine, the molar ratio is preferably ammonia water: furfural = 500:1 to 1000:1.

[0019] The length of the fixed-bed tubular reactor bed is preferably 200 to 800 mm, and the length of the first catalyst bed is 1 to 50 mm.

[0020] The first catalyst is a metal catalyst supported on graphitic carbon nitride. The catalyst composition includes an active metal and a support of graphitic carbon nitride (g-C3N4); the metal loading is 2 wt% to 20 wt%;

[0021] The active metal of the first catalyst is one or two of Ru, Co or Ni, preferably the Ru and Co bimetal;

[0022] The second catalyst is a supported metal catalyst. The catalyst composition includes an active metal and a support; the metal loading is 1 wt% to 15 wt%;

[0023] The active metal of the second catalyst is one, two or more of Ru, Pt, Rh, Cu, Co and Ni;

[0024] The support of the second catalyst is γ-Al2O3, TiO2, SiO2, ZrO2, CeO2, ZSM-5, cerium-zirconium solid solution or activated carbon;

[0025] When the active metal of the second catalyst is Pt and the support of the active metal of the second catalyst is ZrO2, the content of 5-amino-1-pentanol in the product is 50% to 75%; when the active metal of the second catalyst is preferably Pt and the support of the active metal of the second catalyst is cerium-zirconium solid solution, the content of 1-amino-2-pentanol in the product is 40% to 65%; when the active metal of the second catalyst is preferably Rh and Ru and the support of the active metal of the second catalyst is CeO2, the content of 1,5-pentanediamine in the product is 30% to 50%;

[0026] When the active metal of the second catalyst is Cu, Co or Ni, the distributions of the three target products are relatively close and there is no main product.

[0027] The substantial features of the present invention are as follows:

[0028] In the upper section, a catalyst for preparing furfurylamine by furfural amination is filled, and in the lower section, a catalyst for preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine by furfurylamine hydrogenolysis is filled. By changing the catalyst in the lower section, the product distribution can be changed.

[0029] The beneficial effects of the present invention are as follows:

[0030] 1. Using inexpensive and readily available furfural as a raw material, the present invention continuously and efficiently produces 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine in a fixed-bed reactor, realizing the continuous production of 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine under mild conditions;

[0031] 2. The catalysts used in the present invention are all supported catalysts, which are simple to prepare, have good catalyst life stability, are convenient for large-scale industrial production, and significantly improve economic benefits.

[0032] 3. By changing the second catalyst, the product distribution can be changed, realizing the selective production of any one of the three products in the same reactor. Specific Embodiments

[0033] The substantial features and remarkable effects of the present invention can be reflected from the following embodiments, but they do not impose any limitations on the present invention. Those skilled in the art can make some non-essential improvements and adjustments based on the content of the present invention. The present invention will be further described below through specific embodiments.

[0034] The technical route of the present invention is as follows:

[0035]

[0036] Example 1

[0037] Take 3 g of the second catalyst, 5% Pt / ZrO2, and 3 g of the first catalyst, 5% Ru / g-C3N4 catalyst, and place them in sections at the lower and upper parts of a tubular fixed-bed reactor with an inner diameter of 10 mm and a length of 600 mm (the reactor is set vertically). The length of the second catalyst bed is 10 mm, and 200 mm of quartz sand is filled below the second catalyst bed to the outlet at the lower end of the reactor. The length of the first catalyst bed is 15 mm, and 200 mm of quartz sand is filled above the first catalyst to the inlet at the upper end of the reactor. 175 mm of quartz sand is filled between the two catalyst beds. Hydrogen and the raw material liquid introduced by a plunger pump (molar ratio of ammonia water (concentration of ammonia water is 26.5 wt%): furfural = 40:1; for every 1 mmol of furfural, 10 mL of isopropanol is added in the material ratio) are mixed and enter the preheater for preheating, and then enter the reactor bed for reaction. Among them, the temperature of the preheater is 65 °C, the temperature of the reactor is 100 °C, the reaction pressure is 2 MPa, and the hydrogen space velocity is 900 h -1 (30 ml / min), and the space velocity of the raw material liquid is 3 h -1 (0.1 ml / min). After condensation by a condenser and gas-liquid separation, a liquid-phase product is obtained. The conversion rate of furfural is determined to be 100% by the internal standard method, the yield of 5-amino-1-pentanol is 70%, the yield of tetrahydrofurfurylamine is 9%, the yield of piperidine is 2%, the yield of 1-amino-2-pentanol is 11%, and the yield of 1,5-pentanediamine is 3%. The activity does not decrease significantly within 20 h of the reaction.

[0038] The 5% Ru / g-C3N4 catalyst is a well-known material, and its preparation process is as follows: Place a semi-closed alumina crucible containing 20 g of urea or 5 g of melamine in a muffle furnace and calcine it at 500 - 600 °C for 3 - 5 h. After cooling, grind it into powder as the carrier (g-C3N4). Mix 1 g of g-C3N4 with 0.103 g of RuCl3 in 100 mL of deionized water and stir for 2 h, then add 0.05 g of sodium borohydride to the mixture and continue to stir for 2 h. Then wash the solid product with deionized water and ethanol repeatedly 3 times. Collect the solid by filtration and vacuum dry it overnight at 60 °C. The finally obtained catalyst is Ru / g-C3N4 with a loading of 5 wt% (particle size is 0.5 - 3 μm).

[0039] The 5% Pt / ZrO2 catalyst is a well-known material, and its preparation process is as follows: Dissolve 0.133 g of H2PtCl6·6H2O in 1 ml of water to form a solution and impregnate it with 1 g of ZrO2 in an equal volume. Let it stand for 10 - 15 h, dry it at 110 °C for 10 - 12 h, calcine it in a muffle furnace at 550 °C for 2 - 5 h, and finally reduce it with hydrogen at 500 °C for 1 - 3 h (particle size is 50 - 100 nm). Other second catalysts are prepared by the same method.

[0040] Example 2

[0041] Other parts are the same as those in Example 1, except that 5% Pt / ceria-zirconia solid solution is used to replace 5% Pt / ZrO2 as the second catalyst. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 12%, the yield of tetrahydrofurfurylamine is 14%, the yield of piperidine is 2%, the yield of 1-amino-2-pentanol is 63%, and the yield of 1,5-pentanediamine is 2%. According to the different boiling points of each product, the products are separated by rectification subsequently.

[0042] Example 3

[0043] Other parts are the same as those in Example 1, except that 5% Ru / CeO2 is used to replace 5% Pt / ZrO2 as the second catalyst, and the molar ratio of ammonia water:furfural = 600:1. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 20%, the yield of tetrahydrofurfurylamine is 14%, the yield of piperidine is 2%, the yield of 1-amino-2-pentanol is 15%, and the yield of 1,5-pentanediamine is 42%.

[0044] Example 4

[0045] Other parts are the same as those in Example 1, except that the reactor temperature is 150 °C. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 3%, the yield of tetrahydrofurfurylamine is 14%, the yield of piperidine is 65%, the yield of 1-amino-2-pentanol is 15%, and the yield of 1,5-pentanediamine is 1%.

[0046] Example 5

[0047] Other parts are the same as those in Example 1, except that the reactor temperature is 65 °C and the reaction pressure is 4 MPa. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 63%, the yield of tetrahydrofurfurylamine is 24%, the yield of piperidine is 3%, the yield of 1-amino-2-pentanol is 3%, and the yield of 1,5-pentanediamine is 1%.

[0048] Example 6

[0049] Other parts are the same as those in Example 1, except that 5% Rh / CeO2 is used to replace 5% Pt / ZrO2 as the second catalyst, and the molar ratio of ammonia water:furfural = 600:1. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 22%, the yield of tetrahydrofurfurylamine is 24%, the yield of piperidine is 2%, the yield of 1-amino-2-pentanol is 10%, and the yield of 1,5-pentanediamine is 32%.

[0050] Example 7

[0051] Other parts are the same as in Example 2, except that the reactor temperature is 150 °C. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 2%, the yield of tetrahydrofurfurylamine is 14%, the yield of piperidine is 13%, the yield of 1-amino-2-pentanol is 63%, and the yield of 1,5-pentanediamine is 2%.

[0052] Example 8

[0053] Other parts are the same as in Example 2, except that the reactor temperature is 45 °C. The furfural conversion rate is 63%, the yield of 5-amino-1-pentanol is 6%, the yield of tetrahydrofurfurylamine is 5%, the yield of piperidine is 1%, the yield of 1-amino-2-pentanol is 35%, and the yield of 1,5-pentanediamine is 1%.

[0054] Example 9

[0055] Other parts are the same as in Example 3, except that the reactor temperature is 150 °C. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 2%, the yield of tetrahydrofurfurylamine is 15%, the yield of piperidine is 17%, the yield of 1-amino-2-pentanol is 25%, and the yield of 1,5-pentanediamine is 43%.

[0056] Example 10

[0057] Other parts are the same as in Example 3, except that the reactor temperature is 65 °C. The furfural conversion rate is 100%, the yield of 5-amino-1-pentanol is 9%, the yield of tetrahydrofurfurylamine is 15%, the yield of piperidine is 1%, the yield of 1-amino-2-pentanol is 22%, and the yield of 1,5-pentanediamine is 48%.

[0058] Example 11

[0059] Other parts are the same as in Example 1, except that 5% Co / ZrO2 is used to replace 5% Pt / ZrO2 as the second catalyst. The furfural conversion rate is 36%, the yield of 5-amino-1-pentanol is 6%, the yield of tetrahydrofurfurylamine is 5%, the yield of piperidine is 2%, the yield of 1-amino-2-pentanol is 9%, and the yield of 1,5-pentanediamine is 8%.

[0060] Example 12

[0061] Other parts are the same as in Example 1, except that 15% Cu / CeO2 is used to replace 5% Pt / ZrO2 as the second catalyst. The furfural conversion rate is 29%, the yield of 5-amino-1-pentanol is 9%, the yield of tetrahydrofurfurylamine is 3%, the yield of piperidine is 1%, the yield of 1-amino-2-pentanol is 6%, and the yield of 1,5-pentanediamine is 8%.

[0062] Example 13

[0063] Other parts are the same as those in Example 1, except that 15% Ni / TiO2 is used to replace 5% Pt / ZrO2 as the second catalyst. The furfural conversion rate is 41%, the yield of 5-amino-1-pentanol is 10%, the yield of tetrahydrofurfurylamine is 2%, the yield of piperidine is 1%, the yield of 1-amino-2-pentanol is 12%, and the yield of 1,5-pentanediamine is 15%.

[0064] Matters not described in this invention are well-known techniques.

Claims

1. A method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material, characterized in that the method comprises the following steps: After preheating hydrogen and the raw material liquid to 40-80 °C in a preheater, they are simultaneously introduced into a fixed-bed reactor equipped with two sections of catalysts. At 60-120 °C and a reaction pressure of 1-3 MPa, 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine are obtained through the reaction. Among them, Hydrogen space velocity: 900 - 3500 h -1 , liquid hourly space velocity: 3 - 20 h -1 , the raw material liquid is a mixed liquid of furfural, ammonia water and solvent; the molar ratio is ammonia water: furfural = 10:1 - 1000:1; for every 1 mmol of furfural, 2 - 15 mL of solvent is added in the material ratio. The fixed-bed reactor is a tubular reactor. Two types of catalysts are filled in sections inside the tube. The first catalyst is filled near the feed port, and the second catalyst is filled far from the feed port. The length ratio of the first catalyst bed layer to the second catalyst bed layer is 1:1 to 1:

25. Quartz sand is used outside the catalyst bed layer. The solvent is one or more of water, methanol, ethanol, isopropanol, tetrahydrofuran, and 1,4-dioxane. The first catalyst is a metal catalyst supported on graphitic carbon nitride. The composition of the catalyst includes an active metal and a support of graphitic carbon nitride (g-C3N4). The metal loading is 2 wt% - 20 wt%. The active metal of the first catalyst is Ru. The second catalyst is a supported metal catalyst. The composition of the catalyst includes an active metal and a support. The metal loading is 1 wt% - 15 wt%. The active metal of the second catalyst is one, two, or more of Ru, Pt, Rh, Cu, Co, and Ni. The support of the second catalyst is TiO2, ZrO2, CeO2, or a cerium-zirconium solid solution.

2. The method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material according to claim 1, characterized in that When the target product is 5-amino-1-pentanol or 1-amino-2-pentanol, the molar ratio is ammonia:furfural = 10:1 - 50:

1. When the target product is 1,5-pentanediamine, the molar ratio is ammonia:furfural = 500:1 - 1000:

1.

3. The method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material according to claim 1, characterized in that the bed layer length of the fixed-bed reactor is 200 - 800 mm, and the length of the first catalyst bed layer is 1 - 50 mm.

4. The method for continuously preparing 5-amino-1-pentanol, 1-amino-2-pentanol, and 1,5-pentanediamine using furfural as a raw material according to claim 1, characterized in that when the active metal of the second catalyst is Pt and the support of the active metal of the second catalyst is ZrO2, the content of 5-amino-1-pentanol in the product is 50% - 75%. When the active metal of the second catalyst is preferably Pt and the support of the active metal of the second catalyst is a cerium-zirconium solid solution, the content of 1-amino-2-pentanol in the product is 40% - 65%. When the active metal of the second catalyst is preferably Rh and Ru and the support of the active metal of the second catalyst is CeO2, the content of 1,5-pentanediamine in the product is 30% - 50%.

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