Transesterification catalyst, preparation method thereof and application of transesterification catalyst in preparation of amyl alcohol from amyl acetate
By using porous silica support and Nd2O3, Fe2O3, and CeO2 support in the transesterification catalyst, the problem of desalination after the reaction of transesterification catalyst in the prior art is solved, and the continuous transition reaction is achieved, energy consumption and hazardous waste generation are reduced, and the efficiency of the catalyst is improved.
Patent Information
- Application Number
- CN202411639547.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-02-25
AI Technical Summary
The existing transesterification catalysts need to be desalted after the reaction, which consumes a lot of energy and is difficult to achieve continuous production, and produces industrial waste salt.
Porous silica gel is used as the support, and the support is prepared by impregnation, aging, drying and calcining. Combining Nd2O3, Fe2O3 and CeO2 as support, it is loaded in a fixed bed reactor to achieve continuous esterification reaction.
No desalination operation is required, the energy consumption is low, the hazardous waste is low, the catalyst is efficient, and the production cost is greatly reduced.
Smart Images
Figure BDA0005138068170000071
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of chemical reactions, and in particular to an ester exchange catalyst and a preparation method thereof, and application thereof in preparing amyl alcohol from amyl acetate. Background Art
[0002] Transesterification catalysts include alkaline catalysts, acidic catalysts, bio-enzyme catalysts, etc. Alkaline catalysts are currently the most widely used catalysts for transesterification reactions. There are two main types of industrial alkaline catalysts: liquid phase reactions catalyzed by potassium hydroxide, sodium hydroxide, sodium methoxide, etc. that are easily soluble in methanol, and multiphase reactions catalyzed by solid bases. Among them, alkaline catalysts are currently the most widely used catalysts for transesterification reactions. The advantages of using alkaline catalysts are mild reaction conditions and fast reaction speed. However, such catalysts all need to be desalted after the reaction, which consumes a lot of energy, has many environmental problems, and is difficult to achieve continuous production. In industrial production, potassium hydroxide, sodium hydroxide, sodium methoxide, etc., which are easily soluble in methanol, need to be desalted after the transesterification reaction, which consumes a lot of energy and produces a lot of industrial waste salt. Summary of the invention
[0003] The object of the present invention is to provide an ester exchange catalyst and a preparation method thereof and application of the catalyst in preparing amyl alcohol from amyl acetate, so as to solve the problems existing in the prior art.
[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0005] The present invention provides a method for preparing an ester exchange catalyst, comprising the following steps:
[0006] The porous silica gel is first calcined to obtain a carrier;
[0007] NdCl 3 Solution, FeCl 3 Solution and CeCl 3 The solution was mixed and then NaHCO was added 3 The solution is adjusted to be acidic to obtain a mixed solution;
[0008] placing the carrier in the mixed solution for a first impregnation, so that the mixed solution is absorbed by the carrier, and after the first impregnation, immersing the obtained product in a sodium hydroxide solution for aging to obtain a first product;
[0009] The first product is subjected to a first drying and a second calcination to obtain a second product;
[0010] The second product is immersed in a hydrazine hydrate solution for reduction, and the reduced product is subjected to a second drying to obtain an ester exchange catalyst.
[0011] Preferably, in the above-mentioned method for preparing an ester exchange catalyst, the temperature of the first calcination is 500-600° C., and the time of the first calcination is 5-6 hours.
[0012] Preferably, in the above-mentioned method for preparing a transesterification catalyst, the first impregnation time is 20 to 24 hours;
[0013] The aging time is 20 to 24 hours.
[0014] Preferably, in the above-mentioned method for preparing a transesterification catalyst, the temperature of the first drying is 100 to 150° C., and the time of the first drying is 5 to 6 hours;
[0015] The temperature of the second calcination is 500-600° C., and the time of the second calcination is 5-6 hours.
[0016] Preferably, in the above-mentioned method for preparing an ester exchange catalyst, the concentration of the hydrazine hydrate solution is 4 to 8 wt%;
[0017] The reduction time is 20 to 24 hours;
[0018] The second drying temperature is 100-140° C., and the second drying time is 8-10 hours.
[0019] Preferably, in the above-mentioned method for preparing an ester exchange catalyst, the carrier of the ester exchange catalyst is SiO 2 ;
[0020] The Nd 2 O 3 The loading amount is SiO 2 7% to 10% of mass;
[0021] The Fe in the transesterification catalyst 2 O 3 The loading amount is carrier SiO 2 7% to 10% of mass;
[0022] The CeO in the transesterification catalyst 2 The loading amount is carrier SiO 2 10% to 12% of the mass.
[0023] The invention also provides an ester exchange catalyst prepared by the preparation method of the ester exchange catalyst.
[0024] The present invention also provides an application of an ester exchange catalyst in preparing amyl alcohol from amyl acetate.
[0025] Preferably, in the above application, it is characterized in that the application method comprises the following steps:
[0026] The transesterification catalyst is loaded into a fixed bed reactor, and amyl acetate and methanol are mixed and reacted in the fixed bed reactor loaded with the transesterification catalyst to obtain a product.
[0027] Preferably, in one of the above applications, the loading amount of the transesterification catalyst in the fixed bed reactor is 200 to 250 mL;
[0028] The feed rate of amyl acetate is 4 to 10 g / min;
[0029] The feed flow rate of the methanol is 4 to 10 g / min;
[0030] The reaction temperature is 60-140° C.; the reaction pressure is 0.1-2 MPa.
[0031] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:
[0032] (1) The ester exchange catalyst provided by the present invention is SiO 2 As carrier, Nd 2 O 3 , Fe 2 O 3 and CeO 2 The carrier is loaded into a fixed bed reactor, and the alkaline earth metal is used to realize the continuous reaction of transesterification, and no desalination operation is required after the reaction.
[0033] (2) The inventors have found through a large number of experiments that the following two factors affect the conversion rate of the transesterification catalyst: 1) The temperature of the second calcination during the catalyst preparation process, when 500-600°C, the catalyst conversion rate is the highest; 2) The temperature and pressure during the reaction process, when the feed rate of amyl acetate is 5g / min, the feed rate of methanol is 5g / min, the reaction temperature is controlled at 100-120°C, and the reaction pressure is 0.5-1.0MPa, the catalyst conversion rate is the highest. In addition, a fixed bed reactor is used to realize a continuous transesterification reaction, replacing the traditional reaction distillation process.
[0034] (3) The present invention has low energy consumption, less hazardous waste, high catalyst utilization efficiency, and greatly reduced production costs. DETAILED DESCRIPTION
[0035] The present invention provides a method for preparing an ester exchange catalyst, comprising the following steps:
[0036] The porous silica gel is first calcined to obtain a carrier;
[0037] NdCl 3 Solution, FeCl3 Solution and CeCl 3 The solution was mixed and then NaHCO was added 3 The solution is adjusted to be acidic to obtain a mixed solution;
[0038] placing the carrier in the mixed solution for a first impregnation, so that the mixed solution is absorbed by the carrier, and after the first impregnation, immersing the obtained product in a sodium hydroxide solution for aging to obtain a first product;
[0039] The first product is subjected to a first drying and a second calcination to obtain a second product;
[0040] The second product is immersed in a hydrazine hydrate solution for reduction, and the reduced product is subjected to a second drying to obtain an ester exchange catalyst.
[0041] In the present invention, the temperature of the first calcination is preferably 500-600°C, more preferably 520-580°C, more preferably 530-550°C; the time of the first calcination is preferably 5-6h, more preferably 5.25-6h, more preferably 5.5-6h.
[0042] In the present invention, the NaHCO 3 The concentration of the solution is preferably 5% to 10% by weight, more preferably 6% to 9% by weight, and even more preferably 7% to 8% by weight.
[0043] In the present invention, the first immersion time is preferably 20 to 24 hours, more preferably 21 to 23 hours, and more preferably 22 hours.
[0044] In the present invention, the aging time is preferably 20 to 24 hours, more preferably 21 to 23 hours, and more preferably 22 hours.
[0045] In the present invention, the pH of the sodium hydroxide solution is preferably 8.
[0046] In the present invention, the first drying temperature is preferably 100-150°C, more preferably 110-140°C, and more preferably 120-130°C; the first drying time is preferably 5-6h, more preferably 5.25-6h, and more preferably 5.5-6h.
[0047] In the present invention, the temperature of the second calcination is preferably 500-600°C, more preferably 520-580°C, more preferably 530-550°C; the time of the second calcination is preferably 5-6h, more preferably 5.25-6h, more preferably 5.5-6h.
[0048] In the present invention, the concentration of the hydrazine hydrate solution is preferably 4-8 wt %, more preferably 5-7 wt %, and more preferably 6 wt %.
[0049] In the present invention, the reduction time is preferably 20 to 24 hours, more preferably 21 to 23 hours, and more preferably 22 hours.
[0050] In the present invention, after the reduction is completed, the product is washed with water.
[0051] In the present invention, the second drying temperature is preferably 100-140°C, more preferably 110-130°C, and more preferably 120-125°C; the second drying time is preferably 8-10h, more preferably 8.5-10h, and more preferably 9-9.5h.
[0052] In the present invention, the carrier of the transesterification catalyst is preferably SiO 2 ;
[0053] The Nd 2 O 3 The loading amount is preferably the carrier SiO 2 7% to 10% by mass, more preferably 7% to 9%, and more preferably 7% to 8%;
[0054] The Fe in the transesterification catalyst 2 O 3 The loading amount is preferably the carrier SiO 2 7% to 10% by mass, more preferably 7% to 9%, and more preferably 7% to 8%;
[0055] The CeO in the transesterification catalyst 2 The loading amount is preferably the carrier SiO 2 The content is 10 to 12% by mass, more preferably 10 to 11.5%, and even more preferably 10 to 11% by mass.
[0056] The invention also provides an ester exchange catalyst prepared by the preparation method of the ester exchange catalyst.
[0057] The present invention also provides an application of an ester exchange catalyst in preparing amyl alcohol from amyl acetate.
[0058] In the present invention, the application method comprises the following steps:
[0059] The transesterification catalyst is loaded into a fixed bed reactor, and amyl acetate and methanol are mixed and reacted in the fixed bed reactor loaded with the transesterification catalyst to obtain a product.
[0060] In the present invention, the loading amount of the transesterification catalyst in the fixed bed reactor is preferably 200 to 250 mL, more preferably 210 to 240 mL, and even more preferably 220 to 230 mL.
[0061] In the present invention, the pretreatment of methanol is to dehydrate the methanol using a 3A molecular sieve so that the water content of the methanol is reduced to below 10 ppm.
[0062] In the present invention, the feed rate of amyl acetate is preferably 4 to 10 g / min, more preferably 5 to 9 g / min, and even more preferably 6 to 8 g / min.
[0063] In the present invention, the feed flow rate of the methanol is preferably 4 to 10 g / min, more preferably 5 to 9 g / min, and even more preferably 6 to 8 g / min.
[0064] In the present invention, the reaction temperature is preferably 60-140°C, more preferably 80-120°C, and more preferably 100-110°C; the reaction pressure is preferably 0.1-2 MPa, more preferably 0.5-1.5 MPa, and more preferably 1-1.2 MPa.
[0065] In the present invention, the preparation method of amyl acetate comprises the following steps:
[0066] After pentene and acetic acid are mixed, they are preheated to 70-100°C, and an esterification reaction is carried out through a sulfonic acid type cation exchange resin fixed bed. The esterification reaction temperature is 100-150°C, and the reaction pressure is 0.1-1.0 MPa (the molar ratio of pentene to acetic acid is controlled at 1:3-1:5). After the esterification reaction is completed, the obtained product is separated to obtain pentyl acetate.
[0067] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0068] Example 1
[0069] A method for preparing an ester exchange catalyst A comprises the following steps:
[0070] The porous silica gel was calcined at 550°C for 6 hours and then cooled to room temperature to obtain a carrier; the water absorption rate of the carrier was measured;
[0071] According to the amount of porous silica gel and its water absorption rate, the amount of water was calculated and NdCl 3 Solution, FeCl3 Solution, CeCl 3 The solution was then mixed and 5% NaHCO 3 The solution is adjusted to a pH of 2 to obtain a mixed solution;
[0072] The carrier is placed in the mixed solution for immersion for 24 hours, and after the first immersion, the obtained product is immersed in a sodium hydroxide solution with a pH of 8 for aging for 24 hours to obtain a first product;
[0073] The first product is washed with deionized water until chloride ions are undetectable, the washed product is dried at 120° C. for 6 h, and after drying, the obtained product is calcined at 600° C. for 6 h, and then cooled to room temperature to obtain a second product;
[0074] The second product was immersed in a 5wt% hydrazine hydrate solution for reduction for 24h. After the reduction, the obtained product was washed with deionized water for 3 times and then dried at 120°C for 10h to obtain an ester exchange catalyst A; wherein the carrier in the ester exchange catalyst is SiO 2 , Nd 2 O 3 The loading amount is SiO 2 7% by mass; Fe 2 O 3 The loading amount is carrier SiO 2 7% by mass; CeO 2 The loading amount is carrier SiO 2 10% of mass.
[0075] Example 2
[0076] A preparation method of an ester exchange catalyst B is consistent with that in Example 1, except that: the first product is washed with deionized water until chloride ions are undetectable, the washed product is dried at 120°C for 6 hours, and after drying, the obtained product is calcined at 300°C for 6 hours and then cooled to room temperature to obtain a second product.
[0077] Example 3
[0078] A preparation method of an ester exchange catalyst C is consistent with that in Example 1, except that: the first product is washed with deionized water until chloride ions are undetectable, the washed product is dried at 120°C for 6 hours, and after drying, the obtained product is calcined at 400°C for 6 hours and then cooled to room temperature to obtain a second product.
[0079] Example 4
[0080] A method for preparing an ester exchange catalyst D is consistent with that in Example 1, except that: the first product is washed with deionized water until chloride ions are undetectable, the washed product is dried at 120°C for 6 hours, and after drying, the obtained product is calcined at 500°C for 6 hours and then cooled to room temperature to obtain a second product.
[0081] Example 5
[0082] A preparation method of an ester exchange catalyst E is consistent with that in Example 1, except that: the first product is washed with deionized water until chloride ions are undetectable, the washed product is dried at 120°C for 6 hours, and after drying, the obtained product is calcined at 700°C for 6 hours and then cooled to room temperature to obtain a second product.
[0083] Application Examples
[0084] Heating pentene and acetic acid respectively, subjecting the heated pentene and the added acetic acid to an esterification reaction through a fixed bed of a strong acidic cation exchange resin (the molar ratio of pentene to acetic acid is 1:3), obtaining a reaction solution, and distilling the reaction solution twice to obtain pentyl acetate;
[0085] Amyl acetate and methanol are mixed and reacted in a fixed bed reactor to obtain a product; wherein the fixed bed reactor is respectively loaded with 240 mL of the ester exchange catalyst prepared in Examples 1 to 5; and the feeding method is top-in and bottom-out.
[0086] The reaction conditions and reaction conversion rates in the application examples are shown in Table 1.
[0087] Table 1 Reaction conditions and reaction conversion rates of application examples
[0088]
[0089] The composition of the raw materials of the application example is shown in Table 2.
[0090] Table 2 Raw material composition in application example
[0091] Components Content (wt) % Methanol 49.98 Amyl acetate 49.94 Other impurities 0.08
[0092] The components of the product described in Application Example 1 were determined by gas chromatography as shown in Table 3.
[0093] Table 3 Components of the product in Application Example 1
[0094] Components Content (wt) % Methyl acetate 28.49 Methanol 37.62 Amyl alcohol 33.12 Amyl acetate 0.69 Other impurities 0.08
[0095] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing an ester exchange catalyst, characterized in that: The following steps are involved: The porous silica gel is first calcined to obtain a carrier; Mixing NdCl3 solution, FeCl3 solution and CeCl3 solution, and then adding NaHCO3 solution to adjust the solution to acidity to obtain a mixed solution; placing the carrier in the mixed solution for a first impregnation, so that the mixed solution is absorbed by the carrier, and after the first impregnation, immersing the obtained product in a sodium hydroxide solution for aging to obtain a first product; The first product is subjected to a first drying and a second calcination to obtain a second product; The second product is immersed in a hydrazine hydrate solution for reduction, and the reduced product is subjected to a second drying to obtain an ester exchange catalyst.
2. The method for preparing the transesterification catalyst according to claim 1, characterized in that: The temperature of the first calcination is 500-600° C., and the time of the first calcination is 5-6 hours.
3. The method for preparing the transesterification catalyst according to claim 2, characterized in that: The first immersion time is 20 to 24 hours; The aging time is 20 to 24 hours.
4. The method for preparing the transesterification catalyst according to claim 3, characterized in that: The first drying temperature is 100-150° C., and the first drying time is 5-6 hours; The temperature of the second calcination is 500-600° C., and the time of the second calcination is 5-6 hours.
5. The method for preparing the transesterification catalyst according to claim 4, characterized in that: The concentration of the hydrazine hydrate solution is 4-8wt%; The reduction time is 20 to 24 hours; The second drying temperature is 100-140° C., and the second drying time is 8-10 hours.
6. The method for preparing the transesterification catalyst according to claim 5, characterized in that: The carrier of the transesterification catalyst is SiO2; The loading amount of Nd2O3 in the transesterification catalyst is 7% to 10% of the mass of the carrier SiO2; The loading amount of Fe2O3 in the transesterification catalyst is 7% to 10% of the mass of the carrier SiO2; The loading amount of CeO2 in the transesterification catalyst is 10% to 12% of the mass of the carrier SiO2.
7. The ester exchange catalyst obtained by the preparation method of the ester exchange catalyst according to any one of claims 1 to 6.
8. Use of the transesterification catalyst according to claim 7 in preparing amyl alcohol from amyl acetate.
9. The use according to claim 8, characterized in that: The application method comprises the following steps: The transesterification catalyst is loaded into a fixed bed reactor, and amyl acetate and methanol are mixed and reacted in the fixed bed reactor loaded with the transesterification catalyst to obtain a product.
10. The use according to claim 9, characterized in that: The loading amount of the transesterification catalyst in the fixed bed reactor is 200-250 mL; The feed rate of amyl acetate is 4 to 10 g / min; The feed flow rate of the methanol is 4 to 10 g / min; The reaction temperature is 60-140° C.; the reaction pressure is 0.1-2 MPa.