Preparation method of supported catalyst for acrolein hydration reaction

Abstract

The invention discloses a preparation method of a supported catalyst for acrolein hydration reaction, and particularly relates to a method for preparing 3-hydroxypropionaldehyde by supporting inorganic acid on a carrier and hydrating acrolein. Different types of acid catalysts are synthesized by adopting an impregnation loading-modification method and are used for a process of preparing 3-hydroxypropionaldehyde through a hydration reaction. The method has the advantages that the synthesis is simple, the B acid site is suitable, side reactions such as polymerization are inhibited through the polymerization inhibitor, the selectivity of the target product and the stability of the catalyst are improved under the combined action of the catalyst and the polymerization inhibitor, and meanwhile, the problems of separation of homogeneous reaction products and the like can be effectively avoided.

Description

Technical Field

[0001] The present invention discloses a preparation method of a supported catalyst for acrolein hydration reaction, and particularly relates to a method for preparing 3-hydroxypropionaldehyde by hydrating acrolein with an inorganic acid supported on an acidic carrier. Background Art

[0002] 1,3-PDO is widely used in pharmaceutical synthesis and polyester chemical fiber industry. However, the high price of 1,3-PDO directly leads to its limited development achievements only in products and varieties with strong cost digestion ability. Due to the high technical content requirements in production, only a few large foreign chemical companies, such as German Dugessa Company, American Shell Company and Dupont Company, etc., can achieve industrial production at present. In the production process of 1,3-PDO, the hydration of acrolein is the most important step in synthesizing 1,3-PDO from acrolein. However, both acrolein and the reaction product 3-hydroxypropionaldehyde are extremely unstable substances, and are prone to various side reactions such as polymerization and condensation during the hydration reaction, and the side reactions are aggravated with the increase of the reaction temperature. The by-products generated will also deposit on the surface of the catalyst, resulting in the gradual inactivation of the catalyst, thus shortening the service life of the catalyst.

[0003] At present, there are a wide variety of reported acrolein hydration catalysts. According to their catalytic forms in the reaction, they can be divided into homogeneous catalysis and heterogeneous catalysis. However, due to problems such as difficult product separation in homogeneous catalysis, heterogeneous catalysis is mostly selected in modern industry. Heterogeneous catalysts include supported inorganic acids, zeolite molecular sieves, acidic cation resins, chelating resins, etc. Chelating cation exchange resins are the most widely used in this type of reaction, such as the chelating ion exchange resin containing -NH-CH2-PO3H2 functional groups reported in US Patent US 5015789, the chelating ion exchange resin with -CH2-N-(CH2COOH)2 functional groups in US 5015789, the chelating cation exchange resin with thiodiacetamide functional groups reported in Chinese Patent CN13455713, and the chelating cation exchange resin containing carboxylic acid exchanged with rare earth metal ions in CN 1369471; in addition to ion exchange resins, molecular sieves are also applied to the acrolein hydration reaction. However, at present, when using molecular sieves as acrolein hydration catalysts, there are still problems such as low reaction conversion rate, low selectivity and poor stability, and the performance of the catalysts needs to be further improved and optimized. Summary of the Invention

[0004] The main technical problem to be solved by the present invention is to provide a preparation method of a supported catalyst for acrolein hydration reaction. By loading an inorganic acid, the acid amount and acidity of the catalyst are changed to improve the activity of the catalyst; and by adding a polymerization inhibitor, the occurrence of side reactions such as polymerization is inhibited, thereby improving the selectivity of 3-hydroxypropionaldehyde.

[0005] A preparation method of a supported catalyst for acrolein hydration reaction, specifically as follows:

[0006] Adding an acidic support to an inorganic acid aqueous solution, stirring at 25 - 80 °C for 1 - 10 h, then cooling to room temperature, standing for 2 - 24 h, and drying at a drying temperature of 100 - 120 °C for 2 - 12 h; after drying, performing calcination at a calcination temperature of 400 - 650 °C for 2 - 8 h to obtain a supported catalyst for acrolein hydration reaction.

[0007] The inorganic acid includes one or more of H2SO4, H3PO4, HCl, HNO3, H3PO2, H4P2O7, and silicotungstic acid;

[0008] The acidic support includes one or more of HZSM - 5, H - β zeolite molecular sieve, Y - type molecular sieve, HMCM - 22 zeolite molecular sieve, γ - Al2O3, TiO2, and CeO2.

[0009] The concentration of the inorganic acid in the aqueous solution is 0.005 wt% - 20 wt%, preferably 0.005 wt% - 15 wt%.

[0010] The loading amount of the inorganic acid relative to the acidic support is 0.3 wt% - 45 wt%, preferably 0.5 wt% - 30 wt%, more preferably 0.5 wt% - 15 wt%.

[0011] The supported acrolein hydration catalyst prepared by the preparation method can be applied to the process of catalytic acrolein hydration to prepare 3 - hydroxypropionaldehyde.

[0012] This reaction is carried out in a fixed - bed reactor, and the reaction conditions are as follows: the reaction temperature is 30 - 90 °C, preferably 30 - 60 °C; the molar ratio of acrolein to water in the raw material is 1:1 - 1:20, preferably 1:1 - 1:10; the reaction mass space velocity is 0.2 - 6 h -1 , preferably 0.5 - 3 h -1 .

[0013] A polymerization inhibitor is further added to the raw material. The polymerization inhibitor includes one or more of hydroquinone, p - methoxyphenol, phenothiazine, guaiacol, 2,2,6,6 - tetramethyl - 4 - hydroxypiperidine nitroxide radical, and phosphite triester, and the addition amount is 100 - 2000 ppm, preferably 100 - 1000 ppm, based on the weight of acrolein in the raw material.

[0014] The reaction involved in the present invention can be represented by the following reaction equation:

[0015]

[0016] Advantageous technical effects of the present invention:

[0017] Molecular sieve is an important solid acid catalyst and can be used to catalyze the hydration reaction of carbon-carbon double bonds. However, the acidity of the molecular sieve is relatively strong, and side reactions such as the formation of polymers are likely to occur during the hydration process of acrolein, resulting in problems such as low reaction selectivity and poor stability. By loading and modifying with inorganic acids to change the acid amount and distribution of acid centers of the catalyst, the occurrence of side reactions can be effectively inhibited, the selectivity of the target product can be improved, and at the same time, the stability of the catalyst can be maintained through conditions such as air calcination.

[0018] The advantages of the present invention are simple synthesis, appropriate B acid sites, inhibiting the occurrence of side reactions such as polymerization through the inhibitor effect, improving the selectivity of the target product and the stability of the catalyst under the combined action of the catalyst and the inhibitor, and at the same time effectively avoiding problems such as the separation of homogeneous reaction products. Specific embodiments

[0019] The preferred embodiments of the present invention are described in detail below, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0020] Example 1

[0021] Weigh 0.15 g of H2SO4 and add it to 30 g of water and stir evenly; add 30 g of the dried HZSM-5 support to the above solution, mix and stir at room temperature of 25 °C for 3 h; after standing for 24 h, put the above mixture into an oven at 100 °C and dry for 2 h, and finally calcine in a muffle furnace at 450 °C for 6 h to obtain 0.5% SO4 2- / HZSM-5 catalyst.

[0022] Press the obtained sample into tablets with a particle size of 20-60 mesh, and then load it into a stainless steel tube fixed bed reactor (the inner diameter of the fixed bed is 8 mm) for evaluation. The raw material contains 2000 ppm of the inhibitor p-benzoquinone, n 丙烯醛 :n 水 =1:1 (molar ratio, the same below), the reaction temperature is 50 °C, and WHSV = 6 h -1 . Finally, through analysis, the conversion rate of acrolein is 82%, and the selectivity of 3-hydroxypropionaldehyde is 95.5%.

[0023] Example 2

[0024] Weigh 0.10 g of H3PO4 and add it to 10 g of water, then stir evenly; add 30 g of dried H-β molecular sieve support to the above solution, mix and stir at room temperature of 25 °C for 1 h; after standing for 11 h, put the above mixture into an oven at 100 °C and dry for 5 h, and finally calcine in a muffle furnace at 500 °C for 4 h to obtain 1% PO4 3- / H-β molecular sieve catalyst.

[0025] Press the obtained sample into tablets with a particle size of 20 - 60 mesh, then load it into a stainless steel tube fixed-bed reactor (inner diameter of the fixed bed is 8 mm) for evaluation. The raw material contains 500 ppm of inhibitor p-methoxyphenol, n 丙烯醛 :n 水 = 1:10, reaction temperature is 40 °C, WHSV = 1 h -1 . Finally, through analysis, the conversion rate of acrolein is 90%, and the selectivity of 3-hydroxypropanal is 87.0%.

[0026] Example 3

[0027] Weigh 2.03 g of HCl and add it to 18 g of water, then stir evenly; add 5 g of dried Y-type molecular sieve support to the above solution, mix and stir at room temperature of 50 °C for 5 h; after standing for 15 h, put the above mixture into an oven at 120 °C and dry for 5 h, and finally calcine in a muffle furnace at 650 °C for 2 h to obtain 15% Cl - / Y-type molecular sieve catalyst.

[0028] Press the obtained sample into tablets with a particle size of 20 - 60 mesh, then load it into a stainless steel tube fixed-bed reactor (inner diameter of the fixed bed is 8 mm) for evaluation. The raw material contains 800 ppm of inhibitor phenothiazine, n 丙烯醛 :n 水 = 1:4, reaction temperature is 30 °C, WHSV = 5 h -1 . Finally, through analysis, the conversion rate of acrolein is 85%, and the selectivity of 3-hydroxypropanal is 92.1%.

[0029] Example 4

[0030] Weigh 0.75 g of HNO3 and add it to 15 g of water, then stir evenly; add 15 g of dried HMCM-22 zeolite molecular sieve support to the above solution, mix and stir at room temperature of 25 °C for 4 h; after standing for 8 h, put the above mixture into an oven at 120 °C and dry for 2 h, and finally calcine in a muffle furnace at 500 °C for 4 h to obtain 5% NO3 - / HMCM-22 zeolite molecular sieve catalyst.

[0031] The obtained sample was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed is 8 mm) for evaluation. The raw material contains 600 ppm inhibitor guaiacol, n 丙烯醛 :n 水 = 1:5, the reaction temperature is 70 °C, WHSV = 4 h -1 . Finally, through analysis, the conversion rate of acrolein is 87.8%, and the selectivity of 3 - hydroxypropionaldehyde is 89.2%.

[0032] Example 5

[0033] Weigh 1.25 g of H3PO2 and add it to 6 g of water and stir evenly; add 5 g of dried γ - Al2O3 support to the above solution, mix and stir at room temperature of 40 °C for 10 h; after standing for 2 h, put the above mixture into an oven at 120 °C and dry for 2 h, and finally calcine in a muffle furnace at 500 °C for 5 h to obtain 25% PO2 3- / γ - Al2O3 catalyst.

[0034] The obtained sample was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed is 8 mm) for evaluation. The raw material contains 1000 ppm inhibitor 2,2,6,6 - tetramethyl - 4 - hydroxypiperidine 1 - oxyl, n 丙烯醛 :n 水 = 1:10, the reaction temperature is 80 °C, WHSV = 0.5 h -1 . Finally, through analysis, the conversion rate of acrolein is 83%, and the selectivity of 3 - hydroxypropionaldehyde is 94.3%.

[0035] Example 6

[0036] Weigh 1.00 g of H4P2O7 and add it to 6 g of water and stir evenly; add 5 g of dried TiO2 support to the above solution, mix and stir at room temperature of 60 °C for 6 h; after standing for 6 h, put the above mixture into an oven at 100 °C and dry for 6 h, and finally calcine in a muffle furnace at 600 °C for 3 h to obtain 20% PO4 3- / TiO2 catalyst.

[0037] The obtained sample was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed is 8 mm) for evaluation. The raw material contains 500 ppm inhibitor phosphite, n 丙烯醛 :n 水 = 1:15, the reaction temperature is 60 °C, WHSV = 2 h -1 . Finally, through analysis, the conversion rate of acrolein is 89%, and the selectivity of 3 - hydroxypropionaldehyde is 87.9%.

[0038] Example 7

[0039] Weigh 1.5 g of silicotungstic acid and add it to 6 g of water, stirring evenly. The concentration of silicotungstic acid is 20 wt%. Add 5 g of the dried CeO2 support to the above solution, mix, and stir at 80 °C (room temperature) for 2 h. After standing for 10 h, place the above mixture in an oven at 100 °C and dry for 6 h. Finally, calcine it in a muffle furnace at 400 °C for 8 h to obtain the 30% Si(W3O 10 )4 4- / CeO2 catalyst.

[0040] Press the obtained sample into tablets with a particle size of 20 - 60 mesh, then load it into a stainless steel tube fixed-bed reactor (inner diameter of the fixed bed: 8 mm) for evaluation. The raw material contains 100 ppm of the inhibitor hydroquinone, n 丙烯醛 :n 水 = 1:20, the reaction temperature is 90 °C, and WHSV = 0.2 h -1 . Finally, through analysis, the conversion rate of acrolein is 75%, and the selectivity of 3-hydroxypropionaldehyde is 93.3%.

[0041] Example 8

[0042] Weigh 4.5 g of H2SO4 and add it to 30 g of water, stirring evenly. Add 30 g of the dried γ-Al2O3 support to the above solution, mix, and stir at 25 °C (room temperature) for 1 h. After standing for 11 h, place the above mixture in an oven at 100 °C and dry for 2 h. Finally, calcine it in a muffle furnace at 450 °C for 6 h to obtain the 15% SO4 2- / γ-Al2O3 catalyst.

[0043] Press the obtained sample into tablets with a particle size of 20 - 60 mesh, then load it into a stainless steel tube fixed-bed reactor (inner diameter of the fixed bed: 8 mm) for evaluation. The raw material contains 2000 ppm of the inhibitor phenothiazine, n 丙烯醛 :n 水 = 1:1 (molar ratio, the same below), the reaction temperature is 50 °C, and WHSV = 4 h -1 . Finally, through analysis, the conversion rate of acrolein is 83%, and the selectivity of 3-hydroxypropionaldehyde is 94.3%.

[0044] Example 9

[0045] Weigh 0.50 g of H3PO4 and add it to 10 g of water, stirring evenly. Add 30 g of the dried TiO2 support to the above solution, mix, and stir at 25 °C (room temperature) for 5 h. After standing for 15 h, place the above mixture in an oven at 100 °C and dry for 5 h. Finally, calcine it in a muffle furnace at 500 °C for 4 h to obtain the 5% PO4 3- / TiO2 catalyst.

[0046] The obtained sample was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed is 8 mm) for evaluation. The raw material contains 500 ppm of inhibitor p - guaiacol for n 丙烯醛 :n 水 = 1:10, the reaction temperature is 40 °C, WHSV = 0.5 h -1 . Finally, through analysis, the conversion rate of acrolein is 85.6%, and the selectivity of 3 - hydroxypropionaldehyde is 91.5%.

[0047] Example 10

[0048] Weigh 3.38 g of HCl and add it to 18 g of water and stir evenly; add 5 g of dried CeO₂ support to the above - mentioned solution, and stir the mixture at 50 °C (room temperature) for 4 h; after standing for 8 h, put the above - mentioned mixture into an oven at 120 °C and dry for 5 h, and finally calcine it in a muffle furnace at 650 °C for 2 h to obtain 25% Cl - / CeO₂ catalyst.

[0049] The obtained sample was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed is 8 mm) for evaluation. The raw material contains 800 ppm of inhibitor 2,2,6,6 - tetramethyl - 4 - hydroxypiperidine 1 - oxyl, n 丙烯醛 :n 水 = 1:4, the reaction temperature is 30 °C, WHSV = 2 h -1 . Finally, through analysis, the conversion rate of acrolein is 83.4%, and the selectivity of 3 - hydroxypropionaldehyde is 93.9%.

[0050] Example 11

[0051] Weigh 0.75 g of HNO₃ and add it to 15 g of water and stir evenly; add 15 g of dried HZSM - 5 support to the above - mentioned solution, and stir the mixture at 25 °C (room temperature) for 6 h; after standing for 2 h, put the above - mentioned mixture into an oven at 120 °C and dry for 2 h, and finally calcine it in a muffle furnace at 500 °C for 4 h to obtain 5% NO₃ - / HZSM - 5 zeolite molecular sieve catalyst.

[0052] The obtained sample was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed is 8 mm) for evaluation. The raw material contains 600 ppm of inhibitor phosphite, n 丙烯醛 :n 水 = 1:5, the reaction temperature is 70 °C, WHSV = 0.2 h -1 . Finally, through analysis, the conversion rate of acrolein is 85.1%, and the selectivity of 3 - hydroxypropionaldehyde is 92.0%.

[0053] Example 12

[0054] Weigh 0.025 g of H3PO2 and add it to 6 g of water, then stir evenly; add 5 g of dried H-β zeolite molecular sieve support to the above solution, mix them, and stir at room temperature of 40 °C for 10 h; after standing for 24 h, put the above mixture into an oven at 120 °C and dry for 2 h, and finally calcine it in a muffle furnace at 500 °C for 5 h to obtain 0.5% PO2 3- / H-β zeolite molecular sieve catalyst.

[0055] Press the obtained sample into tablets with a particle size of 20 - 60 mesh, then load it into a stainless steel tube fixed-bed reactor (inner diameter of the fixed bed is 8 mm) for evaluation. The raw material contains 1000 ppm of inhibitor hydroquinone, n 丙烯醛 :n 水 = 1:10, the reaction temperature is 80 °C, and WHSV = 1 h -1 . Finally, through analysis, the conversion rate of acrolein is 82.9%, and the selectivity of 3-hydroxypropionaldehyde is 94.5%.

[0056] Example 13

[0057] Weigh 0.05 g of H4P2O7 and add it to 6 g of water, then stir evenly; add 5 g of dried Y-type molecular sieve support to the above solution, mix them, and stir at room temperature of 60 °C for 6 h; after standing for 11 h, put the above mixture into an oven at 100 °C and dry for 6 h, and finally calcine it in a muffle furnace at 600 °C for 3 h to obtain 1% PO4 3- / Y-type molecular sieve catalyst.

[0058] Press the obtained sample into tablets with a particle size of 20 - 60 mesh, then load it into a stainless steel tube fixed-bed reactor (inner diameter of the fixed bed is 8 mm) for evaluation. The raw material contains 500 ppm of inhibitor p-methoxyphenol, n 丙烯醛 :n 水 = 1:15, the reaction temperature is 60 °C, and WHSV = 5 h -1 . Finally, through analysis, the conversion rate of acrolein is 83.9%, and the selectivity of 3-hydroxypropionaldehyde is 93.3%.

[0059] Example 14

[0060] Weigh 1.5 g of silicotungstic acid and add it to 6 g of water, and stir evenly. The concentration of silicotungstic acid is 20 wt%; add 5 g of dried HMCM-22 zeolite molecular sieve support to the above solution, mix them, and stir at room temperature of 80 °C for 2 h; after standing for 10 h, put the above mixture into an oven at 100 °C and dry for 6 h, and finally calcine it in a muffle furnace at 400 °C for 8 h to obtain 30% Si(W3O 10 )4 4- / HMCM-22 zeolite molecular sieve catalyst.

[0061] The obtained sample was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed: 8 mm) for evaluation. The raw material contained 200 ppm of the inhibitor phenothiazine, n 丙烯醛 :n 水 = 1:20, the reaction temperature was 90 °C, and WHSV = 0.2 h -1 . Finally, through analysis, the conversion rate of acrolein was 92.4%, and the selectivity of 3 - hydroxypropionaldehyde was 75.8%.

[0062] Comparative Example 1

[0063] Using the dried HZSM - 5 as the catalyst, it was tableted into 20 - 60 mesh, and then loaded into a stainless - steel tube fixed - bed reactor (inner diameter of the fixed - bed: 8 mm) for evaluation. The raw material contained 2000 ppm of the inhibitor p - benzoquinone, n 丙烯醛 :n 水 = 1:1, the reaction temperature was 50 °C, and WHSV = 6 h -1 . Finally, through analysis, the conversion rate of acrolein was 73%, and the selectivity of 3 - hydroxypropionaldehyde was 89.1%.

[0064] Comparative Example 2

[0065] In a 250 mL three - necked flask, 15.4 g of dried AB - 8 resin, 9.0 g of paraformaldehyde, 20.4 g of anhydrous zinc chloride, 40 mL of concentrated sulfuric acid with a volume fraction of 80%, and 80 mL of glacial acetic acid were added. Under magnetic stirring at 50 - 55 °C, self - made hydrogen chloride gas was introduced and the reaction was carried out for 12 h. After the reaction, it was washed with a large amount of deionized water until neutral, and then washed with ethanol and acetone, and dried in vacuo at 50 °C for 24 h to obtain chloromethylated polystyrene resin (CMCPS), which was placed in a desiccator for standby.

[0066] 6.0 g of CMCPS was taken as the macroinitiator in a 150 mL single-necked flask. At the same time, 10 mL of glycidyl methacrylate, 228 mg of CuBr and 749 mg of 2,2’-bipyridine were added. Then, 100 mL of N,N-dimethylformamide was injected, sealed and purged with nitrogen, and evacuated and circulated 5 times. The reaction was carried out at 60 °C for 16 h. After the reaction, it was washed with a large amount of deionized water and 0.1 mol / L EDTA aqueous solution respectively, then washed with a large amount of deionized water, and washed several times with ethanol and acetone in turn, and dried in vacuo at 50 °C for 24 h to obtain glycidyl methacrylate resin grafted on the surface of CMCPS. The prepared glycidyl methacrylate resin grafted resin was placed in a single-necked flask, soaked and swollen with a certain amount of dimethyl sulfoxide for 12 h, then a certain amount of aqueous solution containing iminodiacetic acid was added, and the reaction was stirred at a constant temperature of 80 °C for 36 h. After filtration, the product was washed repeatedly with hot deionized water to remove unreacted iminodiacetic acid, and washed with ethanol and acetone in turn, and dried in vacuo at 50 °C to obtain the iminodiacetic acid chelating resin catalyst.

[0067] The catalyst was loaded into a stainless steel tube fixed-bed reactor (inner diameter of the fixed bed: 8 mm) for evaluation. The raw material contained 2000 ppm of the polymerization inhibitor p-benzoquinone, n(acrolein):n(water)=1:1, the reaction temperature was 50 °C, and WHSV = 6 h-1. Finally, the conversion rate of acrolein was 75% and the selectivity of 3-hydroxypropionaldehyde was 93% after analysis

[0068] Comparative Example 3

[0069] According to the preparation method of the metal-modified silicoaluminophosphate molecular sieve catalyst described in Patent CN12892584A. 30 g of ZSM-5 molecular sieve (SiO2 / Al2O3 = 25) was added to 150 ml of 1 M calcium nitrate aqueous solution for ion exchange. After three exchanges, the molecular sieve was filtered, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h. The obtained sample was mixed with 70 g of alumina and 20 g of concentrated nitric acid (concentration: 68%), extruded into pellets, and then the extruded sample was dried at 120 °C for 12 h and calcined at 500 °C for 4 h. After calcination, the strip catalyst was crushed and sieved to obtain a granular sample. The prepared granular sample was ion-exchanged in 150 ml of 0.5 M sodium nitrate aqueous solution for 30 min at an ion-exchange temperature of 90 °C. Then the sample was filtered, dried at 120 °C for 12 h, and calcined at 500 °C for 4 h to prepare Catalyst A.

[0070] 1 g of catalyst A particles were loaded into a fixed-bed tubular reactor, and the temperature was raised to 350 °C for pretreatment for 1 hour, and then the reactor temperature was lowered to 60 °C. An aqueous solution of acrolein with a concentration of 20 wt% containing 0.2% hydroquinone inhibitor was introduced into the reactor for reaction, and the mass space velocity of acrolein was 1.0 h-1. After reacting for 1 hour, the effluent was cooled and collected, and the product composition was analyzed by gas chromatography. The conversion rate of acrolein was 81%, and the selectivity of 3-hydroxypropionaldehyde was 87%.

[0071] By comparing Comparative Example 1 with Example 1, it was found that both the activity and selectivity of the catalyst without inorganic acid loading decreased; by comparing Comparative Example 2 with Example 1, it was found that the selectivity of the iminodiacetic acid chelating resin catalyst was better but the catalyst activity was lower. By comparing Comparative Example 3 with Example 1, it was found that the metal-modified silicoaluminophosphate molecular sieve catalyst did not have excellent performance compared with the supported catalyst. The reason may be that the different acidity causes the active acrolein to polymerize itself, resulting in the formation of a large number of by-products, which reduces the selectivity of the target product 3-hydroxypropionaldehyde.

[0072] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A preparation method of a supported catalyst for acrolein hydration reaction, characterized in that: An acidic support is added to an aqueous solution of an inorganic acid, stirred at 25 - 80 °C for 1 - 10 h, cooled to room temperature, allowed to stand for 2 - 24 h, and then dried at a drying temperature of 100 - 120 °C for 2 - 12 h; after drying, it is calcined at a calcination temperature of 400 - 650 °C for 2 - 8 h to obtain a supported catalyst for the acrolein hydration reaction.

2. The preparation method according to claim 1, characterized in that, The inorganic acid includes one or more of H2SO4, H3PO4, HCl, HNO3, H3PO2, H4P2O7, and silicotungstic acid; The acidic support includes one or more of HZSM-5, H-β zeolite molecular sieve, Y-type molecular sieve, HMCM-22 zeolite molecular sieve, γ-Al2O3, TiO2, and CeO2.

3. The preparation method according to claim 1 or 2, characterized in that, The concentration of the inorganic acid in the aqueous solution is 0.005 wt% - 20 wt%, preferably 0.005 wt% - 15 wt%.

4. The preparation method according to claim 1 or 2, characterized in that, The loading amount of the inorganic acid relative to the acidic support is 0.3 wt% - 45 wt%, preferably 0.5 wt% - 30 wt%, more preferably 0.5 wt% - 15 wt%.

5. A supported acrolein hydration catalyst prepared by the preparation method according to any one of claims 1-4.

6. An application of the catalyst according to claim 5, characterized in that: The catalyst can be applied to the process of catalytically hydrating acrolein to prepare 3-hydroxypropionaldehyde.

7. The application according to claim 6, characterized in that: This reaction is carried out in a fixed-bed reactor, and the reaction conditions are as follows: the reaction temperature is 30 - 90 °C, preferably 30 - 60 °C; the molar ratio of acrolein to water in the raw materials is 1:1 - 1:20, preferably 1:1 - 1:10; the reaction mass space velocity is 0.2 - 6 h -1 , preferably 0.5 - 3 h -1 .

8. The method according to claim 7, characterized in that: A polymerization inhibitor is also added to the raw material. The polymerization inhibitor includes one or more of hydroquinone, p-methoxyphenol, phenothiazine, guaiacol, 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide, and phosphite triester, and the addition amount is 100 - 2000 ppm, preferably 100 - 1000 ppm, based on the weight of acrolein in the raw material.

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