Catalyst for preparing n-propyl alcohol through propionaldehyde hydrogenation as well as preparation method and application of catalyst

Abstract

The invention relates to the technical field of catalysts, and particularly discloses a catalyst for preparing n-propyl alcohol through propionaldehyde hydrogenation as well as a preparation method and application of the catalyst. The invention provides a catalyst for preparing normal propyl alcohol through propionaldehyde hydrogenation. The catalyst is prepared from the following components: CuO, ZnO, Al2O3 and an auxiliary agent in a weight ratio of (20-45): (40-65): (0-10): (0.1-5), the content of Al2O3 is not 0; wherein the auxiliary agent is selected from one or more of NiO (nickel oxide), La2O3 (lanthanum oxide) and Cr2O3 (chromium oxide). When the catalyst prepared by the technical scheme of the invention is applied to a reaction for preparing n-propyl alcohol by propionaldehyde hydrogenation, the conversion rate of a propionaldehyde raw material is 99.1% or above, and the selectivity of n-propyl alcohol is 94.5% or above; and the catalyst has good stability in an evaluation reaction process after being used for 400 hours in an experiment for preparing n-propyl alcohol through propionaldehyde hydrogenation.

Description

Technical Field

[0001] The present application relates to the technical field of catalysts, and in particular to a catalyst for hydrogenating propionaldehyde to produce n-propanol, and a preparation method and application thereof. Background Art

[0002] At present, n-propanol is a very important chemical raw material with a wide variety of downstream products. For example, the downstream product n-propyl acetate, as an important organic solvent, is widely used in coatings, inks, color printing, tobacco packaging, flavors and fragrances, resins and other industries. n-propanol is an intermediate for many pharmaceuticals, such as probenecid, sodium valproate, erythromycin, etc. In agriculture, n-propanol is an intermediate for herbicides; at the same time, n-propanol can be used as a coating solvent, a cosmetic solvent, a feed additive, etc. Therefore, n-propanol plays a very important role in many industries in today's society.

[0003] At present, the main way to produce n-propanol in industry is the ethylene carbonylation process, which first synthesizes propionaldehyde from ethylene through carbonylation and then reduces it; another part is isopropanol as a byproduct and separated from the oxidation liquid of low-level alkanes. There are two main catalyst systems for the catalytic hydrogenation of propionaldehyde to propanol: copper and nickel. Compared with nickel catalysts, copper catalysts are cheaper and have lower production costs. Therefore, propionaldehyde catalytic hydrogenation catalysts tend to develop towards copper catalysts, and domestic production equipment also mostly uses copper catalysts.

[0004] The related art discloses a catalyst for producing propanol by gas-phase hydrogenation of propionaldehyde and a preparation method thereof. The catalyst mainly comprises copper oxide, zinc oxide, aluminum oxide, and a modification aid, which is a mixture of one or two of metal element compounds such as potassium, magnesium, calcium, strontium, and barium in the first and second main groups of the periodic table. In the hydrogenation reaction, the catalyst has high low-temperature activity, high propanol selectivity, and catalytic stability.

[0005] A method for preparing n-propanol by hydrogenating propionaldehyde using a nickel-based catalyst is also disclosed in the related art. In this scheme, the catalyst is prepared by an ammonia-induced deposition precipitation method, and the catalyst is composed of a main active component, a metal auxiliary agent and a carrier material. The main active component is Ni, the metal auxiliary agent is selected from one or more of Mg, Na, Ca, Co or Ba metal elements, and the carrier material is selected from one or more of diatomaceous earth, white carbon black, MCM-41, SiO2 microspheres, SiO2 nanoparticles or SBA-15. The catalyst has excellent low-temperature activity and n-propanol product selectivity, reducing the subsequent purification and separation costs of the n-propanol product. However, the ammonia evaporation process releases a large amount of ammonia, and the required time is long, which is not environmentally friendly.

[0006] Higher reaction temperature will lead to polymerization of raw material propanal and condensation of alcohol-aldehyde, thereby reducing the selectivity of target product n-propanol. Therefore, it is urgent to develop a catalyst for hydrogenating propanal to prepare n-propanol with simple preparation method, easy operation, environmental friendliness, low cost and excellent catalytic activity at low temperature. Summary of the invention

[0007] In order to solve the above technical problems, the present application provides a catalyst for hydrogenating propionaldehyde to produce n-propanol, and a preparation method and application thereof.

[0008] In a first aspect, the present application provides a catalyst for hydrogenating propionaldehyde to produce n-propanol, which is composed of the following components in weight ratio: CuO: ZnO: Al2O3: additive = 20-45: 40-65: 0-10: 0.1-5; and Al2O3 is not 0; Wherein, the auxiliary agent is selected from one or more of NiO, La2O3, and Cr2O3.

[0009] Preferably, the catalyst for preparing n-propanol by hydrogenation of propionaldehyde is composed of components in the following weight ratio: CuO: ZnO: Al2O3: auxiliary agent = 35-45: 50-60: 3-7: 0.2-2.0.

[0010] In a specific embodiment, the catalyst for preparing n-propanol by hydrogenation of propionaldehyde is composed of components in the following weight ratio: CuO: ZnO: Al2O3: auxiliary agent = 40: 55: 5: 0.5.

[0011] Through experimental analysis, it can be known that the present application chooses to control the weight ratio between CuO: ZnO: Al2O3: additive within the above range, which further improves the performance of the catalyst.

[0012] Preferably, the catalyst for hydrogenating propionaldehyde to produce n-propanol is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO: La2O3 = 35-45: 50-60: 3-7: 0.1-0.7: 0.8-1.3.

[0013] In a specific embodiment, the catalyst for preparing n-propanol by hydrogenation of propionaldehyde is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO: La2O3 = 35-45: 50-60: 3-7: 0.5: 1.

[0014] Experimental analysis shows that the type of additives will significantly affect the catalytic performance of the catalyst; this application selects NiO and La2O3 as additives, and controls the weight ratio of CuO:ZnO:Al2O3:NiO:La2O3 within the above range, further improving the performance of the catalyst.

[0015] Preferably, the catalyst further comprises a molding agent, and the ratio between the sum of the weights of the CuO, ZnO, Al2O3 and the auxiliary agent and the weight of the molding agent is 100:2-4.

[0016] In a second aspect, the present application provides a method for preparing the above-mentioned catalyst for hydrogenating propionaldehyde to produce n-propanol, wherein the catalyst is prepared by a coprecipitation method, and the specific steps are as follows: (1) Weigh soluble copper salt, soluble zinc salt, soluble aluminum salt and soluble auxiliary salt and dissolve them in water to prepare a 1-1.5 mol / L mixed salt solution, and at the same time prepare an alkaline solution with the same concentration as the mixed salt solution; (2) adding the mixed salt solution and the alkaline solution dropwise to a reaction vessel in parallel, maintaining the dropping process under stirring conditions, a water bath temperature of 70-90° C., and a constant pH value of 7-8 to obtain a slurry; (3) aging the slurry at a water bath temperature of 70-90° C. for 3-5 hours, filtering after aging to retain the filter cake, adding water to the filter cake to slurry and filtering, repeating the process 5-10 times to obtain a coprecipitated product; then drying at 80-120° C., grinding, granulating, and calcining at 300-600° C. for 3-5 hours to obtain a decomposition product; (4) The decomposition product and the molding agent are uniformly mixed in a weight ratio of 100:2-4, and pressed into tablets to obtain a catalyst.

[0017] The present application uses a co-precipitation method to drip a mixed metal salt solution and an alkaline solution into a container in parallel, and the dripping process maintains a certain stirring speed, a certain water bath temperature and a constant pH value; the addition of a soluble salt of a metal additive promotes the high dispersion of copper, avoids its agglomeration during the roasting and decomposition process, and the additive can change the electronic structure of the active component Cu and improve the catalytic performance.

[0018] Preferably, the soluble copper salt is selected from any one or more of copper chloride, copper sulfate, and copper nitrate; The soluble zinc salt is selected from any one or more of zinc chloride, zinc sulfate and zinc nitrate; The soluble aluminum salt is selected from any one or more of aluminum chloride, aluminum sulfate, and aluminum nitrate; The additive soluble salt is selected from any one or more of nickel nitrate, lanthanum nitrate and chromium nitrate; The alkaline solution is selected from any one or more of sodium carbonate solution, sodium bicarbonate solution and sodium hydroxide solution; The molding agent is graphite.

[0019] Preferably, in the mixed salt solution, the concentration of soluble copper salt is 0.25-0.65 mol / L, the concentration of soluble zinc salt is 0.37-0.81 mol / L, the concentration of soluble aluminum salt is 0.019-0.20 mol / L, and the concentration of soluble auxiliary agent salt is 0.0012-0.07 mol / L.

[0020] In a third aspect, the present application provides a method for using the above-mentioned catalyst, wherein the catalyst needs to be subjected to reduction activation treatment before use; the process parameters of the reduction activation treatment are: Heat up to 110-130°C at a heating rate of 20-40°C / h, with pure N2 as the reducing atmosphere; keep warm for 20-40 minutes, and increase the hydrogen concentration to 5% H2+95% N2 as the reducing atmosphere; Heat up to 175-185°C at a heating rate of 5-15°C / h, with a reducing atmosphere of 5% H2+95% N2; keep warm for 100-140 minutes, and increase the hydrogen concentration to a reducing atmosphere of 25% H2+75% N2; The temperature was raised to 195-205°C at a heating rate of 4-6°C / h. While heating, the hydrogen concentration was increased every hour to reduce the atmosphere to 50% H2+50% N2, 70% H2+30% N2, 85% H2+15% N2, and 100% H2; the temperature was kept at 100-140 minutes, the reducing atmosphere was pure H2, and the reduction was completed.

[0021] In a fourth aspect, the present application provides the use of the above catalyst in hydrogenating propionaldehyde to produce n-propanol.

[0022] In a fifth aspect, the present application provides a method for preparing n-propanol by hydrogenating propionaldehyde, wherein the above catalyst is used in the method, and the specific steps are: -1 The mass space velocity is introduced into a continuous fixed bed reactor, and H2 is continuously introduced to control the molar ratio of hydrogen to aldehyde to be 10-100:1. The reaction is carried out at a reaction temperature of 100-170°C and a reaction pressure of 0.3-0.6MPa.

[0023] The catalyst prepared by the technical solution of the present application was crushed, reduced and activated, and then applied to the reaction of hydrogenating propionaldehyde to produce n-propanol. The propionaldehyde raw material conversion rate was above 99.1%, and the n-propanol selectivity was above 94.5%. In the experiment of hydrogenating propionaldehyde to produce n-propanol, the catalyst had good stability during the reaction after being used for 400 hours to evaluate the reaction process.

[0024] In summary, the technical solution of this application has the following effects: The present application uses a coprecipitation method to drip a mixed metal salt solution and an alkaline solution into a container in parallel, and the dripping process maintains a certain stirring speed, a certain water bath temperature and a constant pH value. The addition of metal additives promotes the high dispersion of copper, prevents it from agglomerating during the roasting and decomposition process, and the additives can change the electronic structure of the active component Cu and improve the catalytic performance.

[0025] The catalyst of the present application is applied to the reaction of hydrogenating propionaldehyde to produce n-propanol, and the conversion rate of propionaldehyde raw material is more than 99.1%, and the selectivity of n-propanol is more than 94.5%; and in the experiment of hydrogenating propionaldehyde to produce n-propanol, after using it for 400 hours to evaluate the reaction process, the catalyst has good stability.

[0026] The catalyst for preparing n-propanol by hydrogenation of propionaldehyde provided in the present application is not only simple in preparation method, easy in operation, environmentally friendly, and low in cost, but also has excellent catalytic activity at low temperatures, and has good industrial application prospects. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application. Example Example 1

[0028] Example 1 provides a catalyst for hydrogenating propionaldehyde to produce n-propanol and a preparation method thereof.

[0029] The preparation method of the catalyst for preparing n-propanol by hydrogenation of propionaldehyde in Example 1 is: Weigh 120.8 g of copper nitrate trihydrate (0.5 mol), 202 g of zinc nitrate hexahydrate (0.679 mol), 36.8 g of aluminum nitrate nonahydrate (0.098 mol), and 1.95 g of nickel nitrate hexahydrate (0.007 mol), add 1284 mL of deionized water, and prepare a 1 mol / L mixed salt solution A.

[0030] Weigh 136.1 g of anhydrous sodium carbonate (1.29 mol) and add 1284 mL of deionized water to prepare a 1 mol / L alkaline solution B.

[0031] Salt solution A and alkaline solution B were added dropwise to the reaction container in parallel by a peristaltic pump, with continuous stirring during the addition process. The stirring process was maintained at 130 rpm, the water bath reaction temperature was 80°C, and the pH value was controlled to be 7.5 to obtain a slurry for coprecipitation.

[0032] After the coprecipitation is completed, the mixture is aged at 80°C for 3 hours. After the aging is completed, the precipitate slurry is filtered to obtain a filter cake, and the filter cake is slurried with water and filtered. The operation is repeated 8 times to obtain a coprecipitation product. The mixture is then dried at 100°C for 6 hours, ground, granulated, and calcined at 350°C for 3 hours to obtain a decomposition product.

[0033] The decomposition product and the graphite forming agent are uniformly mixed in a weight ratio of 100:2-4, and pressed into tablets to obtain the final catalyst.

[0034] Calculated by oxide weight ratio, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO = 40: 55: 5: 0.5. Embodiment 2-5

[0035] Examples 2-5 respectively provide a catalyst for hydrogenating propionaldehyde to produce n-propanol and a preparation method thereof.

[0036] The difference between Example 2-5 and Example 1 is that the amount of each substance in the mixed salt solution is different, and the composition of the prepared catalyst is different, as shown below.

[0037] In Example 2: 0.253 mol of copper nitrate trihydrate, 0.802 mol of zinc nitrate hexahydrate, 0.002 mol of aluminum nitrate nonahydrate, and 0.067 mol of nickel nitrate hexahydrate were added with deionized water to prepare a 1 mol / L mixed salt solution A.

[0038] Calculated by oxide weight ratio, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO = 20: 65: 0.1: 5.

[0039] In Example 3: 0.443 mol of copper nitrate trihydrate, 0.741 mol of zinc nitrate hexahydrate, 0.059 mol of aluminum nitrate nonahydrate, and 0.027 mol of nickel nitrate hexahydrate were added with deionized water to prepare a 1 mol / L mixed salt solution A. In terms of oxide weight ratio, the catalyst is composed of the following components in the following weight ratio: CuO: ZnO: Al2O3: NiO = 35:60:3:2.

[0040] In Example 4, 0.569 mol of copper nitrate trihydrate, 0.617 mol of zinc nitrate hexahydrate, 0.137 mol of aluminum nitrate nonahydrate, and 0.0027 mol of nickel nitrate hexahydrate were added with deionized water to prepare a 1 mol / L mixed salt solution A. The catalyst was composed of the following components in weight ratio based on the oxide weight ratio: CuO: ZnO: Al2O3: NiO = 45: 50: 7: 0.2.

[0041] In Example 5: 0.569 mol of copper nitrate trihydrate, 0.494 mol of zinc nitrate hexahydrate, 0.196 mol of aluminum nitrate nonahydrate, and 0.00135 mol of nickel nitrate hexahydrate were added with deionized water to prepare a 1 mol / L mixed salt solution A. In terms of oxide weight ratio, the catalyst is composed of the following components in the following weight ratio: CuO: ZnO: Al2O3: NiO = 45: 40: 10: 0.1.

[0042] The remaining process parameters in the above embodiment are the same as those in embodiment 1. Embodiment 6-11

[0043] Examples 6-11 respectively provide a catalyst for hydrogenating propionaldehyde to produce n-propanol and a preparation method thereof.

[0044] The difference between Example 6-11 and Example 1 is that the types of the auxiliary soluble salt in the mixed salt solution are different, and the composition of the prepared catalyst is different, as shown below.

[0045] In Example 6: Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO: La2O3 = 40: 55: 5: 0.1: 1.3.

[0046] In Example 7: Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO: La2O3 = 40: 55: 5: 0.5: 1.0.

[0047] In Example 8: Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO: La2O3 = 40: 55: 5: 0.7: 0.8.

[0048] In Example 9: Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO: La2O3 = 40: 55: 5: 1.0: 0.5.

[0049] In Example 10: Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO: Cr2O3 = 40: 55: 5: 0.5: 1.0.

[0050] In Example 11: Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: La2O3 = 40: 55: 5: 1.4.

[0051] The remaining process parameters in the above embodiment are the same as those in embodiment 1. Comparative Example Comparative Examples 1-4

[0052] Comparative Examples 1-4 respectively provide a catalyst for preparing n-propanol by hydrogenation of propionaldehyde and a preparation method thereof.

[0053] The difference between Comparative Examples 1-4 and Example 1 is that the amounts of the substances in the mixed salt solution are different, and the compositions of the prepared catalysts are different, as shown below.

[0054] In Comparative Example 1: 0.5 mol of copper nitrate trihydrate, 0.679 mol of zinc nitrate hexahydrate, and 0.098 mol of aluminum nitrate nonahydrate were weighed, and deionized water was added to prepare a 1 mol / L mixed salt solution A (without adding soluble auxiliary salt).

[0055] Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO = 40:55:5.

[0056] In Comparative Example 2: 0.190 mol of copper nitrate trihydrate, 0.864 mol of zinc nitrate hexahydrate, 0.001 mol of aluminum nitrate nonahydrate, and 0.108 mol of nickel nitrate hexahydrate were added with deionized water to prepare a 1 mol / L mixed salt solution A.

[0057] Calculated by weight ratio of oxides, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO = 15: 70: 0.05: 8.

[0058] In Comparative Example 3: 0.632 mol of copper nitrate trihydrate, 0.370 mol of zinc nitrate hexahydrate, 0.235 mol of aluminum nitrate nonahydrate, and 0.0007 mol of nickel nitrate hexahydrate were added with deionized water to prepare a 1 mol / L mixed salt solution A.

[0059] Calculated by oxide weight ratio, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: NiO = 50: 30: 12: 0.05.

[0060] In Comparative Example 4: 0.632 mol of copper nitrate trihydrate, 0.370 mol of zinc nitrate hexahydrate, 0.235 mol of aluminum nitrate nonahydrate, and 0.0125 mol of magnesium nitrate hexahydrate were added with deionized water to prepare a 1 mol / L mixed salt solution A.

[0061] Calculated by oxide weight ratio, the catalyst is composed of components in the following weight ratio: CuO: ZnO: Al2O3: MgO = 50: 30: 12: 0.05.

[0062] The remaining process parameters in the above comparative example are the same as those in Example 1. Performance testing

[0063] (1) Catalyst performance testing The catalysts provided in the above embodiment and comparative example were used to prepare n-propanol, respectively, to evaluate and analyze the catalytic performance of the catalysts. The test results are shown in Table 1.

[0064] The evaluation method is as follows: The above catalyst was crushed into 20-40 mesh particles, 20 mL was weighed and loaded into the reaction tube, the catalyst bed height was 10 cm, and the raw material used was industrial propionaldehyde. Shimadzu gas chromatograph was used to conduct qualitative and quantitative analysis of the product components. The catalyst was reduced and activated before use, and the process parameters were: The temperature was raised to 120°C at a heating rate of 30°C / h, and the reducing atmosphere was pure N2; the temperature was kept for 30 minutes, and the hydrogen concentration was increased to a reducing atmosphere of 5% H2+95% N2; The temperature was raised to 180°C at a heating rate of 10°C / h, and the reducing atmosphere was 5% H2+95% N2; the temperature was kept for 120 min, and the hydrogen concentration was increased to a reducing atmosphere of 25% H2+75% N2; The temperature was raised to 200°C at a heating rate of 5°C / h. While heating, the hydrogen concentration was increased every hour to the reducing atmosphere of 50% H2+50% N2, 70% H2+30% N2, 85% H2+15% N2, and 100% H2; the temperature was kept at this temperature for 120 minutes, the reducing atmosphere was pure H2, and the reduction was completed.

[0065] At a temperature of 110°C and a pressure of 0.5 MPa, propionaldehyde is heated for 0.3-2 hours. -1 The mass space velocity of the raw material was introduced into the continuous fixed bed reactor, and H2 was continuously introduced to control the molar ratio of hydrogen to aldehyde to be 10-100:1 for hydrogenation reaction. The calculation results of the raw material conversion rate and product selectivity are shown in Table 1.

[0066] (2) Stability evaluation The catalysts prepared by the catalysts in the examples and comparative examples were used in the propionaldehyde hydrogenation experiment to produce n-propanol for 400 hours, and the catalytic performance of the catalysts was tested to evaluate the stability of the catalysts. Propionaldehyde feedstock conversion rate stability = propionaldehyde feedstock conversion rate after the catalyst was used for 400 hours / propionaldehyde feedstock conversion rate of the initial catalyst × 100%; n-propanol product selectivity stability = n-propanol product selectivity after the catalyst was used for 400 hours / n-propanol product selectivity of the initial catalyst × 100%; Table 1 Catalyst performance test results in Examples and Comparative Examples

[0067] As can be seen from Table 1, the catalyst prepared in the embodiment of the present application has good performance, the conversion rate of propionaldehyde feedstock is more than 99.1%, and the selectivity of n-propanol is more than 94.5%; and in the propionaldehyde hydrogenation experiment to prepare n-propanol, the catalyst has good stability during the reaction after 400 hours of evaluation.

[0068] By comparing the test results of Example 1 and Comparative Example 1, it can be seen that the catalyst prepared in Comparative Example 1 has no additive added, the catalyst conversion rate is 89.3%, and the n-propanol selectivity is 86.7%.

[0069] By comparing the test results of Example 1 with those of Comparative Examples 2-3, it can be seen that the weight ratio between the raw material components in the catalyst will significantly affect the catalytic performance of the catalyst. The catalyst prepared in Comparative Example 2 is composed of the following weight ratios of components: CuO: ZnO: Al2O3: auxiliary agent = 15: 70: 0.05: 8, the catalyst conversion rate is 88.4%, and the selectivity of n-propanol is 82.4%; the catalyst prepared in Comparative Example 3 is composed of the following weight ratios of components: CuO: ZnO: Al2O3: auxiliary agent = 50: 30: 12: 0.05, the catalyst conversion rate is 91.4%, and the selectivity of n-propanol is 83.5%. In contrast, the catalyst for preparing n-propanol by hydrogenation of propionaldehyde in the present application is composed of CuO: ZnO: Al2O3: auxiliary agent components in a weight ratio of 20-45: 40-65: 0-10: 0.1-5, and the catalytic performance and stability of the prepared catalyst are good.

[0070] Furthermore, by comparing the test results of Examples 1-5, the present application chooses to control the weight ratio of CuO: ZnO: Al2O3: additive to 35-45: 50-60: 3-7: 0.2-2.0, which further improves the performance of the catalyst.

[0071] By comparing the test results of Example 1 with those of Comparative Example 4, it can be seen that the type of auxiliary agent will significantly affect the catalytic performance of the catalyst. The catalyst prepared in Comparative Example 4 is composed of the following components in a weight ratio: CuO: ZnO: Al2O3: MgO = 50: 30: 12: 0.05, that is, the auxiliary agent is MgO, and the prepared catalyst has a conversion rate of 99.1% and a selectivity of 96.1% for n-propanol; however, after being used for 400 hours in the experiment of preparing n-propanol by hydrogenation of propionaldehyde, the stability of the catalyst is poor. In contrast, the auxiliary agent of the present application is selected from one or more of NiO, La2O3, and Cr2O3, and the prepared catalyst has better catalytic performance and stability.

[0072] Furthermore, by comparing the test results of Example 1 with those of Examples 6-11, the present application selects NiO and La2O3 as additives, and controls the weight ratio of CuO:ZnO:Al2O3:NiO:La2O3 to 35-45:50-60:3-7:0.1-0.7:0.8-1.3, thereby further improving the performance of the catalyst.

[0073] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A catalyst for preparing n-propanol by hydrogenation of propionaldehyde, characterized in that: The following weight ratios of components composition: CuO: ZnO:Al2O3:additive=20-45:40-65:0-10:0.1-5; and Al2O3 is not 0; Wherein, the auxiliary agent is selected from one or more of NiO, La2O3, and Cr2O3.

2. The catalyst for preparing n-propanol by hydrogenation of propionaldehyde according to claim 1, characterized in that The following weight ratios of components Composition: CuO: ZnO: Al2O3: additive = 35-45: 50-60: 3-7: 0.2-2.

0.

3. The catalyst for preparing n-propanol by hydrogenation of propionaldehyde according to claim 1, characterized in that The following weight ratios of components Composition: CuO: ZnO: Al2O3: NiO: La2O3 = 35-45: 50-60: 3-7: 0.1-0.7: 0.8-1.

3.

4. The catalyst for preparing n-propanol by hydrogenation of propionaldehyde according to claim 1, characterized in that The catalyst also includes a molding agent, and the ratio between the sum of the weights of the CuO, ZnO, Al2O3 and the auxiliary agent and the weight of the molding agent is 100:2-4.

5. The method for preparing a catalyst for preparing n-propanol by hydrogenation of propionaldehyde according to any one of claims 1 to 4, characterized in that: The catalyst is prepared by a co-precipitation method, and the specific steps are as follows: (1) Weigh soluble copper salt, soluble zinc salt, soluble aluminum salt and soluble auxiliary salt and dissolve them in water to prepare a 1-1.5 mol / L mixed salt solution, and at the same time prepare an alkaline solution with the same concentration as the mixed salt solution; (2) adding the mixed salt solution and the alkaline solution dropwise to a reaction vessel in parallel, maintaining the dropping process under stirring conditions, a water bath temperature of 70-90° C., and a constant pH value of 7-8 to obtain a slurry; (3) aging the slurry at a water bath temperature of 70-90° C. for 3-5 hours, filtering after aging to retain the filter cake, adding water to the filter cake to slurry and filtering, repeating the process 5-10 times to obtain a coprecipitated product; then drying at 80-120° C., grinding, granulating, and calcining at 300-600° C. for 3-5 hours to obtain a decomposition product; (4) The decomposition product and the molding agent are uniformly mixed in a weight ratio of 100:2-4, and pressed into tablets to obtain a catalyst.

6. The method for preparing a catalyst for preparing n-propanol by hydrogenation of propionaldehyde according to claim 5, characterized in that: The soluble copper salt is selected from any one or more of copper chloride, copper sulfate, and copper nitrate; The soluble zinc salt is selected from any one or more of zinc chloride, zinc sulfate and zinc nitrate; The soluble aluminum salt is selected from any one or more of aluminum chloride, aluminum sulfate, and aluminum nitrate; The additive soluble salt is selected from any one or more of nickel nitrate, lanthanum nitrate and chromium nitrate; The alkaline solution is selected from any one or more of sodium carbonate solution, sodium bicarbonate solution and sodium hydroxide solution; The molding agent is graphite.

7. The method for preparing a catalyst for preparing n-propanol by hydrogenation of propionaldehyde according to claim 5, characterized in that: In the mixed salt solution, the concentration of soluble copper salt is 0.25-0.65 mol / L, the concentration of soluble zinc salt is 0.37-0.81 mol / L, the concentration of soluble aluminum salt is 0.019-0.20 mol / L, and the concentration of soluble auxiliary agent salt is 0.0012-0.07 mol / L.

8. A method for using the catalyst according to any one of claims 1 to 4, characterized in that: The catalyst needs to be reduced and activated before use; the process parameters of the reduction and activation treatment are: Heat up to 110-130℃ at a heating rate of 20-40℃ / h, with pure N2 as the reducing atmosphere; keep warm for 20-40min, and increase the hydrogen concentration to 5%H2+95%N2 as the reducing atmosphere; Heat up to 175-185°C at a heating rate of 5-15°C / h, with a reducing atmosphere of 5% H2+95% N2; keep warm for 100-140 minutes, and increase the hydrogen concentration to a reducing atmosphere of 25% H2+75% N2; The temperature was raised to 195-205°C at a heating rate of 4-6°C / h, and the hydrogen concentration was increased in sequence to a reducing atmosphere of 50% H2+50% N2, 70% H2+30% N2, 85% H2+15% N2, and 100% H2; the temperature was kept at 100-140 min, and the reducing atmosphere was pure H2, and the reduction was completed.

9. Use of the catalyst according to any one of claims 1 to 4 in hydrogenating propionaldehyde to produce n-propanol.

10. A method for preparing n-propanol by hydrogenating propionaldehyde, characterized in that: The method uses the catalyst according to any one of claims 1 to 4, and the specific steps are: -1 The mass space velocity is introduced into a continuous fixed bed reactor, and H2 is continuously introduced to control the molar ratio of hydrogen to aldehyde to be 10-100:

1. The reaction is carried out at a reaction temperature of 100-170°C and a reaction pressure of 0.3-0.6MPa.

Images