A preparation method of a liquid-phase hydrorefining catalyst for crude creosote

Abstract

The application discloses a preparation method of a catalyst for liquid-phase refining of crude octanol, and the preparation method comprises the following steps: (1) mixing pretreated fly ash and pseudo-boehmite, adding deionized water and nitric acid, stirring until a colloid is formed, drying the colloid, mixing the dried colloid with kaolin, and obtaining a carrier through kneading, extrusion molding, drying and calcination; (2) taking a nickel salt, a manganese salt and a zinc salt as active components, taking a calcium salt as an auxiliary component, dissolving the active components and the auxiliary component in deionized water to obtain a salt solution, adding n-hexane into the salt solution and stirring uniformly to prepare an impregnation solution, immersing the carrier in the impregnation solution, and obtaining the catalyst through washing, drying and calcination. The catalyst prepared by the method is mainly used in a liquid-phase refining reaction process of crude octanol, and has high activity stability and selectivity.

Description

Technical Field

[0001] This invention relates to the field of catalysts for the liquid-phase hydrogenation refining of crude octanol, and specifically to a method for preparing a catalyst for the liquid-phase hydrogenation refining of crude octanol. Background Technology

[0002] Butyl and octanol are important basic organic chemical raw materials. Currently, the main method for producing butyl and octanol worldwide is the low-pressure rhodium process to produce butyraldehyde, which is then condensed into octenal. Butyraldehyde and octenal are then hydrogenated to obtain butyl and octanol. There are two hydrogenation processes: gas-phase and liquid-phase. Currently, the liquid-phase method produces products of higher quality than the gas-phase method. Various types of liquid-phase hydrogenation catalysts are available internationally. Ni is the preferred active component, while Cu, Cr, Mo, Mn, Co, Fe, K, and Na are common co-catalysts. SiO2 is the preferred support, followed by Al2O3-Fe2O3 or ZrO2.

[0003] Currently, the main production method for butanol and octanol in my country is the carbonyl synthesis method. The hydrogenation process originally included both gas-phase and liquid-phase methods. Currently, most gas-phase methods have added a liquid-phase supplementary hydrogenation step, i.e., a refining process, to improve product quality. Jilin Petrochemical Company's 50,000-ton / year butanol and octanol unit uses a liquid-phase hydrogenation process, employing catalysts from BASF. However, with the continuous rise in the price of imported catalysts, production costs remain high. Therefore, the research and development of low-cost catalysts is particularly urgent for the domestic market.

[0004] Patent CN99107761.X discloses a liquid-phase hydrogenation catalyst, its preparation method, and its application. The catalyst support is selected from SiO2 or diatomaceous earth, with nickel as the first active component and other active components selected from cobalt, molybdenum, chromium, and potassium. By weight percentage, the nickel content is 5-40%, and the cobalt and molybdenum content is 0.2-5.0%. The active components are impregnated or co-precipitated onto the SiO2 or diatomaceous earth support. This invention can be used in the liquid-phase hydrogenation process for preparing saturated alcohols from saturated and unsaturated aldehydes. The catalyst preparation method is simple and low-cost, but the activity and selectivity of the catalyst need to be improved.

[0005] Patent CN201610443254.X discloses an aldehyde hydrogenation catalyst and its preparation method. The catalyst consists of a core-shell structured catalyst unit and an auxiliary agent. The shell of the catalyst unit is composed of NiO and SiO2, and the core is composed of Ni3Si2O5(OH)4. The preparation process includes: firstly, preparing a nickel-silicon precipitate using a precipitation method; then, heat-treating it using constant-temperature forced-air drying and a microwave furnace to obtain the catalyst unit; finally, mixing the catalyst unit with the auxiliary agent and performing a molding process to obtain a core-shell structured aldehyde liquid-phase hydrogenation catalyst. This method improves the selectivity of the catalyst, but the stability of the catalyst prepared by this method still needs to be improved. Summary of the Invention

[0006] To address the issues of high catalyst preparation costs and insufficient stability and selectivity in current liquid-phase hydrogenation refining reactions, this invention provides a method for preparing a catalyst for the liquid-phase hydrogenation refining of crude octanol.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] A method for preparing a catalyst for the liquid-phase hydrogenation purification of crude octanol, the preparation method comprising:

[0009] (1) After mixing the pretreated fly ash and pseudoboehmite, add deionized water and nitric acid, stir until a colloid is formed, dry the colloid and mix it with kaolin, knead, extrude and mold, dry and calcine to obtain the carrier;

[0010] (2) Nickel salt, manganese salt and zinc salt are used as active components, and calcium salt is used as auxiliary component. The active components and auxiliary components are dissolved in deionized water to obtain a salt solution. Hexane is added to the salt solution and stirred evenly to prepare an impregnation solution. The carrier is placed in the impregnation solution for impregnation, and then the catalyst is obtained after washing, drying and calcination.

[0011] Furthermore, the method for pretreating fly ash is as follows: fly ash is sieved to obtain fly ash with uniform particle size, and then fly ash, deionized water and N-methyldiethanolamine are mixed and placed in a hydrothermal reactor. After the reaction is completed, the mixture is filtered and dried to obtain pretreated fly ash.

[0012] Furthermore, the volume ratio of N-methyldiethanolamine to deionized water is 0.5:10.

[0013] Furthermore, the hydrothermal reaction conditions are as follows: reaction at 105°C for 12 hours in a high-pressure reactor lined with polytetrafluoroethylene;

[0014] After the hydrothermal reaction, the reaction solution was cooled to room temperature, filtered to remove the supernatant, washed with deionized water, centrifuged to collect the precipitate, and dried.

[0015] Furthermore, the mass ratio of the pretreated fly ash to boehmite is 1:5-10.

[0016] Furthermore, the amount of kaolin used is 35-50 wt% of the colloid mass, preferably 40 wt% of the colloid mass.

[0017] Furthermore, the nickel salt, manganese salt, zinc salt, and calcium salt are nitrates, and the molar ratio of metals Ni, Mn, Zn, and Ca in the nickel salt, manganese salt, zinc salt, and calcium salt is 5:0.1-2:0.1-2:0.05;

[0018] The volume of n-hexane is 0.5-2% of the volume of the salt solution, preferably 1% of the volume of the salt solution.

[0019] Furthermore, the impregnation is a volumetric impregnation, the impregnation time is 10-15 hours, and the calcination is carried out in a muffle furnace at 700°C for 4-7 hours.

[0020] The crude octanol liquid-phase hydrogenation catalyst was prepared according to the above-described preparation method for the crude octanol liquid-phase hydrogenation catalyst.

[0021] The present invention has the following beneficial effects:

[0022] 1. The present invention provides a method for preparing a catalyst for liquid-phase hydrogenation refining of crude octanol. The catalyst support is prepared using fly ash and boehmite as raw materials. By pretreating the fly ash, the support has high stability and can still show good activity after 500 hours of use. To a certain extent, this method can reduce the cost of the catalyst in the octanol preparation process and improve the overall efficiency of octanol synthesis.

[0023] 2. The present invention provides a method for preparing a catalyst for liquid-phase hydrogenation refining of crude octanol, which forms the active component and auxiliary component of the catalyst by appropriately proportioning nickel salt, manganese salt, zinc salt and calcium salt, so that the catalyst has good activity and selectivity.

[0024] 3. The present invention provides a method for preparing a catalyst for liquid-phase hydrogenation refining of crude octanol. In the process of loading the active component and the auxiliary component onto the support, n-hexane is added to the impregnation solution, and the activity of the catalyst is further improved by controlling the amount of n-hexane added.

[0025] 4. The present invention provides a method for preparing a catalyst for the liquid-phase hydrogenation refining of crude octanol. The catalyst preparation method is easy to control and simple, and is very suitable for industrial production. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. All reagents and equipment used in the present invention are known products or obtained by purchasing commercially available products.

[0027] Example 1

[0028] Fly ash was passed through a 40-mesh sieve to obtain fly ash with uniform particle size. Then, fly ash, deionized water and N-methyldiethanolamine were mixed and placed in a high-pressure reactor lined with polytetrafluoroethylene. The volume ratio of N-methyldiethanolamine to deionized water was 0.5:10, and the fly ash was 40% of the mass of deionized water. The reaction conditions were 105℃ for 12 hours. After the reaction was completed, the reaction solution was cooled to room temperature, filtered to remove the supernatant, washed with deionized water, and the precipitate was collected by centrifugation. The obtained precipitate was dried at 110℃ for 12 hours to obtain pretreated fly ash.

[0029] (1) After mixing the pretreated fly ash and boehmite, add deionized water and nitric acid. The mass ratio of the pretreated fly ash to boehmite is 1:5. The amount of deionized water is 2.5 times the total mass of fly ash and boehmite. The nitric acid is 6 mol / L to adjust the final pH to 4.5. Then stir until a colloid is formed.

[0030] After drying the colloid, it was mixed with kaolin at a mass of 40 wt% of the colloid. The mixture was then kneaded, extruded into a clover shape, dried at 120°C for 8 hours, and then calcined at 650°C for 5 hours in a tube furnace under air atmosphere to obtain the carrier.

[0031] (2) Weigh the corresponding nitrates according to the molar ratio of metals Ni, Mn, Zn and Ca in the nitrates of nickel salt, manganese salt, zinc salt and calcium salt as 5:1:0.5:0.05, and dissolve them in deionized water to obtain a salt solution. Add n-hexane to the salt solution to prepare an impregnation solution. The volume of n-hexane is 0.5% of the volume of the salt solution. Place the support in the impregnation solution and impregnate it by volume for 12 hours. Then wash it with deionized water, dry it in a vacuum drying oven at 100°C for 8 hours, and then calcine it in an air atmosphere at 700°C for 4 hours to obtain the catalyst.

[0032] Example 2

[0033] Fly ash was passed through a 40-mesh sieve to obtain fly ash with uniform particle size. Then, fly ash, deionized water and N-methyldiethanolamine were mixed and placed in a high-pressure reactor lined with polytetrafluoroethylene. The volume ratio of N-methyldiethanolamine to deionized water was 0.5:10, and the fly ash was 40% of the mass of deionized water. The reaction conditions were 105℃ for 12 hours. After the reaction was completed, the reaction solution was cooled to room temperature, filtered to remove the supernatant, washed with deionized water, and the precipitate was collected by centrifugation. The obtained precipitate was dried at 110℃ for 12 hours to obtain pretreated fly ash.

[0034] (1) After mixing the pretreated fly ash and boehmite, add deionized water and nitric acid. The mass ratio of the pretreated fly ash to boehmite is 1:8. The amount of deionized water is 2.5 times the total mass of fly ash and boehmite. The nitric acid is 6 mol / L to adjust the final pH to 5.5. Then stir until a colloid is formed.

[0035] After drying the colloid, it was mixed with kaolin, with the amount of kaolin being 50 wt% of the colloid mass. The mixture was then kneaded, extruded into a clover shape, dried at 120°C for 8 hours, and then calcined at 650°C for 5 hours in a tube furnace under air atmosphere to obtain the carrier.

[0036] (2) Weigh the corresponding nitrates according to the molar ratio of metals Ni, Mn, Zn and Ca in the nitrates of nickel salt, manganese salt, zinc salt and calcium salt as 5:1:0.5:0.05, and dissolve them in deionized water to obtain a salt solution. Add n-hexane to the salt solution to prepare an impregnation solution. The volume of n-hexane is 0.5% of the volume of the salt solution. Place the support in the impregnation solution and impregnate it by volume for 12 hours. Then wash it with deionized water, dry it in a vacuum drying oven at 100°C for 15 hours, and then calcine it in an air atmosphere at 700°C for 4 hours to obtain the catalyst.

[0037] Example 3

[0038] Fly ash was passed through a 40-mesh sieve to obtain fly ash with uniform particle size. Then, fly ash, deionized water and N-methyldiethanolamine were mixed and placed in a high-pressure reactor lined with polytetrafluoroethylene. The volume ratio of N-methyldiethanolamine to deionized water was 0.5:10, and the fly ash was 40% of the mass of deionized water. The reaction conditions were 105℃ for 12 hours. After the reaction was completed, the reaction solution was cooled to room temperature, filtered to remove the supernatant, washed with deionized water, and the precipitate was collected by centrifugation. The obtained precipitate was dried at 110℃ for 12 hours to obtain pretreated fly ash.

[0039] (1) After mixing the pretreated fly ash and boehmite, add deionized water and nitric acid. The mass ratio of the pretreated fly ash to boehmite is 1:10. The amount of deionized water is 2.5 times the total mass of fly ash and boehmite. The nitric acid concentration is 6 mol / L to adjust the final pH to 4.5. Then stir until a colloid is formed.

[0040] After drying the colloid, it was mixed with kaolin at a mass of 40 wt% of the colloid. The mixture was then kneaded, extruded into a clover shape, dried at 120°C for 8 hours, and then calcined at 650°C for 5 hours in a tube furnace under air atmosphere to obtain the carrier.

[0041] (2) Weigh the corresponding nitrates according to the molar ratio of metals Ni, Mn, Zn and Ca in the nitrates of nickel salt, manganese salt, zinc salt and calcium salt as 5:2:2:0.05, and dissolve them in deionized water to obtain a salt solution. Add n-hexane to the salt solution to prepare an impregnation solution. The volume of n-hexane is 1% of the volume of the salt solution. Place the support in the impregnation solution and impregnate it by volume for 10 hours. Then wash it with deionized water, dry it in a vacuum drying oven at 100°C for 8 hours, and then calcine it in an air atmosphere at 700°C for 4 hours to obtain the catalyst.

[0042] Example 4

[0043] Fly ash was passed through a 40-mesh sieve to obtain fly ash with uniform particle size. Then, fly ash, deionized water and N-methyldiethanolamine were mixed and placed in a high-pressure reactor lined with polytetrafluoroethylene. The volume ratio of N-methyldiethanolamine to deionized water was 0.5:10, and the fly ash was 40% of the mass of deionized water. The reaction conditions were 105℃ for 12 hours. After the reaction was completed, the reaction solution was cooled to room temperature, filtered to remove the supernatant, washed with deionized water, and the precipitate was collected by centrifugation. The obtained precipitate was dried at 110℃ for 12 hours to obtain pretreated fly ash.

[0044] (1) After mixing the pretreated fly ash and boehmite, add deionized water and nitric acid. The mass ratio of the pretreated fly ash to boehmite is 1:5. The amount of deionized water is 2.5 times the total mass of fly ash and boehmite. The nitric acid is 6 mol / L to adjust the final pH to 5.5. Then stir until a colloid is formed.

[0045] After drying the colloid, it was mixed with kaolin at a ratio of 35 wt% of the colloid mass. The mixture was then kneaded, extruded into a clover shape, dried at 120°C for 8 hours, and then calcined at 650°C for 5 hours in a tube furnace under air atmosphere to obtain the carrier.

[0046] (2) Weigh the corresponding nitrates according to the molar ratio of metals Ni, Mn, Zn and Ca in the nitrates of nickel salt, manganese salt, zinc salt and calcium salt as 5:0.1:0.1:0.05, and dissolve them in deionized water to obtain a salt solution. Add n-hexane to the salt solution to prepare an impregnation solution. The volume of n-hexane is 1% of the volume of the salt solution. Place the support in the impregnation solution and impregnate it by volume for 15 hours. Then wash it with deionized water, dry it in a vacuum drying oven at 100°C for 8 hours, and then calcine it in an air atmosphere at 700°C for 7 hours to obtain the catalyst.

[0047] Comparative Example 1

[0048] Similar to Example 1, except that the fly ash is not pretreated and is directly passed through a 40-mesh sieve before being used to prepare the carrier.

[0049] Comparative Example 2

[0050] Same as Example 1, except that the mass ratio of pretreated fly ash and pseudoboehmite in step (1) is 0.5:5.

[0051] Comparative Example 3

[0052] Same as Example 1, except that the amount of kaolin used in step (1) is 20 wt% of the colloid mass.

[0053] Comparative Example 4

[0054] Same as Example 1, except that there is no calcium salt in step (2).

[0055] Comparative Example 5

[0056] Same as Example 1, except that in step (3), the volume of n-hexane in the impregnation solution is 5% of the volume of the salt solution.

[0057] Catalyst activity determination method

[0058] The prepared catalyst was reduced using hydrogen gas as the reduction medium at a reduction temperature of 500°C and a hydrogen space velocity of 6000 h⁻¹. -1 Restoring for 10 hours.

[0059] The reaction was carried out in a tubular reactor used in the laboratory. 50 mL of crude octanol feedstock solution was measured and placed in the reactor. The ratio of 2-ethylhexenal to 2-ethylhexanol in the crude octanol feedstock solution was 1:4. 5 g of catalyst was added. The reaction temperature was 110℃, the reaction time was 5 h, the reaction pressure was 4.0 MPa, and the liquid hourly space velocity (LISH) of the crude octanol feedstock solution was 1.1 h⁻¹. -1 The detailed composition of the materials before and after analysis was determined by gas chromatography. The gas chromatography instrument used was a Shimadzu GC-1000 gas chromatograph from Japan, and the normalization method was employed.

[0060] The specific test results are shown in Table 1 below.

[0061] Table 1

[0062] experiment 2-Ethylhexenal conversion rate 2-Ethylhexanol Selectivity Example 1 98.7% 99.3% Example 2 97.9% 99.5% Example 3 99.5% 99.8% Example 4 99.2% 99.3% Comparative Example 1 90.7% 95.2% Comparative Example 2 95.3% 94.6% Comparative Example 3 93.9% 91.8% Comparative Example 4 95.5% 83.2% Comparative Example 5 84.8% 93.1%

[0063] As can be seen from the test results in Table 1 above, since metal salts are important elements that determine the final activity and selectivity of catalysts, when calcium salts are not added as an additive, the selectivity decreases significantly, but the activity is not significantly affected; when the amount of n-hexane added to the impregnation solution exceeds a certain range, the activity of the catalyst decreases significantly.

[0064] The specific test method for detecting the stability of the catalyst is as follows.

[0065] The prepared catalyst was evaluated after 500 hours of operation under the same reaction conditions as the catalyst activity determination method. The composition of the hydrogenated material was analyzed by chromatography, and the results are shown in Table 2.

[0066] Table 2

[0067] project Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 6 5h-2-Ethylhexenal conversion rate 98.7% 90.7% 95.3% 93.9% 500h-2-Ethylhexenal conversion rate 97.1% 75.6% 85.1% 81.4%

[0068] As shown in Table 2 above, the catalyst prepared in Example 1 maintained high activity and exhibited excellent stability after 500 hours of use. In contrast, the activity of fly ash without pretreatment decreased by 16.6% after 500 hours. Furthermore, changes in the mass ratio of fly ash to boehmite and the amount of kaolin used during support preparation also significantly affected the stability of the catalyst.

Claims

1. A method for preparing a catalyst for the liquid-phase hydrogenation refining of crude octanol, characterized in that, The preparation method includes the following steps: (1) After mixing the pretreated fly ash and pseudoboehmite, add deionized water and nitric acid, stir until a colloid is formed, dry the colloid and mix it with kaolin, knead, extrude and mold, dry and calcine to obtain the carrier; (2) Nickel salt, manganese salt and zinc salt are used as active components, and calcium salt is used as auxiliary components. The active components and auxiliary components are dissolved in deionized water to obtain a salt solution. Hexane is added to the salt solution and stirred evenly to prepare an impregnation solution. The carrier is placed in the impregnation solution for impregnation, and then the catalyst is obtained after washing, drying and calcination. The method for pretreating fly ash is as follows: fly ash is sieved to obtain fly ash with uniform particle size, then fly ash, deionized water and N-methyldiethanolamine are mixed and placed in a hydrothermal reactor, and after the reaction is completed, the mixture is filtered and dried to obtain pretreated fly ash; The mass ratio of the pretreated fly ash to boehmite is 1:(5-8); the amount of kaolin used is 35-50 wt% of the colloid mass; the volume of n-hexane is 0.5-2% of the volume of the salt solution. The hydrothermal reaction conditions were as follows: the reaction was carried out at 105°C for 12 hours in a high-pressure reactor lined with polytetrafluoroethylene; after the hydrothermal reaction, the reaction solution was cooled to room temperature, filtered to remove the supernatant, washed with deionized water, centrifuged to collect the precipitate, and the obtained precipitate was dried.

2. The method for preparing the catalyst for liquid-phase hydrogenation refining of crude octanol according to claim 1, characterized in that, The volume ratio of N-methyldiethanolamine to deionized water is 0.5:

10.

3. The method for preparing the catalyst for liquid-phase hydrogenation refining of crude octanol according to claim 1, characterized in that, The amount of kaolin used is 40 wt% of the colloid mass.

4. The method for preparing the catalyst for liquid-phase hydrogenation refining of crude octanol according to claim 1, characterized in that, The nickel salt, manganese salt, zinc salt, and calcium salt are nitrates, and the molar ratio of metals Ni, Mn, Zn, and Ca in the nickel salt, manganese salt, zinc salt, and calcium salt is 5:0.1-2:0.1-2:0.

05.

5. The method for preparing the catalyst for liquid-phase hydrogenation refining of crude octanol according to claim 1, characterized in that, The volume of the n-hexane is 1% of the volume of the salt solution.

6. The method for preparing the catalyst for liquid-phase hydrogenation refining of crude octanol according to claim 1, characterized in that, The impregnation is a volume impregnation, and the impregnation time is 10-15 hours. In step (2), the roasting is carried out in a muffle furnace at 700°C for 4-7 hours.

7. The crude octanol liquid-phase hydrogenation catalyst prepared according to the preparation method of any one of claims 1-6.