A process for the production of n-butenes from iso-butenes
The preparation and application of MgAl2O4 hierarchical porous molecular sieve catalysts have solved the problems of low efficiency and high cost in the preparation of n-butene by isobutene ortho-configuration, and have achieved efficient and stable n-butene production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2024-12-02
- Publication Date
- 2026-06-02
AI Technical Summary
In the existing technology, the method for preparing n-butene by isobutene ortho-configuration suffers from high catalyst cost and low efficiency, and there are few methods for ortho-configuration of C4 olefin skeletons, resulting in poor economic efficiency of n-butene production.
A MgAl2O4 hierarchical porous molecular sieve catalyst was prepared by alkali treatment, acid treatment and high-temperature solid-phase synthesis. The catalyst was used for the reaction of isobutylene to n-butene, which improved the catalyst activity and stability.
It achieves high efficiency and high yield in the preparation of n-butene from isobutene, with excellent catalyst activity and stability, making it suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] This application relates to a method for preparing n-butene from isobutene, which belongs to the field of chemical engineering. Background Technology
[0002] Isobutene isobutene, specifically n-butene, is an important petrochemical feedstock. It can undergo alkylation with isobutane under acid catalysis to produce alkylated oils. Alkylated oils have high octane ratings and are free of olefins and aromatics, making them ideal high-octane gasoline blending components. In recent years, with the accelerated pace of gasoline upgrading in my country and the requirement to reduce olefins and aromatics in gasoline, alkylation plants have been installed on a large scale across the country. This has led to a rapid increase in the demand for n-butene, one of the alkylation feedstocks, resulting in a growing supply-demand imbalance.
[0003] Currently, there are two main production routes for n-butene in China: a dimerization process using ethylene as feedstock, and an extraction or separation process using C4 fraction as feedstock. The C4 fraction extraction process is further divided into oil refining-type C4 extraction and coal-to-olefins C4 extraction. Currently, domestic n-butene is mainly produced using C4 separation processes, with byproducts including 2-butene, n-butane, and isobutane, depending on the distillation range. Although some companies have ethylene dimerization production units, the relatively high price of ethylene makes the equipment uneconomical, and actual production is not optimistic. In recent years, domestic and foreign petrochemical companies have shown great interest in the process of producing n-butene from isobutene. The catalyst used is a key aspect of this process. Because isobutene was previously considered more valuable than n-butene, research and published patents have focused on the skeletal isomerization of n-butene to prepare isobutene. There are currently few reported and published articles and patents on the ortho-skeletal isomerization of C4 olefins. Furthermore, the existing methods for ortho-articulation of C4 olefin skeletons generally use oxide-supported active metal components as isobutylene ortho-articulation catalysts. Summary of the Invention
[0004] To address the aforementioned issues, this application provides a method for preparing MgAl2O4 hierarchical porous molecular sieves, and applies this catalyst in the reaction of isobutene to n-butene.
[0005] According to one aspect of this application, a method for preparing n-butene from isobutene is provided, comprising the following steps:
[0006] The raw material containing isobutylene is contacted with a catalyst and reacted to obtain a product containing n-butene.
[0007] The catalyst is composed of MgAl2O4 and hierarchical porous molecular sieve;
[0008] The mass fraction of MgAl2O4 is 5–35 wt%.
[0009] Optionally, the mass fraction of MgAl2O4 is at least one of 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, or a range between any two.
[0010] The catalyst is obtained through the following steps:
[0011] 1) The molecular sieve is subjected to alkali treatment and acid treatment in sequence to obtain the porous molecular sieve;
[0012] 2) Mix magnesium source and aluminum source wet, calcine to obtain MgAl2O4;
[0013] 3) The porous molecular sieve is mixed with the MgAl2O4 and calcined to obtain the catalyst.
[0014] The molecular sieve is selected from ZSM-35 molecular sieve and / or ZSM-5 molecular sieve;
[0015] The alkaline treatment includes the following steps:
[0016] Molecular sieves are immersed in NaAlO2 solution, treated at 65-90℃ for 1-5 hours, filtered 2-4 times, washed until neutral, dried, and calcined to obtain alkali-treated molecular sieves.
[0017] Optionally, the immersion temperature is at least one of 65°C, 70°C, 75°C, 80°C, 85°C, and 90°C, or a range between any two.
[0018] Optionally, the soaking time is at least one of 1h, 3h, and 5h, or a range between any two.
[0019] Optionally, the number of filtrations is at least one of 2, 3, or 4 times, or a range between any two.
[0020] The concentration of the NaAlO2 solution is 0.2–0.6 mol / L;
[0021] Optionally, the concentration of the NaAlO2 solution is at least one of 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, and 0.6 mol / L, or a range between any two.
[0022] The solid-liquid ratio of the molecular sieve to the NaAlO2 solution is 1:5-10 g / ml;
[0023] Optionally, the solid-liquid ratio of the molecular sieve to the NaAlO2 solution is at least one of 1:5 g / ml, 1:6 g / ml, 1:7 g / ml, 1:8 g / ml, 1:9 g / ml, 1:10 g / ml, or any value between two of these.
[0024] The temperature of the drying process I is 80–130°C;
[0025] Optionally, the temperature of the drying I is at least one of 80°C, 90°C, 100°C, 110°C, 120°C, and 130°C, or a range between any two.
[0026] The drying time for step I is 8–24 hours;
[0027] Optionally, the drying time I is at least one of 8h, 16h, and 24h, or a range between any two.
[0028] The calcination temperature I is 450–650°C;
[0029] Optionally, the calcination temperature I is at least one of 450°C, 550°C, and 650°C, or a range between any two.
[0030] The calcination time is 1 to 6 hours.
[0031] Optionally, the calcination time I is at least one of 1h, 2h, 3h, 4h, 5h, and 6h, or a range between any two.
[0032] The acid treatment includes the following steps:
[0033] The alkali-treated molecular sieve is immersed in hydrochloric acid and treated at 65-90°C for 0.5-1.5 hours. It is then filtered 2-4 times, washed until neutral, dried (II), and calcined (II) to obtain the porous molecular sieve.
[0034] Optionally, the immersion temperature is at least one of 65°C, 70°C, 75°C, 80°C, 85°C, and 90°C, or a range between any two.
[0035] Optionally, the immersion time is at least one of 0.5h, 1h, 1.5h, or a range between any two.
[0036] Optionally, the number of filtrations is at least one of 2, 3, or 4 times, or a range between any two.
[0037] The concentration of the hydrochloric acid is 1–4 mol / L;
[0038] Optionally, the concentration of the hydrochloric acid is at least one of 1 mol / L, 2 mol / L, 3 mol / L, and 4 mol / L, or a range between any two.
[0039] The solid-liquid ratio of the alkali-treated molecular sieve to hydrochloric acid is 1:5-10 g / ml;
[0040] Optionally, the solid-liquid ratio of the alkali-treated molecular sieve to hydrochloric acid is at least one of 1:5 g / ml, 1:6 g / ml, 1:7 g / ml, 1:8 g / ml, 1:9 g / ml, 1:10 g / ml, or any combination thereof.
[0041] The temperature of the drying II process is 80–130°C;
[0042] Optionally, the temperature of the drying II is at least one of 80°C, 90°C, 100°C, 110°C, 120°C, and 130°C, or a range between any two.
[0043] The drying time for step II is 8–24 hours;
[0044] Optionally, the drying time II is at least one of 8h, 16h, and 24h, or a range between any two.
[0045] The calcination temperature II is 450–650°C;
[0046] Optionally, the calcination temperature II is at least one of 450°C, 550°C, and 650°C, or a range between any two.
[0047] The calcination time II is 1 to 6 hours.
[0048] Optionally, the calcination time II is at least one of 1h, 2h, 3h, 4h, 5h, and 6h, or a range between any two.
[0049] The wet mixing process includes the following steps:
[0050] The magnesium source, aluminum source and solvent are mixed, ground for 30-60 min, dried (III), and calcined (III) to obtain MgAl2O4;
[0051] The magnesium source is selected from at least one of magnesium nitrate, magnesium acetate, and magnesium hydroxide.
[0052] The aluminum source is selected from at least one of aluminum nitrate and aluminum oxide;
[0053] The solvent is selected from at least one of deionized water, ethanol, and a mixed solution of ethanol and deionized water;
[0054] The molar ratio of the magnesium source to the aluminum source is 1:1.9 to 2, based on the molar amounts of magnesium and aluminum.
[0055] Optionally, the molar ratio of the magnesium source to the aluminum source is at least one of 1:1.9, 1:1.95, 1:2, or any value between two of them.
[0056] The total mass of the magnesium source and aluminum source is in a solid-liquid ratio of 1:2 to 3 g / ml to the solvent.
[0057] Optionally, the total mass of the magnesium source and aluminum source to the solid-liquid ratio of the solvent is at least one of 1:2 g / ml, 1:2.5 g / ml, 1:3 g / ml, or any combination thereof.
[0058] The temperature of the drying III process is 80–130°C;
[0059] Optionally, the temperature of the drying III is at least one of 80°C, 90°C, 100°C, 110°C, 120°C, and 130°C, or a range between any two.
[0060] The drying time for step III is 6–24 hours;
[0061] Optionally, the drying time III is at least one of 6h, 12h, 18h, and 24h, or a range between any two.
[0062] The calcination temperature III is 600–1200°C;
[0063] Optionally, the calcination temperature III is at least one of 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C, and 1200°C, or a range between any two of them.
[0064] The calcination time for the third stage is 12–24 hours.
[0065] Optionally, the calcination time III is at least one of 12h, 18h, and 24h, or a range between any two.
[0066] The mixing is either mechanical mixing or wet mixing.
[0067] The roasting temperature is 500–600°C;
[0068] Optionally, the calcination temperature is at least one of 500°C, 550°C, and 600°C, or a range between any two.
[0069] The roasting time is 2 to 6 hours.
[0070] Optionally, the roasting time is at least one of 2h, 3h, 4h, 5h, and 6h, or a range between any two.
[0071] In the raw material containing isobutylene, the mass hourly space velocity (HHSV) of isobutylene is 4–6 h⁻¹. -1 ;
[0072] Optionally, the mass hourly space velocity (MSV) of the isobutylene is 4 h⁻¹.-1 5h -1 6h -1 The range of values between at least one or any two of them.
[0073] The reaction temperature is 300–360°C;
[0074] Optionally, the temperature of the reaction is at least one or a range between any two of 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, and 360°C.
[0075] The reaction pressure is 0.05–0.15 MPa.
[0076] Optionally, the pressure of the reaction is at least one of 0.05 MPa, 0.1 MPa, 0.15 MPa, or a range between any two.
[0077] The beneficial effects that this application can produce include:
[0078] 1) The catalyst provided in this application can be applied to the reaction of isobutylene to n-butene, and the prepared MgAl2O4 hierarchical porous molecular sieve has excellent catalytic activity and stability.
[0079] 2) The preparation method of the catalyst provided in this application is stable, controllable, and reproducible.
[0080] 3) The method for preparing n-butene from isobutylene provided in this application uses the catalyst provided in this application, which has a fast reaction rate and high yield, and can be applied to large-scale production.
[0081] 4) Compared with the severe desilication of NaOH, the NaAlO2 solution used in this application for alkaline treatment is relatively mild, and slight etching keeps the molecular sieve structure intact; acid treatment makes it easier to wash away the amorphous aluminum and silicon decomposed from Al(OH)3 and silicates on the surface of the molecular sieve, and the hierarchical porous molecular sieve is more conducive to the diffusion of raw material molecules; the MgAl2O4 synthesized by the high-temperature solid-phase synthesis method has a high degree of crystallinity, which can improve the reaction stability. Detailed Implementation
[0082] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0083] Unless otherwise specified, the raw materials used in the embodiments of this application were purchased commercially or prepared by known methods. Unless otherwise specified, the analytical methods used in the embodiments employed conventional instrument settings and conventional analytical methods.
[0084] In the embodiments of this application, the initial ZSM-35 molecular sieve or ZSM-5 molecular sieve was produced by the catalyst factory of Nankai University.
[0085] Gas chromatography characterization
[0086] The composition of the products from the reaction of isobutylene to n-butene was analyzed using an Agilent 7890B gas chromatograph (FID detector, Pona column).
[0087] Example 1: Preparation of Catalyst
[0088] Maintaining the solution temperature at 80℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:8 was treated with a 0.5 mol / L NaAlO2 solution for 3 hours, washed three times until neutral, dried at 120℃ for 12 hours, and calcined at 500℃ for 6 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 70℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:8 was treated with a 2 mol / L HCl solution for 1.5 hours, washed three times, dried at 120℃ for 12 hours, and calcined at 500℃ for 6 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium nitrate and aluminum nitrate with a Mg / Al molar ratio of 1:2 were mixed with ethanol solvent (solid-liquid ratio 1:2), ground for 40 minutes, dried at 120℃ for 12 hours, and calcined at 1100℃. After 20 hours, MgAl2O4 material was obtained; 15 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 500℃ for 6 hours, which was designated as catalyst 1. # .
[0089] Example 2 Preparation of Catalyst
[0090] Maintaining the solution temperature at 70℃, ZSM-5 molecular sieve with a solid-liquid ratio (g / ml) of 1:6 was treated with a 0.3 mol / L NaAlO2 solution for 2 hours, washed twice until neutral, and dried at 100℃ for 22 hours and calcined at 550℃ for 3 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 80℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:6 was treated with a 1 mol / L HCl solution for 1 hour, washed twice, and dried at 100℃ for 22 hours and calcined at 550℃ for 3 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium acetate and aluminum nitrate with a Mg / Al molar ratio of 1:1.95 were mixed with deionized water solvent (solid-liquid ratio 1:2.5), ground for 50 minutes, dried at 100℃ for 22 hours and calcined at 900℃. After 22 hours, MgAl2O4 material was obtained; 25 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by mechanical mixing and calcined at 550℃ for 3 hours, denoted as catalyst 2. # .
[0091] Example 3: Preparation of Catalyst
[0092] Maintaining the solution temperature at 85℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:9 was treated with a 0.2 mol / L NaAlO2 solution for 1 hour, washed four times until neutral, dried at 130℃ for 14 hours, and calcined at 600℃ for 4 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 65℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:9 was treated with a 3 mol / L HCl solution for 0.5 hours, washed four times, dried at 130℃ for 14 hours, and calcined at 600℃ for 4 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium hydroxide and aluminum oxide with a Mg / Al molar ratio of 1:1.9 were mixed with ethanol + deionized water solvent (solid-liquid ratio 1:3), ground for 55 minutes, dried at 130℃ for 14 hours, and calcined at 700℃. After 24 hours, MgAl2O4 material was obtained; 20 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 600℃ for 2 hours, which was designated as catalyst 3. # .
[0093] Example 4: Preparation of Catalyst
[0094] Maintaining the solution temperature at 75℃, ZSM-5 molecular sieves with a solid-liquid ratio (g / ml) of 1:7 were treated with a 0.4 mol / L NaAlO2 solution for 5 hours, washed twice until neutral, dried at 90℃ for 20 hours, and calcined at 450℃ for 2 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 75℃, the Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:7 was treated with a 4 mol / L HCl solution for 1 hour, washed twice, dried at 90℃ for 20 hours, and calcined at 450℃ for 2 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium nitrate and aluminum nitrate with a Mg / Al molar ratio of 1:1.95 were mixed with ethanol solvent (solid-liquid ratio 1:2), ground for 45 minutes, dried at 90℃ for 20 hours, and calcined at 1200℃. After 12 hours, MgAl2O4 material was obtained; 10 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 500℃ for 4 hours, which was designated as catalyst 4. # .
[0095] Example 5: Preparation of Catalyst
[0096] Maintaining the solution temperature at 90℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:5 was treated with a 0.6 mol / L NaAlO2 solution for 4 hours, washed three times until neutral, dried at 80℃ for 10 hours, and calcined at 650℃ for 1 hour to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 85℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:5 was treated with a 2 mol / L HCl solution for 1.5 hours, washed three times, dried at 80℃ for 10 hours, and calcined at 650℃ for 1 hour to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium nitrate and alumina with a Mg / Al molar ratio of 1:2 were mixed with ethanol + deionized water solvent (solid-liquid ratio 1:3), ground for 30 minutes, dried at 80℃ for 10 hours, and calcined at 1000℃. After 16 hours, MgAl2O4 material was obtained; 5 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by mechanical mixing and calcined at 550℃ for 5 hours, denoted as catalyst 5. # .
[0097] Example 6 Preparation of Catalyst
[0098] Maintaining the solution temperature at 65℃, ZSM-5 molecular sieve with a solid-liquid ratio (g / ml) of 1:10 was treated with a 0.2 mol / L NaAlO2 solution for 3 hours, washed 4 times until neutral, dried at 110℃ for 24 hours, and calcined at 500℃ for 5 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 90℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:10 was treated with a 4 mol / L HCl solution for 0.5 hours, washed 4 times, dried at 110℃ for 24 hours, and calcined at 500℃ for 5 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium acetate and aluminum nitrate with a Mg / Al molar ratio of 1:1.9 were mixed with deionized water solvent (solid-liquid ratio 1:2.5), ground for 60 minutes, dried at 110℃ for 24 hours, and calcined at 800℃ for 3 hours. After 18 hours, MgAl2O4 material was obtained; MgAl2O4 with a content of 35wt% was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 600℃ for 4 hours, which was designated as catalyst 6. # .
[0099] Example 7 Preparation of Catalyst
[0100] Maintaining the solution temperature at 75℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:8 was treated with a 0.5 mol / L NaAlO2 solution for 5 hours, washed twice until neutral, dried at 110℃ for 16 hours, and calcined at 650℃ for 6 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 70℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:8 was treated with a 3 mol / L HCl solution for 1 hour, washed twice, dried at 110℃ for 16 hours, and calcined at 650℃ for 6 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium hydroxide and aluminum oxide with a Mg / Al molar ratio of 1:2 were mixed with ethanol + deionized water solvent (solid-liquid ratio 1:2.5), ground for 35 minutes, dried at 110℃ for 16 hours, and calcined at 600℃. After 20 hours, MgAl2O4 material was obtained; 30 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by mechanical mixing and calcined at 500℃ for 3 hours, which was designated as catalyst 7. # .
[0101] Example 8 Preparation of Catalyst
[0102] Maintaining the solution temperature at 80℃, ZSM-5 molecular sieve with a solid-liquid ratio (g / ml) of 1:7 was treated with a 0.6 mol / L NaAlO2 solution for 2 hours, washed three times until neutral, dried at 100℃ for 18 hours, and calcined at 550℃ for 2 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 65℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:7 was treated with a 1 mol / L HCl solution for 1.5 hours, washed three times, dried at 100℃ for 18 hours, and calcined at 550℃ for 2 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium acetate and aluminum nitrate with a Mg / Al molar ratio of 1:2 were mixed with ethanol solvent (solid-liquid ratio 1:2), ground for 40 minutes, dried at 100℃ for 18 hours, and calcined at 1100℃. After 16 hours, MgAl2O4 material was obtained; 10 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 600℃ for 5 hours, which was designated as catalyst 8. # .
[0103] Example 9 Preparation of Catalyst
[0104] Maintaining the solution temperature at 90℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:6 was treated with a 0.3 mol / L NaAlO2 solution for 1 hour, washed four times until neutral, dried at 120℃ for 8 hours, and calcined at 600℃ for 3 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 85℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:6 was treated with a 4 mol / L HCl solution for 0.5 hours, washed four times, dried at 120℃ for 8 hours, and calcined at 600℃ for 3 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium nitrate and alumina with a Mg / Al molar ratio of 1:1.9 were mixed with ethanol + deionized water solvent (solid-liquid ratio 1:3), ground for 50 minutes, dried at 120℃ for 8 hours, and calcined at 1000℃. After 14 hours, MgAl2O4 material was obtained; 20 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 550℃ for 2 hours, which was designated as catalyst 9. # .
[0105] Example 10 Preparation of Catalyst
[0106] Maintaining the solution temperature at 85℃, ZSM-5 molecular sieves with a solid-liquid ratio (g / ml) of 1:9 were treated with a 0.4 mol / L NaAlO2 solution for 4 hours, washed three times until neutral, dried at 130℃ for 12 hours, and calcined at 450℃ for 4 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 80℃, Na-type hierarchical porous molecular sieve materials with a solid-liquid ratio (g / ml) of 1:9 were treated with a 2 mol / L HCl solution for 0.5 hours, washed three times, dried at 130℃ for 12 hours, and calcined at 450℃ for 4 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium hydroxide and aluminum oxide with a Mg / Al molar ratio of 1:1.95 were mixed with deionized water solvent (solid-liquid ratio 1:3), ground for 60 minutes, dried at 130℃ for 12 hours, and calcined at 900℃. After 24 hours, MgAl2O4 material was obtained; 25 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by mechanical mixing and calcined at 500℃ for 6 hours, which was designated as catalyst 10. # .
[0107] Example 11 Preparation of Catalyst
[0108] Maintaining the solution temperature at 70℃, ZSM-5 molecular sieve with a solid-liquid ratio (g / ml) of 1:5 was treated with a 0.2 mol / L NaAlO2 solution for 3 hours, washed 4 times until neutral, dried at 80℃ for 20 hours, and calcined at 500℃ for 1 hour to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 75℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:5 was treated with a 1 mol / L HCl solution for 1.5 hours, washed 4 times, dried at 80℃ for 20 hours, and calcined at 500℃ for 1 hour to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium nitrate and aluminum nitrate with a Mg / Al molar ratio of 1:1.95 were mixed with deionized water solvent (solid-liquid ratio 1:2), ground for 55 minutes, dried at 80℃ for 20 hours, and calcined at 800℃. After 22 hours, MgAl2O4 material was obtained; 15 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 550℃ for 3 hours, which was designated as catalyst 11. # .
[0109] Example 12 Preparation of Catalyst
[0110] Maintaining the solution temperature at 65℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:10 was treated with a 0.3 mol / L NaAlO2 solution for 1 hour, washed twice until neutral, dried at 90℃ for 14 hours, and calcined at 450℃ for 5 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 90℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:10 was treated with a 3 mol / L HCl solution for 0.5 hours, washed twice, dried at 90℃ for 14 hours, and calcined at 450℃ for 5 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium acetate and alumina with a Mg / Al molar ratio of 1:1.9 were mixed with ethanol + deionized water solvent (solid-liquid ratio 1:2.5), ground for 45 minutes, dried at 90℃ for 14 hours, and calcined at 700℃. After 18 hours, MgAl2O4 material was obtained; 30 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by mechanical mixing and calcined at 600℃ for 6 hours, which was designated as catalyst 12. # .
[0111] Example 13 Preparation of Catalyst
[0112] Maintaining the solution temperature at 80℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:7 was treated with a 0.5 mol / L NaAlO2 solution for 4 hours, washed three times until neutral, dried at 120℃ for 16 hours, and calcined at 600℃ for 3 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 75℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:7 was treated with a 2 mol / L HCl solution for 1 hour, washed three times, dried at 120℃ for 16 hours, and calcined at 600℃ for 3 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium hydroxide and aluminum nitrate with a Mg / Al molar ratio of 1:2 were mixed with ethanol solvent (solid-liquid ratio 1:3), ground for 30 minutes, dried at 120℃ for 16 hours, and calcined at 1200℃. After 12 hours, MgAl2O4 material was obtained; 5 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by mechanical mixing and calcined at 550℃ for 4 hours, which was designated as catalyst 13. # .
[0113] Example 14 Preparation of Catalyst
[0114] Maintaining the solution temperature at 75℃, ZSM-5 molecular sieves with a solid-liquid ratio (g / ml) of 1:8 were treated with a 0.4 mol / L NaAlO2 solution for 2 hours, washed twice until neutral, and dried at 110℃ for 22 hours and calcined at 550℃ for 4 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 70℃, Na-type hierarchical porous molecular sieve materials with a solid-liquid ratio (g / ml) of 1:8 were treated with a 4 mol / L HCl solution for 1.5 hours, washed twice, and dried at 110℃ for 22 hours and calcined at 550℃ for 4 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium acetate and alumina with a Mg / Al molar ratio of 1:1.9 were mixed with ethanol solvent (solid-liquid ratio 1:2.5), ground for 35 minutes, dried at 110℃ for 22 hours and calcined at 1100℃ for 3 hours. After 16 hours, MgAl2O4 material was obtained; MgAl2O4 with a content of 35 wt% was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 500℃ for 5 hours, which was designated as catalyst 14. # .
[0115] Example 15 Preparation of Catalyst
[0116] Maintaining the solution temperature at 85℃, ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:9 was treated with a 0.6 mol / L NaAlO2 solution for 5 hours, washed four times until neutral, dried at 100℃ for 10 hours, and calcined at 650℃ for 5 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 80℃, the Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:9 was treated with a 1 mol / L HCl solution for 1.5 hours, washed four times, dried at 100℃ for 10 hours, and calcined at 650℃ for 5 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium nitrate and alumina with a Mg / Al molar ratio of 1:1.95 were mixed with deionized water solvent (solid-liquid ratio 1:2), ground for 40 minutes, dried at 100℃ for 10 hours, and calcined at 600℃. After 24 hours, MgAl2O4 material was obtained; 15 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by mechanical mixing and calcined at 600℃ for 3 hours, which was designated as catalyst 15. # .
[0117] Example 16 Preparation of Catalyst
[0118] Maintaining the solution temperature at 70℃, ZSM-5 molecular sieve with a solid-liquid ratio (g / ml) of 1:5 was treated with a 0.5 mol / L NaAlO2 solution for 3 hours, washed three times until neutral, dried at 90℃ for 12 hours, and calcined at 500℃ for 6 hours to obtain Na-type hierarchical porous molecular sieve material. Maintaining the solution temperature at 70℃, Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:5 was treated with a 3 mol / L HCl solution for 1 hour, washed three times, dried at 90℃ for 12 hours, and calcined at 500℃ for 6 hours to obtain hydrogen-type hierarchical porous molecular sieve material. Magnesium hydroxide and aluminum nitrate with a Mg / Al molar ratio of 1:2 were mixed with ethanol + deionized water solvent (solid-liquid ratio 1:2.5), ground for 45 minutes, dried at 90℃ for 12 hours, and calcined at 1100℃. After 24 hours, MgAl2O4 material was obtained; 20 wt% MgAl2O4 was mixed with the synthesized hierarchical porous molecular sieve by wet mixing and calcined at 500℃ for 2 hours, which was designated as catalyst 16. # .
[0119] Comparative Example 1
[0120] This embodiment differs from Example 1 in that it does not include the preparation process of MgAl2O4, but is otherwise the same as Example 1. Specifically, the solution temperature is maintained at 80°C, and the ZSM-35 molecular sieve with a solid-liquid ratio (g / ml) of 1:8 is treated with a 0.5 mol / L NaAlO2 solution for 3 hours, washed 3 times until neutral, dried at 120°C for 12 hours, and calcined at 500°C for 6 hours to obtain Na-type hierarchical porous molecular sieve material. The solution temperature is maintained at 70°C, and the Na-type hierarchical porous molecular sieve material with a solid-liquid ratio (g / ml) of 1:8 is treated with a 2 mol / L HCl solution for 1.5 hours, washed 3 times, dried at 120°C for 12 hours, and calcined at 500°C for 6 hours to obtain hydrogen-type hierarchical porous molecular sieve material, denoted as Catalyst 17. # .
[0121] Evaluation of the reaction of the catalyst in the test case
[0122] The catalyst 1 obtained above # ~17 # It is applied to the reaction of isobutylene to n-butene, and the reaction conditions are shown in Table 1.
[0123] Catalyst 1, which has been tableted, pulverized, and sieved, # Up to 17 # The feedstock is loaded into a fixed-bed reactor, heated to the reaction temperature, and then pumped in.
[0124] The composition of the products was analyzed using an Agilent 7890B gas chromatograph (FID detector, Pona column), and the results are shown in Table 1.
[0125] Table 1 Catalyst 1 # ~16 # Catalyst and Comparative Catalyst 17 # Reaction conditions and results for the reaction of isobutylene to n-butene.
[0126]
[0127]
[0128] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing n-butene from isobutene, characterized in that, Includes the following steps: The raw material containing isobutylene is contacted with a catalyst and reacted to obtain a product containing n-butene. The catalyst is composed of MgAl2O4 and hierarchical porous molecular sieve; The mass fraction of MgAl2O4 is 5–35 wt%. The molecular sieve is selected from ZSM-35 molecular sieve and / or ZSM-5 molecular sieve.
2. The method according to claim 1, characterized in that, The catalyst is obtained through the following steps: 1) The molecular sieve is subjected to alkali treatment and acid treatment in sequence to obtain the porous molecular sieve; 2) Mix magnesium source and aluminum source wet, calcine to obtain MgAl2O4; 3) The porous molecular sieve is mixed with the MgAl2O4 and calcined to obtain the catalyst.
3. The method according to claim 2, characterized in that, The alkaline treatment includes the following steps: Molecular sieves are immersed in NaAlO2 solution, treated at 65-90℃ for 1-5 hours, filtered 2-4 times, washed until neutral, dried, and calcined to obtain alkali-treated molecular sieves. The concentration of the NaAlO2 solution is 0.2–0.6 mol / L; The solid-liquid ratio of the molecular sieve to the NaAlO2 solution is 1:5-10 g / ml; The temperature of the drying process I is 80–130°C; The drying time for step I is 8–24 hours; The calcination temperature I is 450–650°C; The calcination time is 1 to 6 hours.
4. The method according to claim 2, characterized in that, The acid treatment includes the following steps: The alkali-treated molecular sieve is immersed in hydrochloric acid and treated at 65-90°C for 0.5-1.5 hours. It is then filtered 2-4 times, washed until neutral, dried (II), and calcined (II) to obtain the porous molecular sieve. The concentration of the hydrochloric acid is 1–4 mol / L; The solid-liquid ratio of the alkali-treated molecular sieve to hydrochloric acid is 1:5-10 g / ml; The temperature of the drying II process is 80–130°C; The drying time for step II is 8–24 hours; The calcination temperature II is 450–650°C; The calcination time II is 1 to 6 hours.
5. The method according to claim 2, characterized in that, The wet mixing process includes the following steps: The magnesium source, aluminum source and solvent are mixed, ground for 30-60 min, dried (III), and calcined (III) to obtain MgAl2O4; The magnesium source is selected from at least one of magnesium nitrate, magnesium acetate, and magnesium hydroxide. The aluminum source is selected from at least one of aluminum nitrate and aluminum oxide; The solvent is selected from at least one of deionized water, ethanol, and a mixed solution of ethanol and deionized water; The molar ratio of the magnesium source to the aluminum source is 1:1.9 to 2, based on the molar amounts of magnesium and aluminum. The total mass of the magnesium source and aluminum source is in a solid-liquid ratio of 1:2 to 3 g / ml to the solvent. The temperature of the drying III process is 80–130°C; The drying time for step III is 6–24 hours; The calcination temperature III is 600–1200°C; The calcination time for the third stage is 12–24 hours.
6. The method according to claim 2, characterized in that, The mixing is either mechanical mixing or wet mixing. The roasting temperature is 500–600°C; The roasting time is 2 to 6 hours.
7. The method according to claim 1, characterized in that, In the raw material containing isobutylene, the mass hourly space velocity (HHSV) of isobutylene is 4–6 h⁻¹. -1 ; The reaction temperature is 300–360°C; The reaction pressure is 0.05–0.15 MPa.