Low-carbon alkane dehydrogenation catalyst as well as preparation method and application thereof

Abstract

The invention discloses a low-carbon alkane dehydrogenation catalyst as well as a preparation method and application thereof, and belongs to the technical field of low-carbon alkane dehydrogenation catalysis. ZMQ-1 molecular sieve dispersion liquid is prepared from a ZMQ-1 molecular sieve and an EDTA (Ethylene Diamine Tetraacetic Acid) solution; carrying out electron beam radiation treatment on the ZMQ-1 molecular sieve dispersion liquid; adding a lanthanum compound and a rhodium compound to obtain a mixed solution; and carrying out electron beam radiation treatment on the mixed solution, and carrying out ball dropping forming, drying and roasting to obtain the low-carbon alkane dehydrogenation catalyst. Through the mode, the light alkane dehydrogenation catalyst is obtained by performing electron beam radiation treatment on the ZMQ-1 molecular sieve dispersion liquid, adding lanthanum and rhodium elements according to a reasonable proportion, performing electron beam radiation treatment on the mixed liquid, and performing ball dropping forming, drying and roasting. On the other hand, the whole preparation process is less than 10 hours, the production cycle of the catalyst is shortened, and the energy consumption of the preparation process is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of light alkane dehydrogenation catalysis, and in particular to a light alkane dehydrogenation catalyst, a preparation method and an application thereof. Background Art

[0002] Light olefins are widely used in the production of plastics, synthetic rubber, pharmaceuticals, gasoline additives, ion exchange resins, detergents, fragrances, and various chemical intermediates. Propylene is the most consumed basic organic chemical raw material after ethylene, and propane dehydrogenation is a key method for producing propylene.

[0003] Chinese invention patent CN112007640B discloses a method for preparing a low-carbon alkane dehydrogenation catalyst. First, a Sn-containing alumina carrier is immersed in a mixed solution containing fatty acids, carbodiimide compounds and paraffins to obtain a modified Sn-containing alumina carrier; the product is then placed in an alcohol solution containing porphyrin platinum to obtain a low-carbon alkane dehydrogenation catalyst precursor; the product is then loaded with an alkali metal additive and calcined to obtain the product. The entire process takes more than 38 hours, the production cycle of the catalyst is long, and the energy consumption cost of the preparation process is high. At the same time, the mechanical strength of the molecular sieve catalyst also needs to be further improved to avoid the molecular sieve catalyst being broken and pulverized by external forces during transportation and loading, which affects the operation of the equipment.

[0004] Chinese invention patent CN 118515294 A discloses a ZMQ-1 molecular sieve containing a three-dimensional pore system consisting of 28×10×10-membered rings. It exhibits high thermal and hydrothermal stability, abundant Brønsted acid sites, and moderately high Brønsted acid strength. However, its application in the catalytic dehydrogenation of light alkanes is limited.

[0005] Based on this, the present invention designs a low-carbon alkane dehydrogenation catalyst and its preparation method and application to solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a low-carbon alkane dehydrogenation catalyst and a preparation method and application thereof.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A low-carbon alkane dehydrogenation catalyst is provided. The ZMQ-1 molecular sieve dispersion is prepared by reacting a ZMQ-1 molecular sieve with an EDTA solution; the ZMQ-1 molecular sieve dispersion is subjected to electron beam irradiation treatment; a lanthanum compound and a rhodium compound are added to obtain a mixed solution; and after the electron beam irradiation treatment, the mixed solution is subjected to drop ball forming, drying, and calcination to obtain the low-carbon alkane dehydrogenation catalyst.

[0009] Furthermore, the mass ratio of lanthanum to rhodium is 2:3.

[0010] Furthermore, the low carbon alkane is propane.

[0011] Furthermore, the electron beam radiation treatment parameters are: electron beam energy: 1.5 to 2 MeV, radiation time: 5 to 10 minutes.

[0012] Furthermore, the particle size of the ZMQ-1 molecular sieve is ground to 3 to 5 microns.

[0013] In order to better achieve the purpose of the present invention, the present invention also provides a method for preparing a low-carbon alkane dehydrogenation catalyst, comprising the following steps:

[0014] First, a ZMQ-1 molecular sieve dispersion was prepared by slowly adding the ZMQ-1 molecular sieve to a 1-2.5 mol / L EDTA solution, stirring with a magnetic stirrer at a speed of 220-350 r / min and stirring at 40-50° C. for 40-65 min to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion.

[0015] Afterwards, the ZMQ-1 molecular sieve dispersion is subjected to electron beam irradiation treatment: a 1.5-2 MeV electron accelerator is used at room temperature and atmospheric pressure for 5-10 minutes;

[0016] Then, a lanthanum compound and a rhodium compound are added to the ZMQ-1 molecular sieve dispersion, and ultrasonic dispersion is performed for 20 to 30 minutes to obtain a mixed solution;

[0017] Afterwards, the mixed solution is subjected to electron beam irradiation treatment: using a 2-2.5 MeV electron accelerator at room temperature and atmospheric pressure for 10-15 minutes;

[0018] Finally, the mixed liquid droplets are formed into ball-shaped balls, dried at 120-125° C. for 1-2 hours, and calcined at 550-580° C. for 5-6 hours to obtain a low-carbon alkane dehydrogenation catalyst.

[0019] Furthermore, the addition rate of ZMQ-1 molecular sieve is 1.8 to 3.3 parts / min; the lanthanum compound is lanthanum acetate; and the rhodium compound is ammonium tetrachlororhodate.

[0020] In order to better achieve the purpose of the present invention, the present invention also provides a low-carbon alkane dehydrogenation catalyst obtained according to the preparation method.

[0021] In order to better achieve the purpose of the present invention, the present invention also provides an application of a low-carbon alkane dehydrogenation catalyst in the catalytic dehydrogenation of low-carbon alkane.

[0022] Furthermore, the light alkane is propane, and the light alkane dehydrogenation catalyst is used for propane dehydrogenation to produce propylene, with a propane conversion rate of ≥37.9%, a propylene selectivity of ≥97.1%, and a catalyst strength of ≥146 N / cm.

[0023] Compared with existing technologies, the present invention offers the following advantages: A light alkane dehydrogenation catalyst is obtained by subjecting a ZMQ-1 molecular sieve dispersion to electron beam irradiation, adding lanthanum and rhodium in a reasonable ratio, and then subjecting the mixture to electron beam irradiation, followed by droplet spherical formation, drying, and calcination. This not only enhances catalyst strength, but also reduces the entire preparation process time by less than 10 hours, thereby reducing the catalyst production cycle and energy consumption. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1: First, a ZMQ-1 molecular sieve dispersion was prepared: 20 parts of ZMQ-1 molecular sieves ground to a particle size of 3 microns were slowly added to 68 parts of 2.5 mol / L EDTA solution at a rate of 3.3 parts / min; a magnetic stirrer was used to stir the mixture at a speed of 220 r / min at 50°C for 40 minutes to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion; the ZMQ-1 molecular sieve dispersion was then subjected to electron beam irradiation treatment. : A 2MeV electron accelerator is used at room temperature and atmospheric pressure for 5 minutes; then, 0.59 parts of lanthanum acetate and 1.2 parts of ammonium tetrachlororhodiumate are added to the ZMQ-1 molecular sieve dispersion, and ultrasonic dispersion is carried out for 30 minutes to obtain a mixed solution; then, the mixed solution is subjected to electron beam irradiation treatment: a 2MeV electron accelerator is used at room temperature and atmospheric pressure for 15 minutes; finally, the mixed solution is droplet-shaped into spheres, dried at 120°C for 2 hours, and calcined at 550°C for 6 hours to obtain a low-carbon alkane dehydrogenation catalyst.

[0026] Example 2: First, a ZMQ-1 molecular sieve dispersion was prepared: 10 parts of ZMQ-1 molecular sieves ground to a particle size of 5 μm were slowly added to 95 parts of 1 mol / L EDTA solution at a rate of 1.8 parts / min; a magnetic stirrer was used to stir the mixture at a speed of 350 r / min and at 40° C. for 65 min to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion; the ZMQ-1 molecular sieve dispersion was then subjected to electron beam irradiation treatment: 1 .5MeV electron accelerator, at room temperature and normal pressure, the irradiation time is 10 minutes; then, 0.57 parts of lanthanum acetate and 0.98 parts of ammonium tetrachlororhodate are added to the ZMQ-1 molecular sieve dispersion, and ultrasonic dispersion is carried out for 20 minutes to obtain a mixed solution; thereafter, the mixed solution is subjected to electron beam irradiation treatment: using a 2.5MeV electron accelerator, at room temperature and normal pressure, the irradiation time is 10 minutes; finally, the mixed solution is droplet-shaped into spheres, dried at 125°C for 1 hour, and calcined at 580°C for 5 hours to obtain a low-carbon alkane dehydrogenation catalyst.

[0027] Example 3: First, a ZMQ-1 molecular sieve dispersion was prepared: 15 parts of ZMQ-1 molecular sieve ground to a particle size of 4 μm were slowly added to 80 parts of 2 mol / L EDTA solution at a rate of 2.2 parts / min; a magnetic stirrer was used to stir the mixture at a speed of 250 r / min at 45°C for 45 minutes to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion; the ZMQ-1 molecular sieve dispersion was then subjected to electron beam irradiation treatment: 1. The method comprises the following steps: using a 5MeV electron accelerator at room temperature and atmospheric pressure for 8 minutes; then, adding 0.68 parts of lanthanum acetate and 1.23 parts of ammonium tetrachlororhodium to the ZMQ-1 molecular sieve dispersion, ultrasonically dispersing for 25 minutes, and obtaining a mixed solution; then, subjecting the mixed solution to electron beam irradiation treatment: using a 2MeV electron accelerator at room temperature and atmospheric pressure for 12 minutes; finally, forming the mixed solution into droplets, drying at 122°C for 1.5 hours, and calcining at 575°C for 5.5 hours, and obtaining a low-carbon alkane dehydrogenation catalyst.

[0028] Comparative Example 1: First, a ZMQ-1 molecular sieve dispersion was prepared: 15 parts of ZMQ-1 molecular sieves with a particle size of 4 microns were slowly added to 80 parts of 2 mol / L EDTA solution, and the addition rate of ZMQ-1 molecular sieves was 2.2 parts / min; a magnetic stirrer was used for stirring, the stirring speed was controlled at 250 r / min, and stirring was carried out at 45°C for 45 minutes to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion; then, 0.68 parts of lanthanum acetate and 1.23 parts of ammonium tetrachlororhodiumate were added to the ZMQ-1 molecular sieve dispersion, and ultrasonic dispersion was carried out for 25 minutes to obtain a mixed solution; thereafter, the mixed solution was subjected to electron beam irradiation treatment: a 2 MeV electron accelerator was used, at room temperature and normal pressure, and the irradiation time was 12 minutes; finally, the mixed solution was droplet-shaped into spheres, dried at 122°C for 1.5 hours, and calcined at 575°C for 5.5 hours to obtain a low-carbon alkane dehydrogenation catalyst.

[0029] Comparative Example 2: First, prepare a ZMQ-1 molecular sieve dispersion: slowly add 15 parts of ZMQ-1 molecular sieves with a particle size of 4 microns to 80 parts of 2 mol / L EDTA solution, and the addition rate of ZMQ-1 molecular sieve is 2.2 parts / min; use a magnetic stirrer to stir, the stirring speed is controlled at 250r / min, and stir at 45°C for 45 minutes to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion; then, the ZMQ-1 molecular sieve dispersion is subjected to electron beam irradiation treatment: a 1.5MeV electron accelerator is used, at room temperature and normal pressure, and the irradiation time is 8 minutes; then, 0.68 parts of lanthanum acetate and 1.23 parts of ammonium tetrachlororhodiumate are added to the ZMQ-1 molecular sieve dispersion, and ultrasonic dispersion is carried out for 25 minutes to obtain a mixed solution; finally, the mixed solution is droplet-shaped into spheres, dried at 122°C for 1.5 hours, and calcined at 575°C for 5.5 hours to obtain a low-carbon alkane dehydrogenation catalyst.

[0030] Comparative Example 3: First, a ZMQ-1 molecular sieve dispersion was prepared: 15 parts of ZMQ-1 molecular sieve ground to a particle size of 4 μm were slowly added to 80 parts of 2 mol / L EDTA solution at a rate of 2.2 parts / min; a magnetic stirrer was used to stir at a speed of 250 r / min at 45°C for 45 min to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion; then, the ZMQ-1 molecular sieve dispersion was subjected to electron beam irradiation treatment: 1. The method comprises the following steps: using a 5MeV electron accelerator at room temperature and atmospheric pressure for 8 minutes; then, adding 0.34 parts of lanthanum acetate and 1.64 parts of ammonium tetrachlororhodium to the ZMQ-1 molecular sieve dispersion, ultrasonically dispersing for 25 minutes, and obtaining a mixed solution; then, subjecting the mixed solution to electron beam irradiation treatment: using a 2MeV electron accelerator at room temperature and atmospheric pressure for 12 minutes; finally, forming the mixed solution into droplets, drying at 122°C for 1.5 hours, and calcining at 575°C for 5.5 hours, and obtaining a low-carbon alkane dehydrogenation catalyst.

[0031] Comparative Example 4: First, a ZMQ-1 molecular sieve dispersion was prepared: 15 parts of ZMQ-1 molecular sieve ground to a particle size of 4 μm were slowly added to 80 parts of 2 mol / L EDTA solution at a rate of 2.2 parts / min; a magnetic stirrer was used to stir at a speed of 250 r / min at 45°C for 45 min to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion; then, the ZMQ-1 molecular sieve dispersion was subjected to electron beam irradiation treatment: 1. The method comprises the following steps: using a 5MeV electron accelerator at room temperature and atmospheric pressure for 8 minutes; then, adding 1.02 parts of lanthanum acetate and 0.82 parts of ammonium tetrachlororhodate to the ZMQ-1 molecular sieve dispersion, ultrasonically dispersing for 25 minutes, and obtaining a mixed solution; then, subjecting the mixed solution to electron beam irradiation treatment: using a 2MeV electron accelerator at room temperature and atmospheric pressure for 12 minutes; finally, forming the mixed solution into droplets, drying at 122°C for 1.5 hours, and calcining at 575°C for 5.5 hours, and obtaining a low-carbon alkane dehydrogenation catalyst.

[0032] Experimental Example: Catalyst Strength and Catalyst Performance Evaluation (Reaction Conditions: 4 g catalyst, propane feed mass space velocity of 5.0 h -1 , hydrogen / propane molar ratio 0.3:1, propane dehydrogenation reaction was carried out at 600°C and normal pressure. The propane conversion rate and propylene selectivity were detected after 2h and 72h of reaction. The results are shown in Table 1.

[0033] Table 1 Catalyst strength and catalyst performance evaluation results

[0034]

[0035]

[0036] The present invention prepares a light alkane dehydrogenation catalyst by subjecting a ZMQ-1 molecular sieve dispersion to electron beam radiation treatment, adding lanthanum and rhodium in a reasonable ratio, and then subjecting the mixture to electron beam radiation treatment, followed by droplet spherical formation, drying, and calcination. This enhances catalyst strength and reduces the catalyst production cycle and energy consumption of the preparation process by taking less than 10 hours.

[0037] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A catalyst for dehydrogenation of light alkanes, characterized in that: Prepare ZMQ-1 molecular sieve dispersion by ZMQ-1 molecular sieve and EDTA solution; A ZMQ-1 molecular sieve dispersion is subjected to electron beam radiation treatment; a lanthanum compound and a rhodium compound are added to obtain a mixed solution; after the mixed solution is subjected to electron beam radiation treatment, it is subjected to drop ball forming, drying, and calcination to obtain a low-carbon alkane dehydrogenation catalyst; the content of the lanthanum element is calculated based on the ZMQ-1 molecular sieve as 1.3-2.5% by mass, and the rhodium element is 2.2-3.6% by mass.

2. The light alkane dehydrogenation catalyst according to claim 1, characterized in that The mass ratio of lanthanum to rhodium is 2:

3.

3. The light alkane dehydrogenation catalyst according to claim 1, characterized in that The low carbon alkane is propane.

4. The light alkane dehydrogenation catalyst according to claim 1, characterized in that The parameters of electron beam radiation treatment are: electron beam energy: 1.5-2 MeV, radiation time: 5-10 min.

5. The light alkane dehydrogenation catalyst according to claim 1, characterized in that The particle size of the ZMQ-1 molecular sieve is ground to 3 to 5 microns.

6. A method for preparing a light alkane dehydrogenation catalyst according to any one of claims 1 to 5, characterized in that: The following steps are involved: First, a ZMQ-1 molecular sieve dispersion was prepared by slowly adding the ZMQ-1 molecular sieve to a 1-2.5 mol / L EDTA solution, stirring with a magnetic stirrer at a speed of 220-350 r / min and stirring at 40-50° C. for 40-65 min to obtain a uniformly dispersed ZMQ-1 molecular sieve dispersion. Afterwards, the ZMQ-1 molecular sieve dispersion is subjected to electron beam irradiation treatment: a 1.5-2 MeV electron accelerator is used at room temperature and atmospheric pressure for 5-10 minutes; Then, a lanthanum compound and a rhodium compound are added to the ZMQ-1 molecular sieve dispersion, and ultrasonic dispersion is performed for 20 to 30 minutes to obtain a mixed solution; Afterwards, the mixed solution is subjected to electron beam irradiation treatment: using a 2-2.5 MeV electron accelerator at room temperature and atmospheric pressure for 10-15 minutes; Finally, the mixed liquid droplets are formed into ball-shaped balls, dried at 120-125° C. for 1-2 hours, and calcined at 550-580° C. for 5-6 hours to obtain a low-carbon alkane dehydrogenation catalyst.

7. The method for preparing a light alkane dehydrogenation catalyst according to claim 6, wherein: The addition rate of ZMQ-1 molecular sieve is 1.8 to 3.3 parts / min; the lanthanum compound is lanthanum acetate; and the rhodium compound is ammonium tetrachlororhodate.

8. A light alkane dehydrogenation catalyst obtained by the preparation method according to claim 7.

9. Use of the light alkane dehydrogenation catalyst according to claim 1, 2, 3, 4, 5 or 8 in the catalytic dehydrogenation of light alkane.

10. Use of the light alkane dehydrogenation catalyst according to claim 9 in light alkane dehydrogenation catalysis, characterized in that: The low-carbon alkane is propane, and the low-carbon alkane dehydrogenation catalyst is used for propane dehydrogenation to produce propylene, with a propane conversion rate of ≥37.9%, a propylene selectivity of ≥97.1%, and a catalyst strength of ≥146 N / cm.

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