A catalytic conversion system combining a counter-current bed and an ascending bed

Abstract

This invention provides a catalytic conversion system combining a counter-bed reactor and an ascending bed reactor. The system includes a combined counter-bed reaction unit and an ascending bed reaction unit. The counter-bed reaction unit comprises a counter-bed reactor, a first catalyst distributor, a first reactant-oil separator, a first catalyst stripper, and a first regeneration zone. The ascending bed reaction unit comprises an ascending bed reactor, a settling tank, a second reactant-oil separator, a second catalyst stripper, and a second regeneration zone. By combining the reactant-oil mixtures of the counter-bed and ascending bed reactors, the counter-bed reactor primarily performs alkane dehydrogenation, while the ascending bed reactor primarily performs olefin cracking. Furthermore, the catalysts in the counter-bed and ascending bed reactors move in opposite directions, enabling the two reactions to proceed in succession and allowing for independent and flexible control of the reaction environment in both reaction zones, thereby improving the yield of the target product.

Description

Technical Field

[0001] This invention relates to the field of petrochemicals, and more specifically to a catalytic conversion system combining a countercurrent bed and an ascending bed. Background Technology

[0002] In petrochemical production, it is common to encounter situations where one or more raw materials are reacted multiple times to produce certain products. Examples include the dehydrogenation and cracking of alkanes, the hydrogenation and cracking of inferior feedstock oils, the isomerization and hydrogen transfer reaction to convert straight-chain olefins in gasoline into multi-branched alkanes in order to improve the properties of gasoline, and the conversion of heavy feedstock oil or crude oil into low-carbon olefin precursors through primary cracking and then into low-carbon olefins through secondary cracking.

[0003] For example, CN104560149A discloses a catalytic conversion method for producing butene. This method uses four reactors. In addition to a double-riseer plus fluidized bed reactor configuration, a fluidized bed reactor is installed outside the settling tank for cracking the gasoline fraction. The reaction products enter the riser reactor for further cracking. The catalyst after the reaction is regenerated by coke burning and then returned to the reactor for recycling. This method uses a mixture containing γ-zeolite and β-zeolite as a catalyst and can achieve high yields of propylene and butene.

[0004] However, it is necessary to further improve the conversion rate of reactants and the yield of target products in catalytic conversion. Summary of the Invention

[0005] The purpose of this invention is to further improve the conversion rate of reactants in catalytic conversion and the yield of target products.

[0006] To achieve the above objectives, the present invention provides a catalytic conversion system combining a counter-bed and an ascending bed reactor. This catalytic conversion system includes a combined counter-bed reaction unit and an ascending bed reaction unit. The counter-bed reaction unit includes a counter-bed reactor, a first catalyst distributor, a first reactant oil separator, a first catalyst stripper, and a first regeneration zone. The first reactant oil separator is located at the top of the counter-bed reactor and has a first reactant oil / gas outlet. The first catalyst distributor is located below the first reactant oil separator. A first catalyst delivery connection is established between the counter-bed reactor and the first catalyst stripper. A first catalyst delivery connection is established between the first catalyst stripper and the first regeneration zone. The stripper is connected to the counter-current bed reactor via a first stripping product conveying connection; the first regeneration zone is connected to the counter-current bed reactor via a first regenerant conveying connection; the ascending bed reaction unit includes an ascending bed reactor, a settling tank, a second reaction oil separator, a second catalyst stripper, and a second regeneration zone; the bottom of the ascending bed reactor is connected to the first reaction oil and gas outlet; the upper end of the ascending bed reactor is connected to the material inlet of the second reaction oil separator located in the settling tank; the lower end of the settling tank is connected to the second catalyst stripper; the second catalyst stripper is connected to the second regeneration zone via a second catalyst delivery connection; the second regeneration zone is connected to the ascending bed reactor via a second regenerant conveying connection.

[0007] Through the above technical solution, the present invention combines the oil agent of the counter-bed reactor and the rising bed reactor. The counter-bed reactor mainly carries out the alkane dehydrogenation reaction, while the rising bed reactor mainly carries out the olefin cracking reaction. Furthermore, the catalysts in the counter-bed reactor and the rising bed reactor move in opposite directions, which enables the relay of the two reactions and allows for independent and flexible control of the reaction environment in the two reaction zones, thereby improving the yield of the target product.

[0008] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0009] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0010] Figure 1 This is a schematic diagram of the structure of a catalytic conversion system according to one embodiment of the present invention.

[0011] Figure 2 This is a schematic diagram of the structure of a catalytic conversion system according to one embodiment of the present invention.

[0012] Figure 3 This is a schematic diagram of one embodiment of the first catalyst distributor in this invention.

[0013] Explanation of reference numerals in the attached figures

[0014] Figure 1 and 2 The reference numerals in the attached figures are explained as follows:

[0015] 1-Reverse bed reactor; 2-First catalyst stripper; 3-Rising bed reactor

[0016] 4-Settler; 5-Second catalyst stripper; 6-First catalyst regeneration zone

[0017] 7-Second catalyst regeneration zone

[0018] 11-Feed pipeline; 12-First catalyst delivery pipeline; 13, 20-Stripping gas

[0019] 14-Oil and gas pipelines

[0020] 15-First catalyst delivery pipe; 16-First catalyst distributor; 17-First reaction oil separator

[0021] 18-Auxiliary feed line; 19-Second reaction oil conveying line; 21-Second spent catalyst conveying line.

[0022] 22-Second Reaction Oil Separator; 23-Reaction Oil and Gas; 24-Second Regenerator Delivery Pipe

[0023] 25-First regenerant delivery pipe; 26-Main air; 27-Fuel gas

[0024] 28, 29 - Cyclone separator; 30 - Regenerated flue gas Detailed Implementation

[0025] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0026] refer to Figure 1 and 2This invention provides a catalytic conversion system combining a counter-bed and an ascending bed reactor. The system includes a combined counter-bed reaction unit and an ascending bed reaction unit. The counter-bed reaction unit includes a counter-bed reactor, a first catalyst distributor, a first reactant oil separator, a first catalyst stripper, and a first regeneration zone. The first reactant oil separator is located at the top of the counter-bed reactor and has a first reactant oil / gas outlet. The first catalyst distributor is located below the first reactant oil separator. A first catalyst to be stripped is connected between the counter-bed reactor and the first catalyst stripper. A first catalyst to be regenerated is connected between the first catalyst stripper and the first regeneration zone. The counter-bed reactors are connected by a first stripping product conveying connection; the first regeneration zone is connected to the counter-bed reactor by a first regenerant conveying connection; the ascending bed reactor unit includes an ascending bed reactor, a settling tank, a second reaction oil separator, a second catalyst stripper, and a second regeneration zone; the bottom of the ascending bed reactor is connected to the first reaction oil and gas outlet; the upper end of the ascending bed reactor is connected to the material inlet of the second reaction oil separator located in the settling tank; the lower end of the settling tank is connected to the second catalyst stripper; the second catalyst stripper and the second regeneration zone are connected by a second catalyst delivery connection; the second regeneration zone and the ascending bed reactor are connected by a second regenerant conveying connection.

[0027] In this invention, the first reaction oil and gas after the material undergoing the first catalytic conversion in the counter-bed reactor is separated from the first stripping catalyst and enters the upward bed reactor to undergo a second catalytic conversion reaction with the second catalyst, which means that the first catalytic conversion reaction and the second catalytic conversion reaction can be carried out in succession.

[0028] Optionally, the counter-current bed reactor is selected from one or more combinations of constant-diameter counter-current bed reactors and variable-diameter counter-current bed reactors, and the ratio of the diameter to the height of the counter-current bed reactor is 1:1 to 5, preferably 1:1.5 to 3.

[0029] Optionally, refer to Figure 3 The first reaction oil separator allows the first reaction oil gas to be drawn out of the counter-bed reactor. It is selected from one or more combinations of filters, filter plates, porous baffles, and fast separation devices, preferably filter plates. The pore size of the filter plate is 5 to 40 μm, preferably 10 to 30 μm.

[0030] Optionally, the first catalyst distributor, which allows the first catalyst to enter the counter-current bed reactor, has an open-circuit disc structure, wherein the open-circuit disc has an opening rate of 50% to 90%, preferably 60% to 80%.

[0031] Optionally, the rising bed reactor is selected from one or more of the following types: bubbling bed reactor, turbulent bed reactor, fast bed reactor, and conveying bed reactor.

[0032] Optionally, the second reaction oil separator is selected from one or more combinations of cyclone rapid separators, three-lobe rapid separators, catapult rapid separators, U-shaped tube separators and wall-mounted cutting rapid separators, with cyclone rapid separators being preferred.

[0033] Optionally, the bottom of the reverse bed reactor has a first feedstock inlet and a first lifting medium inlet; the bottom of the upward bed reactor has a second feedstock inlet and a second lifting medium inlet.

[0034] Optionally, to facilitate heat transfer between the first catalyst regeneration zone and the second catalyst regeneration zone, the first catalyst regeneration zone and the second catalyst regeneration zone are arranged side-by-side. Each of the first catalyst regeneration zone and the second catalyst regeneration zone has a main air inlet.

[0035] Optionally, to facilitate the transport of regenerated flue gas between the first catalyst regeneration zone and the second catalyst regeneration zone, the first catalyst regeneration zone and the second catalyst regeneration zone are arranged in a high-low series configuration, with the first regenerated flue gas outlet of the first catalyst regeneration zone connected to the bottom of the second catalyst regeneration zone. The first catalyst regeneration zone has a main air inlet.

[0036] Optionally, in order to increase the regeneration temperature in the second catalyst regeneration zone, the second catalyst regeneration zone is also provided with a fuel inlet for injecting fuel.

[0037] According to a particularly preferred embodiment of the present invention, the preheated feed oil is injected into the bottom of the counter-bed reactor 1 through the feed pipeline 11 via a nozzle, and comes into contact with the first catalyst from the first catalyst regeneration zone 6 and introduced into the upper part of the counter-bed reactor 1 via the first catalyst distributor 16 to carry out the first catalytic conversion reaction. The resulting first oil-catalyst mixture is separated by the first reactant-oil separator 17 at the top of the counter-bed reactor 1. The first catalyst to be stripped is introduced into the first catalyst stripper 2 for stripping to remove the small amount of reaction oil and gas carried on the catalyst. The resulting first catalyst to be regenerated is introduced into the first catalyst regeneration zone 6 through the first catalyst pipeline 15 for regeneration. The regenerated first catalyst is introduced into the counter-bed reactor 1 for recycling through the first catalyst delivery pipe 25. The first reaction oil gas separated by the first reactant oil separator 17 is introduced into the ascending bed reactor 3 to react with the second catalyst from the second catalyst regeneration zone 7. Optionally, an auxiliary feed can be introduced into the ascending bed reactor 3 through the auxiliary feed line 18. The second catalytic conversion reaction then takes place in the ascending bed reactor 3. The reacted second reaction oil is introduced into the reaction oil separator 22 in the settling tank 4 through the second reaction oil delivery pipe 19. The separated second spent catalyst is introduced into the second catalyst stripper 5 for stripping to remove the small amount of reaction oil gas carried on the catalyst. The resulting second spent catalyst is introduced into the second catalyst regeneration zone 7 through the second spent catalyst delivery pipe 21 for regeneration. The regenerated second catalyst is then introduced into the ascending bed reactor 3 for recycling through the second catalyst delivery pipe 24. A device is provided to remove the reaction oil gas separated by the second reaction oil separator 22.

[0038] The present invention will be described in detail below with reference to embodiments, but this does not limit the scope of the invention.

[0039] Example

[0040] Unless otherwise specified, all reagents used below are chemically pure.

[0041] The low-carbon alkanes used in the examples and comparative examples were mixtures of butane and C5-C8 alkanes, with the composition of the feedstocks shown in Tables 1 and 2. The auxiliary feedstocks were n-butene and n-hexene. The first catalyst used was DH-1, and the second catalyst was RAG-6. The chemical composition and properties of the two catalysts are shown in Table 2.

[0042] Table 1 Chemical composition of mixed butanes

[0043] project Chemical composition / % Isobutane 69.54 n-Butane 30.46 total 100.00

[0044] Table 2 Chemical composition of C5-C8 alkane mixtures

[0045]

[0046]

[0047] Table 3 Composition and properties of catalysts

[0048] project DH-1 RAG-6 Chemical composition / % <![CDATA[Al2O3]]> 93.4 50.4 <![CDATA[SiO2]]> 1.2 43.5 <![CDATA[K2O]]> 0.375 0.302 <![CDATA[P2O5]]> 1.43 <![CDATA[Fe2O3]]> 0.106 1.04 <![CDATA[Cr2O3]]> <![CDATA[La2O3]]> 0.17 <![CDATA[CeO2]]> 1.24 0.244 <![CDATA[Ga2O3]]> 3.06 Relative crystallinity / % 78.1 26.9 BET Full Analysis <![CDATA[ BET total surface area / (m 2 ·g -1 )]]> 137.00 199.44 <![CDATA[Total pore volume / (cm 3 ·g -1 )]]> 0.4680 0.1485

[0049] Example 1

[0050] The experiment was conducted in Figure 1 The system shown has a counter-bed reactor with a diameter of 300 mm and a length of 600 mm, and an ascending bed reactor with a diameter of 20 mm and a height of 1000 mm. The catalyst used in the counter-bed reactor is DH-1, and the catalyst used in the ascending bed reactor is RAG-6. Preheated butane to 150°C is introduced into the bottom of the counter-bed reactor, where it reacts counter-currently with the DH-1 catalyst. The resulting first reaction oil is separated by a first oil separator. The first catalyst to be stripped is introduced into a first stripper and then into a first catalyst regeneration zone for regeneration. The regenerated first catalyst is returned to the counter-bed reactor for recycling. The first reaction oil gas from the first oil separator is introduced into the ascending bed reactor to continue reacting with the RAG-6 catalyst. The resulting second reaction oil is introduced into a second oil separator in a settling tank for separation. The second catalyst to be regenerated is introduced into a second stripper and then into a second catalyst regeneration zone for regeneration. The regenerated second catalyst is returned to the ascending bed reactor for recycling. The reaction oil gas is then extracted through a system. The reaction conditions and results are shown in Table 4.

[0051] Example 2

[0052] The method of Example 1 was followed, except that n-butene was introduced as an auxiliary feedstock into the rising bed reactor for the reaction, and the mass ratio of n-butene to mixed butane was 0.05:1. The reaction conditions and results are shown in Table 4.

[0053] Comparative Example 1

[0054] The experiment was conducted in a single ascending bed reactor with a diameter of 20 mm and a height of 500 mm. RAG-6 catalyst was used. Preheated butane mixture to 150°C was introduced to the bottom of the ascending bed reactor, where it contacted the RAG-6 catalyst and rose together to react. The resulting reaction oil was introduced into an oil separator in a settling tank for separation. The spent catalyst was stripped in a spent catalyst stripper and then introduced into the catalyst regeneration zone for regeneration. The regenerated catalyst was returned to the ascending bed reactor for recycling. The reaction oil and gas extraction system was also included. Reaction conditions and results are shown in Table 4.

[0055] Comparative Example 2

[0056] The method was the same as in Example 1, except that both the counter-current bed reactor and the rising bed reactor used a mixed catalyst obtained by mixing DH-1 and RAG-6 catalysts in a mass ratio of 1:1. The reaction conditions and results are shown in Table 4.

[0057] Table 4. Reaction conditions and results of Examples 1-2 and Comparative Examples 1-2

[0058]

[0059]

[0060] Example 3

[0061] The experiment was conducted in Figure 2 The system shown has a counter-bed reactor with a diameter of 300 mm and a length of 600 mm, and an ascending bed reactor with a diameter of 20 mm and a height of 1200 mm. The catalyst used in the counter-bed reactor is DH-1, and the catalyst used in the ascending bed reactor is RAG-6. C5-C8 alkanes are preheated to 150°C and introduced into the bottom of the counter-bed reactor to react counter-currently with the DH-1 catalyst. The resulting first reaction oil is separated by a first oil separator. The first catalyst to be stripped is introduced into a first stripper and then into a first catalyst regeneration zone for regeneration. The regenerated first catalyst is returned to the counter-bed reactor for recycling. The first reaction oil gas obtained from the first oil separator is introduced into the ascending bed reactor to continue reacting with the RAG-6 catalyst. The resulting second reaction oil is introduced into a second oil separator in a settling tank for separation. The second catalyst to be regenerated is introduced into a second stripper and then into a second catalyst regeneration zone for regeneration. The regenerated second catalyst is returned to the ascending bed reactor for recycling. The regenerated flue gas generated in the first catalyst regeneration zone is introduced into the second catalyst regeneration zone to provide heat for the regeneration of the second catalyst. A reaction oil and gas extraction system is also included. Reaction conditions and results are shown in Table 5.

[0062] Example 4

[0063] The method of Example 3 was followed, except that n-hexene was introduced as an auxiliary feedstock into the rising bed reactor for the reaction, and the mass ratio of n-hexene to C5-C8 alkanes was 0.1:1. The reaction conditions and results are shown in Table 5.

[0064] Comparative Example 3

[0065] The experiment was conducted in a single counter-bed reactor with a diameter of 300 mm and a length of 600 mm, using RAG-6 catalyst. C5-C8 alkanes were preheated to 150°C and introduced into the bottom of the counter-bed reactor to contact and react with the RAG-6 catalyst. The resulting reaction oil was separated by an oil separator. The spent catalyst was stripped in a spent catalyst stripper and then introduced into the catalyst regeneration zone for regeneration. The regenerated catalyst was returned to the counter-bed reactor for recycling. The reaction oil and gas extraction system was also included. Reaction conditions and results are shown in Table 5.

[0066] Comparative Example 4

[0067] The method described in Example 3 was followed, except that both the counter-current bed reactor and the rising bed reactor used a mixed catalyst obtained by mixing DH-1 and RAG-6 catalysts at a mass ratio of 1:1. The reaction conditions and results are shown in Table 5.

[0068] Table 5. Reaction conditions and results of Examples 3-4 and Comparative Examples 3-4

[0069] project Example 3 Example 4 Comparative Example 3 Comparative Example 4 counter-current bed reactor raw material C5-C8 alkanes C5-C8 alkanes C5-C8 alkanes C5-C8 alkanes reaction temperature 615 620 615 620 Agent-to-oil ratio 12 12 12 12 Temperature in the first catalyst regeneration zone / °C 703 705 702 704 Rising bed reactor auxiliary materials n-Hexene reaction temperature 600 605 605 Agent-to-oil ratio 15 15 15 Temperature in the second catalyst regeneration zone / °C 695 700 700 Material balance / weight% dry air 19.01 20.98 16.95 18.31 Liquefied gas 46.79 46.03 43.77 44.69 gasoline 26.88 25.11 31.68 28.68 diesel fuel 4.02 3.98 4.53 4.15 Oil slurry 1.61 1.79 1.43 1.82 coke 1.69 2.11 1.64 2.35 Ethylene yield / wt% 14.26 15.13 8.96 9.56 Propylene yield / wt% 27.69 28.47 21.56 23.78

[0070] As shown in Tables 4 and 5, the conversion rate of reactants and the yield of target products are significantly improved by using the method provided by the present invention.

[0071] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0072] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0073] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A catalytic conversion system combining a counter-current bed and an ascending bed, characterized in that, The catalytic conversion system includes a combined counter-bed reaction unit and an ascending bed reaction unit; The counter-bed reaction unit includes a counter-bed reactor, a first catalyst distributor, a first reaction oil separator, a first catalyst stripper, and a first regeneration zone. The first reaction oil separator is located at the top of the counter-bed reactor and has a first reaction oil / gas outlet. The first catalyst distributor is located below the first reaction oil separator. A first catalyst to be stripped is connected between the counter-bed reactor and the first catalyst stripper. A first catalyst to be generated is connected between the first catalyst stripper and the first regeneration zone. A first stripping product is connected between the first catalyst stripper and the counter-bed reactor. A first regenerator is connected between the first regeneration zone and the counter-bed reactor. The ascending bed reaction unit includes an ascending bed reactor, a settling tank, a second reaction oil separator, a second catalyst stripper, and a second regeneration zone. The bottom of the ascending bed reactor is connected to the first reaction oil and gas outlet. The upper end of the ascending bed reactor is connected to the material inlet of the second reaction oil separator located in the settling tank. The lower end of the settling tank is connected to the second catalyst stripper. A second catalyst feed connection is provided between the second catalyst stripper and the second regeneration zone. A second regenerator feed connection is provided between the second regeneration zone and the ascending bed reactor. In operation, the counter-current bed reactor contains a first catalyst, and the ascending bed reactor contains a second catalyst.

2. The catalytic conversion system according to claim 1, wherein, The reverse bed reactor is selected from one or a combination of two types of equal-diameter reverse bed reactors and variable-diameter reverse bed reactors, and the ratio of the diameter to the height of the reverse bed reactor is 1:1 to 5.

3. The catalytic conversion system according to claim 2, wherein, The diameter to height ratio of the reverse bed reactor is 1:1.5 to 3.

4. The catalytic conversion system according to claim 1, wherein, The first reaction oil separator is selected from one or a combination of two of the following: a filter plate and a porous partition plate; the pore size of the filter plate is 5 to 40 μm.

5. The catalytic conversion system according to claim 4, wherein, The first reaction oil separator is a filter plate; the pore size of the filter plate is 10-30 μm.

6. The catalytic conversion system according to claim 1 or 4, wherein, The first catalyst distributor is a perforated disc structure, and the perforation rate of the perforated disc is 50% to 90%.

7. The catalytic conversion system according to claim 6, wherein, The perforated disk has an opening rate of 60% to 80%.

8. The catalytic conversion system according to claim 1, wherein, The ascending bed reactor is selected from one or more of the following combinations: bubbling bed reactor, turbulent bed reactor, fast bed reactor, and conveying bed reactor; the second reaction oil separator is selected from one or more of the following combinations: cyclone fast separator, three-lobe fast separator, catapult fast separator, U-shaped tube separator, and wall-mounted cutting fast separator.

9. The catalytic conversion system according to claim 8, wherein, The second reaction oil separator is a cyclone rapid separator.

10. The catalytic conversion system according to claim 1, wherein, The bottom of the reverse bed reactor is provided with a first feed oil inlet and a first lifting medium inlet; the bottom of the upward bed reactor is provided with a second feed oil inlet and a second lifting medium inlet.

11. The catalytic conversion system according to claim 1, wherein, The first catalyst regeneration zone and the second catalyst regeneration zone are arranged side by side.

12. The catalytic conversion system according to claim 1, wherein, The first catalyst regeneration zone and the second catalyst regeneration zone are arranged in a high-low series configuration, with the first regeneration flue gas outlet of the first catalyst regeneration zone connected to the bottom of the second catalyst regeneration zone.

13. The catalytic conversion system according to claim 1, wherein, The second catalyst regeneration zone is also equipped with a fuel inlet.

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