Method for producing olefins by catalytic dehydrogenation of alkanes and corresponding apparatus

Abstract

The present invention provides a method for producing olefins by catalytic dehydrogenation of alkanes and an apparatus. The apparatus comprises a reaction unit, a regeneration unit, and a product separation unit; the reaction unit comprises a pre-lift zone, an oil agent contact zone, a reaction zone, a product quenching zone, a reactor outlet zone, an oil agent separation zone, and a stripping zone. The oil agent contact zone is provided with a feeding distributor and a catalyst distributor, and an oil agent contact space is formed between the feeding distributor and the catalyst distributor, enhancing countercurrent contact between an alkane and a catalyst, and better facilitating the initiation of a catalytic dehydrogenation reaction. By bringing an alkane feedstock into contact with a catalyst and then leveraging the shape and parameters of the reactor, the present invention provides a proper reaction environment for a catalytic dehydrogenation reaction, thereby facilitating the catalytic dehydrogenation reaction, and improving the alkane conversion rate. In addition, the method and the apparatus of the present invention allow for alkane dehydrogenation reactions to be conducted under negative pressure, resulting in good safety and further improving alkane conversion rates and olefin selectivity.

Description

Method for producing olefins by catalytic dehydrogenation of alkanes and corresponding device Technical Field

[0001] The present invention relates to the field of petrochemical industry, and in particular to a method for producing olefins by catalytic dehydrogenation of alkanes and a device for implementing the method. Background Art

[0002] Catalytic dehydrogenation of alkanes involves the removal of one molecule of hydrogen from an alkane to produce an olefin over a catalyst. The reaction is simple, with high yields of the target product, and has been widely adopted in industry worldwide. Based on the reactor type, alkane catalytic dehydrogenation technology can be categorized into three types: fixed-bed, moving-bed, and fluidized-bed. Lummus' Catofin process is the most widely used fixed-bed process. However, its development has been limited by the toxicity of its Cr-based catalyst, which poses environmental risks. Furthermore, the frequent switching of fixed-bed reactors during operation complicates operation and requires a large footprint. Moving-bed processes, exemplified by UOP's Oleflex process, utilize Pt-based catalysts, which have high production costs, demanding raw material requirements, and prone to deactivation during the reaction. With the increasing scale and expansion of alkane dehydrogenation equipment, the fluidized-bed process is gaining popularity. Its flexible operation, efficient and stable production process, and the use of environmentally friendly, non-precious metal, and highly efficient dehydrogenation catalysts have led to its increasing popularity among major manufacturers.

[0003] US5656243A discloses a fluidized bed reactor and its application method. In this reactor, gas and solid fluids flow in countercurrents. Horizontal baffles are provided in the reactor, separating the gas and solid fluids as they flow through the baffles, causing gas to flow upward and solid particles to flow downward, with the gas exiting the baffle at a higher position than the solid particles. This reactor is capable of maintaining at least 70% of the gas and solid particles in a fluidized bed during a reaction. US20080161624A1 discloses a fluidized bed reactor for dehydrogenating low-carbon alkanes with backmixing. Alkanes react with a catalyst in a single fluidized bed reactor with backmixing. The deactivated catalyst is then heated and regenerated, and the regenerated catalyst is returned to the fluidized bed reactor with backmixing for recycling, thereby maintaining a reasonable heat level in the fluidized bed reactor. This reactor can improve alkane conversion and olefin selectivity, while reducing equipment construction and operating costs. US20160272559A1 discloses a catalytic dehydrogenation method using an ascending fluidized bed reactor capable of processing feedstocks containing alkanes or alkylaromatics. The fluidized bed reactor comprises one or more reactors, with a reaction temperature of 500-800°C, a weight hourly space velocity of 0.1-1000, and a gas residence time of 0.1-10 seconds. A cyclone separator is used to separate the reacted oil mixture. A cooling device is provided between the reactor and the cyclone separator to terminate the thermal cracking reaction by cooling, thereby effectively improving the overall selectivity of the olefin product. WO2020 / 186937A1 discloses a circulating fluidized bed apparatus for alkane dehydrogenation, comprising a reaction unit and a regeneration unit. The reaction unit includes a reactor and a reaction settler, the reaction settler communicating with the reactor. A catalyst distributor is provided within the reactor, through which the catalyst is sprayed into the reactor along the reactor wall toward the central axis. The regeneration unit includes a regenerator containing the catalyst and a regenerator settler, the regenerator settler being located above the regenerator. The device can achieve higher alkane conversion rate and olefin yield.

[0004] Researchers have also made some progress in developing green, environmentally friendly, non-precious metal, high-efficiency dehydrogenation catalysts. CN104607168A discloses a catalyst for the catalytic dehydrogenation of alkanes and its preparation method. The catalyst comprises components A and B, wherein component A is selected from oxides of one or more of the elements La, Fe, Zn, Cu, Co, or Ce, and its content in the catalyst is between 0.5 and 50 wt%, preferably between 10 and 30 wt%. Component B is selected from a mixed oxide or composite oxide formed by one or more of the elements SiO2, Al2O3, ZrO2, Ga2O3, and MgO, and its content in the catalyst is between 50 and 99.5 wt%, preferably between 70 and 90 wt%. This catalyst has a high single-pass conversion rate for alkanes and high selectivity for olefins, and its reaction performance is very stable after repeated regeneration, making it suitable for use in circulating fluidized bed reactors. CN112264024A discloses an environmentally friendly fluidized bed alkane dehydrogenation catalyst and its preparation method, specifically relating to a fluidized bed alkane dehydrogenation catalyst and its preparation method. This catalyst comprises components A, B, C, D, and E, wherein component A is selected from oxides of any one or more of Fe, Ni, Co, W, and Mo; component B is selected from oxides of any one or more of Ge, Sb, In, and Te; component C is selected from oxides of any one or more of Zn, Cu, Ga, and Mn; and component D is selected from oxides of any one of Ba, Ca, Mg, K, and Na. Component E serves as a carrier. This catalyst contains no precious metal Pt and no environmentally polluting Cr or V, making it a low-cost, environmentally friendly catalyst. It exhibits high alkane conversion and high olefin selectivity and can be used in fluidized bed reactors.

[0005] The propane dehydrogenation reaction is a highly endothermic reaction with an increase in the number of molecules, and its heat of reaction is ΔH298θ = 124.3 kJ / mol. Increasing the reaction temperature and reducing the reaction pressure are beneficial to the propane dehydrogenation reaction. However, as the reaction temperature increases, the thermal cracking reaction intensifies, and the C-C bond cleavage of propane competes with the C-H bond cleavage, resulting in the production of byproducts such as methane, ethane, and ethylene. Therefore, the actual reaction temperature should not be too high. Reducing the reaction pressure can effectively increase the propane conversion rate while minimizing the impact on propylene selectivity. CN109554189A discloses a method for producing light olefins by cracking petroleum hydrocarbons under reduced pressure. A pressure reducing device connected to a cracking furnace is used to maintain a negative pressure in the pipelines through which the petroleum hydrocarbon feedstock flows in the convection section, radiant section, and waste heat boiler of the cracking furnace. The petroleum hydrocarbon feedstock is heated under reduced pressure, mixed with superheated steam, and then vaporized. The gaseous stream is further heated in the convection section to the crossover temperature before entering the radiant section furnace tubes, where the gaseous stream undergoes a cracking reaction at high temperature. This invention not only effectively solves the problem that special heavy cracking raw materials such as crude oil cannot be fully gasified in the convection section, but also can obtain a significantly higher yield of low-carbon olefins than the normal pressure cracking process.

[0006] A review of the prior art reveals that enhancing the contact between the alkane feedstock and the catalyst, optimizing reaction conditions, and optimizing the content and formulation of active components in the catalyst can effectively improve the conversion rate and olefin selectivity of alkane catalytic dehydrogenation reactions. However, due to the presence of restricted reaction zones in the reactors used, failure to promptly terminate the reaction afterward, and the presence of acidic centers in the catalyst, side reactions of the alkanes can hinder further improvements in olefin selectivity. Therefore, given the challenges of the prior art, finding an apparatus and method for catalytic dehydrogenation of alkanes to produce olefins that rapidly terminates the post-reaction oil mixture, avoids or reduces side reactions, and ultimately improves the selectivity of the target olefin product and the conversion rate of the alkane feedstock remains a pressing technical challenge. Summary of the Invention

[0007] In view of the above problems, the inventors of the present invention have conducted in-depth research and found that the above technical problems can be solved by the method with the characteristics of the present invention.

[0008] More specifically, in order to solve the above technical problems, the first aspect of the present invention provides a method for producing olefins by catalytic dehydrogenation of alkanes, characterized in that the method comprises the following steps:

[0009] Contacting step: the alkane feedstock selected from C2 to C8 is contacted with the catalyst in a countercurrent manner in an oil contact zone (12). The oil contact temperature is 500 to 700°C, preferably 520 to 680°C, and the catalyst density in the oil contact zone is 150 to 500 kg / m 3 , preferably 200~400kg / m 3 The residence time of the alkane feedstock and the catalyst in the oil contact zone is 0.05 to 0.5 seconds, preferably 0.1 to 0.2 seconds.

[0010] Catalytic dehydrogenation step: the oil-agent mixture in the oil-agent contact zone enters the upward reactor (13) from the bottom of the reaction zone to undergo catalytic dehydrogenation reaction. The bottom conditions of the reactor (13) include: a temperature of 520-680°C, preferably 540-660°C, a catalyst density of 100-400 kg / m 3 , preferably 150~350kg / m 3 The conditions at the top of the reactor (13) include: a temperature of 480 to 640°C, preferably 500 to 620°C, a catalyst density of 30 to 200 kg / m 3 , preferably 50 to 150 kg / m 3 The residence time of the oil mixture in the reactor (13) is 0.2 to 5 seconds, preferably 0.4 to 2 seconds, and the radial diameter of the reactor gradually increases from upstream to downstream,

[0011] Oil agent separation step: separating the oil agent mixture obtained in the catalytic dehydrogenation step to obtain an oil-gas mixture and a catalyst to be regenerated;

[0012] Product separation step: separation of olefins from the oil and gas mixture;

[0013] Preferably, the method further comprises a preheating step, wherein the alkane feedstock is preheated to 350-500° C. before being transferred to the contacting step.

[0014] Furthermore, the second aspect of the present invention provides an apparatus for producing olefins by catalytic dehydrogenation of alkanes, wherein the apparatus is used to carry out the method for producing olefins by catalytic dehydrogenation of alkanes of the present invention, which comprises a reaction unit (1), a regeneration unit (2) and a product separation unit.

[0015] From upstream to downstream, the reaction unit (1) includes, in sequence, a pre-lifting zone (11), an oil-agent contact zone (12), an upward reactor (13), a product quenching zone (14), a reaction outlet zone (15), an oil-agent separation zone (17), and a stripping zone (16).

[0016] The pre-lifting zone (11) is provided with a pre-lifting gas pipe (101) for introducing pre-lifting gas, and the pre-lifting zone (11) is connected to the inlet of the oil contact zone (12);

[0017] The outlet of the oil-agent contact zone (12) is communicated with the inlet of the reactor (13), and the oil-agent contact zone (12) is provided with a feed distributor (103) and a catalyst distributor (104), and an oil-agent countercurrent contact space is formed between the feed distributor (103) and the catalyst distributor (104);

[0018] The inlet of the product quenching zone (14) is communicated with the outlet of the reactor (13), and the outlet of the product quenching zone (14) is communicated with the inlet of the reaction outlet zone (15). Preferably, a quick separation device (107) is provided between the product quenching zone (14) and the reaction outlet zone (15), the outlet of the product quenching zone (14) is communicated with the quick separation oil agent inlet (301) of the quick separation device (107), the quick separation catalyst outlet (302) of the quick separation device (107) is communicated with the catalyst inlet of the stripping zone (16), and the quick separation oil and gas outlet (303) of the quick separation device (107) is communicated with the inlet of the reaction outlet zone (15);

[0019] The inlet of the oil-agent separation zone (17) is communicated with the outlet of the reaction outlet zone (15), the catalyst outlet of the oil-agent separation zone (17) is communicated with the catalyst inlet of the stripping zone (16), and the oil and gas outlet of the oil-agent separation zone (17) is communicated with the reaction oil and gas outlet (110). Preferably, the oil-agent separation zone (17) is provided with a first two-stage cyclone separator (108); the outlet of the reaction outlet zone (15) is communicated with the inlet of the first two-stage cyclone separator (108); the catalyst outlet of the first two-stage cyclone separator (108) is communicated with the catalyst inlet of the stripping zone (16), and the oil and gas outlet of the first two-stage cyclone separator (108) is communicated with the reaction oil and gas outlet (110);

[0020] The stripping zone (16) is provided with a stripping gas pipe (111) for introducing stripping gas, a stripping oil and gas outlet, and a catalyst outlet. The catalyst outlet is connected to the catalyst inlet of the regeneration unit (2) via the catalyst delivery pipe (105). The catalyst delivery pipe (105) is optionally provided with a slide valve (106). The stripping oil and gas outlet of the stripping zone (16) is connected to the reaction oil and gas outlet (110).

[0021] The regenerated catalyst outlet of the regeneration unit (2) is connected to the catalyst inlet of the catalyst distributor (104) of the oil contact zone (12) through a regenerated catalyst delivery pipe (203), and the regenerated catalyst delivery pipe (203) is optionally provided with a regeneration slide valve (204).

[0022] The inventors of the present invention have discovered that the specific method of catalytic dehydrogenation of alkanes to produce olefins of the present invention provides a suitable reaction environment and conditions for the dehydrogenation of alkanes to produce olefins, thereby promoting the conversion of alkanes to olefins. Furthermore, the specific apparatus of the present invention facilitates the method of the present invention.

[0023] Technical Effects

[0024] (1) In the present invention, by arranging a feed distributor and a catalyst distributor in the oil-agent contact zone, the countercurrent contact between the alkane and the catalyst is strengthened, thereby better promoting the initiation of the catalytic dehydrogenation reaction.

[0025] (2) Ingeniously design the shape and parameters of the reactor, and through a reasonable reactor type, provide a suitable reaction environment for the catalytic dehydrogenation reaction of alkanes, promote the catalytic dehydrogenation reaction, and improve the alkane conversion rate;

[0026] (3) The post-reaction oil mixture is rapidly cooled in the product quenching zone, and then rapidly separated in the quick separation device and further separated in the first two-stage cyclone separator. The rapid cooling combined with the two-stage separation allows the reaction to be terminated quickly, suppressing the occurrence of side reactions and significantly improving the olefin selectivity and alkane conversion rate.

[0027] (4) The present invention further reduces the reaction pressure by providing a negative pressure drive device and adopting negative pressure operation, thereby promoting the alkane dehydrogenation reaction to move in the positive direction, thereby improving the alkane conversion rate and olefin selectivity;

[0028] (5) Furthermore, when the negative pressure driving device is used, the reaction unit and the regeneration unit are connected through the spent agent receiver and the regeneration agent receiver, thereby ensuring the safety of the negative pressure operation in the reaction unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic diagram of a specific embodiment of an apparatus for producing olefins by catalytic dehydrogenation of alkanes according to the present invention;

[0030] FIG2 is a schematic diagram of another specific embodiment of an apparatus for producing olefins by catalytic dehydrogenation of alkanes according to the present invention;

[0031] FIG3 is a schematic diagram of another embodiment of an apparatus for producing olefins by catalytic dehydrogenation of alkanes according to the present invention;

[0032] FIG4 is a schematic diagram of a specific embodiment of an oil agent contact zone in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0033] FIG5 is a schematic diagram of another specific embodiment of an oil agent contact zone in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0034] FIG6 is a schematic diagram (top view) of a specific embodiment of a feed distributor in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0035] FIG7 is a schematic diagram (cross-sectional view) of a specific embodiment of a feed distributor in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0036] FIG8 is a schematic diagram (cross-sectional view) of another specific embodiment of a feed distributor in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0037] FIG9 is a schematic diagram (top view) of a specific embodiment of a catalyst distributor in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0038] FIG10 is a schematic diagram (cross-sectional view) of a specific embodiment of a catalyst distributor in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0039] FIG11 is a schematic diagram of a specific embodiment of a tapered reducing reactor in an apparatus for catalytic dehydrogenation of alkanes to produce olefins according to the present invention;

[0040] 12 and 13 are schematic structural diagrams of a specific embodiment of a heat exchange coil in an alkane catalytic dehydrogenation device for rapidly cooling and quickly separating an oil agent according to the present invention;

[0041] FIG14 is a schematic structural diagram of a specific embodiment of a fast separation device in an alkane catalytic dehydrogenation device for producing olefins according to the present invention;

[0042] FIG15 is a schematic structural diagram of another specific embodiment of the quick separation device in the alkane catalytic dehydrogenation device for producing olefins according to the present invention.

[0043] DESCRIPTION OF REFERENCE NUMERALS 1 reaction unit 2 regeneration unit 11 pre-lifting zone 12 oil agent contact zone 13 reactor 14 product quenching zone 15 reaction outlet zone 16 stripping zone 17 oil agent separation zone 18 spent catalyst receiver 19 negative pressure drive device 20 regenerated agent receiver 21 regeneration heating zone 22 regeneration zone 101 pre-lifting gas pipe 102 alkane feed pipe 103 feed distributor 104 catalyst distributor 105 first spent catalyst 106 spent slide valve delivery pipe 107 quick separation device 108 first two-stage cyclone separator 109 gas collecting chamber 101 pre-lifting gas pipe 102 alkane feed pipe 103 feed distributor 104 catalyst distributor 105 first spent catalyst 106 spent slide valve delivery pipe 107 quick separation device 108 first two-stage cyclone separator 109 gas collecting chamber 10 110 Reaction oil and gas outlet pipe 111 Stripping gas pipe 112 Second regenerated catalyst line delivery pipe 113 Purge mixture gas outlet 114 Reaction oil and gas outlet 115 Purge gas inlet 201 Fuel pipe 202 Fuel heating pipe 203 First regenerated catalyst delivery pipe 204 Regeneration slide valve 205 Second two-stage cyclone separator 206 Regeneration gas collection chamber 207 Regeneration flue gas outlet 208 Main air duct 211 Reduction gas inlet 210 Second regenerated catalyst 209 Reduction mixture gas outlet delivery pipe 301 Oil-agent mixture inlet 302 Catalyst outlet 303 Oil-agent mixture outlet 141 Heat exchange coil α Angle between the axis of the alkane feed hole and the central axis of the feed distributor β Angle between the outer surface of the tapered reducer reactor and the central axis DETAILED DESCRIPTION

[0044] The present application will be further described in detail below through the accompanying drawings and examples, through which the features and advantages of the present application will become more clear and distinct.

[0045] The word "exemplary" is used exclusively herein to mean "serving as an example, example, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0046] Any specific numerical value disclosed in this application (including the endpoints of a numerical range) is not limited to the exact value of the numerical value, but should be understood to also include values ​​close to the exact value, such as all possible values ​​within the range of ±5% of the exact value. Moreover, for a disclosed numerical range, the values ​​between the endpoints of the range, between the endpoints and the specific points in the range, and between the specific points can be arbitrarily combined to form one or more new numerical ranges, and these new numerical ranges should also be considered to be specifically disclosed herein.

[0047] In this application, the terms "upstream" and "downstream" are used in relation to the direction of flow of the reactants. For example, when the reactants flow from bottom to top, "upstream" refers to a position at the bottom in space, while "downstream" refers to a position at the top in space.

[0048] Unless otherwise specified, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined herein and its definition is different from the commonly understood meaning in the art, the definition herein shall prevail.

[0049] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0050] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0051] In the context of the present invention, unless otherwise specified, the physical property values ​​of a substance (such as boiling point) are all measured values ​​at normal temperature / room temperature (25° C.) and normal pressure (101325 Pa).

[0052] A first aspect of the present invention provides a method for producing olefins by catalytic dehydrogenation of alkanes, characterized in that the method comprises the following steps:

[0053] Contacting step: The alkane feedstock selected from C2 to C8 is contacted with the catalyst in a countercurrent manner in the oil contact zone 12. The oil contact temperature is 500 to 700°C, preferably 520 to 680°C. The catalyst density in the oil contact zone is 150 to 500 kg / m 3 , preferably 200~400kg / m 3 The residence time of the alkane feedstock and the catalyst in the oil contact zone is 0.05 to 0.5 seconds, preferably 0.1 to 0.2 seconds.

[0054] Catalytic dehydrogenation step: the oil-agent mixture in the oil-agent contact zone enters the upward reactor 13 from the bottom of the reaction zone to undergo catalytic dehydrogenation reaction. The bottom conditions of the reactor 13 include: a temperature of 520-680°C, preferably 540-660°C, a catalyst density of 100-400 kg / m 3 , preferably 150~350kg / m 3 The conditions at the top of the reactor 13 include: a temperature of 480 to 640°C, preferably 500 to 620°C, a catalyst density of 30 to 200 kg / m 3 , preferably 50 to 150 kg / m 3 The residence time of the oil mixture in the reactor 13 is 0.2 to 5 seconds, preferably 0.4 to 2 seconds, and the radial diameter of the reactor gradually increases from upstream to downstream,

[0055] Oil agent separation step: separating the oil agent mixture obtained in the catalytic dehydrogenation step to obtain an oil-gas mixture and a catalyst to be regenerated;

[0056] Product separation step: separation of olefins from the oil and gas mixture;

[0057] Preferably, the method further comprises a preheating step, wherein the alkane feedstock is preheated to 350-500° C. before being transferred to the contacting step.

[0058] In the present invention, the reactor is a bottom-up, upward-flowing reactor. The reactor is sometimes also referred to as a reaction zone. Therefore, the reactant stream of the present invention enters the reactor / reaction zone from the bottom of the reaction zone / reactor. By using a pre-lift gas, the reactant stream is caused to move upward. In the present invention, the pre-lift gas can be a gas well known to those skilled in the art, such as one or more of water vapor, nitrogen, and dry gas, preferably water vapor.

[0059] As described above, in the contacting step of the present invention, the alkane feedstock of the present invention is first brought into countercurrent contact with the catalyst in the oil contacting zone 12 .

[0060] In the present invention, the alkane feedstock is selected from one or more alkanes having a carbon number of 2 to 8, preferably one or more selected from propane, n-butane, and isobutane. It should be noted that although alkane feedstocks such as propane, n-butane, and isobutane are in the gas phase at room temperature and pressure and are provided to the contacting step in the gas phase, in the present invention, regardless of the state of the alkane feedstock and its conversion products, the alkane feedstock and its conversion products are collectively referred to as oil or oil gas. A person skilled in the art can undoubtedly determine whether oil or oil gas is the alkane feedstock or its conversion products. For example, the "oil" fed to the oil-agent contact zone is the alkane feedstock; while the "oil" in the oil-agent mixture discharged from the reactor is a mixture of the alkane feedstock and its conversion products.

[0061] In the contacting step of the present invention, the catalyst includes a carrier and a dehydrogenation active component, the carrier is selected from one or more of Al2O3, SiO2, ZrO2, TiO2 and molecular sieves, and the dehydrogenation active component is selected from one or more of Zn, Fe, Co, Ni, V, Sn and Mg; based on the weight of the catalyst, the content of the carrier is 10-90%, and the content of the active component is 10-90%; preferably, the content of the carrier is 30-80%, and the content of the active component is 20-70%.

[0062] In one embodiment of the present invention, the catalyst is a regenerated catalyst from the regeneration zone 2. In one embodiment of the present invention, the catalyst is a freshly replenished catalyst.

[0063] In one embodiment of the present invention, in the contacting step, the temperature of the oil agent contact is 500 to 700°C, preferably 520 to 680°C.

[0064] In one embodiment of the present invention, the catalyst density in the oil contact zone is 150 to 500 kg / m 3 , preferably 200~400kg / m 3 .

[0065] In one embodiment of the present invention, the residence time of the alkane feedstock and the catalyst in the oil contact zone is 0.05 to 0.5 seconds, preferably 0.1 to 0.2 seconds.

[0066] In the present invention, the dehydrogenation reaction of the alkane feedstock can be triggered by rapidly bringing the alkane feedstock into countercurrent contact with the catalyst at high temperature. Moreover, due to the short contact time, the oil-agent mixture quickly enters the ascending reactor with a gradually increasing reactor diameter, thereby avoiding the formation of byproducts such as polymerization between olefins.

[0067] In particular, in the present invention, in order to enhance the contact between the alkane feedstock and the catalyst, the alkane feedstock and the catalyst may be brought into countercurrent contact in the contact step.

[0068] In one embodiment of the present invention, in the contacting step, the oil agent contacting zone 12 is provided with a feed distributor 103 and a catalyst distributor 104, and the feed distributor 103 and the catalyst distributor 104 are arranged to form a space for countercurrent contact of the oil agent.

[0069] In one embodiment of the present invention, as shown in Figure 4, when the feed distributor 103 is located upstream of the catalyst distributor 104, the distance between the feed distributor 103 and the bottom of the oil-agent contact zone 12 accounts for 0 to 1 / 2 of the height of the oil-agent contact zone 12, preferably 0 to 1 / 4; the distance between the catalyst distributor 104 and the bottom of the oil-agent contact zone 12 accounts for 1 / 2 to 1 of the height of the oil-agent contact zone 12, preferably 3 / 4 to 1.

[0070] In one embodiment of the present invention, as shown in Figure 5, when the catalyst distributor 104 is located upstream of the feed distributor 103, the distance between the feed distributor 103 and the bottom of the oil-agent contact zone 12 accounts for 1 / 2 to 1 of the height of the oil-agent contact zone 12, preferably 3 / 4 to 1; the distance between the catalyst distributor 104 and the bottom of the oil-agent contact zone 12 accounts for 0 to 1 / 2 of the height of the oil-agent contact zone 12, preferably 0 to 1 / 4.

[0071] In the present invention, a ratio of 0 in the height of the oil contact area 12 means that the area is located at the bottom (upstream end) of the oil contact area 12, and a ratio of 1 in the height of the oil contact area 12 means that the area is located at the top (downstream end) of the oil contact area 12.

[0072] It should be noted that, as shown in Figure 5, the feed distributor 103 can be located in the middle and upper part of the oil contact zone 12, and the catalyst distributor 104 can be located in the middle and lower part of the oil contact zone 12. Conversely, as shown in Figure 4, the feed distributor 103 can be located in the middle and lower part of the oil contact zone 12, and the catalyst distributor 104 can be located in the middle and upper part of the oil contact zone 12. In short, a certain distance needs to be separated between the feed distributor 103 and the catalyst distributor 104 to form an oil contact space. By controlling the distance between the feed distributor and the catalyst distributor and the bottom of the oil contact zone as above, an oil contact space of appropriate volume can be formed between the feed distributor and the catalyst distributor, so that the alkane feedstock and the catalyst can be better countercurrent mixed to initiate the reaction.

[0073] In the present invention, preferably, as shown in FIG5 , the feed distributor 103 can be located in the upper middle portion of the oil-agent contact zone 12, and the catalyst distributor 104 can be located in the lower middle portion of the oil-agent contact zone 12. In this case, in the oil-agent contact zone, the alkane feedstock is sprayed downward through the nozzle of the feed distributor 103, while the lifting gas passes through the catalyst distributor 104, lifting the catalyst. Strong convection is formed between the two, ensuring sufficient contact between the catalyst and the alkane feedstock.

[0074] In one embodiment of the present invention, as shown in Figure 6, the feed distributor 103 is an annular structure with a plurality of alkane feed holes spaced apart thereon. In one embodiment of the present invention, the porosity of the feed distributor 103 is 60-95%, preferably 75-90%; the plurality of alkane feed holes are evenly or unevenly distributed. In one embodiment of the present invention, the diameter of the alkane feed hole is 1 / 4-3 / 4 of the width of the annular feed distributor 103, and the diameters of the plurality of alkane feed holes are equal or unequal.

[0075] In the present invention, the porosity of the feed distributor refers to the percentage of the total area of ​​the openings on the annular structure to the projected area of ​​the top view of the annular structure on the plane, that is: opening area / projected area of ​​the top view of the annular structure on the plane*100%.

[0076] In the present invention, the ring width of the feed distributor refers to the ring width of the projection of the top view of the annular structure on the plane.

[0077] In one embodiment of the present invention, as shown in Figures 7-8, the alkane feed hole is opened upward or downward, depending on the position of the feed distributor in the oil-agent contact zone.

[0078] In one embodiment of the present invention, the angle α between the axis of the alkane feed hole and the central axis of the feed distributor 103 is 15 to 75°.

[0079] It should be noted that when the catalyst distributor is located above the feed distributor, the alkane feed holes are opened upward, and vice versa. The alkane feedstock first enters the feed distributor 103 and is then injected into the oil-agent contact space through the alkane feed holes. By controlling the shape of the feed distributor, the diameter of the alkane feed holes, and the angle between the holes and the central axis of the feed distributor, the alkane feedstock can be injected into the oil-agent contact space in a well-dispersed state, allowing for sufficient contact with the catalyst, thereby better promoting the occurrence of the alkane catalytic dehydrogenation reaction and effectively improving the conversion rate and selectivity of the alkane catalytic dehydrogenation to produce olefins.

[0080] In one embodiment of the present invention, as shown in Figures 9 and 10, the catalyst distributor 104 is a disc-shaped structure having a plurality of catalyst feed holes. In one embodiment of the present invention, the catalyst distributor 104 has a porosity of 50-95%, preferably 70-90%. In one embodiment of the present invention, the plurality of catalyst feed holes are distributed evenly or unevenly; and the diameters of the plurality of catalyst feed holes are equal or unequal.

[0081] In the present invention, the porosity of the catalyst distributor refers to the ratio of the pore area on one surface (top or bottom) of the catalyst distributor to the area of ​​the surface (top or bottom).

[0082] In the present invention, the catalyst feed hole is a through-hole structure, and the axis of the catalyst feed hole is parallel to the central axis of the catalyst distributor 104. Therefore, the catalyst in the catalyst distributor can be lifted by the lifting gas passing through the catalyst distributor.

[0083] In the catalytic dehydrogenation step of the present invention, the pre-contacted oil-agent mixture from the oil-agent contact zone is introduced into an ascending reactor, whose radial diameter gradually increases from downstream to upstream, for catalytic dehydrogenation. The oil-agent mixture enters the ascending reactor through the center of the annular feed distributor (if the feed distributor is downstream of the catalyst distributor); alternatively, the oil-agent mixture enters the ascending reactor through the through-holes of the catalyst distributor (if the catalyst distributor is downstream of the feed distributor).

[0084] In the catalytic dehydrogenation step of the present invention, the ascending reactor is a combination of one or more selected from a bubbling bed reactor, a turbulent bed reactor, a fast bed reactor and a transport bed reactor, preferably a fast bed reactor.

[0085] In the catalytic dehydrogenation step of the present invention, the radial diameter of the upward reactor gradually expands from downstream to upstream, thereby forming an expanding diameter reactor with a small diameter upstream of the reactor and a large diameter downstream of the reactor.

[0086] In one embodiment of the present invention, as shown in Figure 11, the upward reactor is a tapered variable diameter reactor. At this time, the diameter of the reactor gradually increases from upstream to downstream, and the angle β between the outer surface and the central axis is greater than 0 to 20°, and the preferred angle β is 1 to 10°.

[0087] In one embodiment of the present invention, the ratio of the lower diameter to the upper diameter of the tapered reducing reactor is 1: greater than 1 to 10, preferably 1:1.1 to 5, more preferably 1:1.2 to 3, and even more preferably 1:1.2 to 2.

[0088] In the present invention, the lower diameter of a tapered reactor refers to the diameter of the cross section of the reactor's lowest portion. The upper diameter of a tapered reactor refers to the diameter of the cross section of the reactor's highest portion. From the perspective of the reactant flow, the lower diameter portion is the upstream portion of the reactant flow, and the upper diameter portion is the downstream portion of the reactant flow.

[0089] In the present invention, in the device of the tapered reducing reactor shown in FIG2 , the alkane conversion rate and olefin selectivity can be further improved by controlling the angle between the outer surface and the central axis of the tapered reducing reactor and the ratio of the lower diameter to the upper diameter as described above.

[0090] In one embodiment of the present invention, the variable diameter reactor comprises 2 to 20 (preferably 5 to 10) equal diameter reaction sections connected in sequence; and from bottom to top, that is, from upstream to downstream, the diameters of the two connected equal diameter reaction sections gradually increase, and preferably the lengths of the equal diameter reaction sections are equal; the diameter ratio of the two equal diameter reaction sections connected vertically is 1.02 to 1.5:1, preferably 1.03 to 1.2:1, and the ratio of the diameter of the upstream equal diameter reaction section to the diameter of the downstream equal diameter reaction section is 1: greater than 1 to 10, preferably 1:1.1 to 5, more preferably 1:1.2 to 3, and further preferably 1:1.2 to 2.

[0091] In one embodiment of the present invention, the variable diameter reactor comprises 2 to 20 (preferably 5 to 10) variable diameter reaction sections connected in sequence; and from upstream to downstream, that is, from upstream to downstream, the diameter of each variable diameter reaction section gradually increases, and preferably the lengths of the variable diameter reaction sections are equal; the ratio of the upper diameter to the lower diameter of each variable diameter reaction section is 1.01 to 1.2:1, preferably 1.02 to 1.1:1, and the ratio of the lower diameters of the two variable diameter reaction sections connected vertically is 1.02 to 1.5:1, preferably 1.03 to 1.2:1, and the ratio of the lower diameter of the upstream variable diameter reaction section to the upper diameter of the downstream variable diameter reaction section is 1: greater than 1 to 10, preferably 1:1.1 to 5, more preferably 1:1.2 to 3, and further preferably 1:1.2 to 2.

[0092] In the present invention, the lower diameter of a variable diameter reactor refers to the diameter of the cross section of the reactor / reaction section at the spatially lowest end (logistically upper end) of the same reaction section or the entire variable diameter reactor. The upper diameter of a variable diameter reactor refers to the diameter of the cross section of the reactor / reaction section at the spatially lowest end (logistically lower end) of the same reaction section or the entire variable diameter reactor.

[0093] In the present invention, the reactor is a tapered reducing reactor, as shown in Figure 1, and the reactor is a variable diameter reactor comprising 2 to 20 (preferably 5 to 10) sections of equal diameter reaction zones connected in sequence, as shown in Figure 2. When the reactor is a tapered reducing reactor, when the reactant stream flows from bottom to top, the diameter of the tapered reducing reactor gradually increases from bottom to top, thereby reducing the hydrocarbon partial pressure of the alkane feedstock in the reaction system, promoting the conversion of the alkane feedstock, and improving the alkane conversion rate. In particular, by controlling the angle β between the outer surface and the central axis of the tapered reducing reactor to be greater than 0 to 20°, the alkane conversion rate and olefin selectivity can be further improved. In addition, when the reactor is a variable diameter reactor, when the reactant stream flows from bottom to top, the diameter of the reactor gradually increases from bottom to top, thereby reducing the hydrocarbon partial pressure of the alkane feedstock in the reaction system, promoting the conversion of the alkane feedstock, and improving the alkane conversion rate. In particular, by controlling the ratio of the diameter of the most downstream constant-diameter reaction section of the variable-diameter reactor to the diameter of the most upstream constant-diameter reaction section to a specific value, combined with the residence time of the oil mixture in the reactor, the overall height of the reactor can be controlled, which can further improve the alkane conversion rate and olefin selectivity.

[0094] In the present invention, the bottom conditions of the reactor 13 include: a temperature of 520-680°C, preferably 540-660°C, a catalyst density of 100-400 kg / m 3 , preferably 150~350kg / m 3 .

[0095] In the present invention, the bottom conditions of the reactor 13 include: a pressure of 0.05 to 0.2 MPa, preferably 0.05 to 0.15 MPa.

[0096] In the present invention, the conditions at the top of the reactor 13 include: a temperature of 480-640°C, preferably 500-620°C, a catalyst density of 30-200 kg / m 3 , preferably 50 to 150 kg / m 3 .

[0097] In the present invention, the conditions at the top of the reactor 13 include: a pressure of 0.05 to 0.15 MPa, preferably 0.05 to 0.12 MPa.

[0098] In the present invention, the bottom conditions of the reactor 13 refer to the conditions at the lowermost end of the reactor (the uppermost end of the reactant flow in the reactor); the top conditions of the reactor 13 refer to the conditions at the uppermost end of the reactor (the lowermost end of the reactant flow in the reactor).

[0099] In the present invention, the residence time of the oil mixture in the reactor 13 is 0.2 to 5 seconds, preferably 0.4 to 2 seconds. Here, the residence time in the reactor 13 refers to the time from entering the reactor to leaving the reactor.

[0100] In one embodiment of the present invention, a rapid cooling step is further provided between the catalytic dehydrogenation step and the oil separation step.

[0101] In the present invention, in the quenching step, the oil mixture discharged from the upward reactor 13 enters the product quenching zone 14 for cooling. The temperature of the product quenching zone 14 is 200-550°C, preferably 250-500°C.

[0102] In one embodiment of the present invention, the cooled oil-agent mixture enters the quick separation device 107 for separation, the separated catalyst to be regenerated enters the stripping zone 16 for stripping, and the separated oil-agent mixture enters the oil-agent separation step after passing through the reaction outlet zone 15.

[0103] In one embodiment of the present invention, the product quenching zone 14 is provided with a heat exchange coil 141 for introducing a quenching medium. The heat exchange coil 141 comprises a plurality of annular tubes connected end to end. A quenching medium inlet is provided on one side of the top of the heat exchange coil 141, and a quenching medium outlet is provided on one side of the bottom of the heat exchange coil. In one embodiment of the present invention, the quenching medium inlet may be provided on one side of the top annular tube, and the quenching medium outlet may be provided on one side of the bottom annular tube. The quenching medium inlet and the quenching medium outlet may be provided on the same side or on different sides.

[0104] The quenching medium is selected from one or more of quenching oil, quenching water, quenching gas, and an alkane feedstock, preferably an alkane feedstock. The quenching oil is, for example, gasoline, kerosene, diesel, etc., the quenching water is, for example, tap water, circulating water, and the quenching gas is, for example, air, dry gas, liquefied gas, etc.

[0105] It should be noted that in the method of the present invention, by controlling the temperature of the oil mixture in the quenching step as described above, the temperature of the oil mixture after the reaction can be rapidly cooled, and then the catalyst and oil gas can be quickly separated to quickly terminate the reaction, avoid the occurrence of side reactions, and improve olefin selectivity and alkane conversion rate.

[0106] In one embodiment of the present invention, the conditions of the quick separation device 107 include: the linear velocity of the oil-agent mixture at the inlet of the quick separation device is 2 to 20 m / s, preferably 5 to 18 m / s, and the linear velocity of the oil-agent mixture at the outlet of the quick separation device is 2 to 15 m / s, preferably 5 to 10 m / s.

[0107] In one embodiment of the present invention, the rapid separation device 107 is selected from a combination of one or more of a cyclone-type rapid separator, a three-leaf rapid separator, a catapult-type rapid separator, a U-shaped tube separator, a wall-cutting rapid separator, and a cantilever-type rapid separator, preferably a cyclone-type rapid separator. The inlet of the rapid separation device is connected to the outlet of the quenching zone, and the outlet of the rapid separation device is connected to the reaction outlet zone.

[0108] It should be noted that, in the present invention, the quick separation device 107 is selected from one or more combinations of the above-mentioned separators, especially when it is a cyclone-type quick separator. The oil-agent mixture after rapid cooling in the quenching zone can be quickly separated in the first step by the quick separation device, and then the second step of separation is carried out through the oil-agent separation step. This can enable the oil-agent mixture to be efficiently and quickly separated into oil, gas and catalyst, prevent the catalyst from catalyzing side reactions of oil and gas, and further improve the olefin selectivity and alkane conversion rate.

[0109] In one embodiment of the present invention, as shown in Figure 14, the quick separation device 107 includes a connected variable diameter section and a constant diameter section, the constant diameter section is connected to the downstream end of the variable diameter section, and the diameter of the variable diameter section gradually increases from upstream to downstream; the quick separation oil agent inlet 301 is opened on the upper side of the constant diameter section, the quick separation catalyst outlet 302 is located at the bottom of the variable diameter section, and the quick separation oil and gas outlet 303 is located at the top of the constant diameter section.

[0110] In one embodiment of the present invention, as shown in Figure 15, the quick separation device 107 includes an external structure and an internal structure, the external structure includes an external constant diameter section, an external variable diameter section and an external outlet constant diameter section that are connected in sequence, and the diameter of the external variable diameter section gradually decreases from the upstream to the downstream direction; the internal structure includes a constant diameter separation section with one end closed and sleeved inside the external constant diameter section, the quick separation oil agent inlet 301 is located at the bottom of the constant diameter separation section of the internal structure, the quick separation catalyst outlet 302 is opened on the upper side of the equal diameter separation section of the internal structure, and the quick separation oil and gas outlet 303 is located at the top of the external outlet constant diameter section.

[0111] It should be noted that the oil-solvent mixture after the quenching step enters the quick separation device through the quick separation oil-solvent inlet 301 for rapid separation of the catalyst and oil gas. The separated catalyst is output through the quick separation catalyst outlet 302 and enters the stripping zone for stripping. The separated oil-solvent mixture is output through the quick separation oil and gas outlet 303 and enters the reaction outlet zone. By selecting a quick separation device with the structure shown in Figures 14 or 15, the oil-solvent mixture after the quenching step can be more quickly separated, side reactions can be suppressed, and alkane conversion and olefin selectivity can be further improved.

[0112] In the oil separation step of the present invention, the oil mixture obtained in the catalytic dehydrogenation step is separated to obtain an oil-gas mixture and a catalyst to be regenerated. The oil mixture fed to the oil separation step may optionally be cooled in a quenching step and optionally subjected to a first separation in a rapid separation device.

[0113] In one embodiment of the present invention, in the oil-agent separation step, the oil-agent mixture is introduced into the first two-stage cyclone separator 108 for separation, the catalyst to be regenerated separated by the first two-stage cyclone separator 108 enters the stripping zone 16 for stripping, and the separated oil-gas mixture is discharged from the reaction oil-gas outlet.

[0114] In one embodiment of the present invention, stripping gas is introduced into the stripping zone 16 through a stripping gas pipe to remove residual reaction oil gas on the spent catalyst. The stripping gas can be well known to those skilled in the art, such as one or more selected from water vapor, nitrogen, and dry gas, preferably water vapor.

[0115] In the method of the present invention, the product separation step separates the oil-gas mixture from the oil agent separation step to obtain olefins as products. In the present invention, the obtained olefins are C2-C8 lower olefins, preferably at least one of ethylene, propylene, butene, and isobutylene, with propylene being preferred. The separation method in the product separation step can employ methods known in the art for separating olefins, including but not limited to distillation, quenching, membrane separation, and other separation methods. Distillation includes but is not limited to cryogenic distillation, extractive distillation, and adsorptive separation.

[0116] In one embodiment of the present invention, the method of the present invention further includes a regeneration step, wherein the catalyst to be regenerated taken out from the stripping zone 16 is introduced into the regeneration zone 22 for regeneration; and the regenerated catalyst taken out from the regeneration zone 22 is introduced into the oil contact step as a catalyst.

[0117] In one embodiment of the present invention, in the regeneration step, the temperature of the regeneration zone 22 is 600-720°C, preferably 620-700°C, and the catalyst density is 50-500 kg / m 3 , preferably 100~400kg / m 3 , the pressure is 0.05-0.2 MPa, preferably 0.05-0.15 MPa, and the regeneration gas includes oxygen and / or air.

[0118] In one embodiment of the present invention, in the regeneration step, the regeneration zone 22 is provided with a regeneration heat supplement zone 21. In the regeneration heat supplement zone 21, heat is supplemented to the regeneration zone 22 by burning one or more of methane, ethane, dry gas, liquefied gas, fuel oil and dry gas. Preferably, the dry gas is dry gas, and more preferably, the dry gas is obtained as a by-product in the product separation step of the method of the present invention.

[0119] It should be noted that in the regeneration heating zone 21, fuel is introduced through a fuel pipe to be burned, thereby replenishing heat for the regeneration zone and enabling the entire reaction unit and regeneration unit to reach thermal equilibrium. The regenerated catalyst is regenerated in an oxygen-containing atmosphere in the regeneration zone, burning off the coke deposited on the regenerated catalyst and converting the active components in the catalyst into an oxidized state. After regeneration, the catalyst is separated from the regeneration flue gas carried by the second two-stage cyclone separator, and the regeneration flue gas passes through the regeneration gas collection chamber and is led out of the regeneration unit through the regeneration flue gas outlet. The regenerated catalyst flows out of the catalyst outlet of the second two-stage cyclone separator 205 and is supplied to the oil contact step through the regenerated catalyst outlet of the regeneration unit.

[0120] In one embodiment of the present invention, the method further comprises a negative pressure suction step, wherein the negative pressure suction step is performed between the oil separation step and the product separation step to suction the oil-gas mixture from the oil separation step.

[0121] In one embodiment of the present invention, a negative pressure drive device 19 is used in the negative pressure suction step, and the negative pressure drive device 19 is a combination of one or more selected from centrifugal negative pressure fans, axial flow negative pressure fans, diagonal flow negative pressure fans and cross flow negative pressure fans.

[0122] In one embodiment of the present invention, the catalyst to be regenerated taken out from the stripping zone 16 is introduced into the regeneration zone 22 via the spent catalyst receiver 18 for regeneration. Preferably, a purge gas is introduced into the spent catalyst receiver 18 via the purge gas inlet 115, and the purge mixed gas drawn out from the upper part of the spent catalyst receiver 18 enters the oil-agent separation step. The purge gas is an inert gas, and the inert gas is selected from one or more of nitrogen, helium and argon.

[0123] In one embodiment of the present invention, the regenerated catalyst taken out from the regeneration zone 16 is introduced into the oil-agent contact step via the regeneration agent receiver 20. Preferably, the reducing gas is introduced into the regeneration agent receiver 20 via the reducing gas inlet 211, and the reducing mixed gas drawn out from the upper part of the regeneration agent receiver 20 enters the regeneration step. The reducing gas is one or more selected from hydrogen, methane, refinery dry gas and oilfield dry gas.

[0124] In one embodiment of the present invention, the method of the present invention may further include a preheating step, wherein the alkane feedstock is preheated to 350-500° C. before entering the oil-agent contacting step to contact the catalyst.

[0125] The second aspect of the present invention provides an apparatus for producing olefins by catalytic dehydrogenation of alkanes, wherein the apparatus is used to carry out the method for producing olefins by catalytic dehydrogenation of alkanes of the present invention, which comprises a reaction unit 1, a regeneration unit 2 and a product separation unit.

[0126] From upstream to downstream, the reaction unit 1 includes a pre-elevation zone 11, an oil-agent contact zone 12, a reactor 13, a product quenching zone 14, a reaction outlet zone 15, an oil-agent separation zone 17 and a stripping zone 16.

[0127] The pre-lifting zone 11 is provided with a pre-lifting gas pipe 101 for introducing pre-lifting gas, and the pre-lifting zone 11 is connected to the inlet of the oil contact zone 12;

[0128] The outlet of the oil-agent contact zone 12 is communicated with the inlet of the reactor 13. The oil-agent contact zone 12 is provided with a feed distributor 103 and a catalyst distributor 104. An oil-agent countercurrent contact space is formed between the feed distributor 103 and the catalyst distributor 104.

[0129] The inlet of the product quenching zone 14 is communicated with the outlet of the reactor 13, and the outlet of the product quenching zone 14 is communicated with the inlet of the reaction outlet zone 15. Preferably, a quick separation device 107 is provided between the product quenching zone 14 and the reaction outlet zone 15, the outlet of the product quenching zone 14 is communicated with the quick separation oil agent inlet 301 of the quick separation device 107, the quick separation catalyst outlet 302 of the quick separation device 107 is communicated with the catalyst inlet of the stripping zone 16, and the quick separation oil and gas outlet 303 of the quick separation device 107 is communicated with the inlet of the reaction outlet zone 15;

[0130] The inlet of the oil-agent separation zone 17 is communicated with the outlet of the reaction outlet zone 15, the catalyst outlet of the oil-agent separation zone 17 is communicated with the catalyst inlet of the stripping zone 16, and the oil and gas outlet of the oil-agent separation zone 17 is communicated with the reaction oil and gas outlet 110. Preferably, the oil-agent separation zone 17 is provided with a first two-stage cyclone separator 108; the outlet of the reaction outlet zone 15 is communicated with the inlet of the first two-stage cyclone separator 108; the catalyst outlet of the first two-stage cyclone separator 108 is communicated with the catalyst inlet of the stripping zone 16, and the oil and gas outlet of the first two-stage cyclone separator 108 is communicated with the reaction oil and gas outlet 110;

[0131] The stripping zone 16 is provided with a stripping gas pipe 111 for introducing stripping gas, a stripping oil and gas outlet, and a catalyst outlet. The catalyst outlet is connected to the regenerated catalyst inlet of the regeneration unit 2 via a regenerated catalyst delivery pipe 105. The regenerated catalyst delivery pipe 105 is optionally provided with a regenerated slide valve 106. The stripping oil and gas outlet of the stripping zone 16 is connected to the reaction oil and gas outlet 110.

[0132] The regenerated catalyst outlet of the regeneration unit 2 is connected to the catalyst inlet of the catalyst distributor 104 of the oil contact zone 12 through a regenerated catalyst delivery pipe 203 . The regenerated catalyst delivery pipe 203 is optionally provided with a regeneration slide valve 204 .

[0133] As a schematic embodiment, FIG1 , FIG2 and FIG3 show the apparatus for producing olefins by catalytic dehydrogenation of alkanes according to the present invention.

[0134] It should be noted that among the multiple zones included in the reaction unit, any two adjacent zones are fluidically connected, for example, the pre-lifting zone 11 and the oil-agent contact zone 12 are fluidically connected, and the reaction outlet zone 15 and the oil-agent separation zone 17 are fluidically connected. The regenerated catalyst in the regeneration unit 2 is transported to the catalyst distributor 104 via the regenerated catalyst delivery pipe 203 and then enters the oil contact space of the oil contact zone 12. The alkane feedstock enters the oil contact space of the oil contact zone 12 via the feed distributor 103. The catalyst and the alkane feedstock are fully contacted in a countercurrent manner in the oil contact space to initiate a reaction; then the catalyst enters the reactor for reaction, and the oil mixture after the reaction enters the product quenching zone for rapid cooling to avoid or reduce the occurrence of side reactions; in the oil separation zone, the oil mixture is separated, and the separated reaction oil and gas are transported out through the reaction oil and gas outlet. The separated catalyst to be regenerated is stripped in the stripping zone and then enters the regeneration unit for regeneration. The obtained regenerated catalyst returns to the catalyst distributor 104 via the regenerated catalyst delivery pipe 203 and then enters the oil contact space of the oil contact zone 12 to contact with the alkane feedstock in countercurrent for recycling.

[0135] In the device of the present invention, in the reaction unit, the alkane feedstock and the catalyst are fully contacted in the oil-agent contact zone 12, and then introduced into the reactor together with the pre-lifting gas from the pre-lifting zone for reaction. The oil-agent mixture after the reaction is introduced into the product quenching zone, and the temperature of the oil-agent mixture is rapidly reduced and then enters the quick separation device for rapid separation of the catalyst and the oil-gas mixture. The quickly separated catalyst to be regenerated enters the stripping zone for stripping. The quickly separated oil-agent mixture carrying catalyst fine powder is introduced into the oil-agent separation zone after passing through the reaction outlet zone and further oil-agent separation is carried out through the first two-stage cyclone separator. The reaction oil and gas separated by the cyclone are led out of the device, and the catalyst to be regenerated by the cyclone is introduced into the stripping zone for stripping. The stripped catalyst to be regenerated is introduced into the regeneration unit for regeneration, and the regenerated catalyst is returned to the oil-agent contact zone for recycling.

[0136] Therefore, the above-mentioned device of the present invention can provide a fully mixed space and a suitable reaction environment for the catalytic dehydrogenation reaction of alkanes, better avoid the occurrence of side reactions through the cooperation of the product quenching zone and the oil separation zone, and better promote the progress of the catalytic dehydrogenation reaction of alkanes, thereby significantly improving the alkane conversion rate and olefin selectivity.

[0137] In one embodiment of the present invention, a pre-lift gas pipe 101 is connected to the bottom of the pre-lift zone 11. Pre-lift gas can be introduced into the pre-lift zone through the pre-lift gas pipe 101, so that the fully contacted alkane feedstock and catalyst mixture enter the reactor from the oil contact zone to undergo catalytic dehydrogenation reaction.

[0138] In the present invention, the pre-lift gas may be any gas well known to those skilled in the art, such as one or more of water vapor, nitrogen, and dry gas, preferably water vapor.

[0139] In one embodiment of the present invention, the oil contact zone 12 is provided with an alkane feed pipe 102 for introducing the alkane raw material into the feed distributor 103 .

[0140] In one embodiment of the present invention, the stripping zone 16 is provided with a stripping gas pipe 111 for introducing stripping gas.

[0141] In one embodiment of the present invention, the ratio of the diameter to the height of the product quenching zone 14 is 1:1 to 3, preferably 1:1 to 1.5.

[0142] In one embodiment of the present invention, the product quenching zone 14 is provided with a heat exchange coil 141 for introducing a quenching medium. The heat exchange coil 141 comprises a plurality of annular tubes connected end to end. A quenching medium inlet is provided on one side of the top of the heat exchange coil 141, and a quenching medium outlet is provided on one side of the bottom of the heat exchange coil. In one embodiment of the present invention, the quenching medium inlet may be provided on one side of the top annular tube, and the quenching medium outlet may be provided on one side of the bottom annular tube. The quenching medium inlet and the quenching medium outlet may be provided on the same side or on different sides.

[0143] In the apparatus of the present invention, as shown in Figures 1-3, the product quench zone includes the heat exchange coil and the area enclosed by the heat exchange coil. By introducing a quenching medium into the heat exchange coil in the product quench zone, the reaction product (the post-reaction oil-solvent mixture) can be rapidly cooled to a lower temperature, thereby suppressing side reactions and improving olefin selectivity. The quenching medium includes one or more of quench oil, quench water, quench gas, and an alkane feedstock. An alkane feedstock is preferred.

[0144] In one embodiment of the present invention, a quick separation device 107 is provided between the product quenching zone 14 and the reaction outlet zone 15, the outlet of the product quenching zone 14 is connected to the quick separation oil agent inlet 301 of the quick separation device 107, the quick separation catalyst outlet 302 of the quick separation device 107 is connected to the catalyst inlet of the stripping zone 16, and the quick separation oil and gas outlet 303 of the quick separation device 107 is connected to the inlet of the reaction outlet zone 15.

[0145] In one embodiment of the present invention, the quick separation device 107 is a combination of one or more selected from a cyclone quick separator, a three-leaf quick separator, a catapult quick separator, a U-shaped tube separator, a wall-cutting quick separator and a cantilever quick separator, preferably a cyclone quick separator.

[0146] In one embodiment of the present invention, as shown in Figure 14, the quick separation device 107 includes a connected variable diameter section and a constant diameter section, the constant diameter section is connected to the downstream end of the variable diameter section, and the diameter of the variable diameter section gradually increases from upstream to downstream; the quick separation oil agent inlet 301 is opened on the upper side of the constant diameter section, the quick separation catalyst outlet 302 is located at the bottom of the variable diameter section, and the quick separation oil and gas outlet 303 is located at the top of the constant diameter section.

[0147] In one embodiment of the present invention, as shown in Figure 15, the quick separation device 107 includes an external structure and an internal structure, the external structure includes an external constant diameter section, an external variable diameter section and an external outlet constant diameter section that are connected in sequence, and the diameter of the external variable diameter section gradually decreases from the upstream to the downstream direction; the internal structure includes a constant diameter separation section with one end closed and sleeved inside the external constant diameter section, the quick separation oil agent inlet 301 is located at the bottom of the constant diameter separation section of the internal structure, the quick separation catalyst outlet 302 is opened on the upper side of the equal diameter separation section of the internal structure, and the quick separation oil and gas outlet 303 is located at the top of the external outlet constant diameter section.

[0148] In one embodiment of the present invention, the oil separation zone 17 is provided with a first two-stage cyclone separator 108; the outlet of the reaction outlet zone 15 is connected to the inlet of the first two-stage cyclone separator 108; the catalyst outlet of the first two-stage cyclone separator 108 is connected to the catalyst inlet of the stripping zone 16, and the oil and gas outlet of the first two-stage cyclone separator 108 is connected to the reaction oil and gas outlet 110.

[0149] As described above, the oil-solvent mixture, after being quenched in the product quenching zone 14, first enters the quick separation device 107 for rapid separation of the oil-solvent. After the initial rapid separation, the catalyst enters the stripping zone 16 for stripping. The oil and gas carrying the catalyst fines after the initial rapid separation enter the reaction outlet zone and are then introduced into the first two-stage cyclone separator for cyclone separation. The catalyst fines carried by the reaction oil and gas are then separated and then enter the stripping zone for stripping. Specifically, the oil-solvent mixture undergoes initial separation in the quick separation device. Afterwards, the oil and gas containing the catalyst fines pass through the reaction outlet zone and are introduced into the first two-stage cyclone separator for further separation. The catalyst separated by both the quick separation device and the first two-stage cyclone separator enters the stripping zone for stripping. The coordinated operation of these two separation devices allows for rapid separation of the reacted oil-solvent mixture, further suppressing side reactions and improving olefin selectivity. On the other hand, after the quick separation device performs preliminary separation on the reacted oil-agent mixture, it can not only reduce the load of the first two-stage cyclone separators and improve the separation efficiency, but also reduce the oil and gas and catalyst gas velocities at the inlet of the first two-stage cyclone separators, reduce catalyst wear and reduce catalyst loss.

[0150] In one embodiment of the present invention, the oil separation zone 17 is provided with a first two-stage cyclone separator 108 and an air collecting chamber 109. At this time, the oil and gas outlet of the first two-stage cyclone separator 108 is connected to the oil and gas inlet of the air collecting chamber 109, and the oil and gas outlet of the air collecting chamber 109 is the reaction oil and gas outlet 110.

[0151] In one embodiment of the present invention, stripping gas is introduced into the stripping zone 16 through a stripping gas pipe to remove residual reaction oil gas on the spent catalyst. The stripping gas can be well known to those skilled in the art, such as one or more selected from water vapor, nitrogen, and dry gas, preferably water vapor.

[0152] In one embodiment of the present invention, the regeneration unit 2 includes a regeneration zone 22 and a regeneration heating zone 21. The inlet of the catalyst to be regenerated of the regeneration unit 2 is connected to the regeneration zone 22. The catalyst to be regenerated is regenerated in the regeneration zone 22, and the regeneration zone 22 is heated by the regeneration heating zone 21.

[0153] In one embodiment of the present invention, the regeneration zone 22 is provided with a main air duct 208 for introducing regeneration gas, and the catalyst outlet of the regeneration zone 22 is connected to the inlet of the second two-stage cyclone separator 205 .

[0154] In one embodiment of the present invention, in the regeneration zone, a regeneration gas with an oxidizing effect is introduced into the regeneration zone through the main air duct 208 to burn off the coke deposited on the catalyst to be regenerated and convert the active components in the catalyst into an oxidized state, thereby restoring the dehydrogenation activity of the catalyst. The regeneration gas with an oxidizing effect includes oxygen, air and other mixed gases containing oxygen.

[0155] In one embodiment of the present invention, the regeneration flue gas outlet of the second two-stage cyclone separator 205 is connected to the inlet of the regeneration plenum 206, which is provided with a regeneration flue gas outlet 207. The regenerated catalyst outlet of the second two-stage cyclone separator 205 is connected to the regenerated catalyst outlet of the regeneration unit 2. The regeneration flue gas carried by the regenerated catalyst is separated by the second two-stage cyclone separator. The regeneration flue gas passes through the regeneration plenum and is then led out of the regeneration unit through the regeneration flue gas outlet.

[0156] In one embodiment of the present invention, the regeneration and supplementary heating zone 21 is located inside or outside the regeneration zone 22. A fuel pipe 201 is provided in the regeneration and supplementary heating zone 21 for introducing fuel. The heat outlet of the regeneration and supplementary heating zone 21 communicates with the regeneration zone 22 via a fuel supplementary heating pipe 202. Fuel is introduced into the regeneration and supplementary heating zone via the fuel pipe 201 and combusted, thereby replenishing heat in the regeneration zone and achieving thermal equilibrium between the entire reaction unit and the regeneration unit. The fuel can be any fuel well known to those skilled in the art, for example, one or more of methane, ethane, dry gas, liquefied gas, and fuel oil, preferably dry gas produced by the method of the present invention.

[0157] In one embodiment of the present invention, the stripping zone 16 is provided with a stripping gas pipe 111 for introducing stripping gas, a stripping oil and gas outlet, and a catalyst outlet. The catalyst outlet is connected to the catalyst inlet of the regeneration unit 2 via the catalyst delivery pipe 105. The catalyst delivery pipe 105 is provided with a slide valve 106. The flow rate of the catalyst in the catalyst delivery pipe can be adjusted by adjusting the opening of the slide valve. The stripping oil and gas outlet of the stripping zone 16 is connected to the reaction oil and gas outlet 110.

[0158] In one embodiment of the present invention, the regenerated catalyst outlet of the regeneration unit 2 is connected to the catalyst inlet of the catalyst distributor 104 of the oil contact zone 12 through the regenerated catalyst delivery pipe 203. The regenerated catalyst delivery pipe 203 is provided with a regeneration slide valve 204. The flow rate of the regenerated catalyst in the regenerated catalyst delivery pipe can be adjusted by adjusting the opening of the regeneration slide valve.

[0159] In the present invention, the product separation unit includes conventional equipment for separating olefins from an oil-gas mixture, including but not limited to a distillation unit, a quenching unit, a membrane separation unit, and other separation devices. The distillation unit includes but is not limited to a cryogenic distillation unit, an extractive distillation unit, an adsorption separation unit, and the like. The product separation unit is not shown in the drawings of the present invention.

[0160] In one embodiment of the present invention, the device further includes a negative pressure drive device 19; the negative pressure drive device 19 is selected from a combination of one or more of a centrifugal negative pressure fan, an axial flow negative pressure fan, a diagonal flow negative pressure fan and a cross flow negative pressure fan.

[0161] In one embodiment of the present invention, the oil and gas outlet of the oil-agent separation zone 17 is connected to the oil and gas inlet of the negative pressure drive device 19 via an oil and gas pipeline 110, or the oil and gas outlet of the gas collecting chamber 109 is connected to the oil and gas inlet of the negative pressure drive device 19 via an oil and gas pipeline 110, and the negative pressure drive device 19 is also provided with an oil and gas outlet 114.

[0162] Oil and gas can be extracted by the negative pressure drive device 19 of the device of the present invention. The pressure in the reaction unit can be adjusted by adjusting the output power of the negative pressure drive device. By making the reaction zone negative pressure, the dehydrogenation reaction of alkanes to produce olefins can be better carried out in the direction of reacting to produce olefins, thereby improving the alkane conversion rate and olefin selectivity.

[0163] In one embodiment of the present invention, the device further comprises a spent agent receiver 18 and a regenerant agent receiver 20;

[0164] The catalyst outlet of the stripping zone 16 is connected to the catalyst inlet of the spent catalyst receiver 18, and the catalyst outlet of the spent catalyst receiver 18 is connected to the spent catalyst inlet of the regeneration unit 2; the spent catalyst receiver 18 is also provided with a purge gas inlet 115 and a purge mixed gas outlet 113; the purge mixed gas outlet 113 is connected to the upper part of the oil-agent separation zone 17.

[0165] The regenerated catalyst outlet of the regeneration unit 2 is connected to the catalyst inlet of the regeneration agent receiver 20, which is in turn connected to the catalyst inlet of the catalyst distributor 104 in the oil-agent contact zone 12. The regeneration agent receiver 20 is also provided with a reducing gas inlet 211 and a reducing gas mixture outlet 209; the reducing gas mixture outlet 209 is connected to the upper portion of the regeneration zone 22. In the regeneration agent receiver 20, the oxidized regenerated catalyst obtained by regeneration is reduced by the introduced reducing gas, and the reduced regenerated catalyst is recycled.

[0166] In one embodiment of the present invention, in the apparatus, the spent agent receiver 18 and the regenerant agent receiver 20 are lock hoppers.

[0167] At this point, the oil-gas mixture separated by the oil-agent separation zone 17 first enters the negative pressure drive device 19 before being output from the oil-gas outlet 114 of the negative pressure drive device 19. The spent catalyst obtained by stripping in the stripping zone 16 first enters the spent catalyst receiver 18 for oil-gas purging before entering the regeneration unit for regeneration. The regenerated catalyst obtained in the regeneration unit first enters the regenerant receiver 20 for reduction before entering the oil-agent contact zone 12 for recycling. By placing the spent catalyst receiver 18 and the regenerant receiver 20 between the reaction unit and the regeneration unit, the present device avoids direct connection between the negative pressure reaction unit and the constant pressure regeneration unit, enabling the reaction unit to operate under negative pressure while significantly improving safety.

[0168] It should be noted that the spent catalyst receiver 18 can transport the spent catalyst stripped from the negative pressure reaction unit to the regeneration unit at a constant pressure, while the regenerant receiver 20 can transport the regenerated catalyst from the regeneration unit at a constant pressure to the negative pressure reaction unit. Therefore, the spent catalyst receiver 18 and the regenerant receiver 20 can each be independently selected from lock hoppers of different models. Using lock hoppers as the spent catalyst receiver 18 and the regenerant receiver 20, respectively, can collaborate with the negative pressure drive device to effectively control the different pressures in the reaction unit and the regeneration unit, enhancing the safety of the entire device.

[0169] In one embodiment of the present invention, the following technical solution I is provided:

[0170] 1.1 A device for producing olefins by catalytic dehydrogenation of alkanes, characterized by comprising a reaction unit and a regeneration unit;

[0171] From upstream to downstream, the reaction unit includes a pre-lifting zone, an oil-agent contact zone, a reaction zone, a product quenching zone, a reaction outlet zone, an oil-agent separation zone, and a stripping zone in sequence;

[0172] The oil-agent contact zone is provided with a feed distributor and a catalyst distributor, and an oil-agent contact space is formed between the feed distributor and the catalyst distributor;

[0173] The oil separation zone is provided with a reaction oil and gas outlet and a catalyst outlet, and the catalyst outlet is connected to the catalyst inlet of the stripping zone;

[0174] The stripping zone is provided with a stripping oil and gas outlet and a catalyst outlet, wherein the catalyst outlet is connected to the regenerated catalyst inlet of the regeneration unit via a regenerated catalyst delivery pipe;

[0175] The regenerated catalyst outlet of the regeneration unit is connected to the catalyst inlet of the catalyst distributor via a regenerated catalyst delivery pipe;

[0176] I.2. The device according to I.1, characterized in that the reaction zone is a constant diameter reaction zone, a tapered diameter reaction zone, or a variable diameter reaction zone;

[0177] The ratio of the diameter to the height of the constant diameter reaction zone is 1:(5-50);

[0178] The diameter of the tapered variable diameter reaction zone gradually increases from upstream to downstream, and the angle (β) between the outer surface and the central axis is 0 to 20°;

[0179] I.3. The device according to I.1 or I.2, characterized in that the distance between the feed distributor and the bottom of the oil-agent contact zone accounts for 0 to 1 / 2, preferably 0 to 1 / 4, of the height of the oil-agent contact zone; the distance between the catalyst distributor and the bottom of the oil-agent contact zone accounts for 1 / 2 to 1, preferably 3 / 4 to 1, of the height of the oil-agent contact zone;

[0180] or,

[0181] The distance between the feed distributor and the bottom of the oil contact zone accounts for 1 / 2 to 1 of the height of the oil contact zone, preferably 3 / 4 to 1; the distance between the catalyst distributor and the bottom of the oil contact zone accounts for 0 to 1 / 2 of the height of the oil contact zone, preferably 0 to 1 / 4;

[0182] I.4. The device according to I.1 or I.2, characterized in that the feed distributor is an annular structure having a plurality of alkane feed holes spaced apart thereon;

[0183] The opening rate of the feed distributor is 60-95%, preferably 75-90%;

[0184] The plurality of alkane feed holes are distributed evenly or unevenly;

[0185] The diameter of the alkane feed hole is 1 / 4 to 3 / 4 of the ring width of the feed distributor of the annular structure, and the diameters of the plurality of alkane feed holes are equal or unequal;

[0186] The alkane feed hole is opened upward or downward, and the angle (α) between the axis of the alkane feed hole and the central axis of the feed distributor is 15 to 75°;

[0187] I.5. The device according to I.1 or I.2, characterized in that the catalyst distributor is a disc structure having a plurality of catalyst feed holes;

[0188] The catalyst distributor has an opening rate of 50 to 95%, preferably 70 to 90%;

[0189] The plurality of catalyst feed holes are distributed evenly or unevenly;

[0190] The diameters of the plurality of catalyst feed holes are equal or unequal;

[0191] The catalyst feed hole is opened upward or downward, and the axis of the catalyst feed hole is parallel to the central axis of the catalyst distributor;

[0192] I.6. The apparatus according to I.2, characterized in that the ratio of the diameter to the height of the constant diameter reaction zone is 1:(10-30);

[0193] The angle (β) between the outer surface of the tapered variable diameter reaction zone and the central axis is 0 to 10°;

[0194] The ratio of the lower diameter to the upper diameter of the tapered variable diameter reaction zone is 1:1 to 10, preferably 1:1.2 to 5;

[0195] I.7. The device according to I.2, characterized in that the variable diameter reaction zone comprises a plurality of sequentially connected reaction sections of equal diameter, wherein the diameters of the reaction sections of equal diameter gradually increase from bottom to top, and the diameter ratio of the two consecutive reaction sections of equal diameter is (1-2):1, preferably (1-1.5):1;

[0196] or,

[0197] The variable diameter reaction zone includes multiple variable diameter reaction sections connected in sequence; and from bottom to top, the diameter of any variable diameter reaction section gradually increases, and the ratio of the lower diameter to the upper diameter is 1:(1-2), preferably 1:(1-1.5); the ratio of the lower diameters of the two variable diameter reaction sections connected vertically is (1-3):1, preferably (1-1.5):1;

[0198] I.8. ​​The device according to I.1, characterized in that the pre-lifting zone is provided with a pre-lifting gas pipe for introducing pre-lifting gas;

[0199] The oil agent contact zone is provided with an alkane feed pipe for introducing alkane raw materials into the feed distributor;

[0200] The stripping zone is provided with a stripping gas pipe for introducing stripping gas;

[0201] A quick separation device is provided between the product quenching zone and the reaction outlet zone, and a first two-stage cyclone separator is provided in the oil-agent separation zone; the outlet of the product quenching zone is communicated with the inlet of the quick separation device, the catalyst outlet of the quick separation device is communicated with the catalyst inlet of the stripping zone, the oil and gas outlet of the quick separation device is communicated with the inlet of the reaction outlet zone, the outlet of the reaction outlet zone is communicated with the inlet of the first two-stage cyclone separator, and the catalyst outlet of the first two-stage cyclone separator is communicated with the catalyst inlet of the stripping zone;

[0202] The oil separation zone is further provided with an air collecting chamber, the oil and gas outlet of the first two-stage cyclone separator is connected to the oil and gas inlet of the air collecting chamber, and the oil and gas outlet of the air collecting chamber is the reaction oil and gas outlet;

[0203] The stripping oil and gas outlet of the stripping zone is in communication with the reaction oil and gas outlet;

[0204] I.9. The device according to I.1, characterized in that the regeneration unit includes a regeneration zone and a regeneration heating zone;

[0205] The catalyst inlet of the regeneration unit is connected to the regeneration zone, the regeneration zone is provided with a main air duct for introducing oxidizing gas, and the catalyst outlet of the regeneration zone is connected to the second two-stage cyclone separator;

[0206] The regeneration flue gas outlet of the second two-stage cyclone separator is connected to the inlet of the regeneration plenum, the regeneration plenum is provided with a regeneration flue gas outlet, and the regenerated catalyst outlet of the second two-stage cyclone separator is connected to the regeneration catalyst outlet of the regeneration unit;

[0207] The regeneration and heating zone is located inside or outside the regeneration zone, and the regeneration and heating zone is provided with a fuel pipe for introducing fuel, and the heat outlet of the regeneration and heating zone is connected to the regeneration zone through the fuel heating pipe;

[0208] The catalyst delivery pipe to be regenerated is provided with a slide valve to be regenerated, and the catalyst delivery pipe to be regenerated is provided with a slide valve to be regenerated;

[0209] I.10. The apparatus according to I.1, wherein the reaction zone is selected from a combination of one or more of a bubbling bed, a turbulent bed, a fast bed, and a transport bed;

[0210] The product quenching zone is provided with a heat exchange coil for introducing a quenching medium;

[0211] I.11. A method for producing olefins by catalytic dehydrogenation of alkanes, characterized in that the method is implemented based on the apparatus described in any one of I.1 to I.10;

[0212] The alkane raw material enters the oil-agent contact space through the feed distributor, and the catalyst enters the oil-agent contact space through the catalyst distributor;

[0213] Preferably, the alkane feedstock and the catalyst are in countercurrent contact in the oil contact space, the temperature of the oil contact space is 500-700°C, preferably 520-680°C, and the catalyst density is 100-500 kg / m 3 , preferably 150~400kg / m 3 The residence time of the alkane raw material and the catalyst in the oil agent contact space is 0.05 to 0.5 s, preferably 0.1 to 0.3 s;

[0214] I.12. The method according to I.11, characterized in that the catalyst comprises a support and a dehydrogenation-active component;

[0215] The carrier is selected from one or more of Al2O3, SiO2, ZrO2, TiO2 and molecular sieves, and the dehydrogenation active component is selected from one or more of Zn, Fe, Co, Ni, V, Sn and Mg;

[0216] Based on the weight of the catalyst, the content of the carrier is 10-90%, and the content of the active component is 10-90%; preferably, the content of the carrier is 30-80%, and the content of the active component is 20-70%;

[0217] The alkane raw material is selected from one or more alkanes with a carbon number of 2 to 8, preferably one or more of propane, n-butane and isobutane;

[0218] 1.13. The method according to 1.11, characterized in that the conditions at the bottom of the reaction zone include:

[0219] The temperature is 520-680°C, preferably 540-660°C, and the catalyst density is 150-400 kg / m 3 , preferably 200~350kg / m 3 , the pressure is 0.05-0.2MPa, preferably 0.05-0.15MPa;

[0220] The conditions at the top of the reaction zone include:

[0221] The temperature is 480-640°C, preferably 500-620°C, and the catalyst density is 30-200 kg / m 3 , preferably 50 to 150 kg / m 3 , the pressure is 0.05-0.15 MPa, preferably 0.05-0.12 MPa;

[0222] The temperature of the product quenching zone is 200-550°C, preferably 250-500°C;

[0223] The conditions for the quick separation device include:

[0224] The linear velocity of the oil at the inlet of the quick separation device is 2 to 20 m / s, preferably 5 to 18 m / s, and the linear velocity of the oil and gas at the outlet of the quick separation device is 2 to 15 m / s, preferably 5 to 10 m / s;

[0225] I.14. The method according to I.11, characterized in that the temperature in the regeneration zone is 600-720°C, preferably 620-700°C, and the catalyst density is 50-500 kg / m 3 , preferably 100~400kg / m 3 , the pressure is 0.05-0.2MPa, preferably 0.05-0.15MPa;

[0226] The regeneration heat supplement zone supplements heat for the regeneration zone based on the combustion of one or more of methane, ethane, dry gas, liquefied gas, fuel oil and self-produced dry gas.

[0227] In one embodiment of the present invention, the following technical solution II is provided:

[0228] II.1. A catalytic dehydrogenation device for alkane to olefins with rapid cooling and rapid separation of oil, comprising a reaction unit and a regeneration unit;

[0229] The reaction unit includes a pre-lifting zone, an oil-agent contact zone, a reaction zone, a product quenching zone, a reaction outlet zone, an oil-agent separation zone and a stripping zone in sequence;

[0230] A quick separation device is provided between the product quenching zone and the reaction outlet zone, and the oil agent separation zone is provided with a first two-stage cyclone separator; the outlet of the product quenching zone is communicated with the quick separation oil agent inlet of the quick separation device, the quick separation catalyst outlet of the quick separation device is communicated with the catalyst inlet of the stripping zone, the quick separation oil and gas outlet of the quick separation device is communicated with the inlet of the reaction outlet zone; the outlet of the reaction outlet zone is communicated with the inlet of the first two-stage cyclone separator;

[0231] The catalyst outlet of the first two-stage cyclone separator is connected to the catalyst inlet of the stripping zone, and the oil and gas outlet of the first two-stage cyclone separator is connected to the reaction oil and gas outlet;

[0232] The catalyst outlet of the stripping zone is communicated with the catalyst inlet to be regenerated of the regeneration unit, and the regenerated catalyst outlet of the regeneration unit is communicated with the catalyst inlet of the oil contact zone;

[0233] II.2. The alkane catalytic dehydrogenation apparatus according to II.1, wherein the ratio of the diameter to the height of the product quenching zone is 1:(1-3), preferably 1:(1-1.5);

[0234] The product quenching zone is provided with a heat exchange coil, which includes a plurality of annular tubes connected end to end; a quenching medium inlet is provided on one side of the top of the heat exchange coil, and a quenching medium outlet is provided on one side of the bottom of the heat exchange coil;

[0235] II.3. The alkane catalytic dehydrogenation to olefins apparatus according to II.1 or 2, wherein the quick separation device is selected from a combination of one or more of a cyclone quick separator, a three-leaf quick separator, a catapult quick separator, a U-tube separator, a wall-cutting quick separator, and a cantilever quick separator, preferably a cyclone quick separator;

[0236] II.4. The alkane catalytic dehydrogenation device to olefins according to II.3, wherein the quick separation device comprises a variable diameter section and a constant diameter section connected to each other, the constant diameter section being connected to the downstream end of the variable diameter section, and the diameter of the variable diameter section gradually increasing from upstream to downstream; the quick separation oil agent inlet is opened at the upper side of the constant diameter section, the quick separation catalyst outlet is located at the bottom of the variable diameter section, and the quick separation oil and gas outlet is located at the top of the constant diameter section; or,

[0237] The quick separation device includes an external structure and an internal structure. The external structure includes an external constant diameter section, an external reduced diameter section, and an external outlet constant diameter section that are connected in sequence. The diameter of the external reduced diameter section gradually decreases from upstream to downstream. The internal structure includes a constant diameter separation section sleeved within the external constant diameter section. The quick oil separation agent inlet is located at the bottom of the constant diameter separation section. The quick catalyst outlet is opened on the upper side of the constant diameter separation section. The quick oil and gas outlet is located at the top of the external outlet constant diameter section.

[0238] II.5. The alkane catalytic dehydrogenation to olefins apparatus according to II.1, wherein the oil contact zone is provided with an alkane feed distributor and a catalyst feed distributor, and the regenerated catalyst outlet of the regeneration unit is connected to the catalyst feed distributor;

[0239] The pre-lifting zone is provided with a pre-lifting gas pipe, and the stripping zone is provided with a stripping gas inlet;

[0240] II.6. The alkane catalytic dehydrogenation device according to II.1, wherein the regeneration unit comprises a regeneration heat supplement zone and a regeneration zone;

[0241] The regeneration and heating zone is located inside or outside the regeneration zone, and the regeneration and heating zone is provided with a fuel pipe for introducing fuel, and the heat outlet of the regeneration and heating zone is connected to the regeneration zone through the fuel heating pipe;

[0242] The inlet of the regenerated catalyst of the regeneration unit is connected to the regeneration zone, the regeneration zone is provided with an oxygen-containing gas inlet, the catalyst outlet of the regeneration zone is connected to the inlet of the second two-stage cyclone separator; the catalyst outlet of the second two-stage cyclone separator is connected to the regenerated catalyst outlet of the regeneration unit, the flue gas outlet of the second two-stage cyclone separator is connected to the inlet of the regeneration gas collection chamber, and the regeneration gas collection chamber is provided with a regeneration flue gas outlet;

[0243] II.7. The alkane catalytic dehydrogenation apparatus according to II.5, wherein the catalyst outlet of the stripping zone is connected to the regenerated catalyst inlet of the regeneration unit via a regenerated catalyst delivery pipe, wherein the regenerated catalyst delivery pipe is provided with a regenerated slide valve; the regenerated catalyst outlet of the regeneration unit is connected to the catalyst feed distributor of the oil contact zone via a regenerated catalyst delivery pipe, wherein the regenerated catalyst delivery pipe is provided with a regeneration slide valve;

[0244] The oil and gas outlet of the first two-stage cyclone separator is connected to the inlet of the gas collecting chamber, and the outlet of the gas collecting chamber is connected to the reaction oil and gas outlet;

[0245] II.8. A method for catalytic dehydrogenation of alkanes to produce olefins by quenching and rapidly separating an oil agent, wherein the method is implemented based on the apparatus for catalytic dehydrogenation of alkanes to produce olefins described in any one of II.1 to II.7. The oil agent mixture obtained by reacting the alkane feedstock and the catalyst in the reaction zone enters a product quenching zone for cooling. After cooling, the oil agent mixture enters a rapid separation device for separation. The separated catalyst enters a stripping zone for stripping. The separated oil and gas enter an oil agent separation zone after passing through a reaction outlet zone.

[0246] II.9. The method according to II.8, wherein the temperature of the product quenching zone is 200-550°C, preferably 250-500°C;

[0247] The quenching medium entering the heat exchange coil through the quenching medium inlet is selected from one or more of quenching oil, quenching water, quenching gas and alkane feedstock, preferably one or more of alkane feedstock;

[0248] II.10. The method according to II.8, wherein the linear velocity of the oil at the rapid separation oil inlet of the rapid separation device is 2-20 m / s, preferably 5-18 m / s; and the linear velocity of the oil and gas at the rapid separation oil and gas outlet of the rapid separation device is 2-15 m / s, preferably 5-10 m / s.

[0249] II.11. The method according to II.8, wherein the conditions in the oil contact zone include:

[0250] The temperature is 500-700°C, preferably 520-680°C, and the catalyst density is 100-500 kg / m 3 , preferably 150~400kg / m 3 The residence time of the alkane feedstock and the catalyst in the oil contact zone is 0.05 to 0.5 s, preferably 0.1 to 0.3 s;

[0251] The conditions in the reaction zone include:

[0252] The temperature at the bottom of the reaction zone is 520-680°C, preferably 540-660°C, and the catalyst density is 150-400 kg / m 3 , preferably 200~350kg / m 3 , the pressure is 0.05-0.2MPa, preferably 0.05-0.15MPa; the temperature at the top of the reaction zone is 480-640℃, preferably 500-620℃, and the catalyst density is 30-200kg / m 3 , preferably 50 to 150 kg / m 3 , the pressure is 0.05-0.15 MPa, preferably 0.05-0.12 MPa;

[0253] The alkane raw material is selected from C2 to C8 alkanes;

[0254] II.12. The method according to II.8, wherein the conditions of the regeneration unit include:

[0255] The regeneration temperature is 600-720°C, preferably 620-700°C, and the catalyst density is 50-500 kg / m 3 , preferably 100~400kg / m 3 , the pressure is 0.05-0.2MPa, preferably 0.05-0.15MPa;

[0256] The fuel introduced into the regeneration and heating zone through the fuel pipe includes one or more of methane, ethane, dry gas, liquefied gas and fuel oil, preferably the dry gas generated by the device;

[0257] II.13. The method according to II.8, wherein the catalyst comprises an active component and a support;

[0258] The active component is selected from one or more metals or oxides of Zn, Fe, Co, Ni, V, Sn and Mg, and the carrier is selected from one or more of Al2O3, SiO2, ZrO2, TiO2 and molecular sieves;

[0259] Based on the weight of the catalyst, the content of the active component is 10-90%, and the content of the carrier is 10-90%; preferably, the content of the active component is 20-70%, and the content of the carrier is 30-80%.

[0260] In one embodiment of the present invention, the following technical solution III is provided:

[0261] III-1. A negative pressure driven catalytic alkane dehydrogenation device to produce olefins, comprising a reaction unit and a regeneration unit;

[0262] The reaction unit includes a pre-lifting zone, an oil-agent contact zone, a reaction zone, a product quenching zone, a reaction outlet zone, an oil-agent separation zone and a stripping zone in sequence;

[0263] The device further comprises a negative pressure driving device, a spent agent receiver and a regenerant agent receiver;

[0264] The oil and gas outlet of the oil-agent separation zone is connected to the oil and gas inlet of the negative pressure drive device, and the catalyst outlet of the oil-agent separation zone is connected to the catalyst inlet of the stripping zone;

[0265] The catalyst outlet of the stripping zone is communicated with the catalyst inlet of the spent catalyst receiver, and the catalyst outlet of the spent catalyst receiver is communicated with the spent catalyst inlet of the regeneration unit;

[0266] The regenerated catalyst outlet of the regeneration unit is communicated with the catalyst inlet of the regeneration agent receiver, and the catalyst outlet of the regeneration agent receiver is communicated with the catalyst inlet of the oil-agent contact zone;

[0267] III-2. The device according to III-1, wherein the negative pressure drive device is selected from a combination of one or more of a centrifugal negative pressure fan, an axial flow negative pressure fan, a diagonal flow negative pressure fan, and a cross flow negative pressure fan;

[0268] The negative pressure drive device is also provided with a reaction oil and gas outlet;

[0269] III-3. The apparatus according to III-1 or III-2, wherein the spent agent receiver and the regenerant receiver are lock hoppers;

[0270] III-4. The apparatus according to III-1, wherein the pre-lift zone is provided with a pre-lift gas inlet;

[0271] The oil agent contact zone is provided with an alkane feed distributor and a catalyst feed distributor, and the catalyst outlet of the regeneration agent receiver is connected to the catalyst feed distributor;

[0272] The stripping zone is provided with a stripping gas inlet;

[0273] III-5. The apparatus according to III-1, wherein a quick separation device is provided between the product quenching zone and the reaction outlet zone, and the oil separation zone is provided with a first two-stage cyclone separator and a gas collecting chamber;

[0274] The outlet of the product quenching zone is connected to the inlet of the quick separation device, the catalyst outlet of the quick separation device is connected to the catalyst inlet of the stripping zone, and the oil and gas outlet of the quick separation device is connected to the inlet of the reaction outlet zone;

[0275] The outlet of the reaction outlet zone is communicated with the inlet of the first two-stage cyclone separator, the catalyst outlet of the first two-stage cyclone separator is communicated with the catalyst inlet of the stripping zone, the oil and gas outlet of the first two-stage cyclone separator is communicated with the oil and gas inlet of the gas collecting chamber, and the oil and gas outlet of the gas collecting chamber is communicated with the oil and gas inlet of the negative pressure drive device via an oil and gas pipeline;

[0276] III-6. The apparatus according to III-1 or 5, wherein the spent agent receiver is further provided with a purge gas inlet and a purge mixed gas outlet;

[0277] The purge mixed gas outlet is communicated with the upper portion of the oil-agent separation zone;

[0278] III-7. The apparatus according to III-1, wherein the regeneration unit comprises a regeneration heating zone and a regeneration zone;

[0279] The regeneration and heating zone is located inside or outside the regeneration zone, and the regeneration and heating zone is provided with a fuel pipe for introducing fuel, and the heat outlet of the regeneration and heating zone is connected to the regeneration zone through the fuel heating pipe;

[0280] The catalyst inlet of the regeneration unit is connected to the regeneration zone, and the catalyst outlet of the regeneration zone is connected to the inlet of the second two-stage cyclone separator;

[0281] The flue gas outlet of the second two-stage cyclone separator is connected to the inlet of the regeneration plenum, and the regeneration plenum is provided with a regeneration flue gas outlet; the catalyst outlet of the second two-stage cyclone separator is connected to the regeneration catalyst outlet of the regeneration unit;

[0282] III-8. The apparatus according to III-7, wherein the regenerant receiver further comprises a reducing gas inlet and a reducing gas mixture outlet;

[0283] The reducing mixed gas outlet is communicated with the upper portion of the regeneration zone;

[0284] III-9. A method for negative pressure driven catalytic dehydrogenation of alkanes to olefins, wherein the method is implemented based on the apparatus described in any one of III-1 to 8, wherein the alkane feedstock and the catalyst are contacted and mixed in the oil contact zone and then enter the reaction zone for catalytic reaction;

[0285] III-10. The method according to III-9, wherein the purge gas introduced into the spent catalyst receiver through the purge gas inlet is an inert gas, wherein the inert gas is selected from one or more of nitrogen, helium, and argon;

[0286] III-11. The method according to III-9, wherein the reducing gas introduced into the regenerant receiver via the reducing gas inlet is selected from one or more of hydrogen, methane, refinery dry gas and oilfield dry gas;

[0287] III-12. The method according to III-9, wherein the reaction conditions in the reaction zone include:

[0288] The reaction temperature is 520-680°C, preferably 540-660°C; the reaction pressure is -80-0 kPa, preferably -60--20 kPa; the catalyst density is 150-400 kg / m 3 , preferably 200~350kg / m 3 ;

[0289] III-13. The method according to III-12, wherein the regeneration conditions of the regeneration unit include:

[0290] The regeneration temperature is 650-750℃, the regeneration pressure is 0-200kPa, and the catalyst density is 50-500kg / m 3 , the regeneration gas includes oxygen and / or air;

[0291] The reaction pressure is 50 to 250 kPa lower than the regeneration pressure, preferably 80 to 200 kPa lower;

[0292] The fuel introduced into the regeneration and heating zone through the fuel pipe includes one or more of methane, ethane, dry gas, liquefied gas and fuel oil, preferably the dry gas generated by the device;

[0293] The alkane raw material is selected from C2 to C8 alkanes.

[0294] Example

[0295] The present invention is further described in detail below by way of examples, but the present invention is not limited thereto. In the following examples, unless otherwise specified, the experimental instruments and raw materials involved are all commercially available products.

[0296] The raw materials used in the examples and comparative examples are propane, n-butane and isobutane, and the catalyst used is an alkane dehydrogenation catalyst prepared by Sinopec Petrochemical Research Institute Co., Ltd.

[0297] The chemical composition and properties of the alkane dehydrogenation catalyst are shown in Table 1.

[0298] Table 1 Composition and properties of alkane dehydrogenation catalysts

[0299] In the following examples and comparative examples, the calculation methods of alkane conversion and olefin selectivity are described:

[0300] Alkane conversion rate = (mass fraction of alkanes in the feedstock - mass fraction of alkanes in the product) ÷ mass fraction of alkanes in the feedstock;

[0301] Olefin selectivity = (mass fraction of olefins in the product ÷ mass fraction of alkanes in the feed) ÷ alkane conversion.

[0302] In the following embodiments, the quick separation device is specifically a cyclone-type quick separator.

[0303] Example 1

[0304] The experiment was conducted on the reaction-regeneration apparatus shown in Figure 2. The apparatus used in the experiment included a reaction unit and a regeneration unit. The reaction unit included, from upstream to downstream, a pre-lifting zone, an oil-agent contact zone, a reaction zone, a product quenching zone, a reaction outlet zone, an oil-agent separation zone, and a stripping zone. The regeneration unit included a regeneration heat supplement zone and a regeneration zone. The reaction zone was a tapered reducer reactor. The angle β between the outer surface of the tapered reducer reactor and the central axis of the tapered reducer reactor was 3 degrees. The ratio of the lower diameter to the upper diameter of the tapered reducer reactor was 1:1.2.

[0305] The preheated alkane is introduced into the oil-agent contact zone through the feed distributor, contacts with the catalyst introduced into the oil-agent contact zone through the catalyst distributor, and then is introduced into the reactor together with the pre-lifting gas from the pre-lifting zone for reaction. The oil-agent mixture after the reaction is introduced into the product quenching zone. After the temperature of the oil-agent mixture is reduced, it enters the quick separation device for rapid separation of the oil-agent. The quickly separated catalyst enters the stripping zone for stripping. The quickly separated oil-agent mixture carrying catalyst fine powder is introduced from the reaction outlet zone into the oil-agent separation zone for oil-agent separation. The reaction oil and gas after separation are led out of the device, and the obtained catalyst is introduced into the stripping zone for stripping. The catalyst to be regenerated after stripping is introduced into the regeneration zone for regeneration. The regenerated catalyst is introduced into the catalyst distributor for recycling.

[0306] The raw material used in the embodiment is propane, the pre-lift gas is water vapor, and the fuel used in the regeneration and heating zone is dry gas.

[0307] The feed distributor is annular, and the height of the feed distributor from the bottom of the oil-agent contact zone is 1 / 4 of the height of the oil-agent contact zone. The diameter of the feed hole is 3 / 4 of the width of the feed distributor ring. The direction of the feed hole is upward, and the angle α with the central axis of the feed distributor is 60 degrees. The opening rate of the feed distributor is 90%.

[0308] The catalyst distributor is disc-shaped, and the height of the catalyst distributor from the bottom of the oil-agent contact zone accounts for 3 / 4 of the height of the oil-agent contact zone. The catalyst distributor is provided with multiple catalyst feed holes (through holes), and the catalyst enters the contact zone from the feed holes. The opening rate of the catalyst distributor is 85%.

[0309] The reaction conditions and results are shown in Table 2.

[0310] Example 2

[0311] The method of Example 1 was followed, except that the angle β between the outer surface of the tapered reducing reactor and the central axis of the tapered reducing reactor was 1 degree, and the ratio of the lower diameter to the upper diameter of the tapered reducing reactor was 1:1.2. The reaction conditions and results are shown in Table 2.

[0312] Example 3

[0313] The method of Example 1 was followed, except that the angle β between the outer surface of the tapered reducing reactor and the central axis of the tapered reducing reactor was 2 degrees, and the ratio of the lower diameter to the upper diameter of the tapered reducing reactor was 1:1.5. The reaction conditions and results are shown in Table 2.

[0314] Example 4

[0315] The method of Example 1 is followed, except that the feed distributor is annular, the height of the feed distributor from the bottom of the oil-agent contact zone accounts for 3 / 4 of the height of the oil-agent contact zone, the diameter of the feed hole is 3 / 4 of the width of the feed distributor ring, the direction of the feed hole is downward, and the angle α with the central axis of the feed distributor is 60 degrees, and the opening rate of the feed distributor is 90%.

[0316] The catalyst distributor was disc-shaped, its height from the bottom of the oil-agent contact zone accounting for 1 / 4 of the oil-agent contact zone's height. It was provided with multiple catalyst feed holes (through-holes), and the catalyst distributor had an open area ratio of 85%. The reaction conditions and results are shown in Table 2.

[0317] Example 5

[0318] The method of Example 1 is followed, except that the feed distributor is annular, the height of the feed distributor from the bottom of the oil-agent contact zone accounts for 3 / 4 of the height of the oil-agent contact zone, the diameter of the feed hole is 3 / 4 of the width of the feed distributor ring, the direction of the feed hole is downward, and the angle α with the central axis of the feed distributor is 45 degrees, and the opening rate of the feed distributor is 90%.

[0319] The catalyst distributor was disc-shaped, its height from the bottom of the oil-agent contact zone accounting for 1 / 4 of the oil-agent contact zone's height. It was provided with multiple catalyst feed holes (through-holes), and the catalyst distributor had an open area ratio of 85%. The reaction conditions and results are shown in Table 2.

[0320] Example 6

[0321] The experiment was conducted on the reaction-regeneration apparatus shown in Figure 3. The apparatus used in the experiment included a reaction unit and a regeneration unit. The reaction unit included, from upstream to downstream, a pre-lifting zone, an oil-agent contact zone, a reaction zone, a product quenching zone, a reaction outlet zone, an oil-agent separation zone, and a stripping zone. The regeneration unit included a regeneration heat supplement zone and a regeneration zone. The reaction zone was a variable-diameter reactor, which consisted of multiple equal-diameter reaction zones that gradually increased in size from bottom to top. There were 10 zones in total, and the equal-diameter reaction zones were connected in sequence. The diameter ratio of two adjacent equal-diameter reaction zones from bottom to top was 1:1.05.

[0322] The preheated alkane is introduced into the oil-agent contact zone through the feed distributor, fully contacts with the catalyst introduced into the oil-agent contact zone through the catalyst distributor, and then is introduced into the reactor together with the pre-lifting gas from the pre-lifting zone for reaction. The oil-agent mixture after the reaction is introduced into the product quenching zone. After the temperature of the oil-agent mixture is reduced, it enters the quick separation device for rapid separation of the oil-agent. The quickly separated catalyst enters the stripping zone for stripping. The quickly separated oil-agent mixture carrying catalyst fine powder is introduced from the reaction outlet zone into the oil-agent separation zone for oil-agent separation. The reaction oil and gas after separation are led out of the device, and the obtained catalyst is introduced into the stripping zone for stripping. The catalyst to be regenerated after stripping is introduced into the regeneration zone for regeneration. The regenerated catalyst is introduced into the catalyst distributor for recycling.

[0323] The feedstock used in the examples was isobutane, the pre-lift gas was steam, and the fuel used in the regeneration and heating zone was dry gas. The feed distributor was annular in shape, its height from the bottom of the oil-agent contact zone accounting for three-quarters of the oil-agent contact zone's height. The diameter of the feed holes was three-quarters of the feed distributor ring width. The feed holes were oriented downward, with an angle α of 45 degrees with the central axis of the feed distributor. The feed distributor had an open area ratio of 90%.

[0324] The catalyst distributor was disc-shaped, its height from the bottom of the oil-agent contact zone accounting for 1 / 4 of the total height of the oil-agent contact zone. It was provided with multiple catalyst feed holes (through-holes), with an open area ratio of 85%. The reactor was a fast-bed reactor. The reaction conditions and results are shown in Table 2.

[0325] Example 7

[0326] The method of Example 1 was followed, except that the experiment was conducted on the reaction-regeneration apparatus shown in Figure 1. A negative pressure drive device was used. The reaction conditions and results are shown in Table 2.

[0327] Comparative Example 1

[0328] The method of Example 1 was followed, except that a constant diameter reactor was used, where the reactor diameter was equal to the lower diameter of the tapered reducing reactor. The reaction conditions and results are shown in Table 3.

[0329] Comparative Example 2

[0330] The method of Example 1 was followed, except that the catalyst was introduced at the material distributor in the contact zone, and a pre-lift gas was used to elevate the catalyst and alkane feedstock while allowing them to contact in parallel. The reaction conditions and results are shown in Table 3.

[0331] Comparative Example 3

[0332] The method of Example 1 was followed, except that a pre-lift gas was used at the bottom of the reactor to allow the catalyst and alkane feedstock to enter the reactor for reaction. The reaction conditions and results are shown in Table 3.

[0333] Comparative Example 4

[0334] The method of Example 1 was followed, except that the contact time in the contacting step was 0.7 seconds. The reaction conditions and results are shown in Table 3.

[0335] Comparative Example 5

[0336] The method of Example 1 was followed, except that no quenching zone was used. The reaction conditions and results are shown in Table 3.

[0337] Comparative Example 6

[0338] The method of Example 1 was followed, except that the angle β between the outer surface of the tapered reducing reactor and the central axis of the tapered reducing reactor was 30 degrees, and the ratio of the lower diameter to the upper diameter of the tapered reducing reactor was 1:5. The reaction conditions and results are shown in Table 3.

[0339] Table 2 Reaction conditions and reaction results of Examples 1 to 7

[0340] Table 3 Reaction conditions and reaction results of Comparative Examples 1 to 6

[0341] Example 8

[0342] The method of Example 1 was followed, except that n-butane was used as the raw material. The reaction conditions and product distribution were as shown in Table 4.

[0343] Example 9

[0344] The method of Example 3 was followed, except that the raw material used was isobutane. The reaction conditions and product distribution were shown in Table 4.

[0345] Example 10

[0346] The method of Example 6 was followed, except that the raw material used was n-butane. The reaction conditions and product distribution were as shown in Table 4.

[0347] Example 11

[0348] The method of Example 7 was followed, except that the raw material used was isobutane. The reaction conditions and product distribution were as shown in Table 4.

[0349] Comparative Example 7

[0350] The method of Comparative Example 1 was followed, except that the raw material used was n-butane. The reaction conditions and product distribution were shown in Table 5.

[0351] Comparative Example 8

[0352] The method of Comparative Example 3 was followed, except that the raw material used was n-butane. The reaction conditions and product distribution were shown in Table 5.

[0353] Comparative Example 9

[0354] The method of Comparative Example 5 was followed, except that the raw material used was isobutane. The reaction conditions and product distribution were shown in Table 5.

[0355] Comparative Example 10

[0356] The method of Comparative Example 6 was followed, except that the raw material used was isobutane. The reaction conditions and product distribution were shown in Table 5.

[0357] Table 4 Reaction conditions and reaction results of Examples 8 to 11

[0358] Table 5 Reaction conditions and reaction results of Comparative Examples 7 to 10

[0359] As can be seen from Tables 2 to 5, by using the device and method provided by the present invention, the catalytic dehydrogenation reaction of alkanes is enhanced, and the conversion rate of the reactants and the selectivity of the target products are greatly improved.

[0360] Specifically, Tables 2 to 5 demonstrate that contacting the alkane feedstock with the catalyst can improve conversion and selectivity. Furthermore, countercurrent contact between the alkane feedstock and the catalyst can further enhance conversion and selectivity in the alkane dehydrogenation reaction. Furthermore, employing a negative pressure device further facilitates the catalytic dehydrogenation of the alkane.

[0361] In the description of this application, it should be noted that the terms "upper", "lower", "inside", "outside", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships in the working state of this application. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on this application.

[0362] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0363] The present application has been described above in conjunction with preferred embodiments, but these embodiments are merely exemplary and serve only as an illustrative example. On this basis, various replacements and improvements can be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A method for producing olefins by catalytic dehydrogenation of alkanes, characterized in that: The method comprises the following steps: Contacting step: the alkane feedstock selected from C2 to C8 is contacted with the catalyst in a countercurrent manner in an oil contact zone (12). The oil contact temperature is 500 to 700°C, preferably 520 to 680°C, and the catalyst density in the oil contact zone is 150 to 500 kg / m 3 , preferably 200~400kg / m 3 The residence time of the alkane feedstock and the catalyst in the oil contact zone is 0.05 to 0.5 seconds, preferably 0.1 to 0.2 seconds. Catalytic dehydrogenation step: the oil-agent mixture in the oil-agent contact zone enters the upward reactor (13) from the bottom of the reaction zone to undergo catalytic dehydrogenation reaction. The bottom conditions of the reactor (13) include: a temperature of 520-680°C, preferably 540-660°C, a catalyst density of 100-400 kg / m 3 , preferably 150~350kg / m 3 The conditions at the top of the reactor (13) include: a temperature of 480 to 640°C, preferably 500 to 620°C, a catalyst density of 30 to 200 kg / m 3 , preferably 50 to 150 kg / m 3 The residence time of the oil mixture in the reactor (13) is 0.2 to 5 seconds, preferably 0.4 to 2 seconds, and the radial diameter of the reactor gradually increases from upstream to downstream, Oil agent separation step: separating the oil agent mixture obtained in the catalytic dehydrogenation step to obtain an oil-gas mixture and a catalyst to be regenerated; Product separation step: separation of olefins from the oil and gas mixture; Preferably, the method further comprises a preheating step, wherein the alkane feedstock is preheated to 350-500° C. before being transferred to the contacting step.

2. The method for producing olefins by catalytic dehydrogenation of alkanes according to claim 1, characterized in that: In the contacting step, the oil-agent contacting zone (12) is provided with a feed distributor (103) and a catalyst distributor (104), and the feed distributor (103) and the catalyst distributor (104) are arranged to form a space for countercurrent contact of the oil-agent. When the feed distributor (103) is located upstream of the catalyst distributor (104), the distance between the feed distributor (103) and the bottom of the oil-agent contact zone (12) accounts for 0 to 1 / 2 of the height of the oil-agent contact zone (12), preferably 0 to 1 / 4; the distance between the catalyst distributor (104) and the bottom of the oil-agent contact zone (12) accounts for 1 / 2 to 1 of the height of the oil-agent contact zone (12), preferably 3 / 4 to 1; or, When the catalyst distributor (104) is located upstream of the feed distributor (103), the distance between the feed distributor (103) and the bottom of the oil-agent contact zone (12) accounts for 1 / 2 to 1 of the height of the oil-agent contact zone (12), preferably 3 / 4 to 1; the distance between the catalyst distributor (104) and the bottom of the oil-agent contact zone (12) accounts for 0 to 1 / 2 of the height of the oil-agent contact zone (12), preferably 0 to 1 / 4.

3. The method for producing olefins by catalytic dehydrogenation of alkanes according to claim 2, characterized in that: The feed distributor (103) is an annular structure, on which a plurality of alkane feed holes with uniform or uneven hole distribution are spaced apart and meet at least one of the following conditions: The feed distributor (103) has an opening rate of 60 to 95%, preferably 75 to 90%; The diameter of the alkane raw material feed hole is 1 / 4 to 3 / 4 of the ring width of the annular structure of the feed distributor (103), and the diameters of the plurality of alkane raw material feed holes are equal or unequal; and / or The alkane raw material feed hole is opened upward or downward, and the angle (α) between the axis of the alkane raw material feed hole and the central axis of the feed distributor (103) is 15 to 75 degrees.

4. The method for producing olefins by catalytic dehydrogenation of alkanes according to claim 2 or 3, characterized in that: The catalyst distributor (104) is a disc structure, on which a plurality of catalyst feed holes with uniform or uneven hole distribution are opened, and meets at least one of the following conditions: The catalyst distributor (104) has an opening rate of 50 to 95%, preferably 70 to 90%; The diameters of the plurality of catalyst feed holes are equal or unequal; and / or The catalyst feed hole is a through hole, and the axis of the catalyst feed hole is parallel to the central axis of the catalyst distributor (104).

5. The method for producing olefins by catalytic dehydrogenation of alkanes according to any one of claims 1 to 4, characterized in that: The reactor is at least one selected from a bubbling bed, a turbulent bed, a fast bed, and a transport bed, and The reactor is a tapered reactor, wherein the angle (β) between the outer surface of the tapered reactor and the central axis is greater than 0 to 20°, preferably 1 to 10°; preferably, the ratio of the lower diameter to the upper diameter of the tapered reactor is 1: greater than 1 to 10, preferably 1:1.1 to 5, more preferably 1:1.2 to 3, and even more preferably 1:1.2 to 2; or The reactor is a variable diameter reactor, wherein the variable diameter reactor comprises 2 to 20 (preferably 5 to 10) equal diameter reaction sections connected in sequence; and the diameters of two connected equal diameter reaction sections gradually increase from bottom to top, i.e., from upstream to downstream, and preferably, the lengths of the equal diameter reaction sections are equal; the diameter ratio of the two equal diameter reaction sections connected vertically is 1.02 to 1.5:1, preferably 1.03 to 1.2:1, and the ratio of the diameter of the upstream equal diameter reaction section to the diameter of the downstream equal diameter reaction section is 1: greater than 1 to 10, preferably 1:1.1 to 5, more preferably 1:1.2 to 3, and even more preferably 1:1.2 to 2; or The reactor is a variable diameter reactor, wherein the variable diameter reactor comprises 2 to 20 (preferably 5 to 10) variable diameter reaction sections connected in sequence; and the diameter of each variable diameter reaction section gradually increases from upstream to downstream, i.e., from upstream to downstream, and preferably, the lengths of the variable diameter reaction sections are equal; the ratio of the upper diameter to the lower diameter of each variable diameter reaction section is 1.01 to 1.2:1, preferably 1.02 to 1.1:1, and the ratio of the lower diameters of the two variable diameter reaction sections connected vertically is 1.02 to 1.5:1, preferably 1.03 to 1.2:1, and the ratio of the lower diameter of the upstreammost variable diameter reaction section to the upper diameter of the downstreammost variable diameter reaction section is 1: greater than 1 to 10, preferably 1:1.1 to 5, more preferably 1:1.2 to 3, and further preferably 1:1.2 to 2.

6. The method for producing olefins by catalytic dehydrogenation of alkanes according to any one of claims 1 to 5, characterized in that: The catalyst comprises a carrier and a dehydrogenation active component; The carrier is selected from one or more of Al2O3, SiO2, ZrO2, TiO2 and molecular sieves, and the dehydrogenation active component is selected from one or more of Zn, Fe, Co, Ni, V, Sn and Mg; Based on the weight of the catalyst, the content of the carrier is 10-90%, and the content of the active component is 10-90%; preferably, the content of the carrier is 30-80%, and the content of the active component is 20-70%; The alkane raw material is selected from one or more alkanes with a carbon number of 2 to 8, preferably one or more propane, n-butane and isobutane. Preferably, the bottom conditions of the reactor (13) include: a pressure of 0.05 to 0.2 MPa, preferably 0.05 to 0.15 MPa; the top conditions of the reactor (13) include: a pressure of 0.05 to 0.15 MPa, preferably 0.05 to 0.12 MPa.

7. The method for producing olefins by catalytic dehydrogenation of alkanes according to any one of claims 1 to 6, characterized in that: A rapid cooling step is further provided between the catalytic dehydrogenation step and the oil separation step. In the quenching step, the oil mixture discharged from the upward reactor (13) enters the product quenching zone (14) for cooling, and the temperature of the product quenching zone (14) is 200-550°C, preferably 250-500°C. Preferably, a quick separation device (107) is provided after the quenching step for separation, wherein the cooled oil mixture enters the quick separation device (107) for separation, and the separated catalyst to be regenerated enters the stripping zone (16) for stripping, and the separated oil mixture enters the oil separation step after passing through the reaction outlet zone (15). Preferably, the product quenching zone (14) is provided with a heat exchange coil (141) for introducing a quenching medium, wherein the quenching medium is selected from one or more of quenching oil, quenching water, quenching gas and an alkane feedstock, preferably an alkane feedstock; Preferably, the conditions of the quick separation device (107) include: the linear speed of the oil-agent mixture at the inlet of the quick separation device is 2 to 20 m / s, preferably 5 to 18 m / s, and the linear speed of the oil-agent mixture at the outlet of the quick separation device is 2 to 15 m / s, preferably 5 to 10 m / s.

8. The method for producing olefins by catalytic dehydrogenation of alkanes according to any one of claims 1 to 7, characterized in that: In the oil-agent separation step, the oil-agent mixture is introduced into the first two-stage cyclone separator (108) for separation, and the catalyst to be regenerated separated by the first two-stage cyclone separator (108) enters the stripping zone (16) for stripping, and the separated oil-gas mixture is discharged from the reaction oil-gas outlet.

9. The method for producing olefins by catalytic dehydrogenation of alkanes according to any one of claims 1 to 8, characterized in that: The method further comprises a regeneration step, wherein the catalyst to be regenerated taken out from the stripping zone (16) is introduced into the regeneration zone (22) for regeneration; the regenerated catalyst taken out from the regeneration zone (22) is introduced into the oil contact step as a catalyst; The regeneration step satisfies at least one of the following conditions: The temperature of the regeneration zone (22) is 600-720°C, preferably 620-700°C, and the catalyst density is 50-500 kg / m 3 , preferably 100~400kg / m 3 , the pressure is 0.05 to 0.2 MPa, preferably 0.05 to 0.15 MPa, and the regeneration gas includes oxygen and / or air; and / or The regeneration zone (22) is provided with a regeneration heat supplement zone (21), in which heat is supplemented for the regeneration zone (22) by burning one or more of methane, ethane, dry gas, liquefied gas, fuel oil and dry gas, preferably dry gas, more preferably dry gas obtained as a by-product in the product separation step.

10. The method for producing olefins by catalytic dehydrogenation of alkanes according to claims 1-9, characterized in that: The method further comprises a negative pressure suction step, wherein the negative pressure suction step is performed between the oil agent separation step and the product separation step to suction the oil-gas mixture from the oil agent separation step; A negative pressure driving device (19) is used in the negative pressure suction step; Preferably, the negative pressure driving device (19) is a combination of one or more selected from a centrifugal negative pressure fan, an axial flow negative pressure fan, a diagonal flow negative pressure fan and a cross flow negative pressure fan.

11. The method for producing olefins by catalytic dehydrogenation of alkanes according to claim 10, characterized in that: The catalyst to be regenerated taken out from the stripping zone (16) is introduced into the regeneration zone (22) via the spent catalyst receiver (18) for regeneration, a purge gas is introduced into the spent catalyst receiver (18) via the purge gas inlet (115), and the purge mixed gas drawn from the upper part of the spent catalyst receiver (18) enters the oil-agent separation step, wherein the purge gas is an inert gas selected from one or more of nitrogen, helium and argon; The regenerated catalyst taken out from the regeneration zone (16) is introduced into the oil-agent contact step via the regeneration agent receiver (20), and the reducing gas is introduced into the regeneration agent receiver (20) via the reducing gas inlet (211). The reducing mixed gas drawn out from the upper part of the regeneration agent receiver (20) enters the regeneration step, and the reducing gas is selected from one or more of hydrogen, methane, refinery dry gas and oilfield dry gas.

12. An apparatus for producing olefins by catalytic dehydrogenation of alkanes, wherein the apparatus is used to carry out the method for producing olefins by catalytic dehydrogenation of alkanes according to any one of claims 1 to 11, comprising a reaction unit (1), a regeneration unit (2) and a product separation unit. From upstream to downstream, the reaction unit (1) includes, in sequence, a pre-lifting zone (11), an oil-agent contact zone (12), an upward reactor (13), a product quenching zone (14), a reaction outlet zone (15), an oil-agent separation zone (17), and a stripping zone (16). The pre-lifting zone (11) is provided with a pre-lifting gas pipe (101) for introducing pre-lifting gas, and the pre-lifting zone (11) is connected to the inlet of the oil contact zone (12); The outlet of the oil-agent contact zone (12) is communicated with the inlet of the reactor (13), and the oil-agent contact zone (12) is provided with a feed distributor (103) and a catalyst distributor (104), and an oil-agent countercurrent contact space is formed between the feed distributor (103) and the catalyst distributor (104); The inlet of the product quenching zone (14) is communicated with the outlet of the reactor (13), and the outlet of the product quenching zone (14) is communicated with the inlet of the reaction outlet zone (15). Preferably, a quick separation device (107) is provided between the product quenching zone (14) and the reaction outlet zone (15), the outlet of the product quenching zone (14) is communicated with the quick separation oil agent inlet (301) of the quick separation device (107), the quick separation catalyst outlet (302) of the quick separation device (107) is communicated with the catalyst inlet of the stripping zone (16), and the quick separation oil and gas outlet (303) of the quick separation device (107) is communicated with the inlet of the reaction outlet zone (15); The inlet of the oil-agent separation zone (17) is communicated with the outlet of the reaction outlet zone (15), the catalyst outlet of the oil-agent separation zone (17) is communicated with the catalyst inlet of the stripping zone (16), and the oil and gas outlet of the oil-agent separation zone (17) is communicated with the reaction oil and gas outlet (110). Preferably, the oil-agent separation zone (17) is provided with a first two-stage cyclone separator (108); the outlet of the reaction outlet zone (15) is communicated with the inlet of the first two-stage cyclone separator (108); the catalyst outlet of the first two-stage cyclone separator (108) is communicated with the catalyst inlet of the stripping zone (16), and the oil and gas outlet of the first two-stage cyclone separator (108) is communicated with the reaction oil and gas outlet (110); The stripping zone (16) is provided with a stripping gas pipe (111) for introducing stripping gas, a stripping oil and gas outlet, and a catalyst outlet. The catalyst outlet is connected to the catalyst inlet of the regeneration unit (2) via the catalyst delivery pipe (105). The catalyst delivery pipe (105) is optionally provided with a slide valve (106). The stripping oil and gas outlet of the stripping zone (16) is connected to the reaction oil and gas outlet (110). The regenerated catalyst outlet of the regeneration unit (2) is connected to the catalyst inlet of the catalyst distributor (104) of the oil contact zone (12) through a regenerated catalyst delivery pipe (203), and the regenerated catalyst delivery pipe (203) is optionally provided with a regeneration slide valve (204).

13. The device according to claim 12, characterized in that The device also satisfies at least one of the following conditions: The reactor (13) is selected from a combination of one or more of a bubbling bed, a turbulent bed, a fast bed and a transport bed; and / or The oil contact zone (12) is provided with an alkane feed pipe (102) for introducing the alkane raw material into the feed distributor (103); and / or The ratio of the diameter to the height of the product quenching zone (14) is 1:(1-3), preferably 1:(1-1.5); and / or The product quenching zone (14) is provided with a heat exchange coil (141) for introducing a quenching medium, and the heat exchange coil (141) comprises a plurality of annular tubes connected end to end; a quenching medium inlet is provided on one side of the top of the heat exchange coil (141), and a quenching medium outlet is provided on one side of the bottom of the heat exchange coil; and / or The quick separation device (107) is selected from a combination of one or more of a cyclone quick separator, a three-leaf quick separator, a catapult quick separator, a U-shaped tube separator, a wall-cutting quick separator and a cantilever quick separator, preferably a cyclone quick separator; and / or The quick separation device (107) comprises a variable diameter section and a constant diameter section which are connected to each other, the constant diameter section being connected to the downstream end of the variable diameter section, and the diameter of the variable diameter section gradually increasing from upstream to downstream; the quick separation oil agent inlet (301) is opened at the upper side of the constant diameter section, the quick separation catalyst outlet (302) is located at the bottom of the variable diameter section, and the quick separation oil and gas outlet (303) is located at the top of the constant diameter section; or, the quick separation device (107) comprises an external structure and an internal structure, the external The structure comprises an external constant diameter section, an external variable diameter section and an external outlet constant diameter section which are connected in sequence, wherein the diameter of the external variable diameter section gradually decreases from upstream to downstream; the internal structure comprises a constant diameter separation section which is sleeved inside the external constant diameter section and has one end closed, the quick oil separation agent inlet (301) is located at the bottom of the constant diameter separation section, the quick separation catalyst outlet (302) is opened at the upper side of the constant diameter separation section, and the quick oil and gas outlet (303) is located at the top of the external outlet constant diameter section; and / or The oil separation zone (17) is provided with a first two-stage cyclone separator (108) and an air collecting chamber (109). At this time, the oil and gas outlet of the first two-stage cyclone separator (108) is connected to the oil and gas inlet of the air collecting chamber (109), and the oil and gas outlet of the air collecting chamber (109) is the reaction oil and gas outlet (110).

14. The device according to claim 12 or 13, characterized in that The regeneration unit (2) includes a regeneration zone (22) and a regeneration heating zone (21). The catalyst inlet of the regeneration unit (2) is connected to the regeneration zone (22), the regeneration zone (22) is provided with a main air duct (208) for introducing regeneration gas, and the catalyst outlet of the regeneration zone (22) is connected to the inlet of the second two-stage cyclone separator (205); The regeneration flue gas outlet of the second two-stage cyclone separator (205) is communicated with the inlet of the regeneration gas collecting chamber (206), the regeneration gas collecting chamber (206) is provided with a regeneration flue gas outlet (207), and the regenerated catalyst outlet of the second two-stage cyclone separator (205) is communicated with the regeneration catalyst outlet of the regeneration unit (2); The regeneration and heating zone (21) is located inside or outside the regeneration zone (22). The regeneration and heating zone (21) is provided with a fuel pipe (201) for introducing fuel. The heat outlet of the regeneration and heating zone (21) is connected to the regeneration zone (22) via the fuel heating pipe (202).

15. The device according to any one of claims 12 to 14, characterized in that The device further comprises a negative pressure driving device (19); The oil and gas outlet of the oil-agent separation zone (17) is connected to the oil and gas inlet of the negative pressure drive device (19) via an oil and gas pipeline (110), or the oil and gas outlet of the gas collecting chamber (109) is connected to the oil and gas inlet of the negative pressure drive device (19) via an oil and gas pipeline (110), The negative pressure driving device (19) is selected from a combination of one or more of a centrifugal negative pressure fan, an axial flow negative pressure fan, a diagonal flow negative pressure fan and a cross flow negative pressure fan; The negative pressure driving device (19) is further provided with an oil and gas outlet (114). Preferably, the device further comprises a spent agent receiver (18) and a regenerant agent receiver (20); The catalyst outlet of the stripping zone (16) is communicated with the catalyst inlet of the spent catalyst receiver (18), and the catalyst outlet of the spent catalyst receiver (18) is communicated with the spent catalyst inlet of the regeneration unit (2); the spent catalyst receiver (18) is further provided with a purge gas inlet (115) and a purge mixed gas outlet (113); the purge mixed gas outlet (113) is communicated with the upper portion of the oil agent separation zone (17); The regenerated catalyst outlet of the regeneration unit (2) is communicated with the catalyst inlet of the regeneration agent receiver (20), and the catalyst outlet of the regeneration agent receiver (20) is communicated with the catalyst inlet of the catalyst distributor (104) of the oil-agent contact zone (12). The regeneration agent receiver (20) is further provided with a reducing gas inlet (211) and a reducing mixed gas outlet (209); the reducing mixed gas outlet (209) is communicated with the upper part of the regeneration zone (22). Preferably, the spent agent receiver (18) and the regenerant agent receiver (20) are lock hoppers.

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