Device and method for producing olefin through downward alkane catalytic dehydrogenation

Abstract

The invention provides a device and a method for producing olefin through downward alkane catalytic dehydrogenation. The device comprises a reaction unit and a regeneration unit, the reaction unit sequentially comprises an oil agent contact zone, a reaction zone, an oil agent separation zone and a steam stripping zone from top to bottom; the oil agent contact area is provided with a catalyst distributor and an alkane feeding distributor from top to bottom, and an oil agent contact space is formed between the alkane feeding distributor and the bottom of the oil agent contact area; the reaction zone is a downstream reaction zone; the oil agent separation zone is provided with a reaction oil gas outlet and a catalyst outlet, and the catalyst outlet is communicated with the inlet of the steam stripping zone; the oil agent separation area is provided with a settler and a first two-stage cyclone separator, or is provided with a quick separation device; a spent catalyst outlet of the steam stripping area is communicated with a spent catalyst inlet of the regeneration area, and a regenerated catalyst outlet of the regeneration area is communicated with the catalyst distributor. Based on the device and the method provided by the invention, alkanes are produced into alkenes with high alkane conversion rate and selective dehydrogenation of alkenes.

Description

Technical Field

[0001] The present invention relates to the field of petrochemical industry, and in particular to a device and method for producing olefins by catalytic dehydrogenation of descending alkanes. 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] US20080161624A1 discloses a fluidized bed reactor with backmixing for the dehydrogenation of low-carbon alkanes. Alkanes react with a catalyst in a single fluidized bed reactor with backmixing. The deactivated catalyst is heated and then regenerated. The regenerated catalyst is returned to the fluidized bed reactor with backmixing for recycling, thereby maintaining the heat in the fluidized bed reactor with backmixing at a reasonable level. The reactor can improve the alkane conversion rate and olefin selectivity, and reduce the construction and operating costs of the device.

[0004] 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, thereby effectively improving the overall selectivity of the olefin product.

[0005] WO2020 / 186937A1 discloses a circulating fluidized bed apparatus for alkane dehydrogenation, comprising a reaction unit and a regeneration unit. The reaction unit comprises a reactor and a reaction settler, the reactor communicating with the reactor. A catalyst distributor is provided within the reactor, spraying the catalyst into the reactor along the reactor wall toward the central axis. The regeneration unit comprises a regenerator containing the catalyst and a regenerator settler, the regenerator settler being located above the regenerator. This apparatus can achieve high alkane conversion and olefin yields.

[0006] CN115253934A discloses a propane catalytic dehydrogenation fluidized bed reaction-regeneration coupling device and a propane catalytic dehydrogenation process method, comprising a raw material conveying system, a pre-lifting system, a reaction system, a gas-solid separation system and an internal circulation pipeline; the reaction system comprises a conical riser and a turbulent bed reactor; the raw material conveying system, the pre-lifting system, the conical riser, the turbulent bed reactor and the gas-solid separation system are connected in sequence from bottom to top, the bottom outlet of the gas-solid separation system is connected to the inlet of the internal circulation pipeline, the outlet of the internal circulation pipeline is connected to the raw material conveying system and / or the reaction system, and the top of the shell of the gas-solid separation system is provided with a product gas outlet.

[0007] Researchers have also made some progress in the development of green and environmentally friendly non-precious metal high-efficiency dehydrogenation catalysts.

[0008] CN104607168A discloses a catalyst for catalytic dehydrogenation of alkanes and a preparation method thereof. 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%. The catalyst has a high single-pass conversion rate for alkanes and high selectivity for olefins. Furthermore, its reaction performance is very stable after repeated regeneration, and it can be used in a circulating fluidized bed reactor.

[0009] 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. The catalyst comprises components A, B, C, D, and E, wherein component A is selected from any one or more oxides of Fe, Ni, Co, W, and Mo; component B is selected from any one or more oxides of Ge, Sb, In, and Te; component C is selected from any one or more oxides of Zn, Cu, Ga, and Mn; and component D is selected from any one oxide of Ba, Ca, Mg, K, and Na. Component E serves as a carrier. The catalyst contains no precious metal Pt and no environmentally polluting Cr or V, making it an inexpensive, environmentally friendly catalyst. The catalyst exhibits high alkane conversion and high olefin selectivity and can be used in fluidized bed reactors.

[0010] 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, the presence of restricted reaction zones in the reactors used, the failure to promptly terminate the reaction afterward, and the presence of acidic centers in the catalysts can lead to side reactions in the alkanes, hindering 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 better promotes the initiation and occurrence of the alkane dehydrogenation reaction and suppresses side reactions, thereby improving alkane conversion and olefin selectivity, remains a pressing technical challenge. Summary of the Invention

[0011] In view of the above problems, the present invention provides a device and method for producing olefins by catalytic dehydrogenation of alkanes in a downward direction.

[0012] In one aspect, the present invention provides a device for producing olefins by catalytic dehydrogenation of alkanes in a downward-flowing manner, comprising a reaction unit and a regeneration unit; wherein the reaction unit comprises, from top to bottom, an oil-agent contact zone, a reaction zone, an oil-agent separation zone, and a stripping zone;

[0013] The regeneration unit includes a regeneration zone and a regeneration heating zone;

[0014] The oil contact zone is provided with a catalyst distributor and an alkane feed distributor from top to bottom, and an oil contact space is formed between the alkane feed distributor and the bottom of the oil contact zone;

[0015] The reaction zone is a downward reaction zone;

[0016] The oil-agent separation zone is provided with a reaction oil and gas outlet and a catalyst outlet, and the catalyst outlet is connected to the inlet of the stripping zone; the oil-agent separation zone is provided with a settler and a first two-stage cyclone separator, or a quick separation device;

[0017] The outlet of the regenerated catalyst in the stripping zone is communicated with the inlet of the regenerated catalyst in the regeneration zone, and the outlet of the regenerated catalyst in the regeneration zone is communicated with the catalyst distributor.

[0018] On the other hand, the present invention provides a method for producing olefins by catalytic dehydrogenation of alkanes in a downward direction, which is implemented based on the above-mentioned device;

[0019] The alkane feedstock is introduced into the oil-agent contact zone through an alkane feed distributor, and the catalyst is introduced into the oil-agent contact zone through a catalyst distributor; the alkane feedstock and the catalyst are contacted and mixed in the oil-agent contact zone, and then flow downward into the reaction zone, and flow from top to bottom to react; the oil-agent mixture after the reaction enters the oil-agent separation zone for separation, the separated reaction oil gas is output through the reaction oil gas outlet, the separated spent catalyst enters the stripping zone for stripping, the spent catalyst obtained by stripping enters the regeneration zone for regeneration, and the obtained regenerated catalyst is introduced into the oil-agent contact zone through a catalyst distributor for recycling.

[0020] Beneficial effects:

[0021] The present invention strengthens the contact between the alkane feedstock and the catalyst through a high-efficiency oil-agent contact zone, thereby promoting better initiation of the catalytic dehydrogenation reaction; by adopting a downward reaction zone, a large agent-gas ratio and a short reaction time are achieved, providing a suitable reaction environment for the catalytic dehydrogenation reaction of the alkane, thereby promoting better progress of the catalytic dehydrogenation reaction; the oil-agent separation zone enables rapid separation of the reaction oil and gas from the catalyst, rapidly terminates the reaction, and simultaneously suppresses the occurrence of side reactions, thereby significantly improving the alkane conversion rate and olefin selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of an embodiment of a device for producing olefins by catalytic dehydrogenation of downward-flowing alkanes provided by the present invention;

[0023] Figure 2 A schematic structural diagram of another embodiment of a device for producing olefins by catalytic dehydrogenation of alkanes provided by the present invention;

[0024] Figure 3 This is a schematic structural diagram of the oil-agent contact zone in a device for producing olefins by catalytic dehydrogenation of alkanes provided by the present invention;

[0025] Figure 4 This is a schematic structural diagram of a catalyst distributor in a device for producing olefins by catalytic dehydrogenation of alkanes provided by the present invention;

[0026] Figure 5 A schematic structural diagram of an alkane feed distributor in a device for producing olefins by catalytic dehydrogenation of alkane provided by the present invention;

[0027] Figure 6 This is a schematic structural diagram of an embodiment of a reaction zone in a device for producing olefins by catalytic dehydrogenation of alkanes provided by the present invention;

[0028] Figure 7 and Figure 8 This is a schematic structural diagram of another embodiment of a reaction zone in a device for producing olefins by catalytic dehydrogenation of alkanes provided by the present invention;

[0029] Figure 9 A schematic structural diagram of another embodiment of a reaction zone in a device for producing olefins by catalytic dehydrogenation of alkanes provided by the present invention;

[0030] Figures 10-12 Schematic diagrams of the structures of several different embodiments of a fast separation device in a device for producing olefins by catalytic dehydrogenation of alkanes provided by the present invention;

[0031] Description of Reference Numerals

[0032] 1 Oil-agent contact zone 2 Reaction zone 3 Oil-agent separation zone

[0033] 4 Stripping Zone 5 Regeneration Zone 6 Regeneration Heat Supplement Zone

[0034] 1-1 Catalyst distributor 1-2 Alkane feed distributor

[0035] 11 Regeneration slide valve 12 First cyclone separator 13 Second cyclone separator

[0036] 14 First air collecting chamber 15 Stripping baffle 16 Waiting slide valve

[0037] 17 Third cyclone separator 18 Fourth cyclone separator 19 Second air collecting chamber

[0038] 101 Fluidizing medium pipe 102 Alkane feed pipe 103 Regeneration agent delivery pipe

[0039] 104 Reaction oil delivery pipe 105 Stripping gas pipe 106 Reaction oil and gas outlet

[0040] 107 Regenerated agent delivery pipe 108 Main air duct 109 Regeneration flue gas pipe

[0041] 110 fuel inlet 111 material inlet 112 catalyst outlet

[0042] The angle between the direction of the α-alkane feed hole and the central axis of the alkane feed distributor

[0043] The angle between the outer surface of the β-conical variable diameter reaction zone 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] 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.

[0047] In one aspect, the present invention provides a device for producing olefins by catalytic dehydrogenation of alkanes in a downward direction, such as Figure 1 As shown in FIG2 , the reaction unit comprises a reaction unit and a regeneration unit; the reaction unit comprises, from top to bottom, an oil-agent contact zone 1, a reaction zone 2, an oil-agent separation zone 3 and a stripping zone 4;

[0048] The regeneration unit includes a regeneration zone 5 and a regeneration heating zone 6;

[0049] like Figure 3 As shown, the oil contact zone 1 is provided with a catalyst distributor 1-1 and an alkane feed distributor 1-2 from top to bottom, and an oil contact space is formed between the alkane feed distributor 1-2 and the bottom of the oil contact zone 1;

[0050] The reaction zone 2 is a downward reaction zone;

[0051] like Figures 1-2 、 Figures 10-12 As shown, the oil separation zone 3 is provided with a reaction oil gas outlet 106 and a catalyst outlet 112, and the catalyst outlet 112 is connected to the inlet of the stripping zone 4; Figure 1 As shown, the oil separation zone 3 is provided with a settler and a first two-stage cyclone separator, or, as shown Figure 2 As shown, it is equipped with a quick separation device;

[0052] The outlet of the regenerated catalyst in the stripping zone 4 is communicated with the inlet of the regenerated catalyst in the regeneration zone 5 , and the outlet of the regenerated catalyst in the regeneration zone 5 is communicated with the catalyst distributor 1 - 1 .

[0053] It should be noted that, in the device of the present invention, the bottom of the oil-agent contact zone 1 is connected to the top of the reaction zone 2, the bottom of the reaction zone 2 is connected to the oil-agent separation zone 3, and the bottom of the oil-agent separation zone 3 is connected to the top of the stripping zone 4. After passing through the oil-agent separation zone 3, the catalyst and the reaction oil and gas are preliminarily separated, and the separated reaction oil and gas are output through the reaction oil and gas outlet 106. The separated catalyst still retaining a small amount of oil and gas enters the stripping zone 4 for further stripping separation. The stripped reaction oil and gas can be output through the reaction oil and gas outlet 106, and the stripped catalyst to be regenerated can be transported to the regeneration zone 5 through the regeneration agent delivery pipe 107 for regeneration. The regenerated catalyst in the regeneration zone 5 can be transported to the catalyst distributor 1-1 through the regeneration agent delivery pipe 103, and then enter the oil-agent contact zone 1 through the catalyst distributor 1-1 for recycling. A regenerated catalyst delivery pipe 107 may be provided with a regenerated slide valve 16. By adjusting the opening of the regenerated slide valve 16, the flow rate of the regenerated catalyst in the regenerated catalyst delivery pipe 107 can be adjusted in real time. A regeneration slide valve 11 may be provided on the regenerative agent delivery pipe 103. By adjusting the opening of the regeneration slide valve 11, the flow rate of the regenerated catalyst in the regenerative agent delivery pipe 103 can be adjusted in real time.

[0054] The device of the present invention strengthens the contact between the alkane feedstock and the catalyst through the high-efficiency oil-agent contact zone, thereby promoting better initiation of the catalytic dehydrogenation reaction; by adopting a downward reaction zone, a large agent-gas ratio and a short reaction time are achieved, providing a suitable reaction environment for the catalytic dehydrogenation reaction of the alkane, thereby promoting the progress of the catalytic dehydrogenation reaction; the oil-agent separation zone 3 is provided with a settler and a first two-stage cyclone separator, or a fast separation device, to quickly separate the reaction oil gas and the catalyst, quickly terminate the reaction, and simultaneously suppress the occurrence of side reactions, thereby improving the alkane conversion rate and olefin selectivity.

[0055] In one embodiment of the above-mentioned device of the present invention, Figure 3 As shown, the catalyst distributor 1-1 is arranged at the top of the oil contact zone 1, and the distance between the alkane feed distributor 1-2 and the bottom of the oil contact zone 1 accounts for 1 / 3 to 4 / 5 of the height of the oil contact zone 1, preferably 1 / 2 to 3 / 4.

[0056] It should be noted that, in this embodiment, the catalyst sprayed from the catalyst distributor 1-1 first enters the area between the catalyst distributor 1-1 and the alkane feed distributor 1-2, and the catalyst is partially dispersed in this area. Then, the catalyst flows downward into the oil contact space and contacts and mixes with the alkane feed sprayed from the alkane feed distributor 1-2. The catalyst and the alkane feed can be mixed more quickly and evenly and quickly pass through the oil contact zone into the reaction zone. While shortening the contact and mixing time, it can promote better contact between the catalyst and the alkane feed to initiate the reaction, which is beneficial to improving the alkane conversion rate and olefin selectivity.

[0057] Furthermore, the oil-agent contact zone 1 may be provided with a fluidizing medium pipe 101, which may be connected to the bottom of the oil-agent contact zone 1. The outlet of the fluidizing medium pipe 101 may communicate with the oil-agent contact space. Fluidizing medium is introduced into the oil-agent contact zone 1 via the fluidizing medium pipe 101, thereby ensuring more complete contact between the alkane feedstock introduced into the oil-agent contact zone 1 via the alkane feed pipe 102 and the catalyst. Fluidizing medium is well known to those skilled in the art and may be one or more selected from steam, nitrogen, and dry gas, preferably steam. The top of the oil-agent contact zone 1 may be connected to a regeneration agent delivery pipe 103, and the bottom of the oil-agent contact zone 1 may be connected to the top of the reaction zone 2.

[0058] In one embodiment of the above-mentioned device of the present invention, Figure 4 As shown, the catalyst distributor 1-1 is a disc structure, on which catalyst feed holes of equal or unequal diameters are uniformly or unevenly opened;

[0059] The catalyst feed hole is directed downward and parallel to the central axis of the catalyst distributor 1 - 1 . The opening rate of the catalyst distributor 1 - 1 is 50 to 95%, preferably 70 to 90%.

[0060] It should be noted that by setting the structure and opening rate of the catalyst distributor 1-1 as above, the catalyst sprayed from the catalyst distributor 1-1 can better contact and mix with the alkane feedstock, can better initiate the reaction, and further improve the alkane conversion rate and olefin selectivity.

[0061] In another embodiment of the above device of the present invention, Figure 5 As shown, the alkane feed distributor 1-2 is an annular structure, on which alkane feed holes of equal or unequal diameters are uniformly or unevenly opened;

[0062] The diameter of the alkane feed hole is 1 / 4 to 3 / 4 of the ring width of the alkane feed distributor 1-2, the direction of the alkane feed hole is downward, and the angle α between the direction of the alkane feed hole and the central axis of the alkane feed distributor 1-2 is 15 to 75 degrees.

[0063] It should be noted that by controlling the structure and opening direction of the alkane feed distributor 1-2 as described above, the alkane feedstock sprayed from the alkane feed distributor 1-2 can better contact and mix with the catalyst, and can better initiate the reaction, which is conducive to further improving the alkane conversion rate and olefin selectivity.

[0064] In one embodiment of the above-mentioned device of the present invention, Figure 6 As shown, the reaction zone 2 is a constant diameter reaction zone, and the ratio of the diameter to the height of the constant diameter reaction zone is 1:5 to 50, preferably 1:10 to 30.

[0065] It should be noted that the oil mixture flowing out of the lower outlet of reaction zone 2 can be transported to oil separation zone 3 via reaction oil delivery pipe 104. By controlling the diameter-to-height ratio of the equal-diameter reaction zone as described above, the contacted and mixed alkane feedstock and catalyst can better react to produce the target olefin product, thereby further improving the alkane conversion rate and olefin selectivity.

[0066] In another embodiment of the above device of the present invention, Figure 7 and 8 As shown, the reaction zone 2 is a tapered variable diameter reaction zone with a diameter gradually increasing from top to bottom;

[0067] The angle β between the outer surface of the tapered variable diameter reaction zone and the central axis is 0 to 20 degrees, preferably 0 to 10 degrees; the ratio of the upper diameter to the lower diameter of the tapered variable diameter reaction zone is 1:1 to 10, preferably 1:1.2 to 5.

[0068] It should be noted that in this preferred embodiment, the diameter of the reaction zone 2 gradually increases from top to bottom. Such a reaction zone shape is more compatible with the occurrence of the alkane dehydrogenation reaction to produce olefins, which is beneficial to the conversion of alkanes into target olefins, and is therefore beneficial to improving the alkane conversion rate and olefin selectivity. In particular, by further controlling the ratio of the upper diameter to the lower diameter of the tapered variable diameter reaction zone as described above, the alkane conversion rate and olefin selectivity are greatly improved. The angle β between the outer surface of the tapered variable diameter reaction zone and the central axis can be specifically 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, 11 degrees, 12 degrees, 13 degrees, 14 degrees, 15 degrees, 16 degrees, 17 degrees, 18 degrees, 19 degrees, etc.; the ratio of the upper diameter to the lower diameter of the tapered variable diameter reaction zone can be specifically 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, etc.

[0069] In another embodiment of the above device of the present invention, Figure 9 As shown, the reaction zone 2 is a variable diameter reaction zone, which includes multiple equal diameter reaction sections connected in sequence from top to bottom; the diameter ratio of the two equal diameter reaction sections connected up and down is 1:1~2, preferably 1:1~1.5.

[0070] It should be noted that in this embodiment, reaction zone 2 includes multiple equal-diameter reaction sections, with the diameters of the multiple equal-diameter reaction sections gradually increasing from top to bottom. This reaction zone configuration is beneficial for improving alkane conversion and olefin selectivity. Furthermore, by controlling the diameter ratio of the two equal-diameter reaction sections connected vertically as described above, alkane conversion and olefin selectivity can be further improved. The diameter ratio of the two equal-diameter reaction sections connected vertically can specifically be 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, etc.

[0071] In the above-described apparatus of the present invention, the oil-solvent separation zone 3 can be used in conjunction with a settler and a first two-stage cyclone separator to achieve rapid oil-solvent separation, or a rapid separation device can be used to achieve rapid oil-solvent separation. The first two-stage cyclone separator can include a first cyclone separator 12 and a second cyclone separator 13. The reaction oil and gas separated by the first two-stage cyclone separator can first enter a first plenum 14 and then be output through a reaction oil and gas outlet 106.

[0072] In one embodiment of the above-mentioned device of the present invention, Figures 10-12 As shown, the top of the quick separation device is provided with a material inlet 111 connected to the outlet of the reaction zone 2, the catalyst outlet 112 is provided at the bottom of the quick separation device, and the reaction oil and gas outlet 106 is provided at the upper part or side of the quick separation device.

[0073] It should be noted that the oil-agent mixture flowing out of the outlet at the lower end of the reaction zone enters the separation chamber of the quick separation device through the material inlet 111, and the separated reaction oil and gas are output to the outside of the device through the reaction oil and gas outlet 106. The separated spent catalyst still carrying a small amount of oil and gas is output through the catalyst outlet 112 and then enters the stripping zone for stripping. The stripped reaction oil and gas can be output to the outside of the device through the reaction oil and gas outlet 106, and the spent catalyst after stripping can flow to the regeneration zone for regeneration.

[0074] In one embodiment of the above-mentioned device of the present invention, 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-shaped tube separator and a wall-cutting quick separator, preferably a cyclone quick separator.

[0075] It should be noted that the use of the above-mentioned quick separation device can quickly achieve the initial separation of the oil, terminate the reaction in time, and effectively avoid the occurrence of alkane side reactions.

[0076] In one embodiment of the above-mentioned device of the present invention, Figure 10As shown, the quick separation device includes, from top to bottom, a rectangular separation section, a first closing section, and a first outlet section that are interconnected; the top opening of the rectangular separation section is a material inlet 111, at least two opposite side walls of the rectangular separation section are provided with movable shutter-type reaction oil and gas outlets 106, and the lower end opening of the first outlet section is a catalyst outlet 112;

[0077] like Figure 11 As shown, the quick separation device includes a U-shaped tube separation section and a second outlet section that are connected from top to bottom. The height of the first side tube of the U-shaped tube separation section is greater than that of the second side tube. A separation baffle is provided between the first side tube and the second side tube. The separation baffle extends vertically downward from the top of the first side tube. The top opening of the first side tube is a material inlet 111, the top of the second side tube is closed and the side wall opening thereof is a reaction oil and gas outlet 106, and the lower end opening of the second outlet section is a catalyst outlet 112.

[0078] It should be noted that, in Figure 10 In the quick separation device shown, the number and angle of the louvers of the movable louver type reaction oil and gas outlet 106 can be adjusted to conveniently control its flow rate. Figure 11 In the quick separation device shown, the material inlet 111 is higher than the reaction oil and gas outlet 106 to better separate the catalyst and oil and gas. Figure 10 or Figure 11 The quick separation device shown can better and faster separate the oil mixture after the reaction, terminate the reaction more quickly, and further improve the alkane conversion rate and olefin selectivity.

[0079] In another embodiment of the above device of the present invention, Figure 12 As shown, the quick separation device is provided with an inner cylinder and an outer cylinder with upper and lower openings and coaxially sleeved, and at least two fins are provided on the outer wall of the inner cylinder opposite to each other, and the cross section of the fin is C-shaped and parallel to the central axis of the inner cylinder and the outer cylinder; the top opening of the inner cylinder is a material inlet 111, and a reaction oil and gas outlet 106 is formed between the top of the outer cylinder and the inner cylinder; the lower end of the outer cylinder is provided with a second closing section and a third outlet section from top to bottom, and the lower end opening of the third outlet section is a catalyst outlet 112.

[0080] It should be noted that in Figure 12 In the quick separation device shown, the material inlet 111 can be higher than the reaction oil and gas outlet 106. The fins arranged relatively on the outer wall of the inner cylinder are not limited to two, but can also be an even number such as four or six. By providing the fins, a negative pressure space is formed when the inner cylinder rotates, which can further enhance the oil-agent separation effect, so that the oil-agent mixture after the reaction can be separated more quickly, the reaction can be terminated more quickly, and the alkane conversion rate and olefin selectivity are further improved.

[0081] In one embodiment of the above-mentioned device of the present invention, Figure 1As shown, the stripping zone 4 is optionally provided with a stripping baffle 15 .

[0082] It should be noted that the stripping zone 4 may be provided with a stripping gas pipe 105, through which stripping gas is introduced into the stripping zone 4 to remove residual reaction oil and gas on the regenerated catalyst. The stripping gas is well known to those skilled in the art and may be one or more selected from water vapor, nitrogen, and dry gas, preferably water vapor.

[0083] In one embodiment of the above-mentioned device of the present invention, Figure 1 As shown in FIG2 , the regeneration and heating zone 6 is located outside or inside the regeneration zone 5 , and the regeneration and heating zone 6 is provided with a fuel inlet 110 .

[0084] It should be noted that to compensate for the heat deficiency during the regeneration process, fuel is introduced into the regeneration heating zone 6 through the fuel inlet 110. The fuel combustion replenishes heat in the regeneration zone 5, thereby achieving thermal equilibrium between the entire reaction unit and the regeneration unit. The regeneration zone 5 may be equipped with a main air duct 108. An oxidizing gas is introduced into the regeneration zone 5 through the main air duct 108 to burn off coke deposited on the regenerated catalyst and convert the active components in the catalyst to an oxidized state, thereby restoring the catalyst's dehydrogenation activity. Oxidizing gases include oxygen, air, and other oxygen-containing mixed gases.

[0085] Furthermore, the regeneration zone 5 may be provided with a second two-stage cyclone separator and a second plenum 19. The regenerated catalyst is separated from the regeneration flue gas carried by the second two-stage cyclone separator. The regeneration flue gas passes through the second plenum 19 and then exits the regeneration unit through a regeneration flue gas pipe 109. The separated regenerated catalyst is transported to the catalyst distributor 1-1 through a regeneration agent delivery pipe 103. The second two-stage cyclone separator may include a third cyclone separator 17 and a fourth cyclone separator 18.

[0086] On the other hand, the present invention provides a method for producing olefins by catalytic dehydrogenation of alkanes in a downward direction, wherein the method is implemented based on the above-mentioned device;

[0087] The alkane feedstock is introduced into the oil-agent contact zone 1 through the alkane feed distributor 1-2, and the catalyst is introduced into the oil-agent contact zone 1 through the catalyst distributor 1-1; the alkane feedstock and the catalyst are contacted and mixed in the oil-agent contact zone 1, and then flow downward into the reaction zone 2, and flow from top to bottom to react; the oil-agent mixture after the reaction enters the oil-agent separation zone 3 for separation, and the separated reaction oil gas is output through the reaction oil gas outlet 106, and the separated spent catalyst enters the stripping zone 4 for stripping. The spent catalyst obtained by stripping enters the regeneration zone 5 for regeneration, and the regenerated catalyst is introduced into the oil-agent contact zone 1 through the catalyst distributor 1-1 for recycling.

[0088] In the method of the present invention, the alkane feedstock can be preheated to 350-500°C, specifically 360°C, 370°C, 380°C, 390°C, 400°C, 420°C, 440°C, 460°C, 480°C, etc., and then introduced into the alkane feed distributor 1-2 through the alkane feed pipe 102. The regenerated catalyst from the regeneration zone 5 is introduced into the catalyst distributor 1-1 through the regeneration agent delivery pipe 103. The alkane feedstock and the catalyst are fully contacted in the oil agent contact zone 1.

[0089] In one embodiment of the above method of the present invention, the temperature of the oil contact zone 1 is 560-700°C, preferably 580-680°C, and the catalyst density is 100-500 kg / m 3 , preferably 150~400kg / m 3 , the pressure is 0.05 to 0.2 MPa, preferably 0.05 to 0.15 MPa; and / or

[0090] The temperature at the outlet of the reaction zone 2 is 520-660°C, preferably 540-640°C, and the catalyst density is 10-200 kg / m 3 , preferably 30 to 150 kg / m 3 , a pressure of 0.05 to 0.20 MPa, preferably 0.05 to 0.15 MPa; and / or

[0091] A quick separation device is provided inside the oil separation zone 3, wherein the oil and gas linear velocity at the inlet of the quick separation device is 2-20 m / s, preferably 5-18 m / s, and the oil and gas linear velocity at the outlet is 2-15 m / s, preferably 5-12 m / s; and / or

[0092] The temperature of the regeneration zone 5 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.

[0093] It should be noted that the aforementioned pressure may be gauge pressure. By controlling the conditions in the oil-contact zone 1 as described above, the alkane feedstock and catalyst can be better contacted and mixed to initiate the reaction; by controlling the conditions in the reaction zone 2 as described above, the alkane feedstock and catalyst can be better reacted to produce the target olefins; by controlling the conditions in the quick separation device as described above, the oil-contact mixture can be separated more quickly, and the reaction can be terminated more quickly, further improving the alkane conversion rate and olefin selectivity; and by controlling the conditions in the regeneration zone 5 as described above, the catalyst can be better regenerated, resulting in a regenerated catalyst with improved catalytic activity.

[0094] In another embodiment of the above method of the present invention, 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;

[0095] The catalyst comprises a carrier, a dehydrogenation active component and a binder, wherein the carrier is selected from one or more of Al2O3, SiO2, ZrO2, TiO2 and molecular sieves, the dehydrogenation active component is selected from one or more of Zn, Fe, Co, Ni, V, Sn, Mg and Ga as a single substance or oxide, and the binder is selected from one or more of pseudo-boehmite, alumina sol and silica sol; based on the weight of the catalyst, the content of the carrier is 5-90%, the content of the dehydrogenation active component is 5-90%, and the content of the binder is 5-90%; preferably, the content of the carrier is 20-80%, the content of the dehydrogenation active component is 10-70%, and the content of the binder is 10-70%; and / or

[0096] A regeneration and heating zone 6 is provided inside or outside the regeneration zone 5, and fuel is introduced into the regeneration and heating zone 6 through a fuel inlet 110. The fuel is selected from one or more of methane, ethane, dry gas, liquefied gas, and fuel oil, preferably dry gas generated by the device.

[0097] It should be noted that, in the method of the present invention, the catalyst of the above composition is selected to better match the device of the present invention for the alkane dehydrogenation reaction to form olefins, thereby further improving the alkane conversion rate and olefin selectivity.

[0098] 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.

[0099] 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 the Sinopec Research Institute of Petroleum Processing.

[0100] The chemical composition and properties of the alkane dehydrogenation catalyst are shown in Table 1.

[0101] Table 1 Composition and properties of alkane dehydrogenation catalysts

[0102] project Physical and chemical properties Chemical composition / %(w) <![CDATA[Al2O3]]> 23.30 <![CDATA[SiO2]]> 0.30 MgO 0.43 <![CDATA[TiO2]]> 35.00 <![CDATA[Fe2O3]]> 0.22 <![CDATA[ZrO2]]> 5.00 ZnO 35.30 BET Full Analysis <![CDATA[BET total surface area / (m 2 ·g -1 )]]> 24.00 <![CDATA[Total pore volume / (cm 3 ·g -1 )]]> 0.1038

[0103] In the following examples, the calculation method of alkane conversion and olefin selectivity is as follows:

[0104] Alkane conversion rate = (mass fraction of alkanes in the feedstock - mass fraction of alkanes in the product) ÷ mass fraction of alkanes in the feedstock;

[0105] Olefin selectivity = (mass fraction of olefins in the product ÷ mass fraction of alkanes in the feed) ÷ alkane conversion.

[0106] Example 1

[0107] The test Figure 1 The reaction-regeneration device shown in the figure was used. The device used in the test includes a reaction unit and a regeneration unit, wherein the reaction unit includes an oil-agent contact zone, a reaction zone, an oil-agent separation zone and a stripping zone from top to bottom, and the regeneration unit includes a regeneration zone and a regeneration heat supplement zone.

[0108] The alkane feed distributor is located half the height of the oil-agent contact zone from the bottom of the oil-agent contact zone. The alkane feed distributor is an annular structure with a feed hole diameter equal to half the ring width. The feed hole is oriented downward at an angle α of 45 degrees to the central axis of the alkane feed distributor. A disc-shaped catalyst distributor is located at the top of the oil-agent contact zone, with the catalyst feed hole oriented downward and parallel to the central axis. The open area of ​​the catalyst distributor is 80%. Preheated alkane is introduced into the oil-agent contact zone through the alkane feed distributor, where it fully contacts the catalyst introduced through the catalyst distributor. It is then introduced into the descending reaction zone along with fluidizing gas from the fluidizing medium pipe for reaction. The reacted oil-agent mixture is then introduced into the oil-agent separation zone. The separated reaction oil and gas are then removed from the device. The resulting catalyst is then introduced into the stripping zone for stripping. The stripped catalyst is then regenerated in the regeneration zone. The regenerated catalyst is then recycled back into the catalyst distributor.

[0109] The raw material used in the embodiment is propane, the fluidizing gas is water vapor, and the fuel used in the regeneration heating zone is dry gas. Figure 6 The reaction zone has a diameter-to-height ratio of 1:20. The oil separation zone includes a settler and a two-stage cyclone separator. The reaction conditions and results are shown in Table 2.

[0110] Example 2

[0111] The test Figure 2 The reaction-regeneration device shown in the figure is carried out according to the method of Example 1, except that the height of the alkane feed distributor from the bottom of the oil contact zone accounts for 3 / 4 of the height of the oil contact zone, the diameter of the feed hole is 3 / 4 of the diameter of the alkane feed distributor ring width, the feed hole is directed downward, and the angle α with the central axis of the alkane feed distributor is 30 degrees. The reaction zone is Figure 7 and Figure 8 The angle β between the outer surface of the tapered variable diameter reaction zone and the central axis of the tapered variable diameter reaction zone is 8 degrees, and the ratio of the upper diameter to the lower diameter of the reaction zone is 1:1.5. Figure 10The quick separation device shown in FIG, the oil and gas linear velocity at the inlet of the quick separation device is 15m / s, and the oil and gas linear velocity at the outlet is 12m / s. The reaction conditions and results are shown in Table 2.

[0112] Comparative Example 1

[0113] The apparatus used in the experiment consisted of a reaction unit and a regeneration unit. The reaction unit consisted, from bottom to top, of a pre-lift zone, a reaction zone, an oil-agent separation zone, and a stripping zone. The regeneration unit consisted of a regeneration and heating zone and a regeneration zone. Preheated alkanes and catalyst were introduced to the bottom of the reaction zone and, along with pre-lift gas from the pre-lift zone, were introduced into the reaction zone for reaction. The reacted oil-agent mixture was then introduced into the oil-agent separation zone. The separated reaction oil and gas were then withdrawn from the device. The resulting catalyst was then introduced into the stripping zone for stripping. The stripped catalyst was then introduced into the regeneration zone for regeneration. The regenerated catalyst was then introduced into the catalyst distributor for recycling.

[0114] The comparative example used propane as the raw material, steam as the pre-lift gas, and dry gas as the fuel in the regeneration and reheating zone. The reaction zone was a constant-diameter, ascending reaction zone with a diameter-to-height ratio of 1:20. The oil-agent separation zone consisted of a settler and a two-stage cyclone separator. The reaction conditions and results are shown in Table 2.

[0115] Comparative Example 2

[0116] The method of Comparative Example 1 was followed, except that the reaction unit further included an oil contact zone, the bottom of the oil contact zone was connected to the top of the pre-elevation zone, and the top of the oil contact zone was connected to the bottom of the reaction zone. The reaction conditions and results are shown in Table 2.

[0117] Table 2 Reaction conditions and reaction results of Examples 1-2 and Comparative Examples 1-2

[0118]

[0119]

[0120] Example 3

[0121] The method of Example 2 is as follows, except that the raw material used is n-butane, and the reaction zone is Figure 9 The variable diameter reaction zone shown is composed of multiple equal diameter reaction sections with gradually increasing diameters from top to bottom, connected in sequence. The diameter ratio of two adjacent equal diameter reaction sections from top to bottom is 1:1.1. Figure 11 The quick separation device shown in FIG, has an inlet oil and gas linear velocity of 15 m / s and an outlet oil and gas linear velocity of 12 m / s. The reaction conditions and product distribution are shown in Table 3.

[0122] Example 4

[0123] The method of Example 2 is the same except that the raw material used is isobutane and the oil separation zone is Figure 12 The quick separation device shown in FIG, has an inlet oil and gas linear velocity of 15 m / s and an outlet oil and gas linear velocity of 12 m / s. The reaction conditions and product distribution are shown in Table 3.

[0124] Comparative Example 3

[0125] The method of Comparative Example 1 was followed, except that the raw material used was n-butane. The reaction conditions and product distribution were as shown in Table 3.

[0126] Comparative Example 4

[0127] The method of Comparative Example 2 was followed, except that the raw material used was isobutane. The reaction conditions and product distribution were shown in Table 3.

[0128] Table 3 Reaction conditions and reaction results of Examples 3 to 4 and Comparative Examples 3 to 4

[0129]

[0130]

[0131] As can be seen from Table 2 and Table 3, by using the device and method provided by the present invention, different reactions are enhanced, and the conversion rate of reactants and the selectivity of target products are greatly improved.

[0132] 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.

[0133] 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.

[0134] 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 device for producing olefins by catalytic dehydrogenation of alkanes in a downward direction, comprising a reaction unit and a regeneration unit; wherein: The reaction unit comprises, from top to bottom, an oil-agent contact zone (1), a reaction zone (2), an oil-agent separation zone (3) and a stripping zone (4); The regeneration unit includes a regeneration zone (5) and a regeneration heating zone (6); The oil contact zone (1) is provided with a catalyst distributor (1-1) and an alkane feed distributor (1-2) from top to bottom, and an oil contact space is formed between the alkane feed distributor (1-2) and the bottom of the oil contact zone (1); The reaction zone (2) is a downward reaction zone; The oil-agent separation zone (3) is provided with a reaction oil gas outlet (106) and a catalyst outlet (112), and the catalyst outlet (112) is communicated with the inlet of the stripping zone (4); the oil-agent separation zone (3) is provided with a settler and a first two-stage cyclone separator, or a quick separation device; The outlet of the catalyst to be regenerated of the stripping zone (4) is communicated with the inlet of the catalyst to be regenerated of the regeneration zone (5), and the outlet of the regenerated catalyst of the regeneration zone (5) is communicated with the catalyst distributor (1-1).

2. The device according to claim 1, wherein The catalyst distributor (1-1) is arranged at the top of the oil contact zone (1), and the distance between the alkane feed distributor (1-2) and the bottom of the oil contact zone (1) accounts for 1 / 3 to 4 / 5 of the height of the oil contact zone (1), preferably 1 / 2 to 3 / 4.

3. The device according to claim 1 or 2, wherein: The catalyst distributor (1-1) is a disc structure, on which catalyst feed holes of equal or unequal diameters are uniformly or unevenly opened; The catalyst feed hole is directed downward and parallel to the central axis of the catalyst distributor (1-1). The opening rate of the catalyst distributor (1-1) is 50-95%, preferably 70-90%.

4. The device according to claim 1 or 2, wherein: The alkane feed distributor (1-2) is an annular structure, on which alkane feed holes of equal or unequal diameters are uniformly or unevenly opened; The diameter of the alkane feed hole is 1 / 4 to 3 / 4 of the ring width of the alkane feed distributor (1-2), the direction of the alkane feed hole is downward, and the angle (α) between the direction of the alkane feed hole and the central axis of the alkane feed distributor (1-2) is 15 to 75 degrees.

5. The device according to claim 1, wherein The reaction zone (2) is a constant diameter reaction zone, and the ratio of the diameter to the height of the constant diameter reaction zone is 1:5 to 50, preferably 1:10 to 30.

6. The device according to claim 1, wherein The reaction zone (2) is a tapered variable diameter reaction zone with a diameter gradually increasing from top to bottom; The angle (β) between the outer surface of the tapered variable diameter reaction zone and the central axis is 0 to 20 degrees, preferably 0 to 10 degrees; the ratio of the upper diameter to the lower diameter of the tapered variable diameter reaction zone is 1:1 to 10, preferably 1:1.2 to 5.

7. The device according to claim 1, wherein The reaction zone (2) is a variable diameter reaction zone, which comprises multiple equal diameter reaction sections connected in sequence from top to bottom; the diameter ratio of the two equal diameter reaction sections connected in sequence is 1:1 to 2, preferably 1:1 to 1.

5.

8. The device according to claim 1, wherein The top of the quick separation device is provided with a material inlet (111) connected to the outlet of the reaction zone (2), the catalyst outlet (112) is provided at the bottom of the quick separation device, and the reaction oil and gas outlet (106) is provided at the upper part or side of the quick separation device.

9. The device according to claim 8, 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-shaped tube separator and a wall-cutting quick separator, preferably a cyclone quick separator.

10. The device according to claim 8, wherein The quick separation device comprises, from top to bottom, a rectangular separation section, a first closing section, and a first outlet section which are connected to each other; the top opening of the rectangular separation section is a material inlet (111); at least two opposite side walls of the rectangular separation section are provided with movable shutter-type reaction oil and gas outlets (106); and the lower end opening of the first outlet section is a catalyst outlet (112); The quick separation device comprises a U-shaped tube separation section and a second outlet section connected from top to bottom. The height of the first side tube of the U-shaped tube separation section is greater than that of the second side tube. A separation baffle is provided between the first side tube and the second side tube. The separation baffle extends vertically downward from the top of the first side tube. The top opening of the first side tube is a material inlet (111). The top of the second side tube is closed and the side wall opening is a reaction oil and gas outlet (106). The lower end opening of the second outlet section is a catalyst outlet (112).

11. The device according to claim 8, wherein The quick separation device is provided with an inner cylinder and an outer cylinder with upper and lower openings and coaxially sleeved. At least two fins are provided on the outer wall of the inner cylinder opposite to each other. The cross section of the fins is C-shaped and parallel to the central axis of the inner cylinder and the outer cylinder. The top opening of the inner cylinder is a material inlet (111), and a reaction oil and gas outlet (106) is formed between the top of the outer cylinder and the inner cylinder. The lower end of the outer cylinder is provided with a second closing section and a third outlet section in sequence from top to bottom, and the lower end opening of the third outlet section is a catalyst outlet (112).

12. The device according to claim 1, wherein The stripping zone (4) is optionally provided with a stripping baffle (15).

13. The device according to claim 1, wherein The regeneration and heating zone (6) is located outside or inside the regeneration zone (5), and the regeneration and heating zone (6) is provided with a fuel inlet (110).

14. A method for producing olefins by catalytic dehydrogenation of alkanes, wherein: The method is implemented based on the device according to any one of claims 1 to 13; An alkane feedstock is introduced into an oil-agent contact zone (1) through an alkane feed distributor (1-2), and a catalyst is introduced into the oil-agent contact zone (1) through a catalyst distributor (1-1); the alkane feedstock and the catalyst are contacted and mixed in the oil-agent contact zone (1), and then flow downward into a reaction zone (2), and flow from top to bottom to react; the oil-agent mixture after the reaction enters an oil-agent separation zone (3) for separation, the separated reaction oil gas is output through a reaction oil gas outlet (106), the separated spent catalyst enters a stripping zone (4) for stripping, the spent catalyst obtained by stripping enters a regeneration zone (5) for regeneration, and the obtained regenerated catalyst is introduced into the oil-agent contact zone (1) through a catalyst distributor (1-1) for recycling.

15. The method according to claim 14, wherein The temperature of the oil contact zone (1) is 560-700°C, preferably 580-680°C, and the catalyst density is 100-500 kg / m 3 , preferably 150~400kg / m 3 , the pressure is 0.05 to 0.2 MPa, preferably 0.05 to 0.15 MPa; and / or The temperature at the outlet of the reaction zone (2) is 520-660°C, preferably 540-640°C, and the catalyst density is 10-200 kg / m 3 , preferably 30 to 150 kg / m 3 , a pressure of 0.05 to 0.20 MPa, preferably 0.05 to 0.15 MPa; and / or The oil separation zone (3) is provided with a quick separation device, wherein the oil and gas linear velocity at the inlet of the quick separation device is 2 to 20 m / s, preferably 5 to 18 m / s, and the oil and gas linear velocity at the outlet of the quick separation device is 2 to 15 m / s, preferably 5 to 12 m / s; and / or The temperature of the regeneration zone (5) 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.

16. The method according to claim 14, wherein 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; The catalyst comprises a carrier, a dehydrogenation active component and a binder, wherein the carrier is selected from one or more of Al2O3, SiO2, ZrO2, TiO2 and molecular sieves, the dehydrogenation active component is selected from one or more of Zn, Fe, Co, Ni, V, Sn, Mg and Ga as a single substance or oxide, and the binder is selected from one or more of pseudo-boehmite, alumina sol and silica sol; based on the weight of the catalyst, the content of the carrier is 5-90%, the content of the dehydrogenation active component is 5-90%, and the content of the binder is 5-90%; preferably, the content of the carrier is 20-80%, the content of the dehydrogenation active component is 10-70%, and the content of the binder is 10-70%; and / or A regeneration and heating zone (6) is provided inside or outside the regeneration zone (5), and fuel is introduced into the regeneration and heating zone (6) through a fuel inlet (110). The fuel is selected from one or more of methane, ethane, dry gas, liquefied gas, and fuel oil, preferably dry gas generated by the device.

Images