COUPLED FLUIDIZED BEDS REACTOR-REGENERATOR APPARATUS FOR CATALYTIC DEHYDROGENATION OF PROPANE

Abstract

A coupled fluidized beds reactor-regenerator apparatus for catalytic dehydrogenation of propane. The fluidized bed reactor comprising a raw material delivery system, a pre-rising system, a reaction system, a gas-solid separation system and an internal circulation pipeline, the reaction system includes a conical riser and a turbulent bed reactor; the raw material delivery system, the pre-rising system, the conical riser, the turbulent bed reactor, and the gas-solid separation system are consecutively connected in this order from bottom to top; the bottom outlet of the gas-solid separation system is connected to the inlet of the internal circulation pipeline, and the outlet of the internal circulation pipeline is connected to the raw material delivery system and/or the reaction system. The coupled fluidized beds reactor-regenerator apparatus for catalytic dehydrogenation of propane includes the fluidized bed reactor, a gas-solid airlift loop regenerator, a recirculation inclined pipe and a regeneration inclined pipe.

Claims

1. A fluidized bed reactor comprising a raw material delivery system, a pre-rising system, a reaction system, a gas-solid separation system, and an internal circulation pipeline, wherein: the reaction system comprises a conical riser and a turbulent bed reactor, and the cross-sectional diameter of the conical riser gradually increases from an inlet to an outlet; the raw material delivery system, the pre-rising system, the conical riser, the turbulent bed reactor, and the gas-solid separation system are consecutively connected in this order from bottom to top, wherein the bottom of the gas-solid separation system is provided with an outlet connected to an inlet of the internal circulation pipeline, and an outlet of the internal circulation pipeline is connected to the raw material delivery system and/or the reaction system; and the gas-solid separation system is provided with a product gas outlet.

2. The fluidized bed reactor according to claim 1, wherein the angle between the wall generatrix of the conical riser and the central vertical line of the conical riser is between 0 and 10, and wherein the ratio of the outlet diameter to the inlet diameter of the conical riser is less than or equal to 3 and greater than 1.

3. The fluidized bed reactor according to claim 1, wherein: the bottom of the turbulent bed reactor is provided with a first perforated distribution plate; the turbulent bed reactor is further provided with one or more layers of grids located above the first perforated distribution plate and arranged in layers along the vertical direction; and a catalyst bed is formed in the inner space of the turbulent bed reactor, and at least the uppermost layer of grid is located inside the catalyst bed.

4. The fluidized bed reactor according to claim 1, wherein the vertical distance between the lowermost layer of grid and the first perforated distribution plate is greater than or equal to 500 mm.

5. The fluidized bed reactor according to claim 1, wherein the grids are one or more groups of cross-flow grids including two layers of grids in each group, wherein the vertical distance between the two layers of grids in the same group is greater than or equal to 300 mm, and wherein the vertical distance between two adjacent groups of grids is 500 mm to 4000 mm.

6. The fluidized bed reactor according to claim 1, wherein the gas-solid separation system comprises a casing, wherein a gas collection hood, a dilute phase pipe, a low-wear gas-solid separation device and a cyclone separator are provided inside the casing, wherein an inlet of the gas collection hood is connected to an outlet of the turbulent bed reactor, and wherein the gas collection hood, the dilute phase pipe, the low-wear gas-solid separation device and the cyclone separator are consecutively connected in this order.

7. The fluidized bed reactor according to claim 6, wherein the gas collection hood is located above the catalyst bed, and wherein the vertical distance between the gas collection hood and the upper surface of the catalyst bed is 1500 mm to 6000 mm.

8. The fluidized bed reactor according to claim 6, wherein: the dilute phase pipe is located above the gas collection hood; the low-wear gas-solid separation device is provided with a solid outlet downward opened and a gas outlet upward opened; the gas outlet of the low-wear gas-solid separation device is connected to an inlet of the cyclone separator; and a gas outlet of the cyclone separator is connected to the product gas outlet.

9. The fluidized bed reactor according to claim 6, wherein the low-wear gas-solid separation device comprises a cantilever type gas-solid fast separator or an ultra-short fast separator, wherein the cantilever type gas-solid fast separator comprises a cover and a cantilever located inside the cover, an inlet of the cantilever is connected to an outlet of the dilute phase pipe, an end of the cantilever is provided with a solid outlet, the bottom of the cover is open, and the top of the cover is provided with a gas outlet.

10. The fluidized bed reactor according to claim 1, wherein the internal circulation line is a first catalyst circulation line having an inlet connected with the gas-solid separation system and an outlet connected with the raw material delivery system.

11. The fluidized bed reactor according to claim 1, wherein the internal circulation pipeline comprises a first catalyst circulation pipeline having an inlet connected with the gas-solid separation system and an outlet connected to the turbulent bed reactor, and a second catalyst circulation pipeline having an inlet connected to the turbulent bed reactor and an outlet connected to an inlet of the raw material delivery system, wherein: when the turbulent bed reactor is provided with a first perforated distribution plate and the grids, and the internal circulation line comprises the first catalyst circulation line and the second catalyst circulation line, the outlet of the first catalyst circulation line is connected to the reaction system above the uppermost layer of grid, and the inlet of the second catalyst circulation line is connected to the reaction system between the lowermost layer of grid and the first perforated distribution plate.

12. The fluidized bed reactor according to claim 1, wherein the fluidized bed reactor further comprises a product gas separation system comprising a compression condensing unit, a first separation unit and a second separation unit, wherein: an inlet of the compression condensing unit is connected to the product gas outlet of the fluidized bed reactor, and a gas phase outlet of the compression condensing unit is connected to an inlet of the first separation unit, and a liquid phase outlet of the compression condensing unit is connected to an inlet of the second separation unit; the first separation unit is provided with a hydrogen outlet and a light hydrocarbon outlet, and the second separation unit is provided with a propylene outlet, a propane outlet and a fuel hydrocarbon outlet, wherein the light hydrocarbon outlet of the first separation unit is connected to an inlet of the second separation unit; and the propane outlet of the second separation unit is connected to at least one of the gas-solid separation system, the pre-rising system, and the raw material delivery system in the fluidized bed reactor.

13. A gas-solid airlift loop regenerator, comprising a first regeneration system, a second regeneration system and a first stripper consecutively connected in this order, wherein: the first regeneration system includes a first casing and a main air distributor, a first ring pipe distributor and a first draft tube arranged inside the first casing, wherein the main air distributor is arranged at the bottom of the first casing, the first draft tube is arranged above the main air distributor, and the first ring pipe distributor is arranged between the first casing and the first draft tube in the horizontal direction, and wherein the top of the first casing is provided with a fuel feed nozzle extending from the outside to the inside of the first casing and located above the first draft tube; the second regeneration system includes a second casing, a second ring pipe distributor, and a combined cyclone separator located inside the second casing, wherein the second ring pipe distributor is arranged at the bottom of the second casing and below the combined cyclone separator, and wherein the top of the second casing is provided with a gas outlet; the first stripper is used to remove an oxygen-containing flue gas, and is provided with a gas outlet, an inlet and a solid outlet, wherein the inlet of the first stripper is connected to the bottom of the second casing; and a regenerant circulation line is connected between the second regeneration system and the first regeneration system.

14. The gas-solid airlift loop regenerator according to claim 13, wherein the vertical distance between the bottom end of the first draft tube and the top end of the first ring pipe distributor is less than or equal to 500 mm, and the vertical distance between the first draft tube and the first main air distributor is greater than or equal to 300 mm, and wherein the vertical distance between the fuel feed nozzle and the first draft tube is 200 mm to 1500 mm.

15. The gas-solid airlift loop regenerator according to claim 13, wherein the second regeneration system further comprises a second draft tube arranged at the inner bottom of the second casing, and wherein the second ring pipe distributor is arranged between the second draft tube and the second casing in the horizontal direction.

16. The gas-solid airlift loop regenerator according to claim 15, wherein the vertical distance between the bottom end of the second draft tube and the second ring pipe distributor is less than or equal to 500 mm.

17. The gas-solid airlift loop regenerator according to claim 13, wherein the gas-solid airlift loop regenerator further comprises a catalyst activator for loading a metal active component onto the regenerant, the catalyst activator being provided with a raw material inlet, a solid outlet, a regenerant inlet and a gas outlet in this order from bottom to top, wherein the regenerant inlet of the catalyst activator being connected to the solid outlet of the first stripper, and wherein a third perforated distribution plate is provided above the raw material inlet of the catalyst activator.

18. A coupled fluidized bed reactor-regenerator apparatus for catalytic dehydrogenation of propane, comprising: (1) a recirculation inclined pipe; (2) a regeneration inclined pipe; (3) the fluidized bed reactor according to claim 1; and (4) a gas-solid airlift loop regenerator, the gas-solid airlift loop regenerator comprising a first regeneration system, a second regeneration system and a first stripper consecutively connected in this order, wherein: (a) the first regeneration system includes a first casing and a main air distributor, a first ring pipe distributor and a first draft tube arranged inside the first casing, wherein the main air distributor is arranged at the bottom of the first casing, the first draft tube is arranged above the main air distributor, and the first ring pipe distributor is arranged between the first casing and the first draft tube in the horizontal direction, and wherein the top of the first casing is provided with a fuel feed nozzle extending from the outside to the inside of the first casing and located above the first draft tube; (b) the second regeneration system includes a second casing, a second ring pipe distributor, and a combined cyclone separator located inside the second casing, wherein the second ring pipe distributor is arranged at the bottom of the second casing and below the combined cyclone separator, and wherein the top of the second casing is provided with a gas outlet; (c) the first stripper is used to remove an oxygen-containing flue gas, and is provided with a gas outlet, an inlet and a solid outlet, wherein the inlet of the first stripper is connected to the bottom of the second casing; and (d) a regenerant circulation line is connected between the second regeneration system and the first regeneration system; wherein: an inlet of the recirculation inclined pipe is connected to the turbulent bed reactor in the fluidized bed reactor, and an outlet of the recirculation inclined pipe is connected to an inlet of the first regeneration system in the gas-solid airlift loop regenerator; an inlet of the regeneration inclined pipe is connected to the solid outlet of the first stripper, and an outlet of the regeneration inclined pipe is connected to the pre-rising system in the fluidized bed reactor; when the gas-solid airlift loop regenerator includes the catalyst activator, the solid outlet of the catalyst activator is connected to the inlet of the regeneration inclined pipe, and the gas outlet of the catalyst activator is connected to the gas-solid separation system in the fluidized bed reactor; when the fluidized bed reactor includes the product gas separation system, the fuel hydrocarbon outlet of the second separation unit in the product gas separation system is connected to the fuel feed nozzle of the first regeneration system; and when the gas-solid airlift loop regenerator includes the catalyst activator and the fluidized bed reactor includes the product gas separation system, the raw material inlet of the catalyst activator is connected to the propane outlet of the second separation unit.

19. The coupled fluidized bed reactor-regenerator apparatus for catalytic dehydrogenation of propane according to claim 18, wherein when the gas-solid airlift loop regenerator includes the catalyst activator and the fluidized bed reactor includes the product gas separation system, the product gas separation system further includes a primary condensation unit and a gas-solid separation unit, and the product gas outlet of the fluidized bed reactor, the primary condensation unit, the gas-solid separation unit and the compression condensing unit are consecutively connected in this order.

20. The coupled fluidized bed reactor-regenerator apparatus for catalytic dehydrogenation of propane according to claim 18, wherein: a part of the catalyst in the turbulent bed reactor is delivered into the recirculation inclined pipe, and the remaining catalyst entrained by the gas is delivered from the turbulent bed reactor to the gas-solid separation system for gas-solid separation; separated gas is discharged from the gas outlet of the gas-solid separation system, allowing the separated catalyst to fall to the bottom of the casing of the gas-solid separation system to form a dense phase bed, and the internal circulation pipeline is used to deliver the catalyst in the dense phase bed to the raw material delivery system and/or the reaction system for recycling.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0142] FIG. 1 is a schematic structural view of the coupled apparatus in Example 1.

[0143] FIG. 2 is a schematic structural view of the fluidized bed reactor in Example 1.

[0144] FIG. 3 is a schematic structural view of a part of the fluidized bed reactor in Example 1.

[0145] FIG. 4 is a schematic structural diagram of the cross-flow grids of the present disclosure.

[0146] FIG. 5 is a schematic structural view of the gas-solid airlift loop regenerator in Example 1.

[0147] FIG. 6 is a schematic structural view of the first stripper in Example 1.

[0148] FIG. 7 is a schematic structural view of the coupled apparatus in Example 2.

[0149] FIG. 8 is a schematic structural view of the coupled apparatus in Example 3.

[0150] FIG. 9 is a schematic structural view of the coupled apparatus in Example 5.

[0151] FIG. 10 is a schematic structural view of the coupled apparatus in Example 7.

[0152] FIG. 11 is a schematic structural view of the catalyst activator in Example 7.

DESCRIPTION OF NUMERALS

[0153] Raw material delivery pipeline 1, ring distributor 2, regeneration inclined pipe 3, pre-riser 4, conical riser 5, first perforated distribution plate 6, first catalyst circulation pipeline 7, recirculation inclined pipe 8, turbulent bed reactor 9, cross-flow grids 10, gas collection hood 11, ring pipe distributor 12, dilute phase pipe 13, cantilever type separator 14, cover secondary cyclone separator 16, product gas outlet 17, second catalyst circulation pipeline 34, outlet pipe 35 at the top of the cover, ultra-short horizontal fast separator 36, central pipe 361 of the ultra-short horizontal fast separator, gas phase outlet pipe 362 of the ultra-short horizontal fast separator, catalyst bed 90, upper surface 901 of the catalyst bed, and splash zone 91. [0154] Main air distributor 18, first ring pipe distributor 19, first draft tube 20, regenerant circulation pipeline 21, fuel feed nozzle 22, second perforated distribution plate 23, second ring pipe distributor 37, second draft tube 38, combined cyclone separator 24, gas outlet 25 of the second regeneration system, inlet 26 of the first stripper, ring baffle 27, disc baffle 28, third draft tube 29, ring pipe steam distributor 30, stripping steam distributor 31, solid outlet 32 of the first stripper, oil and gas outlet pipeline 33. [0155] Primary condensation unit 44, gas-solid separation unit 45, compression condensing unit 41, first separation unit 42, and second separation unit 43. [0156] Catalyst activator 50, third perforated distribution plate 51, raw material inlet 52, regenerant inlet 53, solid outlet 54, and gas outlet 55.

DETAILED DESCRIPTION OF EMBODIMENTS

[0157] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present disclosure, the technical solutions of the present disclosure will now be described below in details, but it should not be construed as limiting the implementable scope of the present disclosure.

Example 1

[0158] This example provides a coupled fluidized beds reactor-regenerator apparatus for catalytic dehydrogenation of propane. As shown in FIG. 1, the coupled apparatus includes a fluidized bed reactor, a gas-solid airlift loop regenerator, a recirculation inclined pipe 8 and a regeneration inclined pipe 3.

[0159] As shown in FIG. 2, the fluidized bed reactor comprises a raw material delivery system, a pre-rising system, a reaction system, a gas-solid separation system and an internal circulation pipeline.

[0160] The raw material delivery system is used to deliver reaction raw materials to the pre-rising system. In this example, the raw material delivery system is the raw material delivery pipeline 1. The raw material delivery pipeline 1 is used to receive reaction raw materials, including propane raw materials, catalyst raw materials, and the like.

[0161] The pre-rising system is used to mix homogeneously the reaction raw materials and deliver the reaction raw materials to the reaction system. In this example, the pre-rising system is the pre-riser 4. The pre-riser 4 has a cylindrical structure, in which the inlet of the pre-riser 4 is provided with a ring distributor 2, and the outlet of the pre-riser 4 is a tapered and constricted neck structure with a thin top and a thick bottom.

[0162] The reaction system is used for catalytic dehydrogenation reaction of propane. The reaction system includes a turbulent bed reactor 9 and a conical riser 5, wherein:

[0163] The conical riser 5 is in the shape of a conical structure with a thick top and a thin bottom. The ratio of the outlet diameter to the inlet diameter of the conical riser 5 is less than or equal to 3 and greater than 1. The angle between the wall generatrix and the central vertical line of the conical riser 5 is between 0 and 10.

[0164] As shown in FIG. 3, a first perforated distribution plate 6 and one or more groups of cross-flow grids 10 are arranged inside the turbulent bed reactor 9. Inside the turbulent bed reactor 9, there is generally a catalyst bed 90 formed by catalyst particles above the upper surface of the first perforated distribution plate 6, and the height of the catalyst bed 90 is 2-m. When the catalytic dehydrogenation reaction of propane is carried out, the catalyst on the upper surface 901 of the catalyst bed is in a fluctuating state, and a splash zone 91 is formed above the catalyst bed, and the height of the splash zone 91 is 1500 mm-60000 mm.

[0165] The inlet section of the turbulent bed reactor 9 is an expanded neck structure with a thin bottom and a thick top, and the first perforated distribution plate 6 is arranged on the upper part of the inlet section. The aperture of the first perforated distribution plate is preferably 100 mm-250 mm.

[0166] The cross-flow grids 10 are composed of multiple groups of grids arranged in layers in the vertical direction. Each group includes two layers of grids, as shown in FIG. 4, and the vertical distances d1 and d2 between the two layers of grids in the same group are greater than or equal to 300 mm, and the vertical distance d3 between two adjacent groups of grids is 500 mm to 4000 mm; wherein the lowermost layer of grid is located above the first perforated distribution plate 6, and the vertical distance therebetween is greater than or equal to 500 mm. The uppermost layer of grid is immersed in the catalyst bed 90, and the vertical distance between the uppermost layer of grid and the upper surface 901 of the catalyst bed is more than or equal to 500 mm. The openings of each layer of grids can be rectangular, square or the like, and the side length of the openings in each layer of grids is generally 100 mm-500 mm.

[0167] The gas-solid separation system is used to separate the gas and solid phases discharged from the reaction system and collect the dense phase catalyst. The gas-solid separation system includes a casing, a gas collection hood 11, a dilute phase pipe 13, a low-wear gas-solid separation device and a secondary cyclone separator 16, wherein the low-wear gas-solid separation device is a cantilever type gas-solid fast separator 14. The gas collection hood 11, the dilute phase pipe 13, the cantilever type gas-solid fast separator 14, and the secondary cyclone separator 16 are arranged coaxially inside the casing of the gas-solid separation system from bottom to top.

[0168] The top of the casing of the gas-solid separation system is provided with a product gas outlet 17.

[0169] The gas collection hood 11 is tapered with a thin top and a thick bottom, which is conducive to the rapid collection of materials. The angle between the generatrix of the gas collection hood and the central axis is 30-70. The bottom end of the gas collection hood 11 is located above the splash zone 91 in the reaction system. The distance between the bottom end of the gas collection hood 11 and the upper surface 901 of the catalyst bed is 1500 mm-6000 mm.

[0170] The top of the dilute phase pipe 13 is closed, and the lateral side is provided with a square outlet or a rectangular outlet. The outlets on both lateral sides of the dilute phase pipe 13 are arranged symmetrically along the central axis of the dilute phase pipe 13.

[0171] The cantilever type gas-solid fast separator 14 includes a cover 15 and two or more cantilevers. Herein, the cover 15 is in a cylindrical shape with an opening at the bottom. An outlet pipe 35 is provided on the top of the cover 15, and the outlet pipe 35 is connected to the inlet of the secondary cyclone separator 16.

[0172] The cantilever is located inside the cover 15, and the cantilever is in one-to-one correspondence with the outlets on the side of the dilute phase pipe 13. The extension direction of the cantilever is horizontal extension or downward spiral extension. The radial distance between the end of the cantilever and the inner wall of the cover 15 is relatively short, generally within 500 mm, so that the catalyst separated by the cantilever can quickly settle down along the inner wall of the cover 15 after it is discharged, and the settled catalyst piles up at the bottom of the casing of the gas-solid separation system to form a dense phase bed.

[0173] The bottom of the annular space between the cover 15 and the casing of the gas-solid separation system is provided with a ring distributor 12, which is located below the bottom opening of the cover 15, and used to provide fluidization power for the catalyst in the dense phase bed.

[0174] In this example, the internal circulation pipeline specifically includes a first catalyst circulation pipeline 7 and a second catalyst circulation pipeline 34. Among them, the first catalyst circulation line 7 is used to deliver the dense phase catalyst collected in the gas-solid separation system to the turbulent bed reactor 9, and the second catalyst circulation line 34 is used to deliver the catalyst with low coke yield collected in the turbulent bed reactor 9 to the raw material delivery pipeline 1.

[0175] The inlet of the first catalyst circulation line 7 is connected to the casing of the gas-solid separation system, and the connection is located above the ring pipe distributor 12; the outlet of the first catalyst circulation line 7 is connected to the turbulent bed reactor 9, and the connection is located above the uppermost layer of grid in the cross-flow grids 10.

[0176] The inlet of the second catalyst circulation line 34 is connected to the turbulent bed reactor 9, and the connection therebetween is located between the lowermost layer of grid in the cross-flow grids 10 and the first perforated distribution plate 6, and the outlet of the second catalyst circulation line 34 is connected to the inlet of the raw material delivery pipeline 1.

[0177] The pre-riser 4, the conical riser 5, the turbulent bed reactor 9, the gas collection hood 11, the dilute phase pipe 13, the cantilever type separator 14, and the secondary cyclone separator 16 are generally arranged coaxially.

[0178] In the above fluidized bed reactor, the connection relationship of the systems is as follows: the raw material delivery pipeline 1 runs through the inlet of the pre-riser 4 from bottom to top and extends into the inside of the pre-riser 4, and the outlet of the raw material delivery pipeline 1 is located above the ring distributor 2; the outlet of the pre-riser 4 is connected to the inlet of the conical riser 5; the outlet of the conical riser 5 is connected to the inlet of the turbulent bed reactor 9; the outlet of the turbulent bed reactor 9 is connected to the inlet of the gas collection hood 11; the outlet of the gas collection hood 11 is connected to the inlet of the dilute phase pipe 13; the outlet on the lateral side of the dilute phase pipe 13 is connected to the inlet of the cantilever type gas-solid fast separator 14; the outlet of the cantilever in the cantilever type gas-solid fast separator 14 is connected to the solid outlet and the gas outlet of the cover 15; the gas outlet of the cover 15 is connected to the inlet of the secondary cyclone separator 16.

[0179] As shown in FIGS. 1, 5 and 6, the gas-solid airlift loop regenerator includes a first regeneration system, a second regeneration system, and a first stripper communicating in this order. The first regeneration system is located below the second regeneration system. The first regeneration system is used to carry out the first coke-burning regeneration on the catalyst. The first regeneration system includes a first casing, a main air distributor 18, a first ring pipe distributor 19 and a first draft tube 20.

[0180] The main air distributor 18, the first ring pipe distributor 19 and the first draft tube 20 are located inside the first casing. The first draft tube 20 is located in the middle of the first casing, and the height of the first draft tube 20 is 1 m-5 m. The main air distributor 18 is located below the vertical projection area of the first draft tube 20, and the vertical distance between the main air distributor 18 and the first draft tube 20 is greater than or equal to 300 mm. The first ring pipe distributor 19 is arranged in the vertical projection area between the first draft tube 20 and the first casing, and the vertical distance between the top of the first ring pipe distributor 19 and the bottom end of the first draft tube 20 is less than or equal to 500 mm. Thus, the interior of the first regeneration system is divided by the first draft tube into the inner space of the draft tube and the annulus area between the first draft tube and the first casing. The lower part of the first casing is provided with an inlet, the top of the first casing is provided with an outlet, and a fuel feed nozzle 22 is provided between the outlet of the first casing and the first draft tube 20, and the fuel feed nozzle 22 is connected to the internal space of the first casing, and the vertical distance between the fuel feed nozzle 22 and the first draft tube 20 is 200 mm-1500 mm. In this example, there are multiple fuel feed nozzles 22, and the outlets of the multiple fuel feed nozzles 22 are evenly distributed along the circumferential direction of the first casing.

[0181] The second regeneration system is used to carry out a further coke-burning regeneration on the catalyst. The second regeneration system includes a second casing, a second perforated distribution plate 23, a second ring pipe distributor 37, a second draft tube 38 and a combined cyclone separator 24. Among them, the second perforated distribution plate 23, the second ring pipe distributor 37, the second draft tube 38, and the combined cyclone separator 24 are located inside the second casing. The bottom of the second casing is provided with an inlet having a thick top and a thin bottom, the top of the second casing is provided with a gas outlet 25, and the bottom of the second casing is provided with a solid outlet. The second perforated distribution plate 23 is arranged above the inlet of the second casing, the second draft tube 38 is arranged above the second perforated distribution plate 23, and the second ring pipe distributor 37 is provided in the vertical projection area between the second draft tube 38 and the second casing. The height of the second draft tube 38 is 1 m-3 m, and the vertical distance between the lower end of the second draft tube 38 and the second ring pipe distributor 37 is less than or equal to 500 mm.

[0182] A regenerant circulation pipeline 21 is connected between the bottom of the second regeneration system and the bottom of the first regeneration system. The regenerant circulation pipeline 21 is used to balance the accumulation height of the catalyst in the first regeneration system and the second regeneration system.

[0183] The first stripper is used to separate the catalyst entrained in the oxygen-containing flue gas.

[0184] The first stripper includes a third casing, a partition member, a third draft tube 29, a ring pipe steam distributor 30 and a stripping steam distributor 31. A ring baffle 27, a disk baffle 28, the third draft tube 29, and the stripping steam distributor 31 are arranged in this order from top to bottom inside the third casing. The ring pipe steam distributor 30 is arranged in the vertical projection area between the third casing and the third draft tube 29. The first stripper is respectively provided with an oil and gas outlet pipeline 33, an inlet 26 and a solid outlet 32 from top to bottom.

[0185] The outlet of the first regeneration system is connected to the inlet of the second regeneration system, and the solid outlet of the second regeneration system is connected to the inlet 26 of the first stripper. The oil and gas outlet pipeline 33 of the first stripper is connected to the inner space of the second regeneration system.

[0186] The fluidized bed reactor and the gas-solid airlift loop regenerator are arranged in parallel in the horizontal direction, connected by the recirculation inclined pipe 8 and the regeneration inclined pipe 3. Specifically, the inlet of the recirculation inclined pipe 8 is connected to the turbulent bed reactor 9 in the fluidized bed reactor, and the connection between the recirculation inclined pipe 8 and the turbulent bed reactor 9 is located above the connection between the first catalyst circulation pipeline 7 and the turbulent bed reactor 9; the outlet of the recirculation inclined pipe 8 is connected to the inlet of the first regeneration system. The inlet of the regeneration inclined pipe 3 is connected to the solid outlet 32 of the first stripper, the outlet of the regeneration inclined pipe 3 is connected to the inlet of the pre-riser 4, and the connection between the regeneration inclined pipe 3 and the pre-riser 4 is not below the outlet of the raw material delivery pipeline 1.

[0187] In some specific embodiments, a second stripper may be further connected between the recirculation inclined pipe 8 and the first regeneration system to replace the propylene product gas adsorbed in the spent catalyst.

Example 2

[0188] This example provides a coupled fluidized beds reactor-regenerator apparatus for catalytic dehydrogenation of propane. As shown in FIG. 7, the coupled apparatus is similar in structure to the coupled apparatus in Example 1, only except that in this example, the cantilever type gas-solid fast separator 14 in Example 1 is replaced with an ultra-short horizontal fast separator 36 as a low-wear gas-solid separation device. The use of the ultra-short horizontal fast separator 36 can further reduce the contact time of the gas and solid phases and reduce the secondary reaction.

[0189] In this example, the outlet of the dilute phase pipe 13 is arranged at the top, and the top outlet is connected to the central pipe 361 of the ultra-short horizontal fast separator, and the solid outlet of the central pipe 361 of the ultra-short horizontal fast separator is downward. The outlet of the gas phase outlet pipe 362 of the ultra-short horizontal fast separator is located above the gas collection hood 11.

Example 3

[0190] This example provides a coupled fluidized beds reactor-regenerator apparatus for catalytic dehydrogenation of propane. As shown in FIG. 8, the coupled apparatus is similar in structure to the coupled apparatus in Example 2, only except that in this example, the gas collection hood 11 is partially immersed in the splash zone 91, and meanwhile the second catalyst circulation pipeline is omitted in this example, but the inlet of the first catalyst circulation pipeline 7 is connected to the bottom of the casing of the gas-solid separation system and the outlet of the first catalyst circulation pipeline 7 is connected to the raw material delivery pipeline 1.

Example 4

[0191] This example provides a process for catalytic dehydrogenation of propane, which is carried out in the coupled apparatus of Example 1. The process comprises the following steps.

[0192] The propane and catalyst are delivered to the pre-riser 4 through the raw material delivery pipeline 1, and then enter the conical riser 5 for rising movement and catalytic dehydrogenation reaction of propane to produce gaseous products such as propylene.

[0193] In the conical riser 5, the product gas (propylene) and unreacted raw material gas (propane) entrain catalyst particles and rise along the conical riser 5 together. In the conical riser 5, the catalytic dehydrogenation of propane is carried out at a reaction temperature of 600-680 C., a reaction pressure of less than or equal to 1 MPa, for a reaction time of 5 s-15 s. The gas and solid phases composed of catalyst particles, raw material gas and product gas output from the conical riser 5 enter the turbulent bed reactor 9 through the first perforated distribution plate 6 at a uniform speed, and continuously react for catalytic dehydrogenation and move upward.

[0194] The catalyst with a low coke yield between the first perforated distribution plate 6 and the lowermost layer of grid enters the second catalyst circulation pipeline 34 and then returns to the raw material delivery pipeline 1, and then enters the pre-riser 4 again to participate in the reaction process. The rest of the catalyst is entrained by the gas and continues to move upward. Under the action of the cross-flow grids 10, bubbles generated during rising of the gas and solid phases are broken, and back-mixing is suppressed. In the turbulent bed reactor 9, catalytic dehydrogenation of propane is carried out at a reaction temperature of 500-620 C. and a reaction pressure of less than or equal to 1 MPa for a reaction time of 5 s-15 s. When the gas and solid phases reaches the uppermost layer of grid of the cross-flow grids 10, most of the catalyst with a relatively high coke yield that needs to be regenerated in the turbulent bed reactor 9 enters the recirculation inclined pipe 8, and the catalyst entering the recirculation inclined pipe is the spent catalyst. The remaining and small amount of catalyst (about 10% of the total amount of catalyst) is entrained by the gas and moves upwards into the gas collection hood 11.

[0195] The gas entraining the catalyst enters the dilute phase pipe 13 quickly after being collected by the gas collection hood 11, and then enters the cantilever type gas-solid fast separator 14 through the dilute phase pipe 13 for gas-solid separation, wherein the separated solid catalyst escaping from the cantilever is blocked by the inner wall of the cover 15, falls to the bottom of the cover 15, and accumulates to form a dense phase bed. The gas separated by the cantilever type gas-solid fast separator 14 moves upward inside the cover 15, and enters the secondary cyclone separator 16 through the outlet pipe 35 at the top of the cover for further gas-solid separation. The gas separated by the secondary cyclone separator 16 is discharged and collected by the product gas outlet 17, while the solid catalyst separated by the secondary cyclone separator 16 falls to the dense phase bed, and under the blowing effect of the ring pipe distributor 12, the catalyst in the dense phase bed is delivered back to the turbulent bed reactor 9 by the first catalyst circulation pipeline 7, and then enters the recirculation inclined pipe 8.

[0196] The spent catalyst in the recirculation inclined pipe 8 then enters the first regeneration system, and under the blowing action of the main air distributor 18 and the first ring pipe distributor 19, the spent catalyst moves upward in the draft tube and when it reaches the fuel feed nozzle 22, the temperature rises under the action of the fuel. The heated spent catalyst enters downward into the annulus area between the first draft tube 20 and the first ring pipe distributor 19, and then moves radially into the draft tube again for circulating flow, so that the temperature in the regeneration system is maintained at the temperature required for the coke-burning reaction. During the circumfluence movement of the spent catalyst, the high-temperature spent catalyst that is in contact with the fuel is quickly mixed with the low-temperature spent catalyst that is not in contact with the fuel, so that the whole spent catalyst in the first regeneration system is maintained at a relatively high temperature (620-750 C.) and the temperature is evenly distributed to achieve efficient and stable coke-burning regeneration. In a specific embodiment, the coke-burning temperature of the spent catalyst in the first regeneration system can be controlled by regulating the temperature and flow rate of the main air distributor 18 and the flow rate of the fuel. Generally speaking, the greater the gas flow rate of the main air distributor 18 and the greater the flow rate of the fuel, the more sufficient the coke-burning degree of the spent catalyst is.

[0197] After the first coke-burning regeneration, the spent catalyst enters the second regeneration system along with the entrainment of the flue gas. Inside the second regeneration system, the spent catalyst first passes through the second perforated distribution plate 23 to achieve uniform distribution in the inner space, and then it is circulated inside the second draft tube 38 and in the annular area between the second draft tube 38 and the second casing. During the flow process, the high-temperature spent catalyst is subjected to the second coke-burning regeneration, and the spent catalyst is regenerated through the continuous coke-burning regeneration process, recovers its catalytic activity, and is converted into a regenerant. Then the regenerant is entrained by the flue gas and moves upwards, and enters the combined cyclone separator 24 for oil and gas separation. The separated flue gas is discharged from the outlet 25, and the separated spent catalyst enters the first stripper through the solid outlet of the second casing and the inlet 26 in turn.

[0198] The spent catalyst passes through the ring baffle 27 and the disc baffle 28 successively and enters the third draft tube 29 in the first stripper, and is circulated under the action of the ring pipe steam distributor 30 and the stripping steam distributor 31. The oxygen-containing flue gas is removed during the movement, and then the regenerant returns to the pre-riser 4 through the solid outlet 32 of the first stripper to participate in the catalytic dehydrogenation reaction of propane again.

[0199] In the above process for catalytic dehydrogenation of propane, the raw material propane and catalyst enter the pre-riser 4 from the bottom through the delivery pipe 1, and the regenerant particles enter the middle part of the pre-riser 4 through the regeneration inclined pipe 3. When two streams of materials are fast mixed in the pre-riser 4, it enters the conical riser 5 from the outlet of the pre-riser 4, and flows upward along the axis of the conical riser while the catalytic dehydrogenation reaction of propane proceeds. Since the catalytic dehydrogenation reaction of propane is a molecule increased reaction, new gas is continuously generated, and the gas flow is getting faster and faster. The shape of thick top and thin bottom of the conical riser 5 can maintain the speed of the gas and solid phases unchanged substantially, so as to ensure an advection flow while reducing the catalyst wear.

[0200] The advection flow can eliminate the back-mixing of the gas and solid phases, improve the selectivity of the reaction without additional rising media, and reduces the load and energy consumption of the device. The inlet section of the turbulent bed reactor 9 is a expanded neck structure, which can be well connected with the outlet of the conical riser 5, and the first perforated distribution plate 6 with a large diameter can be provided at the inlet section of the turbulent bed reactor 9, which is favorable for uniform distribution of the catalyst particles after entering the turbulent bed reactor 9. In the turbulent bed reactor 9, the gas and solid phases continue to react, thereby further prolonging the reaction time, and the first catalyst pipeline 7 continuously deliver the dense phase catalyst collected by the gas-solid separation system to the turbulent bed reactor 9 to ensure a high catalyst-to-oil ratio. The cross-flow grids 10 arranged above the first perforated distribution plate 6 can break the bubbles generated during rising of the gas and solid phases, increase the specific surface area of the gas-solid contact (that is, the contact area between the gas phase and the solid phase in a unit volume), and greatly reduce the back-mixing phenomenon in the turbulent bed reactor 9 and reduce the secondary reaction.

[0201] During the catalytic dehydrogenation of propane, the catalyst with low coke yield at the bottom of the turbulent bed reactor 9 enters the second catalyst circulation pipeline 34, and then merges into the raw material delivery pipeline 1, and is again delivered to the conical riser 5 through the pre-riser 4 to participate in the reaction. In the present disclosure, by adopting the design of the internal circulation pipeline, the catalyst with a low coke yield in the turbulent bed reactor 9 is delivered again to the conical riser 5, which can greatly supplement and increase the catalyst concentration in the conical riser 5, and meanwhile adjust the amount of catalyst involved in the reaction flexibly in time.

[0202] At the uppermost layer of grid of the cross-flow grids 10 in the turbulent bed reactor 9, most of the catalyst with a relatively high coke yield is used as the spent catalyst and enters the gas-solid airlift loop regenerator from the recirculation inclined pipe 8 for coke-burning regeneration.

[0203] The gas coming out of the turbulent bed reactor 9 entrains the remaining small amount of catalyst particles into the gas collection hood 11. Because the gas collection hood 11 is closer to the catalyst bed 90 in the turbulent bed reactor 9 but higher than the splash zone 91, the gas and solid phases discharged from the turbulent bed reactor 9 can quickly enter the gas-solid separation system through the gas collection hood 11 for gas-solid separation, which greatly shortens the further contact time between the gas and the catalyst in addition to the time required for the propane dehydrogenation reaction, and reduces the degree of secondary reaction. The gas and solid phases entering the gas-solid separation system first passes through the dilute phase pipe 13 and enters the cantilever type gas-solid fast separator 14 for the first gas-solid separation. A mixture of the catalyst and the gas is drawn out from multiple cantilevers of the cantilever type gas-solid fast separator 14. The distance between the outlet of the cantilever and the wall of the cover 15 is short, and the catalyst particles coming out of the cantilever only need to move a small radial distance to quickly reach the inner wall of the cover 15, so that efficient separation can be achieved at a low tangential velocity, and the gas-solid separation efficiency can reach 98% or more, while greatly reducing the pressure drop in the separation. The catalyst particles fall along the cover 15, and form a dense phase bed at the lower part of the cover 15. The dense phase bed forms a material seal to prevent gaseous products from flowing out from the lower end of the cover 15. The separated gaseous product moves upward along the cover 15, and enters the settling section (that is, the outer cylinder part of the cantilever type separator 14) from the outlet pipe 35 at the top of the cover, and then enters the secondary cyclone separator 16. Since about 98% of the catalyst particles are separated from the cantilever type gas-solid fast separator 14, the amount of particles entering the secondary cyclone separator 16 is low, which greatly avoids the wear of a large amount of catalyst in the secondary cyclone separator 16. The catalyst particles separated from the secondary cyclone separator 16 fall back into the dense phase bed at the lower end of the cover 15 along the dipleg. The catalyst in the dense phase bed falls into the turbulent bed reactor 9 along the first catalyst circulation pipeline 7 under the blowing effect of the ring pipe distributor 12. The gas separated from the secondary cyclone separator 16 is discharged from the gas-solid separation system along the product gas outlet 17.

[0204] The recirculation inclined pipe 8 first delivers the spent catalyst collected from the turbulent bed reactor 9 to the first regeneration system. Since the amount of gas introduced into the inner area of the first draft tube 20 is greater than the amount of gas introduced into the annulus area, the density of the spent catalyst in the inner area of the first draft tube 20 is smaller than that in the annulus area, so that the pressure in the an annulus area is greater than the pressure in the inner area of the first draft tube 20. The pressure difference pushes the spent catalyst particles to flow upward in the first draft tube 20 and downward in the annulus area. The fuel is injected into the fuel feed nozzle 22 above the first draft tube 20. Due to the significant radial flow near the fuel feed nozzle 22, the high-temperature catalyst and the surrounding low-temperature catalyst can be quickly mixed to ensure the uniform distribution of temperature in the first regeneration system and achieve a stable coke-burning regeneration. The spent catalyst after the first coke-burning is entrained by the flue gas and enters the second regeneration system through the second large-hole distribution plate 23. It is circulated along the inner space of the second draft tube 38 and the annulus area between the second draft tube 38 and the second casing, and undergoes the second coke-burning reaction during the movement. After two coke-burning, the spent catalyst has completely recovered its activity and converted to a regenerant. The regenerant enters the stripper, and is stripped countercurrently by the first stripper to remove the oxygen-containing flue gas adsorbed among the solid particles, and then the regenerant is delivered back to the pre-riser 4, and again participates in the catalytic dehydrogenation reaction of propane as a catalyst. The flue gas discharged from the first stripper is delivered to the combined cyclone separator 24 through the oil and gas outlet pipeline 33 for gas-solid separation, so as to separate the regenerant particles entrained in the flue gas.

[0205] The processes of catalytic dehydrogenation of propane carried out in Example 2 and Example 3 are similar to the above, only except: [0206] as compared with Example 1, in the process carried out by the coupled apparatus in Example 2, the gas and solid phases output from the turbulent bed reactor 9 enters the ultra-short horizontal fast separator 36 through the gas collection hood 11 and the dilute phase pipe 13 for rapid gas-solid separation; [0207] as compared with Example 2, in the process carried out by the coupled apparatus in Example 3, the catalyst in the dense phase bed at the bottom of the gas-solid separation system is directly delivered to the raw material delivery pipeline 1 through the first catalyst circulation pipeline 7.

[0208] In practical production, the propylene yield in the above process for catalytic dehydrogenation of propane can reach 37%-40%, the single-pass conversion rate can reach 42%-47%, and the selectivity can reach 90% or more, with high production efficiency and yield.

Example 5

[0209] This example provides a coupled fluidized beds reactor-regenerator apparatus for catalytic dehydrogenation of propane. This apparatus is similar in structure to the coupled apparatus in Example 1, only except that the product gas outlet 17 of the fluidized bed reactor in this example is further connected with a product gas separation system.

[0210] As shown in FIG. 9, the product gas separation system includes a compression condensing unit 41, a first separation unit 42 and a second separation unit 43.

[0211] The compression condensing unit 41 is used to carry out stagewise compression condensation and gas-liquid separation on the gas, and includes multi-stage compressors, inter-stage cooling equipment and inter-stage separation tanks arranged between the multi-stage compressors. The multi-stage compressors are used to compress the gas sequentially, the inter-stage cooling equipment is used to reduce the gas temperature, and the inter-stage separation tank is used to separate the condensed liquid phase. The compression condensing unit 41 is provided with an inlet, a gas phase outlet and a liquid phase outlet. Among them, the inlet of the compression condensing unit 41 is connected to the product gas outlet 17, and the gas phase outlet of the compression condensing unit 41 is connected to the inlet of the first separation unit 42, and the liquid phase outlet of the compression condensing unit 41 is connected to the inlet of the second separation unit 43.

[0212] The first separation unit 42 is used to separate hydrogen and light hydrocarbons (C1, C2 and liquid phase impurities) in the gas phase. The first separation unit 42 is provided with a hydrogen outlet and a light hydrocarbon outlet, and the light hydrocarbon outlet of the first separation unit 42 is connected to the inlet of the second separation unit 43.

[0213] The second separation unit 43 is provided with a plurality of depropanizers, and the separation of light hydrocarbons, propylene, propane and C4+ heavier hydrocarbons can be achieved through a rectification process. The second separation unit 43 is provided with a propylene outlet, a propane outlet and a fuel hydrocarbon outlet. The fuel hydrocarbon outlet of the second separation unit 43 is connected to the fuel feed nozzle 22 in the gas-solid airlift loop regenerator, for delivering the separated light hydrocarbons and C4+ to the first regeneration system as fuel. The propane outlet of the second separation unit 43 is respectively connected to the ring pipe distributor 12, the ring distributor 2 and the raw material delivery pipeline 1. The propane entering the ring pipe distributor 12 and the ring distributor 2 as a fluidizing gas can promote the flow of the catalyst particles, and the propane entering the raw material delivery pipeline 1 is used as the raw material gas together with fresh propane to participate in the catalytic dehydrogenation reaction of propane.

Example 6

[0214] This example provides a process for catalytic dehydrogenation of propane, which is carried out in the coupled apparatus of Example 5. The process includes all the steps of the process of Example 4, and further includes the following steps.

[0215] The gas discharged from the product gas outlet 17 first enters the compression condensing unit 41 for stagewise compression condensation and gas-liquid separation, and the separated gas phase (containing hydrogen and light hydrocarbons) enters the first separation unit 42, and the separated liquid phase (containing propane, propylene and C4+) enters the second separation unit 43.

[0216] The gas phase is subjected to gas separation in the first separation unit, and the separated hydrogen is used as a product gas and discharged from the device; the separated light hydrocarbons enter the second separation unit 43.

[0217] The second separation unit 43 separates propylene, propane, light hydrocarbons and C4+ respectively by rectification technology, wherein: propylene is used as a product gas and discharged from the device, the light hydrocarbons and C4+ are introduced into the fuel feed nozzle 22 as fuel after decompression, and propane is divided into three parts, wherein one enters the ring pipe distributor 12 as the fluidizing gas, another one enters the ring distributor 2 as the fluidizing gas, and the remaining one enters the raw material delivery pipeline 1 to be mixed with fresh propane as the reaction raw material.

Example 7

[0218] This example provides a coupled fluidized beds reactor-regenerator apparatus for catalytic dehydrogenation of propane. As shown in FIG. 10, this apparatus is similar in structure to the coupled apparatus in Example 5, only except for the following differences.

[0219] In this example, the product gas separation system further includes a primary condensation unit 44 provided with an inlet and an outlet, and a gas-solid separation unit 45 provided with an inlet, a solid outlet and a gas outlet.

[0220] The inlet of the primary condensation unit 44 is connected to the product gas outlet 17, and the outlet of the primary condensation unit 44 is connected to the inlet of the gas-solid separation unit 45. The gas outlet of the gas-solid separation unit 45 is connected to the inlet of the compression condensing unit.

[0221] The gas-solid airlift loop regenerator in this example further includes a catalyst activator 50 for supplementing the regenerant with a metal active component. As shown in FIG. 11, the inner bottom of the catalyst activator 50 is provided with a third perforated distribution plate 51. The catalyst activator 50 is provided with a raw material inlet 52, a solid outlet 54, a regenerant inlet 53 and a gas outlet 55 in this order from bottom to top. Catalyst Activator 50. The raw material inlet 52 is used to receive the raw materials (generally propane gas and a metal oxide) for forming the metal active component, the regenerant inlet 53 is connected to the solid outlet 32 of the first stripper, the solid outlet 54 is connected to the regeneration inclined pipe 3, and the gas outlet 55 is in communication with the gas-solid separation system, specifically, it may be connected to the ring pipe distributor 12.

Example 8

[0222] This example provides a process for catalytic dehydrogenation of propane, which is carried out in the coupled apparatus of Example 7. The process includes all the steps of the process of Example 4, and further includes the following steps.

[0223] The regenerant output from the first stripper enters the catalyst activator 50 through the regenerant inlet 53, and the metal oxide in the catalyst activator 50 is reduced by propane to a metal elementary substance. The metal elementary substance is deposited in the regenerant to form the metal active component, so that the catalytic activity of the regenerant is improved, and the regenerant supplemented with the metal active component enters the regeneration inclined pipe through the solid outlet 54. The gas in the catalyst activator 50 enters the gas-solid separation system through the gas outlet 55 for gas-solid separation. The catalyst particles separated from the secondary cyclone separator 16 settle to the dense phase bed, and the gas separated by the secondary cyclone separator 16 enters the product gas separation system through the product gas outlet 17.

[0224] The gas discharged from the product gas outlet 17 first enters the primary condensation unit 44 for condensation, and the metal vapor in the gas is condensed into metal particles, and then the gas entrained with the metal particles enters the gas-solid separation unit 45 to separate the metal particles from the gas. The separated metal particles are discharged from the product gas separation system, and sent to the catalyst activator 50 as a raw material after oxidization. The separated gas enters the compression condensing unit 41.

[0225] In the compression condensing unit 41, the gas is subjected stagewise compression condensation and gas-liquid separation. The separated gas phase (containing hydrogen and light hydrocarbons) enters the first separation unit 42, and the separated liquid phase (containing propane, propylene and C4+) enters the second separation unit 43.

[0226] The gas phase is subjected to gas separation in the first separation unit, and the separated hydrogen is used as a product gas and discharged from the device; the separated light hydrocarbons enter the second separation unit 43.

[0227] the second separation unit 43 separates propylene, propane, light hydrocarbons and C4+ respectively by rectification technology, wherein: propylene is used as a product gas and discharged from the device, the light hydrocarbons and C4+ are introduced into the fuel feed nozzle 22 as fuel after decompression, and propane is divided into four parts, wherein one enters the ring pipe distributor 12 as the fluidizing gas, another one enters the ring distributor 2 as the fluidizing gas, a further one enters the raw material delivery pipeline 1 to be mixed with fresh propane as the reaction raw material, and the remaining one enters the catalyst activator 50 as the raw material.

[0228] As compared with the process of Example 4, the process of this example includes a procedure of supplementing the catalyst with the active component after the catalyst is regenerated, which can further improve the catalyst activity, so that the propylene yield, single-pass conversion rate and selectivity of the catalytic dehydrogenation of propane process are significantly improved as compared with the effect of Example 4.