Apparatus and method for separating gas-solids mixtures

Abstract

A device and a method for separating a particulate solid-gas mixture, the device and the method comprising / using: a substantially vertical inlet pipe (23) adapted to receive the particulate solid-gas mixture (13); a substantially 90° first elbow (24) connected to a bottom end of the inlet pipe and having a substantially vertical top inlet and a substantially horizontal bottom outlet; a substantially 90° second elbow (27) connected to a bottom end of the first elbow and having a substantially horizontal top inlet and a substantially vertical bottom outlet; a gas exhaust pipe (25) connected to a concave side of the first elbow, a projection of the gas exhaust pipe into a symmetry plane of the first elbow forming an angle a1 between 5° and 85° with respect to a vertical plane, and a projection of the gas exhaust pipe into a horizontal plane forming an angle a2 between 0° and 90° with respect to the symmetry plane of the first elbow.

Description

Technical Field

[0001] The background of this invention is catalytic cracking units. In particular, this invention relates to apparatus for separating and optionally stripping gas-solid mixtures exiting a gas-solid co-flow fluidized bed riser reactor (upflow reactor) or a gas-solid co-flow fluidized bed downflow reactor (downflow reactor). This invention also relates to the use of said apparatus in catalytic cracking processes for hydrocarbon conversion. Background Technology

[0002] Catalytic cracking processes (FCC or fluid catalytic cracking, and HSFCC or high-severity fluid catalytic cracking) make it possible to convert heavy hydrocarbon feedstocks (e.g., vacuum gas oil, vacuum residue, atmospheric residue, plastics, biomass) into lighter hydrocarbon fractions (e.g., gasoline, GPL, or liquefied petroleum gas) and heavier fractions (referred to as LCO or light cycle oil, and HCO or heavy cycle oil). The reactors used in catalytic cracking units are typically riser or downpipe type reactors.

[0003] The prior art in the field of gas-solid separation at the riser or downcomer outlet of a catalytic cracking unit is very extensive, and the following documents will be considered particularly relevant to the present invention: Patent EP 0 852 963 describes a direct-wound gas-solid separator for particles contained in a gas mixture and its use in fluidized bed catalytic cracking or thermal cracking. This device is suitable for risers where the upper portion appears in the stripping zone, which is not the case with this invention.

[0004] Patent FR 2 767 715 describes a separation and stripping device for the main riser of an FCC unit. In the cited document, the riser is one in which the upper portion appears in the stripping zone. The path of the gaseous effluent exhibits a lateral shift because the gas, after a deflection occurring in chamber 2, is displaced into chamber 3, as described in the cited document. Figure 3 As seen in the text.

[0005] US Patent 8383051 describes a gas-solid separation device suitable for use with an external riser (i.e., a riser not at least partially contained within the casing of a stripper). The main stream of the gas-solid suspension is divided into two parts, and the device has an impact plate (referred to in the cited text as a "dividing baffle") that makes it possible to collect the solids by abruptly reducing the velocity of the gas-solid suspension. The described device is connected to a stripping chamber. This invention can be considered an improvement upon the cited document.

[0006] Patent EP1017762 describes a gas-solid separation system having a set of separation chambers and stripping chambers arranged alternately around a riser. This system makes it possible to perform the following operations simultaneously: - Separating gases and particles in a separation chamber. - By using a conduit that minimizes hydrocarbon entrainment, most of the catalyst separated in the separation chamber is introduced into the stripper. - By transferring the gas from the separation chamber into the stripping chamber, it becomes possible to improve the separation between the gas and catalyst particles and to mix the gas with the effluent from the stripper. - All gaseous effluents generated by the riser and stripping chamber are rapidly discharged into the reactor's cyclone separator for final separation before leaving the reactor.

[0007] Patent application FR3104467 relates to an apparatus and process for separating and stripping a gas mixture and solid particles. The apparatus and process include a plurality of separation chambers and pre-stripping chambers distributed around a central reactor. Each pre-stripping chamber includes an outer wall, two substantially vertical lateral walls (which are also lateral walls of the separation chamber), a lower inlet opening adapted to communicate with the stripping chamber for stripper gas, and an upper outlet opening adapted to communicate with a second separation stage for the gas mixture and stripper gas. A deflector is disposed between the stripping chambers and the pre-stripping chambers and adapted to deflect upwardly flowing stripper gas and restrict the stripper gas to a movement that is at least substantially horizontal.

[0008] Patent application FR3104469 relates to an apparatus and process for separating and stripping a gas mixture and solid particles. The apparatus and process include a plurality of separation chambers and pre-stripping chambers distributed around a central reactor. Each pre-stripping chamber includes an outer wall, a lower outlet opening for solid particles adapted to communicate with the stripping chamber, an upper outlet opening for the gas mixture and stripper gas adapted to communicate with a second separation stage, and a lateral inlet opening for the stripper gas. Summary of the Invention

[0009] The first objective of this specification is to provide an apparatus and process for gas-solid (solid particle) separation, achieving a solids efficiency of greater than 80% and a gas efficiency of greater than 90%. The second objective of this specification is to provide an apparatus and process for rapid gas-solid separation using two bends in a single series. The third objective of this specification is to provide an apparatus and process for mixing gaseous effluent with stripper gas while still performing gas-solid separation.

[0010] According to a first aspect, the present invention relates to an apparatus for separating particulate solid-gas mixtures, the apparatus comprising: - A basically vertical inlet pipe, which is suitable for receiving particulate solid-gas mixtures; - A first bend of approximately 90°, which connects to the bottom end of the inlet pipe and has a substantially vertical top inlet and a substantially horizontal bottom outlet; - A second bend, approximately 90°, which connects to the bottom end of the first bend and has a substantially horizontal top inlet and a substantially vertical bottom outlet; - An exhaust pipe connected to the concave side of a first bend, the projection of the exhaust pipe into the plane of symmetry of the first bend forming an angle α1 between 5° and 85° with a preferred value between 10° and 60° and preferably between 10° and 45° with respect to the vertical plane, and the projection of the exhaust pipe into the horizontal plane forming an angle α2 between 0° and 90° with respect to the plane of symmetry of the first bend, the preferred value between 10° and 80° and preferably between 15° and 75° with respect to the horizontal plane.

[0011] According to one or more embodiments, the inlet pipe has a diameter D2 and a length H1, for a length between 0.1 m. 3 / s and 170m 3 A gas volumetric flow rate between / s is achieved, with diameter D2 selected to achieve a gas velocity between 1 m / s and 80 m / s, wherein a preferred value is between 3 m / s and 50 m / s, and preferably between 3 m / s and 15 m / s, wherein H1 is between 1*D2 and 40*D2, wherein a preferred value is between 1*D2 and 30*D2, and preferably between 1*D2 and 20*D2. According to one or more embodiments, diameter D2 is between 0.05 m and 16 m and / or length H1 is between 0.05 m and 20 m.

[0012] According to one or more embodiments, the first bend and the second bend have radii of curvature between 1.5*D² and 4*D², with a preferred value between 2*D² and 4*D², and preferably between 2*D² and 3*D². According to one or more embodiments, the radius of curvature of the bend includes those between 0.075 m and 20 m and / or the diameter of the bend is substantially equal to D².

[0013] According to one or more embodiments, for a depth between 0.1 m 3 / s and 170 m 3 The exhaust pipe has a gas volumetric flow rate between / s and has a diameter D3 between 0.2*D2 and 2*D2, with a preferred value between 0.3*D2 and 1.5*D2, and preferably between 0.5*D2 and 1.1*D2. According to one or more embodiments, the diameter D3 includes values ​​between 0.025 m and 20 m.

[0014] According to one or more embodiments, the device includes a feed leg connected to the bottom outlet of a second bend.

[0015] According to one or more embodiments, the first feed leg has a diameter D4, which is selected to achieve a particle mass flow rate between 0.002 tn / s and 8 tn / s, and is chosen to achieve a flow rate between 10 kg / m³. 2 / s and 400 kg / m 2 Between / s, with the preferred value between 20 kg / m 2 / s and 350 kg / m 2 Between / s and preferably between 20 kg / m 2 / s and 150 kg / m 2 Solid flow rate between / s. According to one or more embodiments, the diameter D4 preferably includes a range between 0.1 m and 20 m.

[0016] According to one or more embodiments, the device includes: - A second pipe, which connects to the upper end of the exhaust pipe; and - Pre-stripping chamber, which is connected to the second pipe; The pre-stripping chamber includes: - A cylindrical member, that is, a basically cylindrical tube with vertical walls, having a closed upper end and an open lower end; - A vertical outlet pipe that is connected to the upper end of the cylindrical member and opens the upper end substantially along the vertical central axis of the cylindrical member; - A narrowing cone extending downward from the vertical wall of the cylindrical member, wherein the lower end of the narrowing cone has a diameter lower than the diameter of the upper end of the narrowing cone, and the wall of the narrowing cone forms an angle α3 between the lower end and the lower end, which is between 45° and 88°, wherein the preferred value is between 50° and 85° and preferably between 60° and 80°; - A tube, which is positioned at the center of the narrowing cone along the vertical central axis of the cylindrical member, with the lower end of the tube positioned below the lower end of the narrowing cone. The diameter of the tube is strictly smaller than the diameter of the lower end of the narrowing cone, and the tube and the lower end of the narrowing cone together form an annular space. - A widened cone extending downwards, wherein the lower end of the widened cone has a diameter greater than the diameter of the upper end of the widened cone, and the wall of the widened cone forms an angle α4 with the horizontal plane between 45° and 88°, wherein the preferred value is between 50° and 85° and preferably between 60° and 80°.

[0017] According to one or more embodiments, the outlet end of the second tube is substantially horizontal and is preferably substantially tangentially connected to the vertical wall of the cylindrical member.

[0018] According to one or more embodiments, the second tube is connected to the top portion of the vertical wall of the cylindrical member and preferably to the top end of the vertical wall of the cylindrical member.

[0019] According to one or more embodiments, for a depth between 0.1 m 3 / s and 170 m 3 For a gas volumetric flow rate between 3 m / s and 50 m / s, the channel cross-section of the second tube is selected to achieve a gas velocity between 4 m / s and 40 m / s, and preferably between 5 m / s and 30 m / s. According to one or more embodiments, the second tube has a circular cross-section with a diameter L1 or preferably a rectangular cross-section with a height H3 and a width L1, wherein the ratio of H3 to L1 is between 1 and 20, with a preferred value between 2 and 10, and preferably between 2 and 7. According to one or more embodiments, the length H3 is preferably between 0.05 m and 20 m, and the length L1 is between 0.01 m and 20 m.

[0020] According to one or more embodiments, the vertical outlet pipe has a diameter D8, for a diameter between 0.11 m and... 3 / s and 275 m 3 The diameter is selected to achieve a gas volumetric flow rate between 1 m / s and 80 m / s, with a preferred value between 3 m / s and 50 m / s, and preferably between 3 m / s and 25 m / s. According to one or more embodiments, the diameter D8 is preferably between 0.05 m and 20 m.

[0021] According to one or more embodiments, the height H6 (the length of the penetrating cylindrical part of the vertical outlet pipe) is included between 0 and 8*D8, wherein the preferred value is between 0 and 5*D8 and preferably between 0 and 3*D8.

[0022] According to one or more embodiments, the cylindrical member has a diameter D5 between (2*L1 + 1*D8) and (10*L1 + 5*D8), and preferably between (2*L1 + 1*D8) and (3*L1 + 2*D8), where L1 is the length or diameter of the second tube.

[0023] According to one or more embodiments, the cylindrical member has a height H4 between 1*D5 and 10*D5, wherein the preferred value is between 1*D5 and 7*D5 and preferably between 1*D5 and 3*D5.

[0024] According to one or more embodiments, the annular space has a width L2, which is selected to achieve a solid particle mass flow rate between 0.002 tn / s and 8 tn / s, and is chosen to achieve a flow rate between 100 kg / m³. 2 / s and 1000 kg / m 2 Between / s, with the preferred value between 200 kg / m 2 / s and 900 kg / m 2 Between / s and preferably between 350 kg / m 2 / s and 750 kg / m 2 Solid particle flow rate between / s.

[0025] According to one or more embodiments, the height H7 between the lower end of the narrowing cone and the lower end of the tube is between 0 and 20*L2, with a preferred value between 1*L2 and 10*L2, and preferably between 2*L2 and 8*L2. According to one or more embodiments, the length L2 is preferably between 0.01 m and 5 m.

[0026] According to one or more embodiments, the height H5 is between 1*H7 and 1.5*H4, wherein the preferred value is between 1*H7 and 1*H4 and preferably between 1*H7 and 0.8*H4.

[0027] According to one or more embodiments, the diameter D7 of the lower end of the widened cone is between (2*L2 + 1*D6) and (3*L2 + 2*D6).

[0028] According to one or more embodiments, the pipe has a diameter D6, for a diameter between 0.01 m and... 3 / s and 105 m 3 The diameter is selected to achieve a gas volumetric flow rate between 1 m / s and 30 m / s, with a preferred value between 2 m / s and 25 m / s, and preferably between 3 m / s and 18 m / s. According to one or more embodiments, the diameter D6 is preferably between 0.02 m and 10 m.

[0029] According to one or more embodiments, the device includes: - A third pipe, which connects to the upper end of the vertical outlet pipe; and - At least one cyclone separator connected to a third pipe.

[0030] According to a second aspect, the present invention relates to a stripping chamber comprising the apparatus according to the first aspect.

[0031] According to a third aspect, the present invention relates to a catalytic cracking (e.g., FFCC HS-FCC) unit comprising a stripping chamber according to a second aspect.

[0032] According to a fourth aspect, the present invention relates to a process for separating particulate solid-gas mixtures using an apparatus according to a first aspect and / or a stripping chamber according to a second aspect and / or a catalytic cracking unit according to a third aspect, the process comprising the following steps: - Introduce the mixture into the inlet pipe; - Separate the mixture to produce at least one proportion of particles, as well as gas and unseparated particles; - Extract gas and unseparated particles through the exhaust pipe; - Extract at least one proportion of the particles toward the bottom outlet of the second bend.

[0033] According to one or more embodiments, the operating conditions of the stripping chamber are selected from the following conditions: - Temperatures between 480℃ and 730℃; - Absolute total pressure between 0.1 MPa and 0.5 MPa; - Gas surface velocity between 0.1 m / s and 0.5 m / s; - Between 25 kg / m 2 / s and 200 kg / m 2 Solid flow rate between / s; - Dense-phase bed solids volume fraction between 0.25 and 0.6; - Residence time of the catalyst in the dense phase bed of the stripping chamber: between 10 seconds and 300 seconds.

[0034] Other features and advantages of the invention in the foregoing aspects will become apparent when reading the following description of non-limiting exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0035] Figure 1 The apparatus according to the invention is illustrated schematically, comprising an external riser, a separator referred to as a rapid separator, a pre-stripping chamber, and a cyclone separator.

[0036] Figure 2 The apparatus according to the invention is illustrated schematically, comprising a downcomer, a separator referred to as a fast separator, a pre-stripping chamber, and a cyclone separator.

[0037] Figure 3 It schematically shows the following based on Figure 1 The separator is called a fast separator.

[0038] Figure 4 It schematically shows the following based on Figure 3 The top view of the separator, which is called a fast separator.

[0039] Figure 5 It schematically shows the following based on Figure 2 The separator is called a fast separator.

[0040] Figure 6 It schematically shows the following based on Figure 1 and Figure 2 The pre-stripping chamber.

[0041] Figure 7 The illustration shows the passage according to Figure 6 A cross-sectional view of the pre-stripping chamber.

[0042] Figure 8 A schematic cross-sectional view is shown through the pre-stripping chamber connected to multiple inlets.

[0043] Figure 9 A schematic cross-sectional view through the reference pre-stripping chamber is shown. Detailed Implementation

[0044] Embodiments according to the foregoing aspects will now be described in detail. Numerous specific details are disclosed in the following detailed description to provide a more thorough understanding of the apparatus and process according to the invention. However, it will be apparent to those skilled in the art that the apparatus can be used without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0045] In this description, the term "comprise" is synonymous with "have," "include," and "contain" (meaning the same thing) and is inclusive or open-ended, not excluding other elements not stated. It will be understood that the verb "comprise" includes the exclusive and closed term "consisting of." Additionally, in this specification, the terms "essentially," "substantially," or "approximately" correspond to approximate values ​​of ±10%, preferably ±5%, and very preferably ±1%. For example, substantially 90° corresponds to 90° ± 9°, preferably ± 4° or 5°, and very preferably ± 1°. In this specification, the term "*" indicates a multiplication sign. In this specification, the term "pilot-scale unit" refers to an experimental unit designed on a small scale.

[0046] In this specification, the terms "solid efficiency" and "gas efficiency" are defined as follows.

[0047] Mathematical Formula 1 Mathematical formula 2 .

[0048] The present invention relates to an apparatus and process for separating gas-solid (particulate) mixtures (suspensions) and optionally for stripping solid particles contained in gas-solid mixtures, the gas-solid mixtures being generated by an external riser or downcomer of an FCC or HS-FCC unit. Figure 1 and Figure 2 The general setup of the separation and stripping apparatus and process according to the invention is presented with the external riser 1 and the downcomer 20 respectively. The riser / downcomer is connected to a stripping chamber 3, which is adapted to house a fluidized bed located in the lower portion of the stripping chamber 3. During operation, a gas-solid mixture 13 circulating in the external riser 1 or the downcomer 20 enters the stripping chamber 3 and creates a fluidized bed, which separates into a phase referred to as the dense phase 6 and a phase referred to as the dilute phase 8. Figure 1 and Figure 2 In the stripping chamber 3, interface 7 defines the interval between the two phases. Additionally, the fluidized solids in the dense phase 6 exit the stripping chamber 3 through outlet pipe 19. Preferably, fluidizing gas 16 is introduced into the stripping chamber 3, specifically to fluidize the dense phase 6.

[0049] This invention relates to an apparatus for separating and optionally stripping a gas-solid mixture, the apparatus comprising: a separator referred to as a rapid separator 4; optionally a pre-stripping chamber 10; and optionally one or more cyclone separators 12, the apparatus being adapted to process the gas-solid mixture entering the stripping chamber 3. Figure 1 In the case of the external riser 1, the connection between the external riser 1 and the fast separator 4 is formed by the first pipe 2. Figure 2 In the case of the downpipe 20, the first pipe 2 is optional. Preferably, only one end portion of the first pipe 2 and the downpipe 20 penetrates the stripping chamber 3. However, the first pipe 2 and the downpipe 20 may also be positioned primarily or even entirely inside the stripping chamber 3.

[0050] The rapid separator 4, the pre-stripping chamber 10, and the cyclone separator 12 are located in the dilute phase 8 of the stripping chamber 3. Preferably, the rapid separator 4 and / or the cyclone separator 12 are provided with feed legs for causing the separated solids to descend toward the dense phase 6 (or even directly into the dense phase); see Figure 1 and Figure 2 The first feed leg 5 is used in the fast separator 4, and the second feed leg 21 is used in the cyclone separator 12. Depending on the pressure balance of the FCC or HS-FCC unit, these feed legs may be immersed in the dense phase to a greater or lesser extent.

[0051] refer to Figure 1 and 2The gas-solid mixture 13, circulating in the external riser 1 or downcomer 20, enters the rapid separator 4, where the gas and solid particles are separated. A first proportion of particles 14 separates from the gas and descends through the first feed leg 5 toward the dense phase 6. The gas and unseparated particles 15 are then guided through the second pipe 9 toward the pre-stripping chamber 10. In the pre-stripping chamber 10, a second proportion of particles 14 separates from the gas and falls into the dilute phase 8 so that they subsequently encounter the dense phase 6. Advantageously, the fluidizing gas 16 of the dense phase 6 returns to the pre-stripping chamber 10 without re-entraining particles 14 by means of the apparatus described below. The fluidizing gas 16, along with the gas from the riser and the remaining unseparated particles 17, are then guided through the third pipe 11 toward a cyclone separator 12, as known to those skilled in the art. The implementation of a cyclone separator is not strictly necessary; one or more cyclone separator stages may also be present. In the cyclone separator 12, the third proportion of separated particles 14 are guided toward the dense phase bed 6 via the first feed leg 21, and the gas 18 (and optionally the fluidized gas 16) leaves the stripping chamber 3 via the fourth tube 32.

[0052] although Figure 1 and Figure 2 The presence of the pre-stripping chamber 10 is shown, but it should be understood that the presence of the pre-stripping chamber 10 is optional. The same applies to the cyclone separator 12.

[0053] According to one or more embodiments, the external lifter 1 or the downpipe 20 is adapted to be: - Gas velocities between 1 m / s and 80 m / s, with a preferred value between 3 m / s and 50 m / s and preferably between 3 m / s and 25 m / s; and / or - Between 10 kg / m 2 / s and 2000 kg / m 2 Between / s, with the preferred value between 50 kg / m 2 / s and 1500 kg / m 2 Between / s and preferably between 100 kg / m 2 / s and 1200 kg / m 2 Particle flow rate between / s.

[0054] Figure 3 , Figure 4 and Figure 5 The geometry of the fast separator 4 in either the external riser configuration or the downpipe configuration is shown.

[0055] In the external riser tube 1 (see Figure 3In the case of a gas-solid mixture 13, the gas-solid mixture 13 is introduced from the first pipe 2 into a pipe called the inlet pipe 23 of the rapid separator 4. The inlet pipe 23 is substantially vertical and adapted for a downward flow of gas / particles. Preferably, the first pipe 2 is substantially horizontal and is connected to the top of the inlet pipe 23 by means of a bend (e.g., a substantially 90° bend) called a connecting bend 22. In the downlink pipe 20 (see... Figure 5 In the case of [missing information], the gas-solid mixture 13 is directly introduced from the downcomer 20 to the top of the inlet pipe 23 of the rapid separator 4. (Reference) Figure 3 and Figure 5 The first pipe 2, the downpipe 20, and the connecting bend 22 have a diameter D1, and the inlet pipe 23 is adapted for a downward flow of gas / particles and has a diameter D2 and a length H1. It should be understood that the connecting bend may have a diameter between D1 and D2.

[0056] At the outlet (bottom end) of the inlet pipe 23, the fast separator 4 includes a deceleration bend having a series of first bends 24 (pipes in the form of bends) and second bends 27 (pipes in the form of bends), which together form a tortuous path. Specifically, the first bends 24, which are substantially 90°, have a substantially vertical top inlet (connected to the inlet pipe 23) and a substantially horizontal bottom outlet; and the second bends 27, which are substantially 90°, have a substantially horizontal top inlet (connected to the first bends 24) and a substantially vertical bottom outlet. Preferably, the bends are directly connected to each other.

[0057] refer to Figure 3 , Figure 4 and Figure 5 The pipe referred to as exhaust pipe 25 (which is substantially straight) (via its lower end) lies in the vertical plane “xz” (the plane of symmetry of the first bend 24; see Figure 3 and 5 (in the horizontal plane "xy") at an angle α1 relative to the vertical plane (see) Figure 4 The first bend 24 is connected to the concave side of the second bend 27 at an angle α2 relative to the vertical plane “xz”. Advantageously, the order of the first bend 24 and the second bend 27, and the positioning of the exhaust pipe 25, make it possible to separate the first proportion of particles 14 and gas (by centrifugation). The separated first proportion of particles 14 then descends back into the first feed leg 5 through the second bend 27. The gas and unseparated particles 15 exit through the exhaust pipe 25 (at its upper end), then through an optional vertical pipe 26, and finally through the second pipe 9. Preferably, the second pipe 9 is substantially horizontal. (Reference) Figure 3 and Figure 5Pipes 25 and 26 have a diameter D3, and pipe 26 has a height H2. Additionally, the first feed leg 5 (a straight, vertical pipe) has a diameter D4. As shown, the first feed leg 5 can be immersed in the dense phase 6. This achieves an operation in which gas cannot pass through the feed leg 5 and is therefore forced to pass through the exhaust pipe 25. The second pipe 9 has a circular cross-section with a diameter L1 or preferably a rectangular cross-section with a height H3 and a width L1 (also described below). Figure 6 , Figure 7 and Figure 8 ).

[0058] According to one or more embodiments, the gas volumetric flow rate (of the gas-solid mixture 13) passing through the external riser 1, the downcomer 20, and the inlet pipe 23 includes 0.1 m³ / s. 3 / s and 170 m 3 The mass flow rate of solid particles (of the gas-solid mixture 13) passing through the external riser 1, downpipe 20 and inlet pipe 23 is between 0.002 tn / s and 8 tn / s.

[0059] According to one or more embodiments, the diameter D1 is selected to achieve a gas velocity between 1 m / s and 80 m / s, with a preferred value between 3 m / s and 50 m / s, and preferably between 3 m / s and 25 m / s. Depending on the volumetric flow rate range of the incoming gas presented above, the diameter D1 is preferably included between 0.05 m and 16 m.

[0060] According to one or more embodiments, the diameter D2 is selected to achieve a gas velocity between 1 m / s and 80 m / s, with a preferred value between 3 m / s and 50 m / s, and preferably between 3 m / s and 15 m / s. Depending on the volumetric flow rate range of the incoming gas presented above, the diameter D2 is preferably between 0.05 m and 16 m.

[0061] According to one or more embodiments, H1 is between 1*D2 and 40*D2, wherein the preferred value is between 1*D2 and 30*D2, and preferably between 1*D2 and 20*D2. Depending on the volumetric flow rate range of the incoming gas presented above, the length H1 is preferably between 0.05 m and 20 m.

[0062] According to one or more embodiments, the bend has a radius of curvature between 1.5*D² and 4*D², with a preferred value between 2*D² and 4*D², and preferably between 2*D² and 3*D². Depending on the range of volumetric flow rates of the incoming gas presented above, the radius of curvature of the bend is preferably between 0.075 m and 20 m. According to one or more embodiments, the diameter of the bend is substantially equal to D².

[0063] According to one or more embodiments, the diameter D4 is selected to achieve a value between 10 kg / m 2 / s and 400 kg / m 2 / s, where the preferred value is between 20 kg / m 2 / s and 350 kg / m 2 Between / s and preferably between 20 kg / m 2 / s and 150 kg / m 2 The solid flow rate is between / s. Depending on the range of volumetric flow rates of the incoming solid particles presented above, the diameter D4 is preferably between 0.1 m and 20 m.

[0064] According to one or more embodiments, the angle α1 (the angle between the vertical midpoint of the inlet pipe 23 and the midpoint of the exhaust pipe 25 in the plane “xz”) includes between 5° and 85°, wherein the preferred value is between 10° and 60° and preferably between 10° and 45°.

[0065] According to one or more embodiments, the angle α2 (the angle between the vertical midpoint of the inlet pipe 23 and the midpoint of the exhaust pipe 25 in the plane "xy") includes between 0° and 90°, wherein the preferred value is between 10° and 80° and preferably between 15° and 75°.

[0066] According to one or more embodiments, D3 is included between 0.2*D2 and 2*D2, wherein the preferred value is between 0.3*D2 and 1.5*D2, and preferably between 0.5*D2 and 1.1*D2. Depending on the volumetric flow rate range of the incoming gas presented above, the diameter D3 is preferably included between 0.025 m and 20 m.

[0067] Figure 6 , Figure 7 and Figure 8 The geometry of the pre-stripping chamber 10, located (directly) downstream of the fast separator 4, is shown. Gas and unseparated particles 15 enter the pre-stripping chamber 10 through the second pipe 9. Figure 7 It presents a configuration with a single tube 9. Figure 8A configuration with multiple (four) tubes 9 is presented, which are connected to one or more (four) rapid separators 4. In the pre-stripping chamber 10, gas and unseparated particles 15 enter a cylindrical member 27, i.e., a substantially vertical cylindrical tube, the upper end (substantially circular base) of which is closed (without voids) and the lower end (substantially circular base) is open. The cylindrical member has a diameter D5 and a height H4 to initiate centrifugal separation between the gas and particles, with the particles descending along the vertical wall of the cylindrical member 27 and the gas exiting the cylindrical member 27 along its vertical central axis through a vertical outlet tube 31 located in the upper portion. To achieve this, a second tube 9 is preferably connected substantially tangentially to the vertical wall of the cylindrical member 27, such as... Figure 7 As shown in the diagram. One or more tangential tubes 9 may be implemented, such as... Figure 7 and Figure 8 As shown in the diagram. Preferably, the outlet end of the second pipe 9 is substantially horizontal. Preferably, the second pipe 9 is connected to the top portion (e.g., the upper half, preferably the top third, or even the top quarter) of the vertical wall of the cylindrical member 27. Very preferably, the second pipe 9 is connected to the top end of the vertical wall of the cylindrical member 27. The vertical outlet pipe 31 has a diameter D8, and the height H6 of this pipe penetrates the interior of the cylindrical member 27. A narrowing cone 28 (tapered pipe) is placed below the cylindrical member 27 to extend downwards along the vertical wall of the cylindrical member 27. The upper end of the narrowing cone 28 has a diameter D5, and the lower end of the narrowing cone 28 has a diameter less than D5. The cylindrical member 27 and the narrowing cone 28 share the same vertical axis of symmetry. In addition, the wall of the narrowing cone 28 forms an angle α3 with the plane (substantially horizontal plane) formed by the lower end, and has a height H8.

[0068] refer to Figure 6 A straight tube 29 is positioned at the center of the narrowing cone 28 along the vertical central axis of the cylindrical member 27, and extends below the narrowing cone (28) to the lower end of the tube 29. The lower end of the tube 29 is positioned at a height H7 below the lower end of the narrowing cone 28, and the upper end of the tube 29 is positioned at a height H5 below the lower end of the vertical outlet tube 31. Furthermore, the tube 29 has a diameter D6 that is strictly smaller than the diameter of the lower end of the narrowing cone 28, which has a diameter of (1*D6 + 2*L2). A widening cone 30 (tapered tube) is positioned at the lower end of the tube 29. The upper end of the widening cone 30 has a diameter D6, and the lower end of the widening cone 30 has a diameter D7, which is strictly larger than D6. Furthermore, the widening cone 30 forms an angle α4 with the horizontal plane (or the plane formed by the lower open end of the tube 29) and has a height H9.

[0069] The operating principle of the pre-stripping chamber 10 is as follows. Gas and unseparated particles 15 are tangentially returned to the cylindrical member 27, causing centrifugal separation of the particles. Then, a second proportion of particles 14 fall towards the narrowing cone 28 and encounter the dilute phase 8 of the stripping chamber 3 via an annular space of width L2. L2 is the length between the lower end of the narrowing cone 28 and the tube 29. Additionally, fluidizing gas 16 enters the pre-stripping chamber 10 through the interior of the narrowing cone 30 and is then guided upwards through the tube 29. At the outlet of the tube 29, the fluidizing gas 16 encounters the proportion of gas and unseparated particles 15 to form a gaseous mixture 17, which exits the pre-stripping chamber through the vertical outlet tube 31. The gaseous mixture 17 can then exit the stripping chamber 3 (directly) or be sent to one or more cyclone separators 12 via a third tube 11. Advantageously, the implementation of the widened cone 30 and tube 29 allows the fluidizing gas 16 to enter the pre-stripping chamber 10 without re-entraining the second proportion of particles 14.

[0070] According to one or more embodiments, the volumetric flow rate of the stripper gas 16 includes 0.01 m³ / s. 3 / s and 105 m 3 Between / s. According to one or more embodiments, the sum of the gas volumetric flow rate (of the gas-solid mixture 13) and the gas volumetric flow rate of the stripper gas 16 passing through the cylindrical member 27 and entering the vertical outlet pipe 31 includes 0.11 m... 3 / s and 275 m 3 Between / s.

[0071] According to one or more embodiments, the channel cross-section (e.g., H3*L1) of the second pipe 9 is selected to achieve a gas velocity between 3 m / s and 50 m / s, with a preferred value between 4 m / s and 40 m / s, and preferably between 5 m / s and 30 m / s. According to one or more embodiments, the ratio of H3 to L1 is included between 1 and 20, with a preferred value between 2 and 10, and preferably between 2 and 7. Depending on the volumetric flow rate range of the incoming gas presented above, the length H3 is preferably included between 0.05 m and 20 m, and the length L1 is included between 0.01 m and 20 m.

[0072] According to one or more embodiments, the diameter D8 is selected to achieve a gas velocity between 1 m / s and 80 m / s, with a preferred value between 3 m / s and 50 m / s, and preferably between 3 m / s and 25 m / s. Depending on the volumetric flow rate range of the incoming gas presented above, the diameter D8 is preferably included between 0.05 m and 20 m.

[0073] According to one or more embodiments, the diameter D5 of the cylindrical member 27 is between (2*L1 + 1*D8) and (10*L1 + 5*D8), and preferably between (2*L1 + 1*D8) and (3*L1 + 2*D8).

[0074] According to one or more embodiments, the height H4 of the cylindrical member 27 is between 1*D5 and 10*D5, wherein the preferred value is between 1*D5 and 7*D5 and preferably between 1*D5 and 3*D5.

[0075] According to one or more embodiments, L2 is selected to realize the annular space between the lower end of the narrowed cone 28 and the tube 30 for obtaining a density between 100 kg / m 2 / s and 1000 kg / m 2 Between / s, with the preferred value between 200 kg / m 2 / s and 900kg / m 2 Between / s and preferably between 350 kg / m 2 / s and 750 kg / m 2 The solid particle flow rate is between / s. Depending on the range of incoming solid flow rates presented above, the length L2 is preferably between 0.01 m and 5 m.

[0076] According to one or more embodiments, the angle α3 between the horizontal plane and the wall of the narrowing cone 28 is between 45° and 88°, with a preferred value between 50° and 85° and preferably between 60° and 80°. The height H8 is generated by the angle α3 and the lengths D6 and L2.

[0077] According to one or more embodiments, the diameter D6 is selected to achieve a fluidized gas velocity between 1 m / s and 30 m / s, with a preferred value between 2 m / s and 25 m / s, and preferably between 3 m / s and 18 m / s. Depending on the volumetric flow rate range of the incoming gas presented above, the diameter D6 is preferably included between 0.02 m and 10 m.

[0078] According to one or more embodiments, the height H7 between the lower end of the narrowing cone 28 and the lower end of the tube 29 is between 0 and 20*L2, wherein the preferred value is between 1*L2 and 10*L2 and preferably between 2*L2 and 8*L2.

[0079] According to one or more embodiments, the height H5 is between 1*H7 and 1.5*H4, wherein the preferred value is between 1*H7 and 1*H4 and preferably between 1*H7 and 0.8*H4.

[0080] According to one or more embodiments, the height H6 (the length of the penetrating cylindrical member 27 of the vertical outlet pipe 31) is included between 0 and 8*D8, wherein the preferred value is between 0 and 5*D8 and preferably between 0 and 3*D8.

[0081] According to one or more embodiments, the angle α4 between the horizontal plane and the wall of the widened cone 30 is between 45° and 88°, with a preferred value between 50° and 85° and preferably between 60° and 80°. According to one or more embodiments, the diameter D7 of the lower end of the widened cone 30 is between (2*L2 + 1*D6) and (3*L2 + 2*D6). The height H9 is generated by the angle α4 and the diameter D7.

[0082] According to one or more embodiments, the operating conditions of the stripping chamber 3 are selected from the following conditions: - Temperatures between 480℃ and 730℃; - Absolute total pressure between 0.1 MPa and 0.5 MPa; - Gas surface velocity between 0.1 m / s and 0.5 m / s; - Between 25 kg / m 2 / s and 200 kg / m 2 Solid flow rate between / s; - Dense-phase bed solids volume fraction between 0.25 and 0.6; - The residence time of the catalyst in the dense phase bed of the stripping chamber 3 is between 10 seconds and 300 seconds.

[0083] Example As a first example, a comparison will be made between the following two: a reference FCC pilot unit that includes a stripping chamber comprising two cyclone separators (counterexample); and an FCC pilot unit according to the invention that includes a stripping chamber 3 comprising a rapid separator 4, a pre-stripping chamber 10, and two cyclone separators 12 (example according to the invention).

[0084] The main dimensions of the pilot unit are shown below: - Riser pipe diameter: 1.5 cm - Stripper diameter: 10 cm - D1 = 1.5 cm - D2 = 2.1 cm - D3 = 2.1 cm - D4 = 2.1 cm - α1=70° - α2=30° - H1 = 30 cm - H2 = 10 cm - H3 = 3 cm - L1 = 1 cm - L2 = 0.4 cm - H4 = 8cm - H5 = 7.5 cm - H6 = 0 cm - H7 = 3 cm - H8 = 9 cm - H9 = 3.5 cm - α3=80° - α4=70° - D5 = 4 cm - D6 = 1.7 cm - D7 = 2.9 cm - D8 = 1.4 cm. In this first example, the FCC pilot unit is in adiabatic mode, and the feed is depressurized gas oil in contact with the FCC equilibrium catalyst.

[0085] Table 1 below presents a comparison between the reference FCC pilot unit and the FCC pilot unit according to the present invention.

[0086] Table 1 .

[0087] As can be seen from Table 1, the pilot unit according to the invention makes it possible to reduce residence time (measured by residence time determination or RTD technology) and also reduce coking (lower Δcoke). Advantageously, the temperature at the regenerator is reduced, and the C / O ratio is increased. Furthermore, better conversion (relatively +3.2%), less dry gas (relatively -23.5%), improved propylene yield (relatively +2.3%), improved olefin content of C3 fraction (relatively +5%), and improved light gasoline yield (relatively +7.9%) are achieved.

[0088] Specifically, the rapid separator 4 makes it possible to reduce the residence time of the gas and improve the performance of the unit, as shown above. Furthermore, the pre-stripping chamber 10 makes it possible to remix the stripper gas with the riser effluent while still performing gas-solid separation.

[0089] As a second example and reference Figure 9 A comparison will be made between the diagram of the reference pre-stripping chamber 40 and the pre-stripping chamber 10 according to the present invention. In particular, Figure 9 A diagram of a reference pre-stripping chamber 40 with two side inlets 41 is shown, through which a mixture 15 of gaseous effluent and solid particles enters. Stripper gas 16 enters at the bottom through a lower inlet 42, and a gaseous mixture 17 (which is a mixture of flows 15 and 16) exits at the top through an upper outlet 43.

[0090] The gas efficiency and solid efficiency of the pre-stripping chamber 40 are known. The solid efficiency of the pre-stripping chamber 10 according to the present invention was measured on a pilot-scale basis, wherein: - L1 = 1 cm - H3 = 3 cm - H4 = 8cm - H5 = 7.5 cm - H6 = 0 cm - H7 = 3 cm - H8 = 9 cm - H9 = 3.5 cm - α3=80° - α4=70° - D5 = 4 cm - D6 = 1.7 cm - D7 = 2.9 cm - D8 = 1.4 cm. The table below compares the gas efficiency and solid efficiency of the reference pre-stripping chamber 40 with that of the pre-stripping chamber 10 according to the present invention.

[0091] Table 2 .

[0092] The new invention offers higher solid efficiency while maintaining the same gas efficiency.

Claims

1. An apparatus for separating particulate solid-gas mixtures, the apparatus comprising: - A substantially vertical inlet pipe (23) adapted to receive the particulate solid-gas mixture (13). - A first bend (24) of approximately 90°, which is connected to the bottom end of the inlet pipe (23) and has a substantially vertical top inlet and a substantially horizontal bottom outlet; - A second bend (27) of approximately 90°, which is connected to the bottom end of the first bend (24) and has a substantially horizontal top inlet and a substantially vertical bottom outlet; - An exhaust pipe (25) is connected to the concave side of the first bend (24), the projection of the exhaust pipe into the plane of symmetry of the first bend (24) forms an angle α1 between 5° and 85° with a preferred value between 10° and 60° and preferably between 10° and 45° with respect to the vertical plane, and the projection of the exhaust pipe into the horizontal plane forms an angle α2 between 0° and 90° with respect to the plane of symmetry of the first bend (24), the preferred value between 10° and 80° and preferably between 15° and 75° with respect to the horizontal plane; - Material leg (5), which is connected to the bottom outlet of the second bend (27), The first bend (24) and the second bend (27) have radii of curvature between 1.5*D2 and 4*D2, with a preferred value between 2*D2 and 4*D2 and preferably between 2*D2 and 3*D2, and the diameter D2 is between 0.05m and 16m.

2. The apparatus according to claim 1, wherein, The inlet pipe (23) has a diameter D2 and a length H1, for a length between 0.1 m. 3 / s and 170 m 3 The gas volumetric flow rate is between / s, and the diameter D2 is selected to achieve a gas velocity between 1 m / s and 80 m / s, wherein the preferred value is between 3 m / s and 50 m / s and preferably between 3 m / s and 15 m / s, wherein H1 is between 1*D2 and 40*D2, wherein the preferred value is between 1*D2 and 30*D2 and preferably between 1*D2 and 20*D2.

3. The apparatus according to claim 1 or claim 2, wherein, For values ​​between 0.1 m 3 / s and 170 m 3 The exhaust pipe (25) has a gas volume flow rate between / s and has a diameter D3 between 0.2*D2 and 2*D2, wherein the preferred value is between 0.3*D2 and 1.5*D2 and preferably between 0.5*D2 and 1.1*D2.

4. The apparatus according to claim 1, wherein, The feed leg (5) has a diameter D4, which is selected to achieve a particle mass flow rate between 0.002 tn / s and 8 tn / s, and is chosen to achieve a flow rate between 10 kg / m³. 2 / s and 400 kg / m 2 Between / s, with the preferred value between 20 kg / m 2 / s and 350 kg / m 2 Between / s and preferably between 20 kg / m 2 / s and 150 kg / m 2 Solid flow rate between / s, wherein the diameter D4 is between 0.1 m and 20 m.

5. The apparatus according to any one of the preceding claims, comprising: - A second pipe (9), which is connected to the upper end of the exhaust pipe (25); as well as - Pre-stripping chamber (10), which is connected to the second pipe (9); The pre-stripping chamber (10) includes: - Cylindrical component (27), i.e., a basically cylindrical tube with vertical walls, having a closed upper end and an open lower end; - A vertical outlet pipe (31) is connected to the upper end of the cylindrical member (27) and opens the upper end substantially along the vertical central axis of the cylindrical member (27); - A narrowing cone (28) extending downward from the vertical wall of the cylindrical member (27), wherein the lower end of the narrowing cone (28) has a diameter lower than the diameter of the upper end of the narrowing cone (28), and the wall of the narrowing cone (28) forms an angle α3 between the lower end and the lower end, which is between 45° and 88°, wherein the preferred value is between 50° and 85° and preferably between 60° and 80°; - A tube (29) is disposed at the center of the narrowing cone (28) along the vertical central axis of the cylindrical member (27), the lower end of the tube (29) is disposed below the lower end of the narrowing cone (28), the diameter of the tube (29) is strictly smaller than the diameter of the lower end of the narrowing cone (28), and the tube (29) and the lower end of the narrowing cone (28) together form an annular space; - A widened cone (30) extending downward from the tube (29), wherein the lower end of the widened cone (30) has a diameter greater than the diameter of the upper end of the widened cone (30), and the wall of the widened cone (30) forms an angle α4 with the horizontal plane between 45° and 88°, wherein the preferred value is between 50° and 85° and preferably between 60° and 80°.

6. The apparatus according to claim 5, wherein, The outlet end of the second tube (9) is substantially horizontal and is preferably substantially tangentially connected to the vertical wall of the cylindrical member (27).

7. The apparatus according to claim 5 or claim 6, wherein, The second tube (9) is connected to the top portion of the vertical wall of the cylindrical member (27) and preferably to the top end of the vertical wall of the cylindrical member (27).

8. The apparatus according to any one of claims 5 to 7, comprising: - A third pipe (11), which is connected to the upper end of the vertical outlet pipe (31); as well as - At least one cyclone separator (12) is connected to the third pipe (11).

9. A stripping chamber comprising the apparatus according to any one of claims 1 to 8.

10. A catalytic cracking unit comprising the stripping chamber according to claim 9.

11. A process for separating particulate solid-gas mixtures using the apparatus according to any one of claims 1 to 8, the process comprising the following steps: - The mixture (13) is introduced into the inlet pipe (23); - Separate the mixture (13) to produce at least one proportion of particles (14) as well as gas and unseparated particles (15); - The gas and the unseparated particles (15) are extracted through the exhaust pipe (25); - Extract at least one proportion of the particles (14) toward the bottom outlet of the second bend (27).

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