Method and device for stripping solid particles in a pulsed fluidized bed

Abstract

The present invention relates to a method and a device for stripping solid particles, wherein at least a portion of a stripping gas is fed in a pulsed manner into a stripping chamber (15) containing the solid particles.

Description

[0001] Pulsed fluidized bed stripping process and device.

[0002] technical field

[0003] The invention relates to the field of refining and upgrading heavy hydrocarbon feedstocks such as crude oil and biomass, particularly through cracking and pyrolysis processes. Specifically, the invention relates to processes and devices for stripping (gas extraction or "stripping" according to Anglo-Saxon terminology) solid catalysts from cracking and pyrolysis units to extract (e.g., desorb) chemicals, such as hydrocarbons.

[0004] Previous technique

[0005] Cracking, particularly fluid catalytic cracking (FCC), is classically used in refining to convert a heavy feedstock, characterized by a boiling point close to 340°C, often above 380°C, into lighter products that can be used as fuels, especially gasoline, the first product of an FCC unit, characterized by boiling points close to ambient and boiling points of 160°C or even 220°C depending on whether it is light gasoline or not.

[0006] Pyrolysis, in particular so-called fast or flash catalytic pyrolysis (“catalytic fast pyrolysis” or CFP according to Anglo-Saxon terminology), is classically used for the valorization of biomass and makes it possible to produce various compounds such as aromatic compounds (e.g. BTX for Benzene, Toluene, Xylenes), olefins, as well as carbon monoxide (CO) and carbon dioxide (CO2), the latter of which can be recycled and / or valorized to produce various additional compounds (e.g. alcohols, naphtha, aromatic compounds).

[0007] In particular, FCC and CFP processes typically use circulating fluidized beds of solid catalysts to collect all the hydrocarbon products formed. A catalyst stripping step is then carried out before the regeneration step (combustion of the coke formed on the catalyst). This stripping consists of injecting a gas (called a "stripping gas"), preferably a highly polar gas such as steam, in the opposite direction to the circulating catalyst.

[0008] Figure 1 shows a schematic of reference FCC or CFP processes in which a liquid FCC or solid CFP feedstock 1, preferably sprayed as fine droplets or powder, is introduced into a fluidized bed reactor 2 (dense or conveyed) where it is mixed with a catalyst source 3 (fresh and / or regenerated solid catalyst particles) coming at least in part from a regenerator 10 to produce on the one hand a gaseous effluent 4 and on the other hand a spent catalyst 5 (e.g. coked) by means of a gas / solid separator known to those skilled in the art (not shown). The spent catalyst 5 is distributed to a stripping device 6, in which the spent catalyst 5 is contacted counter-currently with a stripping gas 7, to produce stripped catalyst 9 and a gas mixture 8 comprising stripping gas and chemicals extracted from the catalyst, e.g. hydrocarbons adsorbed on the surface or in the pores of the spent catalyst 5.The stripped catalyst 9 is then directed to the regenerator 10, where, for example, the exothermic combustion of the coke regenerates the stripped catalyst 9 into a regenerated catalyst 11. At the outlet of the regenerator 10, the regenerated catalyst 11 feeds the catalyst source 3.

[0009] Applications WO9911739 A1 and WO2018140448 A1 describe examples of FCC unit stripping processes.

[0010] Applications WO2014165223 A2 and WO2016081527 A2 describe examples of CFP unit stripping processes.

[0011] Application WO9848932 A1 describes a pulsed fluidized bed, the bed being compartmentalized so that each compartment is fluidized intermittently via a rotary valve, particularly to improve fluidization when the solid particles are of non-uniform size.

[0012] Summary of the invention

[0013] A first object of the present invention is to increase the efficiency of stripping devices. A second object of the present invention is to reduce the consumption of stripping gas in stripping devices.

[0014] For these purposes, according to a first aspect, the present invention relates to a method of stripping solid particles, in which at least a part of a stripping gas pulses into a stripping chamber containing the solid particles.

[0015] According to one or more embodiments, at least a portion of the stripping gas is pulsed by: at least one pulse distributor disposed in the stripping chamber; and / or at least one pulse valve adapted to supply at least one distributor disposed in the stripping chamber.

[0016] In one or more embodiments, the impulse distributor is an electrical, pneumatic, or mechanical impulse distributor, and / or the impulse valve is an electrical, pneumatic, or mechanical impulse valve. In one or more embodiments, at least a portion of the stripping gas is pulsed at a pulse frequency between 0.5 Hz and 10 Hz, preferably between 1 Hz and 9 Hz, and most preferably between 3 Hz and 8 Hz.

[0017] According to one or more embodiments, the process includes supplying solid particles to the stripping chamber through a solid particle inlet disposed above the stripping chamber, and in which the impulse distributor or the distributor supplied by the impulse valve is disposed below the solid particle inlet; is preferably the distributor closest to the solid particle inlet.

[0018] According to one or more embodiments, the solid particle inlet comprises at least one return leg plunging into the stripping chamber; and the impulse distributor or the distributor fed by the impulse valve: is disposed below the at least one return leg; is preferably the distributor closest to the at least one return leg.

[0019] According to one or more embodiments: the impulse distributor or the distributor fed by the impulse valve has a diameter D1 and is disposed at a distance L1 from a return leg of the inlet of solid particles plunging into the stripping chamber, and the ratio L1 on D1 is between 0.05 and 1, preferably between 0.1 and 0.8, very preferably between 0.15 and 0.7; and / or the impulse distributor or the distributor fed by the impulse valve has a diameter D1 and is disposed at a distance L2 from at least one flow uniformization element, and the ratio L2 to D1 is between 0.05 and 1, preferably between 0.1 and 0.8, most preferably between 0.15 and 0.7; and / or the impulse distributor or the distributor fed by the impulse valve has a diameter D1, the stripping chamber has a diameter D2, and the ratio D1 to D2 is between 0.1 and 0.9, preferably between 0.3 and 0.85, most preferably between 0.4 and 0.8.

[0020] According to a second aspect, the present invention also relates to a device for stripping solid particles in a stripping chamber, comprising: at least one impulse distributor disposed in the stripping chamber and adapted to supply the stripping chamber with stripping gas; and / or at least one impulse valve adapted to supply at least one distributor disposed in the stripping chamber with stripping gas.

[0021] According to one or more embodiments, the impulse distributor is an electrical, pneumatic or mechanical impulse distributor, and / or the impulse valve is an electrical, pneumatic or mechanical impulse valve.

[0022] According to one or more embodiments, the impulse distributor and / or the impulse valve are adapted to provide a pulse frequency between 0.5 Hz and 10 Hz, preferably between 1 Hz and 9 Hz, most preferably between 3 Hz and 8 Hz.

[0023] According to a third aspect, the present invention also relates to a stripping chamber comprising the device according to the second aspect.

[0024] According to a fourth aspect, the present invention also relates to a cracking unit comprising a stripping chamber according to the third aspect.

[0025] According to one or more embodiments, the cracking unit is adapted for catalytic fluidized bed cracking of a hydrocarbon feedstock, preferably at least part of a crude oil.

[0026] According to a fifth aspect, the present invention also relates to a pyrolysis unit comprising a stripping chamber according to the third aspect.

[0027] According to one or more embodiments, the pyrolysis unit is adapted for so-called rapid or flash catalytic pyrolysis of biomass, preferably of at least part of a lignocellulosic biomass.

[0028] Other features and advantages of the invention, according to the aspects mentioned above, will become apparent from the description below and from non-limiting examples of implementations, with reference to the figures attached and described below.

[0029] List of figures

[0030] Figure 1 shows a diagram of a reference FCC or CFP process.

[0031] Figure 2 shows a diagram of a stripping device for an FCC unit according to the present invention.

[0032] Figure 3 shows a schematic of a stripping device for one CFP unit according to the present invention. Figure 4 shows the normalized helium concentration measured at the top of the stripping chamber as a function of the pulse frequency of the air injected at the bottom of the stripping chamber, in a reference stripping device and in a stripping device according to the present invention.

[0033] Detailed description of the invention

[0034] Embodiments of the process and device according to the aforementioned aspects will now be described in detail. In the following detailed description, numerous specific details are presented to provide a more thorough understanding of the process and device. However, it will be apparent to those skilled in the art that the process and device can be implemented without these specific details. In other cases, features well known to those skilled in the art have not been described in detail to avoid unnecessarily complicating the description.

[0035] In what follows, the term "understand" is synonymous with (means the same as) "include" and "contain," and is inclusive or open-ended, not excluding other, unstated elements. It is understood that the term "understand" includes the exclusive and closed term "consist."

[0036] In addition, when used in this description, the terms "essentially" or "substantially" or "approximately" in relation to a reference value correspond to an approximation of ± 10%, preferably ± 5%, most preferably ± 2%, or even more preferably ± 1% of that reference value, which may be, for example, a temperature, pressure, distance, speed, flow rate, compound content, frequency, etc.

[0037] In accordance with the present invention, the various embodiments presented can be implemented separately or in combination with one another, without limitation as to the number of combinations where technically feasible. For example, in accordance with the present invention, a preferred range of distance values ​​can be combined with a preferred range of frequency values.

[0038] The stripping process and device according to the present invention are applicable to gas / solid separation units, and more particularly to the separation chambers of FCC and CFP units.

[0039] A stripping device according to the present invention adapted to an FCC unit is shown in Figure 2. The stripping device comprises a separation chamber 12 containing (from bottom to top) a catalyst outlet 13 for the extraction of stripped catalyst 14, a stripping chamber 15 containing spent catalyst 16, a solid particle inlet 23, and a gaseous effluent outlet 21. Solid particles generally refer to the catalyst in this description, in particular the spent catalyst.

[0040] The stripping chamber 15 (bed of solid particles to be stripped) includes one or more distributors 17 for distributing the stripping gas (e.g., steam). Preferably, at least one distributor is located on the lower part of the stripping chamber 15. Preferably, the distributors 17 are all immersed in the bed of solid particles (e.g., spent catalyst). According to one or more embodiments, the stripping chamber 15 includes means or elements for uniforming the flow 18 of the solid particles and the gas. Preferably, the flow uniforming elements 18 are located, at least partially, at a height greater than that of at least one distributor 17. The flow uniforming elements 18, in particular, facilitate contact between the solid particles and the stripping gas. Preferably, the flow uniformization elements 18 are (all) immersed in the bed of solid particles (i.e., worn catalyst). These elements promoting the uniformity of the gas-solid flow can be inclined plates arranged in baffles, packings (in Anglo-Saxon terminology) optionally structured or other elements, a non-limiting description of which can be found in patents US 2440620, US 2472502, US 2481439 or US 6224833 or in books such as "Materials and Equipment", Volume 4 of the Encyclopedia of Petroleum Refining, by P. Trambouze published by Technip, 1999.

[0041] Generally, a stripping device of an FCC unit further includes an internal gas / solid separator 19, a second separation stage 20 (including for example one or more cyclones) adapted to direct the gases towards the outlet of gaseous effluents 21. According to one or more embodiments, the gas / solid separator 19 is defined by a shell containing a plurality of separation chambers and a plurality of pre-stripping chambers (not shown in Figure 2) distributed alternately around (e.g. the upper end) a central reactor 22 of substantially vertical and elongated shape (e.g. tubular), closed by a top section, and in which circulate a gaseous mixture (unconverted feed and conversion products) and solid particles (catalyst) to be separated.

[0042] According to one or more embodiments, the feed of the FCC unit (i.e., the feed of the central reactor 22) is generally a hydrocarbon feed, preferably a heavy feed, characterized by a boiling point close to 340°C, often exceeding 380°C, such as crude oil or a heavy cut, for example from a vacuum distillation unit, such as vacuum gas oil (VGO), vacuum residue, coking gas oil, or a hydrocracking stage recycle, alone or in mixtures. Upon contact with the hot solid catalyst, the pulverized feed vaporizes, and endothermic cracking reactions occur along the central reactor 22, thus lowering the temperature and producing valuable products (e.g.C1-C4 gas; a gasoline cut; a light cycle oil cut (LCO); a heavy cycle oil cut (HCO); and a slurry-like oil and a solid residue (coke) adsorbed onto the catalyst.

[0043] According to one or more embodiments, the operating conditions of the central reactor 22 are as follows: gas surface velocity: between 3 and 35 m / s; temperature: between 500 and 700°C and preferably less than 650°C; pressure: between 0.1 and 0.6 MPaa (MPaa meaning an absolute pressure expressed in MPa); contact time less than 1 second (e.g. between 0.1 second and 0.9 second); and a mass ratio of the catalyst to the C / O charge: between 3 and 50.

[0044] The catalyst for an FCC application is a solid catalyst (e.g., density, size, and shape of grains chosen for use in a fluidized bed). The densities, sizes, and shapes of catalysts for fluidized beds are known to those skilled in the art and are not described further. In one or more embodiments, the catalyst contains what is commonly called a matrix made of clay, silica, or silica alumina, a binder, and zeolite, for example, 15 to 50% by weight of zeolite relative to the weight of the catalyst, preferably a Y zeolite and / or a ZSM-5 zeolite. In one or more embodiments, the catalyst comprises a ZSM-5 zeolite. In one or more embodiments, the grain density of the catalyst is between 1000 and 2000 kg / m³. 3 According to one or more embodiments, the grain density of the catalyst is between 1250 and 1750 kg / m³. 3 .

[0045] According to one or more embodiments, the operating conditions of the stripping chamber 15 are as follows: temperature between 450°C and 650°C; pressure between 0.1 and 0.6 MPaa; surface gas velocity between 0.05 and 0.5 m / s and preferably between 0.1 and 0.4 m / s; solid flux between 15 kg / m³ 2 / s and 150 kg / m 2 / s and preferably between 30 kg / m 2 / s and 90 kg / m 2 / s.

[0046] An example of the operation of an FCC unit is as follows: the gas mixture and the solid particles to be separated exit the central reactor 22 and enter a separation chamber of the gas / solid separator 19, where the solid particles are separated and directed to the stripping chamber 15 by the solid particle inlet 23 (for example, by means of one or more return legs or "diplegs") and the gas mixture is directed to the pre-stripping chamber of the gas / solid separator 19. In the pre-stripping chamber, the gas mixture is drawn to the second separation stage 20 by an upward stripping gas distributed by the stripping chamber 15. The gas stream entering the second separation stage 20 is separated from residual solid particles, which are directed to the stripping chamber 15 by means of the return legs. The gas stream is then discharged to the gaseous effluent outlet 21.Finally, the solid particles are stripped of residual gas in the stripping chamber 15 and are evacuated through the catalyst outlet 13 to a regenerator (not shown).

[0047] A stripping device according to the present invention adapted to a CFP unit is shown in Figure 3. The stripping device comprises a separation chamber 12 containing (from bottom to top) a catalyst outlet 13 for the extraction of stripped catalyst 14, a stripping chamber 15 containing spent catalyst 16, a solid particle inlet 23 and a gaseous effluent outlet 21.

[0048] The stripping chamber 15 includes one or more distributors 17 for distributing the stripping gas (e.g., water vapor). Preferably, at least one distributor is located on the lower part of the stripping chamber 15. Preferably, the distributors 17 are all immersed in the bed of solid particles (i.e., spent catalyst). According to one or more embodiments, the stripping chamber 15 includes flow uniformity elements 18 for the solid particles and gas. Preferably, the flow uniformity elements 18 are located, at least partially, at a height greater than that of at least one distributor 17. The flow uniformity elements 18, in particular, promote contact between said solid particles and the stripping gas. Preferably, the flow uniformity elements 18 are all immersed in the bed of solid particles (i.e., spent catalyst).

[0049] Although gas / solid separation devices are typically disposed in or out of CFP reactors, it is understood that a stripping device of a CFP unit may optionally include an internal gas / solid separator (not shown) and / or a separation stage (including, for example, one or more cyclones) disposed in the separation chamber 12 (for example, above the stripping chamber 15), such as, for example, described in Figure 2, to improve gas / solid separation in the separation chamber 12.

[0050] In one or more embodiments, the feed of the CFP unit (i.e., the feed of the CFP reactor not shown) comprises or is made up of biomass, preferably lignocellulosic biomass or one or more lignocellulosic biomass constituents selected from the group consisting of cellulose, hemicellulose, and lignin. The lignocellulosic biomass may include wood, agricultural waste, or plant waste. Other, non-limiting examples of lignocellulosic biomass include agricultural residues (straw, corn stalks, etc.), forestry residues (first-thinning products), forestry products, dedicated crops (short-rotation coppice), food processing residues, household organic waste, waste from wood processing facilities, used construction timber, and paper, whether recycled or not.Lignocellulosic biomass can also come from by-products of the paper industry such as Kraft lignin, or black liquors from the manufacture of paper pulp.

[0051] Lignocellulosic biomass can advantageously undergo at least one pretreatment step before being introduced into the CFP unit according to the invention. Preferably, the biomass is ground and dried until a desired moisture content and particle size are achieved.

[0052] According to one or more embodiments, the operating conditions of the CFP reactor are as follows: gas surface velocity: between 3 and 35 m / s in the riser section where the feed is injected, and between 0.3 and 1.5 m / s in the turbulent fluidized bed reactor; temperature: between 500°C and 1000°C, preferably between 550°C and 800°C, preferably between 600°C and 750°C; pressure: between 0.1 and 1 MPaa; a catalyst mass ratio to feed C / B: between 3 and 50; and a mass spatial velocity hour (WHSV) between 0.01 and 10 h -1 preferably between 0.01 and 5 hours -1 and preferably between 0.1 and 3 hours -1 . WHSV is the ratio of the mass flow rate of charge to the mass of catalyst used in the turbulent fluidized bed reactor.

[0053] The catalyst for a CFP application is a solid catalyst (e.g., density, grain size, and shape chosen for use in a fluidized bed). The densities, sizes, and shapes of fluidized bed catalysts are known to those skilled in the art and are not described further. Preferably, the catalyst is a zeolite catalyst comprising, and preferably consisting of, at least one zeolite selected from ZSM-5, ferrierite, beta zeolite, Y zeolite, mordenite, ZSM-23, ZSM-57, EU-1, and ZSM-11. Preferably, the catalyst is a catalyst comprising only ZSM-5. The zeolite used in the catalyst implemented in the catalytic pyrolysis step may advantageously be doped, preferably with a metal selected from iron, gallium, zinc, and lanthanum.

[0054] According to one or more embodiments, the operating conditions of the stripping chamber 15 are as follows: temperature between 450°C and 950°C; pressure between 0.1 and 1 MPaa; surface gas velocity between 0.05 and 0.5 m / s and preferably between 0.1 and 0.4 m / s; solid flux between 15 kg / m³ 2 / s and 150 kg / m 2 / s and preferably between 30 kg / m 2 / s and 90 kg / m 2 / s.

[0055] An example of the operation of a CFP unit is as follows: the solid particles of spent catalyst are separated from the gas mixture (unconverted feed and conversion products) in the CFP reactor. The spent catalyst 16 enters the stripping chamber 15 through the solid particle inlet 23 and is stripped of residual gas by contact with stripping gas introduced into the stripping chamber 15 by the distributor(s) 17. The stripped catalyst 14 is discharged through the catalyst outlet 13 to a regenerator (not shown).

[0056] According to the invention, at least a portion of the stripping gas is sent in a pulsed manner into the stripping chamber 15 of the separation chamber 12 containing the solid particles (intermittently or non-continuously), for example by means of an electrically, pneumatically, or mechanically operated pulse distributor, or by means of an electrically, pneumatically, or mechanically operated pulse valve. For example, with reference to Figures 2 and 3, at least one pulse distributor 24 may be arranged in the stripping chamber 15 to supply the stripping chamber 15 with stripping gas; and / or at least one pulse valve 25 may be arranged to supply at least one distributor 17 arranged in the stripping chamber 15 with stripping gas.

[0057] According to one or more embodiments, the pulse frequency of the pulse distributor 24 and / or the pulse valve 25 is between 0.5 Hz and 10 Hz, preferably between 1 Hz and 9 Hz, most preferably between 3 Hz and 8 Hz.

[0058] According to one or more embodiments, the impulse distributor 24 or the distributor 17 supplied by the impulse valve 25: is disposed below the solid particle inlet 23; is preferably the closest distributor (of the distributors disposed below) to the solid particle inlet 23.

[0059] According to one or more embodiments, the solid particle inlet 23 comprises at least one return leg plunging into the stripping chamber 15; and the impulse distributor 24 or the distributor 17 supplied by the impulse valve 25, is disposed below the at least one return leg; is preferably the closest distributor (of the distributors disposed below) to the at least one return leg.

[0060] According to one or more embodiments, the impulse distributor 24 or the distributor 17 supplied by the impulse valve 25, is arranged below the flow uniformization elements 18; is preferably the closest distributor (of the distributors arranged below) to the flow uniformization elements 18; and is optionally arranged closest (or adjacent) to the flow uniformization elements 18.

[0061] According to one or more embodiments, the impulse distributor 24 or the distributor 17 supplied by the impulse valve 25 has a diameter D1 (e.g. circular, ring, star distributor, etc.) and is disposed at a distance L1 from the return leg plunging into the stripping chamber 15; and the ratio L1 on D1 is between 0.05 and 1, preferably between 0.1 and 0.8, very preferably between 0.15 and 0.7.

[0062] According to one or more embodiments, the impulse distributor 24 or the distributor 17 supplied by the impulse valve 25 has a diameter D1 (e.g. circular, ring, star distributor, etc.), and is disposed at a distance L2 from the flow uniformization elements 18; and the ratio L2 on D1 is between 0.05 and 1, preferably between 0.1 and 0.8, very preferably between 0.15 and 0.7.

[0063] According to one or more embodiments, the impulse distributor 24 or the distributor 17 supplied by the impulse valve 25 has a diameter D1 (e.g. circular, ring, star distributor, etc.), the stripping chamber 15 has a diameter D2 and the ratio D1 to D2 is between 0.1 and 0.9, preferably between 0.3 and 0.85, very preferably between 0.4 and 0.8.

[0064] According to one or more embodiments, each distributor 17 is a pulse distributor 24 or supplied by the pulse valve 25.

[0065] In one or more embodiments, at least one distributor 17 is adapted to continuously supply the stripping chamber 15. Preferably, the distributor 17 located at the bottom of the stripping chamber 15 supplies the stripping chamber 15 continuously. In one or more embodiments, a continuous distributor 17 is located as close as possible to the bottom of the stripping chamber 15, and a pulse distributor 24 or a distributor 17 supplied by the pulse valve 25 is located as close as possible to the top of the stripping chamber 15.

[0066] Examples

[0067] In a stripping chamber with an internal diameter of 8 cm and a height of 1 m, a fluidized bed of FCC catalyst is placed and circulates under ambient conditions. Gas tracing is performed to quantify the stripping efficiency. Air is injected either continuously (reference example) or intermittently (example according to the invention) at the bottom of the stripping chamber, at different pulse frequencies between 1 Hz and 7 Hz. The gas pulse is generated via a solenoid-type pulse valve. These tracings were carried out for solid fluxes of 15 and 32 kg / m³. 2 / s, representative of the solid fluxes in an FCC stripping chamber. The tracer gas, helium, is injected into the return leg of a cyclone penetrating the bed of solid particles constituting the stripping chamber. Given the significant solid particle fluxes in this return leg (60 and 128 kg / m³), 2 / s), the vast majority of the helium is carried along with the catalyst into the stripping chamber. The greater the stripping efficiency, the higher the helium concentration measured in the stripper's gas outlet will be (and the lower it will be at the bottom of the stripping chamber).

[0068] Figure 4 shows the concentration of helium [He] n measured at the top of the stripping chamber as a function of the pulse frequency of the air injected at the bottom of the stripping chamber, normalized with respect to the helium concentration at the top of the stripping chamber measured for a continuous air flow: for a zero pulse frequency (continuous air flow), the normalized concentration is therefore 1.

[0069] For all pulse frequencies tested between 1 Hz and 7 Hz, the stripping efficiency is higher than that measured for continuous air injection. The increase in stripping efficiency reaches 40% at a frequency of 7 Hz for a solids flow rate of 32 kg / m³. 2 / s.

Claims

Demands 1. A method for stripping solid particles, in which at least a portion of a stripping gas pulses into a stripping chamber (15) containing the solid particles.

2. Stripping method according to claim 1, wherein at least a portion of the stripping gas is pulsed by: at least one pulse distributor (24) disposed in the stripping chamber (15); and / or at least one pulse valve (25) adapted to supply at least one distributor (17) disposed in the stripping chamber (15).

3. Method according to claim 1 or claim 2, wherein the impulse distributor (24) is an electrical, pneumatic or mechanical impulse distributor, and / or the impulse valve (25) is an electrical, pneumatic or mechanical impulse valve.

4. A method according to any one of claims 1 to 3, wherein at least a portion of the stripping gas is pulsed at a pulse frequency between 0.5 Hz and 10 Hz, preferably between 1 Hz and 9 Hz, most preferably between 3 Hz and 8 Hz. 5 Method according to any one of claims 2 to 4, comprising supplying solid particles to the stripping chamber (15) by means of a solid particle inlet (23) disposed above the stripping chamber (15), and wherein the impulse distributor (24) or the distributor (17) supplied by the impulse valve (25) is disposed below the solid particle inlet (23); is preferably the distributor closest to the solid particle inlet (23).

6. Method according to claim 5, wherein the solid particle inlet (23) comprises at least one return leg plunging into the stripping chamber (15); and the impulse distributor (24) or distributor (17) supplied by the impulse valve (25): is disposed below the at least one return leg; is preferably the distributor closest to the at least one return leg.

7. A method according to any one of claims 2 to 6, wherein: the impulse distributor (24) or the distributor (17) supplied by the impulse valve (25) has a diameter D1 and is disposed at a distance L1 from a return leg of the solid particle inlet (23) plunging into the stripping chamber (15), and the ratio L1 to D1 is between 0.05 and 1, preferably between 0.1 and 0.8, most preferably between 0.15 and 0.7; and / or the impulse distributor (24) or the distributor (17) supplied by the impulse valve (25) has a diameter D1 and is disposed at a distance L2 from at least one flow uniformization element (18), and the ratio L2 to D1 is between 0.05 and 1, preferably between 0.1 and 0.8, most preferably between 0.15 and 0.7; and / or the impulse distributor (24) or the distributor (17) supplied by the impulse valve (25) has a diameter D1, the stripping chamber (15) has a diameter D2, and the ratio D1 to D2 is between 0.1 and 0.9, preferably between 0.3 and 0.85, most preferably between 0.4 and 0.

8.

8. Device for stripping solid particles in a stripping chamber, the device comprising: at least one impulse distributor (24) disposed in the stripping chamber (15) and adapted to supply the stripping chamber (15) with stripping gas; and / or at least one impulse valve (25) adapted to supply at least one distributor (17) disposed in the stripping chamber (15) with stripping gas.

9. Device according to claim 8, wherein the impulse distributor (24) is an electrical, pneumatic or mechanical impulse distributor, and / or the impulse valve (25) is an electrical, pneumatic or mechanical impulse valve.

10. Device according to claim 8 or claim 9, wherein the impulse distributor (24) and / or the impulse valve (25) are adapted to provide a pulse frequency between 0.5 Hz and 10 Hz, preferably between 1 Hz and 9 Hz, most preferably between 3 Hz and 8 Hz.

11. Stripping chamber comprising the device according to any one of claims 8 to 10.

12. Cracking unit comprising a stripping chamber according to claim 11.

13. Cracking unit according to claim 12, adapted for catalytic fluidized bed cracking of a hydrocarbon feedstock, preferably at least a portion of a crude oil.

14. Pyrolysis unit comprising a stripping chamber according to claim 11.

15. Pyrolysis unit according to claim 14, adapted for so-called rapid or flash catalytic pyrolysis of biomass, preferably of at least a part of a lignocellulosic biomass.

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