Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G11/14—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts
  • C10G11/18—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts according to the "fluidised-bed" technique
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/70—Spray-mixers, e.g. for mixing intersecting sheets of material
  • B01F25/72—Spray-mixers, e.g. for mixing intersecting sheets of material with nozzles
  • B01F25/721—Spray-mixers, e.g. for mixing intersecting sheets of material with nozzles for spraying a fluid on falling particles or on a liquid curtain
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
  • B01J8/1818—Feeding of the fluidising gas
  • B01J8/1827—Feeding of the fluidising gas the fluidising gas being a reactant
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
  • B01J8/1872—Details of the fluidised bed reactor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
  • B01J8/1881—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles with particles moving downwards while fluidised
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00548—Flow
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00743—Feeding or discharging of solids
  • B01J2208/00769—Details of feeding or discharging
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00796—Details of the reactor or of the particulate material
  • B01J2208/00823—Mixing elements
  • B01J2208/00831—Stationary elements
  • B01J2208/0084—Stationary elements inside the bed, e.g. baffles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00796—Details of the reactor or of the particulate material
  • B01J2208/00893—Feeding means for the reactants
  • B01J2208/00902—Nozzle-type feeding elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00796—Details of the reactor or of the particulate material
  • B01J2208/00938—Flow distribution elements

Definitions

• the invention relates to the field of refining and petrochemicals and to processes and units for the chemical transformation of petroleum products, in particular hydrocarbon cuts, by Fluidized Bed Catalytic Cracking (“Fluid Catalytic Cracking” or FCC according to Anglo-Saxon terminology) for the production of light olefins (i.e., olefins comprising between 2 and 4 carbon atoms), and more particularly ethylene and propylene, and also aromatics (e.g. BTX), and more particularly paraxylene.
• Fluidized Bed Catalytic Cracking or FCC according to Anglo-Saxon terminology
• light olefins i.e., olefins comprising between 2 and 4 carbon atoms
• ethylene and propylene ethylene and propylene
• aromatics e.g. BTX
• the invention is part of the improvement of the design of the established flow zone of fluidized bed reactors with descending gas-solid co-current ("downer” or “down flow reactor” according to the Anglo-Saxon terminology), called hereinafter downflow reactors, used for example for high severity catalytic cracking (HS-FCC).
• downflow reactors used for example for high severity catalytic cracking (HS-FCC).
• Ethylene, Propylene, Butene, Butadiene and aromatics such as Benzene, Toluene and Xylene (BTX) represent the basic products for the petrochemical industry. These products are generally obtained by catalytic reforming and/or thermal cracking (steam cracking) of hydrocarbons such as naphtha, kerosene or gas oil. These compounds are also obtained by fluidized bed catalytic cracking (FCC) of hydrocarbons, such as a Vacuum Distillate (DSV, or “vacuum gas oil” or VGO according to Anglo-Saxon terminology) and/or a residue ( under vacuum or atmospheric) distillation of hydrocarbons and/or naphtha, gas oils, complete crudes.
• FCC fluidized bed catalytic cracking
• the high severity catalytic cracking (HS-FCC) process aims to increase yields of propylene and ethylene through high temperature reaction conditions, very short contact times (e.g. ⁇ 1 s), high flow rate ratios mass C of catalyst and mass flow rate O of charge (C/O).
• the HS-FCC process uses a downflow reactor, where the catalyst and feed are set in motion under gravity with a flow which approaches that of a piston type flow.
• the downward gas-solid flow in a reactor avoids back-mixing and over-cracking of products while the use of high C/O ratios ensures the predominance of catalytic reactions.
• the high temperature favors the formation of reaction intermediates such as light olefins while a controlled and short contact time avoids secondary reactions which are responsible for the consumption of such intermediates.
• the initial mixture between catalyst and feed conditions the vaporization of the hydrocarbons and the gas-solid contact throughout the downflow reactor.
• the initial mixing is generally carried out in a fraction of a second with, for a typical HS-FCC, a flow rate of around 400 to 700 t/h of feed and 7000 to 21000 t/h of catalyst which requires efficient technology to have a mixing chamber that approximates a perfectly agitated zone.
• Patent FR 2 753 453 B1 describes a downward flow cracking reactor comprising a contact zone between the hydrocarbons and the catalyst in which the injectors are oriented so as to direct droplets of charge against the current of the downward flow of catalyst particles, at an angle relative to the horizontal equal for example to 15°, but which can be between 2° and 45°.
• a first object of the present invention is to overcome the problems of the prior art and to provide a device for catalytic cracking in a fluidized bed with a descending gas-solid co-current with homogeneous catalyst flow, i.e. , in which the solid concentration in the cross section of the reactor is substantially uniform.
• the device according to the invention makes it possible to obtain a homogeneous catalyst concentration between the central zone and the annular zone (i.e., in the proximity of the wall) of the descending gas-solid co-current reactor.
• a second object of the present invention is to provide a device for catalytic cracking in fluidized bed with downward gas-solid co-current in which the concentration of the catalyst in the central zone is higher with less accumulation near the walls in the mixing chamber, which results in better contact with the vaporized load.
• a third object of the present invention is to provide a device for catalytic cracking in a fluidized bed with a descending gas-solid co-current in which the arrangement of the injectors is optimized according to the C/O ratio. According to a first aspect, the aforementioned objects, as well as other advantages, are obtained by a device for catalytic cracking in a fluidized bed with a descending gas-solid co-current comprising, from top to bottom:
• a mixing chamber connected to the pipe and adapted to be supplied by the pipe in a downward flow, the mixing chamber comprising at least one first hydrocarbon feed injector;
• the vector of the resulting momentum calculated from the vector sum of the charge momentum and the catalyst momentum, has an angle ⁇ with respect to a horizontal plane of between 70° and 80° ;
• the ratio of the vertical component of the quantity of load movement and the catalyst movement quantity is between -0.2 and 0.1.
• the device makes it possible to homogenize the concentration of catalyst particles along the fluidized bed reactor.
• the device makes it possible to improve the contact between the catalyst and the vaporized charge.
• the device makes it possible to optimize the arrangement and orientation of the injectors according to the operating conditions envisaged.
• the mixing chamber comprises between 2 and 12 first injectors, preferably between 3 and 8 first injectors.
• the vector of the quantity of the resulting movement has an angle ⁇ with respect to a horizontal plane of between 72° and 77°; and/or the ratio of the vertical component of the vector of the momentum of the charge movement and the momentum of the catalyst is between -0.13 and 0.04.
• the first injectors are arranged countercurrent to the descending flow at an angle a of between 15° and 45° relative to the horizontal.
• at least one first injector has an orientation offset relative to the diameter of the mixing chamber at an angle 0 greater than 0° and less than or equal to 45°, and preferably between 10° and 20°.
• first injectors are arranged in one or more horizontal rows.
• the mixing chamber comprises at least a second diluent injector.
• the second injectors have an angle p relative to the horizontal of between 0° and 80°, and preferably between 10° and 45°.
• second injectors are arranged in one or more horizontal rows.
• the radial position of second injectors is in a separation space between the adjacent radial positions of two first injectors.
• the radial position of at least a second injector is arranged relative to the radial position of an adjacent first injector at an angle 5 substantially equal to half of a separation angle y between two first adjacent injectors.
• At least one second injector has an orientation offset relative to the diameter of the mixing chamber at an angle o greater than 0° and less than or equal to 45°, and preferably between 10° and 20°.
• At least part of the mixing chamber comprises a central bulky part arranged substantially along a central/vertical axis of the mixing chamber and defining an annular orifice of the mixing chamber , whereby the catalyst particles spill and/or flow into the mixing chamber.
• a process for catalytic cracking in a fluidized bed with a descending gas-solid co-current comprising the following steps:
• the ratio of the vertical component of the quantity of load movement and the quantity of movement (vertical and downward) of catalyst is between -0.2 and 0.1.
• the method comprises at least one of the following operating conditions:
• the catalyst particles comprise a matrix made of clay, silica or silica alumina, optionally binder, optionally dopant, and/or zeolite, for example from 15% to 70% by weight of zeolite relative to the weight of the catalyst, preferably a Y zeolite and/or a ZSM-5 zeolite, very preferably a ZSM-5 zeolite, optionally doped;
• the grain density of the catalyst particles is between 1000 kg/m 3 and 2000 kg/m 3 , preferably between 1250 kg/m 3 and 1750 kg/m 3 .
• - reactor outlet temperature between 520°C and 750°C and preferably less than 650°C; absolute total pressure between 0.1 MPa and 0.5 MPa; - mass ratio of the catalyst to the C/O hydrocarbon load between 5° (kg/h)/(kg/h) and 35 (kg/h)/(kg/h) and preferably between 15 (kg/h) /(kg/h) and 30 (kg/h)/(kg/h);
• Figure 1 represents a section diagram of an FCC device according to one or more embodiments of the present invention comprising injectors for the homogenization of the catalyst flow.
• Figure 2 shows a schematic and sectional view showing fluid flow in the mixing chamber of an FCC device according to one or more embodiments of the present invention.
• Figure 3 shows a schematic top view of the mixing chamber of an FCC device according to one or more embodiments of the present invention.
• Figure 4 shows 3D views of an FCC device according to one or more embodiments of the present invention.
• Figure 5 shows 3D views of a diagram A of a reference FCC device, and of a diagram B of an FCC device according to one or more embodiments of the present invention.
• Figure 6 shows 3D views of diagrams A and B of the volume fraction of the catalyst averaged over time in the reference FCC device of Figure 5, and in the FCC device according to the invention of Figure 5, respectively.
• Figure 7 shows the radial profiles A and B of the fraction of the solid and mass flow of the solid at 2.8 m below the injectors of the reference FCC device of Figure 5, and of the FCC device according to the invention of the Figure 5, respectively.
• the term “comprising” is synonymous with (means the same as) “comprising”, “include” and “contain”, and is inclusive or open and does not exclude other elements not recited. It is understood that the term “understand” includes the exclusive and closed term “consist”. Furthermore, in the present description, the terms “essentially” or “substantially” or “approximately” correspond to an approximation of ⁇ 10%, preferably ⁇ 5%, most preferably ⁇ 1%.
• the invention relates to a device and a method for fluidized bed catalytic cracking for the chemical transformation of petroleum products (FCC), used for example for high severity catalytic cracking (HS-FCC).
• FCC petroleum products
• HS-FCC high severity catalytic cracking
• An FCC unit generally treats a hydrocarbon cut (called heavy) from the vacuum distillation unit as a vacuum gas oil or a vacuum residue, or even an atmospheric residue, alone or in a mixture.
• An FCC unit can also process a hydrocarbon cut (called light) such as a gasoline cut or a diesel cut, alone or in a mixture. It is also possible to process a mixture of light and heavy hydrocarbon cuts, or even a complete crude.
• the devices and catalytic cracking processes In order to increase the yields of propylene and ethylene using high severity reaction conditions (high temperature, very short contact times, high C/O ratios between the catalyst flow rate C and the feed flow rate O), the devices and catalytic cracking processes generally use a fluidized bed reactor with a descending gas-solid co-current (“downer” or “down flow reactor” according to Anglo-Saxon terminology), hereinafter called a downward flow reactor.
• the device according to one or more embodiments of the present invention comprises from top to bottom:
• Line 1 is suitable for supplying mixing chamber 2 with solid catalyst (particles).
• Line 1 mainly transports solids, as well as a fluidization gas entrained by the descending solid.
• Pipe 1 presents a flow like a supply column (“standpipe” according to Anglo-Saxon terminology) well known to those skilled in the art.
• the mixing chamber 2 is connected to pipe 1 and is adapted to feed the downflow reactor 3 with a mixture comprising catalyst particles, a hydrocarbon feedstock and optionally a diluent.
• the downflow reactor 3 is connected to the mixing chamber 2 and is adapted to at least partially crack the hydrocarbon feed in the presence of the catalyst particles to produce an effluent comprising at least partially coked catalyst and gaseous cracking products, and optionally unconverted vaporized charge.
• the pipe 1 supplies the mixing chamber 2 with a descending flow 4 of (hot) catalyst particles, the mixing chamber 2 comprising one or more first injectors 5 of hydrocarbon feed 6.
• the first injector(s) 5 is adapted to inject diluent (eg water vapor) with the load.
• the mixing chamber 2 comprises one or more second injectors 7 of diluent 8.
• the descending flow 4 comes into contact with the hydrocarbon feed 6 atomized using the or first injectors 5 and optionally with diluent 8, introduced for example by the second injector(s) 7.
• the injection of diluent 8 makes it possible to reduce the partial pressure of the hydrocarbon feed and to reduce secondary reactions.
• the injection of diluent 8 makes it possible to improve the atomization of the hydrocarbon feedstock 6.
• the diluent 8 is chosen from the group consisting of water vapor, nitrogen , CO2, light hydrocarbons (eg C1-C5 compounds), combustion fumes.
• the diluent 8 comprises or consists of water vapor.
• the pipe 1 has a constant section geometry, such as cylindrical, square, rectangular or hexagonal, or a variable section, such as a truncated pyramid or cone, or a combination of different geometric shapes.
• the pipe 1 is cylindrical in shape and optionally of variable diameter.
• the pipe 1 is at least partially frustoconical in shape.
• the mixing chamber 2 has a constant section geometry, such as cylindrical, square, rectangular or hexagonal, or a variable section, such as a truncated pyramid or cone, or a combination of different geometric shapes.
• the mixing chamber can be equipped with central internals, such as a central bulk part described below with reference to Figure 5.
• the mixing chamber 2 is of cylindrical shape and optionally of variable diameter.
• the mixing chamber 2 is at least partially frustoconical in shape.
• the ratio of the vertical component of the vector of the quantity of movement of charge Mev and the quantity of movement of catalyst M 4 is between -0.2 and 0.1 and preferably between -0.13 and 0.04 .
• At least a first injector 5 can have an orientation (according to a projection on a horizontal plane) offset from the diameter of the mixing chamber 2 at an angle 0 (theta) greater than 0° and less than or equal to 45°, and preferably between 10° and 20°.
• first adjacent off-axis injectors 5 have respectively positive and negative angles 0, in particular to improve turbulence.
• the radial position of second injectors 7 is in a separation space between the adjacent radial positions of two first injectors 5.
• the position radial of at least a second injector 7 is arranged relative to the radial position of a first injector 5 adjacent a second injector 7 (according to a projection on a horizontal plane) at an angle 5 (delta) substantially equal to half of the separation angle y between two first adjacent injectors 5.
• the mixing chamber 2 feeds the downflow reactor 3 with a mixture of hydrocarbon feed 6, catalyst particles and optionally diluent 8.
• the hydrocarbon feed 6 and the catalyst particles give rise to to the cracking reactions which are completed in the downward flow reactor 3 of a height L (along the central/vertical axis Z) to produce a hydrocarbon effluent 9 comprising cracking products, spent catalyst and potentially part of the unreacted hydrocarbon load.
• At least part of the mixing chamber 2 comprises a central bulky part 10 ("plug" according to Anglo-Saxon terminology) arranged substantially along the central/vertical axis Z and defining an annular orifice 11 of the mixing chamber 2, through which the catalyst particles spill and/or flow into the mixing chamber 2.
• the vertical position of the first injectors 5 and/or the second injectors 7 is between the upper end and the lower end of the central bulk part 10, ie, the load 6 and optionally the diluent 8 are introduced into the annular orifice 11 of the mixing chamber 2.
• the downward flow reactor 3 has a constant section geometry, such as cylindrical, square, rectangular or hexagonal, preferably cylindrical. According to one or more embodiments, the downward flow reactor 3 is cylindrical in shape and optionally of variable diameter. According to one or more embodiments, the diameter of the downward flow reactor 3 is defined such that the superficial speed of the gas passing through it is between 2 m/s and 26 m/s, preferably between 6 m/s and 16 m/s. s.
• the catalyst is a solid catalyst (e.g. particles of density, size and grain shape chosen for use in a fluidized bed).
• the densities, sizes and shapes of the catalysts for fluidized beds are known to those skilled in the art, and will not be described further.
• the catalyst may be any type of catalytic cracking catalyst.
• the catalyst is an FCC type catalyst, containing for example what is commonly called a matrix made of clay, silica or silica alumina, optionally binder, and/or zeolite, for example example from 15% to 70% by weight of zeolite relative to the weight of the catalyst, preferably a Y zeolite and/or a ZSM-5 zeolite.
• the catalyst comprises a ZSM-5 zeolite.
• the grain density of the catalyst is between 1000 kg/m 3 and 2000 kg/m 3 .
• the grain density of the catalyst is between 1250 kg/m 3 and 1750 kg/m 3 .
• the catalyst comprises at least one binder (e.g. from 30% to 85% by weight) chosen from alumina, silica, silica-alumina, magnesia, titanium oxide, zirconia , clays and boron oxide, alone or in a mixture and preferably among silica, silica-alumina and clays, alone or in a mixture.
• binder e.g. from 30% to 85% by weight
• the hydrocarbon feed 6 is a hydrocarbon feed (so-called heavy), characterized by a start-of-boiling temperature of substantially 340°C, or even greater than 340°C, often greater than 380°C, such as a heavy hydrocarbon cut, for example from a vacuum distillation unit, such as vacuum gas oil/distillate (“vacuum gas oil” or “VGO” according to Anglo-Saxon terminology) or a vacuum residue , an atmospheric residue, a vacuum gas oil from a conversion unit, such as a coking gas oil ("Heavy Coker Gas Oil” or "HCGO” according to Anglo-Saxon terminology) or a heavy hydrocarbon cut from a bubbling bed or entrained bed hydroconversion unit (such as the H-Oil, LC-Fining, EST, VCC or Uniflex processes), a recycle of a hydrocracking stage, alone or in a mixture.
• a vacuum distillation unit such as vacuum gas oil/distillate (“vacuum gas oil” or “VGO” according to
• Light Cycle Oil or LCO according to Anglo-Saxon terminology
• Heavy Cycle Oil or HCO according to Anglo-Saxon terminology
• the process according to the present invention comprises a catalytic cracking step for the production of light olefins (and in particular ethylene and propylene), aromatics (and in particular benzene, toluene and xylenes), and gasoline (and optionally LCO, HCO and slurry), by catalytic cracking of the hydrocarbon feed 6 (fed by the first injector 5) by contact with the descending flow 4 of hot catalyst particles (fed by line 1), and optionally the diluent 8 (supplied by the second injector 7) in the mixing chamber 2 then in the downflow reactor 3.
• catalytic cracking step for the production of light olefins (and in particular ethylene and propylene), aromatics (and in particular benzene, toluene and xylenes), and gasoline (and optionally LCO, HCO and slurry), by catalytic cracking of the hydrocarbon feed 6 (fed by the first injector 5) by contact with the descending flow 4 of hot catalyst particles (fed by line
• the downward flow 4 of the catalyst particles in line 1 upstream of the mixing chamber 2 is in a dense fluidized regime and preferably with a mass flow greater than 200 kg/m 2 s, for for example preferably allowing a regime with descending bubbles.
• the term “dense fluidized bed” means a gas-solid fluidized bed operating in a homogeneous regime, in a bubbling regime or in a turbulent regime.
• the term “homogeneous fluidized bed” means a gas-solid fluidized bed whose gas speed is between the minimum fluidization speed and the minimum bubbling speed. These speeds depend on the properties of the solid catalyst (density, size, shape of the grains, etc.).
• the solid volume fraction is between a value close to 0.45 and the maximum solid volume fraction corresponding to a fixed, non-fluidized bed, generally close to 0.6.
• the term “bubbling fluidized bed” means a gas-solid fluidized bed whose gas speed is between the minimum bubbling speed and the transition speed to the turbulent regime. These speeds depend on the properties of the solid catalyst (density, size, shape of the grains, etc.). The volume fraction of solid is between a value close to 0.35 and a value close to 0.45.
• turbulent fluidized bed means a gas-solid fluidized bed whose gas speed is between the transition speed to the turbulent regime and the transport speed.
• the volume fraction of solid is between a value close to 0.25 and a value close to 0.35.
• the term “transported fluidized bed” means a gas-solid fluidized bed whose gas velocity is greater than the transport velocity.
• the solid volume fraction is less than a value close to 0.25.
• speed of transport corresponds to the speed with which essentially all the solid is carried away by the gas.
• the injectors 5 are adapted to atomize the hydrocarbon feed 6 (liquid) and penetrate the catalyst flow.
• the operating conditions of the pipe 1 and/or the downflow reactor 3 are chosen from the following conditions:
• the contact time t c is defined as the product of the solid volume fraction E S by the bed height H s (eg reactor height L), divided by the superficial gas velocity vsg, this integrating all along the height of the bed, as defined below in the mathematical formula Math 1.
• a quantity of diluent 8 (e.g. nitrogen and/or water vapor) is added to the charge to reduce the partial pressure of hydrocarbons of the charge and the diluent is introduced at a rate of one quantity representing 0% or 0.1% to 40% by weight, preferably 1% to 35% by weight and preferably between 1% and 30% by weight relative to the mass of the hydrocarbon filler 6.
• diluent 8 e.g. nitrogen and/or water vapor
• the gaseous products and the catalyst, and optionally the feed unconverted vaporized are separated in the gas/solid separator (not shown) enclosing a dense fluidized bed where the cracking reactions can continue.
• the operating conditions of the separator are chosen from the following conditions:
• the coked catalyst is sent to an optional stripper (not shown) to strip the hydrocarbons remaining adsorbed on the surface of the catalyst by means of a second diluent.
• the operating conditions of the stripper are chosen from the following conditions:
• - residence time of the catalyst in the stripper between 10 seconds and 180 seconds, preferably between 30 seconds and 120 seconds;
• the coked solid is transported into a regenerator (not shown) in which an air supply burns the coke from the catalyst to produce a hot regenerated catalyst and combustion gases , the hot regenerated catalyst being able to supply the descending flow 4 with hot catalyst particles.
• the operating conditions of the regenerator are chosen from the following conditions:
• the reference device A includes:
• a pipe 1 composed of a cylindrical section, a narrowing cone and a cylindrical section;
• frustoconical mixing chamber 2 (S1/S2 being less than 1) comprising a central bulk part 10 defining an annular orifice 11;
• the device according to the invention B comprises:
• frustoconical mixing chamber 2 (S1/S2 being less than 1) comprising a central bulk part 10 defining an annular orifice 11;
• the catalyst has a diameter dso of 73 pm and a grain density of 1418 kg/m 3 (ie, group A of the Geldart classification);
• the air flow rate of 1.85 kg/s presents a ratio between the first injectors 5 to the second injectors 7 of 70/30;
• the first injectors 5 are positioned 0.2 m above the second injectors 7;
• a central bulky part 10 is positioned in the center of the mixing chamber 2.
• Figure 6 presents the Volume Fraction of Particles, denoted FVP, for the two configurations A and B of the reference device A and the device according to the invention B, respectively, over 13 sections.
• the first two sections are respectively at the height of the first and second injectors 5 and 7, and the following sections are spaced 0.35 m apart.
• the radial distribution of the solid throughout the downward flow reactor 3 is always more homogeneous for the device according to the invention B compared to the reference device A.
• Figure 7 shows the radial profiles A and B of the volume fraction of the particles FVP, and of the Mass Flux of the Particles, denoted FM P, of the reference device A and the device according to the invention B of Figure 5, respectively.
• the radial profiles A and B are produced in a direction x (perpendicular to the central/vertical axis Z) at a height of 2.8 m below the first injectors 5. It can be noted that the device according to the invention B produces a more homogeneous radial profile B with better phase distribution.
• the coefficient of variation of the volume fraction values of the FVP particles on these radial profiles A and B is 40% for the reference device A and 15% for the device according to the invention B.
• the coefficient of variation of the mass flow values of the FMP particles for profiles A and B is 59% for the reference device A and 16% for the device according to the invention B, which indicates better dispersion of the catalyst on the section for the device according to the invention B.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Combustion & Propulsion (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• General Chemical & Material Sciences (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)

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• 2022
  • 2022-10-13 FR FR2210518A patent/FR3140778B1/fr active Active
• 2023
  • 2023-10-02 CN CN202380072250.3A patent/CN120077117A/zh active Pending
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