Process to conduct an endothermic dehydrogenation and/or aromatisation reaction in a fluidized bed reactor

Abstract

The disclosure relates to a process to perform an endothermic dehydrogenation and/or aromatization reaction of hydrocarbons, said process comprising the steps of providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles; putting the particles in a fluidized state to obtain a fluidized bed; heating the fluidized bed to a temperature ranging from 480° C. to 700° C. to conduct the reaction; and obtaining a reactor effluent containing hydrogen, unconverted hydrocarbons, and olefins and/or aromatics; wherein the particles of the bed comprise electrically conductive particles and particles of a catalytic composition, wherein at least 10 wt. % of the particles are electrically conductive particles and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at 500° C. and wherein the step of heating the fluidized bed is performed by passing an electric current of through the fluidized bed.

Claims

1. A process to perform an endothermic dehydrogenation and/or aromatization of hydrocarbons having at least two carbons to produce olefins and/or aromatics said process comprising the steps of: a) providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles; b) putting the particles of the bed in a fluidized state by passing upwardly through the said bed a vaporized fluid stream to obtain a fluidized bed; c) heating the fluidized bed to a temperature ranging from 480° C. to 700° C. to conduct the endothermic dehydrogenation and/or aromatisation reaction; and d) obtaining a reactor effluent containing hydrogen, unconverted hydrocarbons, and olefins and/or aromatics; characterized in that the particles of the bed comprise electrically conductive particles and particles of a catalytic composition, wherein at least 10 wt. % of the particles based on the total weight of the particles of the bed are electrically conductive particles and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at 500° C., wherein the catalytic composition comprises one or more metallic compounds; in that the void fraction of the bed is ranging from 0.5 to 0.8; in that the particles of the bed have an average particle size ranging from 5 to 300 μm as determined by sieving according to ASTM D4513-11; and in that the step (c) of heating the fluidized bed is performed by passing an electric current through the fluidized bed; further wherein: the process is a paraffin dehydrogenation process and the catalyst composition comprises one or more catalyst materials selected from gallium, zinc, chromium, iron, metal of the group VIII or mixtures thereof; and one or more catalytic supports; or that said process is an alkyl-aromatic dehydrogenation process and the catalyst composition comprises from 50 to 85 wt. % of Fe.sub.2O.sub.3 based on the total weight of the catalyst composition; from 3 to 25 wt. % of K.sub.2O; from 3 to 30 wt. % of CeO.sub.2; from 0.1 to 5 wt. % of CaO; from 0.1 to 5 wt. % of Na.sub.2O and from 0.1 to 150 ppm of at least one element selected from Pb, Pt, Os, Jr, Ru, Re, Pd, Ag, Au, Sn or any mixture thereof; or said process is a naphtha reforming process and the catalyst composition comprises from 0.01 to 3.0 wt. % of one or more metals of the group VIII based on the total weight of the catalyst composition; from 0.1 to 3.5 wt. % of a halide; and from 0.01 to 5.0 wt. % of one or more metals selected from groups IIIA, IVA, IB, VIB and/or VIIB; or said process is a paraffin aromatisation process and the catalyst composition comprises from 5.0 to 90.0 wt. % of one or more zeolites comprising at least one 10-membered ring channel and based on the total weight of the catalyst composition; from 0.1 to 5.0 wt. % of a halide; and from 0.05 to 10.0 wt. % of one or more catalyst materials selected from Ga, In, Zn, Cu, Re, Mo, W; or from 0.005 to 1.0 wt. % of one or more metals of the group VIII or mixtures thereof based on the total weight of the catalyst composition.

2. The process according to claim 1, characterized in that the electrically conductive particles of the bed are or comprise one or more particles selected from the group consisting of one or more metallic alloys, one or more non-metallic resistors, one or more metallic carbides, one or more transition metal nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides being doped with one or more lower-valent cations, one or more mixed sulphides being doped with one or more lower-valent cations and/or any mixture thereof.

3. The process according to claim 1, characterized in that from 50 wt. % to 100 wt. % of the electrically conductive particles of the bed based on the total weight of the electrically conductive particles of the bed are one or more particles selected from the group consisting of one or more metallic alloys, one or more non-metallic resistors, one or more metallic carbides, one or more transition metal nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides being doped with one or more lower-valent cations, one or more mixed sulphides being doped with one or more lower-valent cations, and any mixture thereof.

4. The process according to claim 1, characterized in that the electrically conductive particles of the bed are or comprise one or more non-metallic resistors selected from the group consisting of silicon carbide, molybdenum disilicide and a mixture thereof.

5. The process according to claim 1, characterized in that the electrically conductive particles of the bed are or comprise one or more mixed oxides being doped with one or more lower-valent cations that are one or more oxides having a cubic fluorite structure being at least partially substituted with one or more lower-valent cations.

6. The process according to claim 5, characterized in that said one or more lower-valent cations are selected from the group consisting of Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, and Eu.

7. The process according to claim 5, characterized in that the mixed oxides being doped with one or more lower-valent cations are selected from the group consisting of: one or more ABO.sub.3-perovskites with A and B tri-valent cations being at least partially substituted in A position with one or more lower-valent cations and comprising at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and/or a mixture thereof in B position, characterized in that said one or more lower-valent cations are selected from Ca, Sr, or Mg; one or more ABO.sub.3-perovskites with A bi-valent cation and B tetra-valent cation, being at least partially substituted with one or more lower-valent cations in the B position or with a mixture of different B elements in the B position, characterized in that said one or more lower-valent cations are selected from Mg, Sc, Y, Nd or Yb; and one or more A.sub.2B.sub.2O.sub.7-pyrochlores with A tri-valent cation and B tetra-valent cation being at least partially substituted in A position with one or more lower-valent cations and comprising at least one of Sn, Zr and Ti in B position, characterized in that said one or more lower-valent cations are selected from Ca or Mg.

8. The process according to claim 1, characterized in that the electrically conductive particles of the bed are or comprise one or more metallic alloys.

9. The process according to claim 1, characterized in that the electrically conductive particles of the bed are or comprise one or more superionic conductors selected from the group consisting of LiAlSiO.sub.4, Li.sub.10GeP.sub.2S.sub.12, Li.sub.3.6Si.sub.0.6P.sub.0.4O.sub.4, sodium superionic conductors, and sodium beta alumina.

10. The process according to claim 1, characterized in that the process is selected from a paraffin dehydrogenation process, an alkyl-aromatic dehydrogenation process, a naphtha reforming process and a paraffin aromatization process.

11. The process according to claim 1, characterized in that said process is a paraffin dehydrogenation process and in that said one or more catalytic support is one or more refractory materials.

12. The process according to claim 11, characterized in that the step c) of heating the fluidized bed to a temperature ranging from 480° C. to 700° C. to conduct the endothermic dehydrogenation and/or aromatization of hydrocarbons further comprises the sub step of recovering the particles from the reaction zone and recycling them to the heating zone.

13. The installation according to claim 12, characterized in that the installation further comprises a desulfurization reactor arranged upstream the fluidized bed reactor.

14. The installation according to claim 13, characterized in that the at least one fluidized bed reactor (18, 19, 37, 39) further comprises means (35) to transport the particles of the bed (25) from the reaction zone (29) back to the heating zone (27).

15. The installation according to claim 13, characterized in that it comprises at least two fluidized bed reactors (37, 39) connected one to each other wherein at least one reactor (37) is the heating zone (27) and at least another reactor (39) is the reaction zone (29).

16. The installation according to claim 13, characterized in that the at least one fluidized bed reactor (19) is a single one fluidized bed reactor wherein the heating zone (27) is the bottom part of the fluidized bed reactor (19) while the reaction zone (29) is the top part of the fluidised bed reactor (19).

17. The installation according to claim 13, characterized in that the at least one fluidized bed (18) comprises at least two lateral zones being an outer zone and an inner zone wherein the outer zone is surrounding the inner zone, with the outer zone being the heating zone (27) and the inner zone being the reaction zone (29).

18. The installation according to claim 12 to perform an endothermic dehydrogenation and/or aromatisation reaction in a process that is a naphtha reforming process or a paraffin aromatisation process, characterized in that the at least one fluidized bed reactor (18, 19, 37, 39) comprises a heating zone (27) and a reaction zone (29), one or more fluid nozzles (23) to provide a reaction fluid to the reaction zone (29).

19. The process according to claim 1, characterized in that, wherein the at least one fluidized bed reactor provided in step a) comprises a heating zone and a reaction zone and wherein the vaporized fluid stream provided in step b) is provided to the heating zone and comprises diluent gases, the step c) of heating the fluidized bed to a temperature ranging from 480° C. to 700° C. to conduct the endothermic dehydrogenation and/or aromatization of hydrocarbons comprises the following sub steps: heating the fluidized bed to a temperature ranging from 480° C. to 700° C. by passing an electric current at a voltage of at most 100 V through the heating zone of the at least one fluidized bed, transporting the heated particles from the heating zone to the reaction zone, in the reaction zone, putting the heated particles in a fluidized state by passing upwardly through the said bed of the reaction zone a fluid stream comprising one or more hydrocarbons and optional diluent gases to obtain a fluidized bed and to conduct the endothermic dehydrogenation and/or aromatization of hydrocarbons.

20. An installation for a process to perform an endothermic dehydrogenation and/or aromatisation reaction, according to claim 1, said installation comprising a vaporizer and at least one fluidized bed reactor (18, 19, 37, 39) arranged downstream the vaporizer, wherein the at least one fluidized bed reactor comprises: at least two electrodes (13); a reactor vessel (3); one or more fluid nozzles (21, 23) for the introduction of a fluidizing gas and/or of a reaction fluid within at least one fluidized bed reactor (18, 19, 37, 39); and a bed (25) comprising particles; the installation is characterized in that the particles of the bed (25) comprise electrically conductive particles and particles of a catalytic composition, wherein at least 10 wt. % of the particles based on the total weight of the particles of the bed (25) are electrically conductive particles and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at 500° C.; wherein the void fraction of the bed is ranging from 0.5 to 0.8, wherein, the particles of the bed have an average particle size ranging from 5 to 300 μm as determined by sieving according to ASTM D4513-11; wherein the catalytic composition comprises one or more metallic compounds; further wherein the process is a paraffin dehydrogenation process and the catalyst composition comprises one or more catalyst materials selected from the group consisting of gallium, zinc, chromium, iron, metal of the group VIII or mixtures thereof; and one or more catalytic supports; or that said process is an alkyl-aromatic dehydrogenation process and the catalyst composition comprises from 50 to 85 wt. % of Fe.sub.2O.sub.3 based on the total weight of the catalyst composition; from 3 to 25 wt. % of K.sub.2O; from 3 to 30 wt. % of CeO.sub.2; from 0.1 to 5 wt. % of CaO; from 0.1 to 5 wt. % of Na.sub.2O and from 0.1 to 150 ppm of at least one element selected from Pb, Pt, Os, Jr, Ru, Re, Pd, Ag, Au, Sn or any mixture thereof; or said process is a naphtha reforming process and the catalyst composition comprises from 0.01 to 3.0 wt. % of one or more metals of the group VIII based on the total weight of the catalyst composition; from 0.1 to 3.5 wt. % of a halide; and from 0.01 to 5.0 wt. % of one or more metals selected from groups IIIA, IVA, IB, VIB and/or VIIB; or said process is a paraffin aromatisation process and the catalyst composition comprises from 5.0 to 90.0 wt. % of one or more zeolites comprising at least one 10-membered ring channel and based on the total weight of the catalyst composition; from 0.1 to 5.0 wt. % of a halide; and from 0.05 to 10.0 wt. % of one or more catalyst materials selected from the group consisting of Ga, In, Zn, Cu, Re, Mo, and W; or from 0.005 to 1.0 wt. % of one or more metals of the group VIII or mixtures thereof based on the total weight of the catalyst composition.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 illustrates an installation according to the prior art.

(2) FIG. 2 illustrates an installation according to the disclosure with one reactor wherein the heating zone and reaction zone are the same.

(3) FIG. 3 illustrates an installation according to the disclosure with one reactor wherein the heating zone and reaction zone are arranged one above the other.

(4) FIG. 4 illustrates an installation according to the disclosure with one reactor wherein the heating zone and reaction zone are arranged one lateral to the other.

(5) FIG. 5 illustrates an installation according to the disclosure with two reactors.

DETAILED DESCRIPTION

(6) For the disclosure, the following definitions are given:

(7) The terms “comprising”, “comprises” and “comprised of” as used herein are synonymous with “including”, “includes” or “containing”, “contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. The terms “comprising”, “comprises” and “comprised of” also include the term “consisting of”.

(8) The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g., 1 to 5 can include 1, 2, 3, 4, 5 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of endpoints also includes the recited endpoint values themselves (e.g., from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

(9) Zeolite codes (e.g., CHA . . . ) are defined according to the “Atlas of Zeolite Framework Types”, 6.sup.th revised edition, 2007, Elsevier, to which the present application also refers.

(10) The present disclosure provides for a process to perform a dehydrogenation and/or aromatisation of hydrocarbons having at least two carbons to produce olefins and/or aromatics, said process comprising the steps of: a) providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles; b) putting the particles of the bed in a fluidized state by passing upwardly through the said bed a fluid stream to obtain a fluidized bed; c) heating the fluidized bed to a temperature ranging from 480° C. to 700° C. to conduct the endothermic dehydrogenation and/or aromatisation reaction; and d) obtaining a reactor effluent containing hydrogen, unconverted hydrocarbons, and olefins and/or aromatics;
the process is remarkable in that the particles of the bed comprise electrically conductive particles and particles of a catalytic composition, wherein at least 10 wt. % of the particles based on the total weight of the particles of the bed are electrically conductive particles and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at 500° C. wherein the catalytic composition comprises one or more metallic compounds and in that the step (c) of heating the fluidized bed is performed by passing an electric current through the fluidized bed.

(11) In a preferred embodiment, the at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles is devoid of packing.

(12) With preference, the catalytic composition comprises: one or more catalyst materials selected from gallium, zinc, chromium, iron, metal of the group VIII or mixtures thereof, and one or more catalytic supports; or from 50 to 85 wt. % of Fe.sub.2O.sub.3 based on the total weight of the catalyst composition; from 3 to 25 wt. % of K.sub.2O; from 3 to 30 wt. % of CeO.sub.2; from 0.1 to 5 wt. % of CaO; from 0.1 to 5 wt. % of Na.sub.2O and from 0.1 to 150 ppm of at least one element selected from Pb, Pt, Os, Ir, Ru, Re, Pd, Ag, Au, Sn or any mixture thereof; or from 0.01 to 3.0 wt. % of one or more metals of the group VIII based on the total weight of the catalyst composition, from 0.1 to 3.5 wt. % of a halide; and from 0.01 to 5.0 wt. % of one or more metals selected from groups IIIA, IVA, IB, VIB and/or VIIB; or from 5.0 to 90.0 wt. % of one or more zeolites comprising at least one 10-membered ring channel and based on the total weight of the catalyst composition, from 0.1 to 5.0 wt. % of a halide; and from 0.05 to 10.0 wt. % of one or more catalyst materials selected from Ga, In, Zn, Cu, Re, Mo, W; or from 0.005 to 1.0 wt. % of one or more metals of the group VIII or mixtures thereof based on the total weight of the catalyst composition.

(13) For example, the step of heating the fluidized bed is performed by passing an electric current at a voltage of at most 300 V through the fluidized bed, preferably at most 200 V, more preferably at most 150 V, even more preferably at most 120 V, most preferably at most 100 V, even most preferably at most 90 V.

(14) The solid particulate material in the fluidized bed reactor is typically supported by a porous plate, a perforated plate, a plate with nozzles or chimneys, known as a distributor. The fluid is then forced through the distributor up and travelling through the voids between the solid particulate material. At lower fluid velocities, the solids remain settled as the fluid passes through the voids in the material, known as a packed bed reactor. As the fluid velocity is increased, the particulate solids will reach a stage where the force of the fluid on the solids is enough to counterbalance the weight of the solid particulate material. This stage is known as incipient fluidization and occurs at this minimum fluidization velocity. Once this minimum velocity is surpassed, the contents of the reactor bed begin to expand and become fluidized.

(15) Depending on the operating conditions and properties of the solid phase various flow regimes can be observed in such reactors. The minimum fluidization velocity needed to achieve bed expansion depends upon the size, shape, porosity and density of the particles and the density and viscosity of the upflowing fluid. (P. R. Gunjal, V. V. Ranade, in Industrial Catalytic Processes for Fine and Specialty Chemicals, 2016).

(16) Four different categories of fluidization based on the mean particle have been differentiated by Geldart that determine the fluidization regimes: type A, aeratable fluidization (medium size, medium density particles which are easier to fluidize; Particles of typically 30-100 μm, density˜1500 kg/m.sup.3); type B, sand-like fluidization (heavier particles which are difficult to fluidize; Particles of typically 100-800 μm, density between 1500 and 4000 kg/m.sup.3); type C, cohesive fluidization (typical powder-like solid particle fluidization; Fine-size particles (˜20 μm) with dominance of intraparticle or cohesive forces); and type D, spoutable fluidization (large density and larger particle˜1-4 mm, dense and spoutable).

(17) Fluidization may be broadly classified into two regimes (Fluid Bed Technology in Materials Processing, 1999 by CRC Press): homogeneous fluidization and heterogeneous fluidization. In homogeneous or particulate fluidization, particles are fluidized uniformly without any distinct voids. In heterogeneous or bubbling fluidization, gas bubbles devoid of solids are distinctly observable. These voids behave like bubbles in gas-liquid flows and exchange gas with the surrounding homogeneous medium with a change in size and shape while rising in the medium. In particulate fluidization, the bed expands smoothly with substantial particle movement and the bed surface is well defined. Particulate fluidization is observed only for Geldart-A type particles. A bubbling fluidization regime is observed at much higher velocities than homogeneous fluidization, in which distinguishable gas bubbles grow from the distributor, may coalesce with other bubbles and eventually burst at the surface of the bed. These bubbles intensify the mixing of solids and gases and bubble sizes tend to increase further with a rise in fluidization velocity. A slugging regime is observed when the bubble diameter increases up to the reactor diameter. In a turbulent regime, bubbles grow and start breaking up with the expansion of the bed. Under these conditions, the top surface of the bed is no longer distinguishable. In fast fluidization or pneumatic fluidization, particles are transported out of the bed and need to be recycled back into the reactor. No distinct bed surface is observed.

(18) Fluidized bed reactors have the following advantages:

(19) Uniform Particle Mixing: Due to the intrinsic fluid-like behavior of the solid particulate material, fluidized beds do not experience poor mixing as in packed beds. The elimination of radial and axial concentration gradients also allows for better fluid-solid contact, which is essential for reaction efficiency and quality.

(20) Uniform Temperature Gradients: Many chemical reactions require the addition or removal of heat. Local hot or cold spots within the reaction bed are avoided in a fluidized situation.

(21) Ability to Operate Reactor Continuously: The fluidized bed nature of these reactors allows for the ability to continuously withdraw the product(s) and introduce new reactants into the reaction vessel. On top of continuous operation of the chemical reactions, the fluidized bed allows also to continuously or at a given frequency withdraw solid material or add continuously or at a given frequency new fresh solid material thanks to the flowable solid particulate material.

(22) Heat can be produced by passing an electrical current through a conducting material that has sufficiently high resistivity (the resistor) to transform electricity into heat. Electrical resistivity (also called specific electrical resistance or volume resistivity, is an intrinsic property independent of shape and size) and its inverse, electrical conductivity, is a fundamental property of a material that quantifies how strongly it resists or conducts electric current (SI unit of electrical resistivity is the ohm-meter (Ω.Math.m) and for conductivity Siemens per meter (S/m)).

(23) When electricity is passed through a fixed bed of electrically conducting particulate solids, having a sufficient resistivity, the bed offers resistance to the flow of current; this resistance depends on many parameters, including the nature of the solid, the nature of the linkages among the particles within the bed, the bed voidage, the bed height, the electrode geometry, etc. If the same fixed bed is fluidized by passing gas, the resistance of the bed increases; the resistance offered by the conducting particles generates heat within the bed and can maintain the bed in isothermal conditions (termed an electrothermal fluidized bed or electrofluid reactor). In many high-temperature reactions, electrofluid reactors offer in situ heating during the reaction and are particularly useful for operating endothermic reactions and hence save energy because no external heating or transfer of heat is required.

(24) It is a prerequisite that at least part of the solid particulate material is electrically conducting but non-conducting solid particulates can be mixed and still result in enough heat generation. Such non-conducting or very high resistivity solids can play a catalytic role in the chemical conversion. The characteristics of the bed material determine the resistance of an electrothermal fluidized bed furnace; as this is a charge resistor type of heat generation, the specific resistivity of the particles affects the bed resistance. The size, shape, composition, and size distribution of the particles also influence the magnitude of the bed resistance. Also, when the bed is fluidized, the voids generated between the particles increases the bed resistance. The total resistance of the bed is the sum of two components, e.g. the electrode contact-resistance (i.e., the resistance between the electrode and the bed) and the bed resistance. A large contact-resistance will cause extensive local heating in the vicinity of the electrode while the rest of the bed stays rather cool.

(25) The following factors determine the contact-resistance: current density, fluidization velocity, type of bed material, electrode size and the type of material used for the electrodes. The electrode compositions can be advantageously metallic like iron, cast iron or other steel alloys, copper or a copper-based alloy, nickel or a nickel-based alloy or refractory like metal, intermetallics or an alloy of Zr, Hf, V, Nb, Ta, Cr, Mo, W or ceramic-like carbides, nitrides or carbon-based like graphite. The area of contact between the bed material and the electrodes can be adjusted, depending on the electrode submergence and the amount of particulate material in the fluidized bed. Hence, the electrical resistance and the power level can be manipulated by adjusting these variables. Advantageously, to prevent overheating of the electrodes compared to the fluidised bed, the resistivity of the electrode should be lower (and hence the joule heating) than of the particulate material of the fluidized bed. In a preferred embodiment, the electrodes can be cooled by passing a colder fluid inside or outside the electrodes. Such fluids can be any liquid that vaporises upon a heating, gas stream or can be a part of the colder feedstock that first cools the electrode before entering the fluidised bed.

(26) Bed resistance can be predicted by the ohmic law. The mechanism of current transfer in fluidized beds is believed to occur through current flow along continuous chains of conducting particles at low operating voltages. At high voltages, a current transfer occurs through a combination of chains of conducting particles and arcing between the electrode and the bed as well as particle-to-particle arcings that might ionize the gas, thereby bringing down the bed resistance. Arcing inside the bed, in principle, is not desirable as it would lower the electrical and thermal efficiency. The gas velocity impacts strongly the bed resistance, a sharp increase in resistance from the settled bed onward when the gas flow rate is increased; a maximum occurred close to the incipient fluidization velocity, followed by a decrease at higher velocities. At gas flow rates sufficient to initiate slugging, the resistance again increased. Particle size and shape impact resistance as they influence the contacts points between particles. In general, the bed resistivity increases 2 to 5 times from a settled bed (e.g. 20 Ohm.Math.cm for graphite) to the incipient fluidisation (60 Ohm.Math.cm for graphite) and 10 to 40 times from a settled bed to twice (300 Ohm.Math.cm for graphite) the incipient fluidisation velocity. Non or less-conducting particles can be added to conducting particles. If the conducting solid fraction is small, the resistivity of the bed would increase due to the breaking of the linkages in the chain of conducting solids between the electrodes. If the non-conducting solid fraction is finer in size, it would fill up the interstitial gaps or voidage of the larger conducting solids and hence increase the resistance of the bed.

(27) In general, for a desired high heating power, a high current at a low voltage is preferred. The power source can be either AC or DC. Voltages applied in an electrothermal fluidized bed are typically below 100 V to reach enough heating power. The electrothermal fluidized bed can be controlled in the following three ways:

(28) 1. Adjusting the gas flow: Because the conductivity of the bed depends on the extent of voidage or gas bubbles inside the bed, any variation in the gas flow rate would change the power level; hence the temperature can be controlled by adjusting the fluidizing gas flow rate. The flow rate required for optimum performance corresponds to a velocity which equals or slightly exceeds the minimum fluidization velocity.

(29) 2. Adjusting the electrode submergence: The power level can also be controlled by varying the electrode immersion level inside the bed because the conductivity of the bed is dependent on the area of contact between the conducting particles and the electrode: the surface area of the electrode available for current flow increases with electrode submergence, leading to a reduction in overall resistance.

(30) 3. Adjusting the applied voltage: although changing the power level by using the first two methods is often more affordable or economical than increasing the applied voltage, however in electrothermal fluidized beds three variables are available to control the produced heating power.

(31) The wall of the reactor is generally made of graphite, ceramics (like SiC), high-melting metals or alloys as it is versatile and compatible with many high-temperature reactions of industrial interest. The atmosphere for the reaction is often restricted to the neutral or the reducing type as an oxidising atmosphere can combust carbon materials or create a non-conducting metal oxide layer on top of metals or alloys. The wall and/or the distribution plate itself can act as an electrode for the reactor. The fluidized solids can be graphite, carbon, or any other high-melting-point, electrically conducting particles. The other electrodes, which is usually immersed in the bed, can also be graphite or a high-melting-point metal, intermetallics or alloys.

(32) It may be advantaged to generate the required reaction heat by heating the conductive particles and/or catalyst particles in a separate zone of the reactor where substantially no hydrocarbons are present, but only diluent gases. The benefit is that the appropriate conditions of fluidization to generate heat by passing an electrical current through a bed of conductive particles can be optimized whereas the optimal reaction conditions during hydrocarbon transformation can be selected for the other zone of the reactor. Such conditions of optimal void fraction and linear velocity might be different for heating purposes and chemical transformation purposes.

(33) In an embodiment of the present disclosure, the installation comprises two zones arranged in series, namely a first zone being a heating zone and a second zone being a reaction zone, where the conductive particles and catalyst particles are continuously moved or transported from the first zone to the second zone and vice versa. The first and second zones can be different parts of a fluidized bed reactor or can be located in separate fluidized bed reactors connected to each other.

(34) In the said embodiment, the process to perform a dehydrogenation and/or aromatisation of hydrocarbons comprises the steps of: a) providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles; b) putting the particles of the bed in a fluidized state by passing upwardly through the said bed a fluid stream to obtain a fluidized bed; c) heating the fluidized bed to a temperature ranging from 480° C. to 700° C. to conduct the endothermic dehydrogenation and/or aromatisation reaction; and d) obtaining a reactor effluent containing hydrogen, unconverted hydrocarbons, and olefins and/or aromatics;
wherein the particles of the bed comprise electrically conductive particles and particles of a catalytic composition,
wherein at least 10 wt. % of the particles based on the total weight of the particles of the bed are electrically conductive particles and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at 500° C.
wherein the catalytic composition comprises one or more metallic compounds
wherein the at least one fluidized bed reactor provided in step (a) comprises a heating zone and a reaction zone and wherein the fluid stream provided in step (b) is provided to the heating zone and comprises diluent gases and the step (c) of heating the fluidized bed to a temperature ranging from 480° C. to 700° C. to conduct the endothermic dehydrogenation and/or aromatisation reaction comprises the following sub-steps: heating the fluidized bed to a temperature ranging from 480° C. to 700° C. by passing an electric current at a voltage of at most 100 V through the heating zone of the at least one fluidized bed; transporting the heated particles from the heating zone to the reaction zone; in the reaction zone, putting the heated particles in a fluidized state by passing upwardly through the said bed of the reaction zone a fluid stream comprising one or more hydrocarbons and optional diluent gases to obtain a fluidized bed and to conduct the endothermic dehydrogenation and/or aromatisation reaction; optionally, recovering the particles from the reaction zone and recycling them to the heating zone.

(35) For example, the diluent gases can be one or more selected from steam, hydrogen, carbon dioxide, methane, ethane, argon, helium, and nitrogen.

(36) For example, the at least one fluidized bed reactor is at least two fluidized bed reactors connected one to each other, wherein at least one of said at least two fluidized bed reactors is the reaction zone. With preference, the at least one fluidized bed reactor being the heating zone comprises gravitational or pneumatic transport means to transport the particles from the heating zone to the reaction zone and/or the installation comprises means arranged to inject one or more hydrocarbons to the at least one fluidized bed reactor being the reaction zone. The installation is devoid of means to inject one or more hydrocarbons to the at least one fluidized bed reactor being the heating zone. For example, the at least one fluidized bed reactor is a single fluidized bed reactor wherein the heating zone is the bottom part of the fluidized bed reactor while the reaction zone is the top part of the fluidised bed reactor. With preference, the installation comprises means to inject one or more hydrocarbons between the two zones.

(37) Step (c) provides that the dehydrogenation and/or aromatisation of hydrocarbons is performed on one or more hydrocarbons which implies that one or more hydrocarbons are provided. It is understood that the one or more hydrocarbons are provided to the reaction zone and that when the heating zone is separated from the reaction zone, then, with preference, no hydrocarbons are provided to the heating zone. It is understood that in addition to the reaction fluid provided to the reaction zone, steam can be provided to the reaction zone. When the heating zone and the reaction zone are mixed (i.e. the same zone); the fluid stream provided in step (b) comprises one or more hydrocarbons.

(38) It is a specific embodiment of the present disclosure that the distance between the heat sources, being the hot particulate material and the feedstock is significantly reduced because of the small size of the particulates and the mixing of the particulates in the vaporous fluidising stream, compared to multitubular catalytic reactors having typically 5 to 25 cm internal diameter or multitubular interheaters or shell-and-tube heat exchanger requiring large temperature gradients to concur the large distance that heat has to travel.

(39) In a preferred embodiment, the volumetric heat generation rate is greater than 0.1 MW/m.sup.3 of fluidized bed, more preferably greater than 1 MW/m.sup.3, in particular, greater than 3 MW/m.sup.3.

(40) The Bed Comprising Particles

(41) According to the disclosure, the particles of the bed comprises electrically conductive particles and catalytic particles. For example, the catalytic particles are electrically conductive. For example, the electrically conductive particles are a mixture of catalytic particles and non-catalytic particles.

(42) To achieve the required temperature necessary to carry out the dehydrogenation and/or aromatisation reaction, at least 10 wt. % of the particles based on the total weight of the particles of the bed are electrically conductive and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at 500° C.

(43) For example, the electrically conductive particles have a resistivity ranging from 0.005 to 400 Ohm.Math.cm at 500° C., preferably ranging from 0.01 to 300 Ohm.Math.cm at 500° C.; more preferably ranging from 0.05 to 150 Ohm.Math.cm at 500° C. and most preferably ranging from 0.1 to 100 Ohm.Math.cm at 500° C.

(44) For example, the electrically conductive particles have a resistivity of at least 0.005 Ohm.Math.cm at 500° C.; preferably of at least 0.01 Ohm.Math.cm at 500° C., more preferably of at least 0.05 Ohm.Math.cm at 500° C.; even more preferably of at least 0.1 Ohm.Math.cm at 500° C., and most preferably of at least 0.5 Ohm.Math.cm at 500° C.

(45) For example, the electrically conductive particles have a resistivity of at most 400 Ohm.Math.cm at 500° C.; preferably of at most 300 Ohm.Math.cm at 500° C., more preferably of at most 200 Ohm.Math.cm at 500° C.; even more preferably of at most 150 Ohm.Math.cm at 500° C., and most preferably of at most 100 Ohm.Math.cm at 500° C.

(46) For example, the particles of the bed have an average particle size ranging from 5 to 300 μm as determined by sieving according to ASTM D4513-11, preferably ranging from 10 to 200 μm and more preferably ranging from 20 to 200 μm or from 30 to 150 μm.

(47) For example, the electrically conductive particles of the bed have an average particle size ranging from 5 to 300 μm as determined by sieving according to ASTM D4513-11, preferably ranging from 10 to 200 μm and more preferably ranging from 20 to 200 μm or from 30 to 150 μm.

(48) For example, the particles of a catalytic composition have an average particle size ranging from 5 to 300 μm as determined by sieving according to ASTM D4513-11, preferably ranging from 10 to 200 μm and more preferably ranging from 20 to 200 μm or from 30 to 150 μm.

(49) The electrical resistance is measured by a four-probe DC method using an ohmmeter. A densified power sample is shaped in a cylindrical pellet that is placed between the probe electrodes. Resistivity is determined from the measured resistance value, R, by applying the known expression ρ=R×A/L, where L is the distance between the probe electrodes typically a few millimetres and A the electrode area.

(50) The solid particulate material can exhibit electronic, ionic or mixed electronic-ionic conductivity. The ionic bonding of many refractory compounds allows for ionic diffusion and correspondingly, under the influence of an electric field and appropriate temperature conditions, ionic conduction.

(51) The electrical conductivity, σ, the proportionality constant between the current density j and the electric field E, is given by
σ=j/E=Σc.sub.i×Z.sub.iq×μ.sub.i
where c.sub.i is the carrier density (number/cm.sup.3), μ.sub.i the mobility (cm.sup.2/Vs), and Z.sup.iq the charge (q=1.6×0.sup.−19 C) of the ith charge carrier. The many orders of magnitude differences in σ between metals, semiconductors and insulators generally result from differences in c rather than μ. On the other hand, the higher conductivities of electronic versus ionic conductors are generally due to the much higher mobilities of electronic versus ionic species.

(52) The most common materials that can be used for resistive heating can be subdivided into nine groups: (1) Metallic alloys for temperatures up to 1200-1400° C., (2) non-metallic resistors like silicon carbide (SiC), molybdenum disilicide (MoSi.sub.2), nickel silicide (NiSi), sodium silicide (Na.sub.2Si), magnesium silicide (Mg.sub.2Si), platinum silicide (PtSi), titanium silicide (TiSi.sub.2) and tungsten silicide (WSi.sub.2) up to 1600-1900° C., (3) several mixed oxides and/or mixed sulphides being doped with one or more lower-valent cations with variable temperature optima, (4) carbons like graphite up to 2000° C., (5) metallic carbides, (6) transition metal nitrides, (7) metallic phosphides, (8) superionic conductors and (9) phosphate electrolytes.

(53) A first group of metallic alloys, for temperatures up to 1150-1250° C., is constituted by Ni—Cr alloys with low Fe content (0.5-2.0%), preferably alloy Ni—Cr (80% Ni, 20% Cr) and (70 Ni, 30% Cr). Increasing the content of Cr increases the material resistance to oxidation at high temperatures. A second group of metallic alloys having three components are Fe—Ni—Cr alloys, with maximum operating temperature in an oxidizing atmosphere to 1050-1150° C. but which can be conveniently used in reducing atmospheres or Fe—Cr—Al (chemical composition 15-30% Cr, 2-6% Al and Fe balance) protecting against corrosion by a surface layer of oxides of Cr and Al, in oxidizing atmospheres can be used up to 1300-1400° C. Silicon carbide as non-metallic resistor can exhibit wide ranges of resistivity that can be controlled by the way they are synthesized and the presence of impurities like aluminium, iron, oxide, nitrogen or extra carbon or silicon resulting in non-stoichiometric silicon carbide. In general silicon carbide has a high resistivity at low temperature but has good resistivity in the range of 500 to 1200° C. In an alternative embodiment, the non-metallic resistor can be devoid of silicon carbide, and/or can comprise molybdenum disilicide (MoSi.sub.2), nickel silicide (NiSi), sodium silicide (Na.sub.2Si), magnesium silicide (Mg.sub.2Si), platinum silicide (PtSi), titanium silicide (TiSi.sub.2), tungsten silicide (WSi.sub.2) or a mixture thereof.

(54) Graphite and amorphous carbon (like coke, petroleum coke, and/or carbon black) have rather low resistivity values, with a negative temperature coefficient up to about 600° C. after which the resistivity starts to increase.

(55) Many mixed oxides and/or mixed sulphides being doped with one or more lower-valent cations, having in general too high resistivity at low temperature, become ionic or mixed conductors at high temperature. The following circumstances can make oxides sufficient conductors for heating purposes: ionic conduction in solids is described in terms of the creation and motion of atomic defects, notably vacancies and interstitials of which its creation and mobility is very positively dependent on temperature. Such mixed oxides are ionic conductors, namely being doped with one or more lower-valent cations. Three mechanisms for ionic defect formation in oxides are known: (1) Thermally induced intrinsic ionic disorder (such as Schottky and Frenkel defect pairs resulting in non-stoichiometry), (2). Redox-induced defects and (3) Impurity-induced defects. The first two categories of defects are predicted from statistical thermodynamics and the latter form to satisfy electroneutrality. In the latter case, high charge carrier densities can be induced by substituting lower valent cations for the host cations. Mixed oxides and/or mixed sulphides with fluorite, pyrochlore or perovskite structure are very suitable for substitution by one or more lower-valent cations.

(56) Several sublattice disordered oxides or sulphides have high ion transport ability at increasing temperature. These are superionic conductors, such as LiAlSiO.sub.4, Li.sub.10GeP.sub.2S.sub.12, Li.sub.3.6Si.sub.0.6P.sub.0.4O.sub.4, NaSICON (sodium (Na) Super Ionic CONductor) with the general formula Na.sub.1+xZr.sub.2P.sub.3-xSi.sub.xO.sub.12 with 0<x<3, for example Na.sub.3Zr.sub.2PSi.sub.2O.sub.12 (x=2), or sodium beta alumina, such as NaA.sub.11O.sub.17, Na.sub.1.6Al.sub.11O.sub.17.3, and/or Na.sub.1.76Li.sub.0.38Al.sub.10.62O.sub.17.

(57) High concentrations of ionic carriers can be induced in intrinsically insulating solids and creating high defective solids. Thus, the electrically conductive particles of the bed are or comprise one or more mixed oxides being an ionic or mixed conductor, namely being doped with one or more lower-valent cations and/or one or more mixed sulphides being an ionic or mixed conductor, namely being doped with one or more lower-valent cations. With preference, the mixed oxides are selected from one or more oxides having a cubic fluorite structure being at least partially substituted with one or more lower-valent cations, preferentially selected from Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, Eu; and/or from one or more ABO.sub.3-perovskites with A and B tri-valent cations, being at least partially substituted in A position with one or more lower-valent cations, preferentially selected from Ca, Sr, or Mg, and comprising at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and/or a mixture thereof in B position; and/or from one or more ABO.sub.3-perovskites with A bivalent cation and B tetra-valent cation, being at least partially substituted with one or more lower-valent cations, preferentially selected from Mg, Sc, Y, Nd or Yb in the B position or with a mixture of different B elements in the B position; and/or from one or more A.sub.2B.sub.2O.sub.7-pyrochlores with A trivalent cation and B tetra-valent cation being at least partially substituted in A position with one or more lower-valent cations, preferentially selected from Ca or Mg, and comprising at least one of Sn, Zr and Ti in B position.

(58) With preference, the one or more mixed sulphides are selected from one or more sulphides having a cubic fluorite structure being at least partially substituted with one or more lower-valent cations, preferentially selected from Sm, Gd, Y, Sc, Yb, Mg, Ca, La, Dy, Er, Eu; and/or from one or more ABS.sub.3 structures with A and B tri-valent cations, being at least partially substituted in A position with one or more lower-valent cations, preferentially selected from Ca, Sr, or Mg, and comprising at least one of Ni, Ga, Co, Cr, Mn, Sc, Fe and/or a mixture thereof in B position; and/or from one or more ABS.sub.3 structures with A bivalent cation and B tetra-valent cation, being at least partially substituted with one or more lower-valent cations, preferentially selected from Mg, Sc, Y, Nd or Yb in the B position or with a mixture of different B elements in the B position; and/or from one or more A.sub.2B.sub.2S.sub.7 structures with A trivalent cation and B tetra-valent cation being at least partially substituted in A position with one or more lower-valent cations, preferentially selected from Ca or Mg, and comprising at least one of Sn, Zr and Ti in B position.

(59) With preference, the one or more mixed sulphides are selected from one or more ABS.sub.3 structures with A and B tri-valent cations, being at least partially substituted in A position with one or more lower-valent cations, preferentially selected from Ca, Sr, or Mg, and comprising at least Ni, Ga, Co, Cr, Mn, Sc, Fe and/or a mixture thereof in B position; and/or from one or more ABS.sub.3 structures with A bivalent cation and B tetra-valent cation, being at least partially substituted with one or more lower-valent cations, preferentially selected from Mg, Sc, Y, Nd or Yb in the B position or with a mixture of different B elements in the B position; and/or from one or more A.sub.2B.sub.2S.sub.7 structures with A trivalent cation and B tetra-valent cation being at least partially substituted in A position with one or more lower-valent cations, preferentially selected from Ca or Mg, and comprising at least Sn, Zr and Ti in B position.

(60) With preference, the degree of substitution in the one or more mixed oxides doped with one or more lower-valent cations and having a cubic fluorite structure is between 1 and 15 atom % based on the total number of atoms present in the one or more oxides having a cubic fluorite structure, preferably between 3 and 12 atom %, more preferably between 5 and 10 atom %.

(61) With preference, the degree of substitution in the one or more mixed oxides doped with one or more lower-valent cations is between 1 and 50 atom % based on the total number of atoms present in the one or more ABO.sub.3-perovskites with A and B tri-valent cations, in the one or more ABO.sub.3-perovskites with A bivalent cation and B tetra-valent cation or in the one or more A.sub.2B.sub.2O.sub.7-pyrochlores with A trivalent cation and B tetra-valent cation respectively, preferably between 3 and 20 atom %, more preferably between 5 and 15 atom %.

(62) With preference, the degree of substitution in the one or more mixed sulphides doped with one or more lower-valent cations and having a cubic fluorite structure is between 1 and 15 atom % based on the total number of atoms present in the one or more oxides having a cubic fluorite structure, preferably between 3 and 12 atom %, more preferably between 5 and 10 atom %.

(63) With preference, the degree of substitution in the one or more mixed sulphides doped with one or more lower-valent cations is between 1 and 50 atom % based on the total number of atoms present in the one or more ABS.sub.3 structures with A and B tri-valent cations, in the one or more ABS.sub.3 structures with A bivalent cation and B tetra-valent cation or in the one or more A.sub.2B.sub.2S.sub.7 structures with A trivalent cation and B tetra-valent cation respectively, preferably between 3 and 20 atom %, more preferably between 5 and 15 atom %.

(64) Said one or more oxides having a cubic fluorite structure, said one or more ABO.sub.3-perovskites with A and B tri-valent cations, said one or more ABO.sub.3-perovskites with A bivalent cation and B tetra-valent cation or said one or more A.sub.2B.sub.2O.sub.7-pyrochlores with A trivalent cation and B tetra-valent cation being at least partially substituted with lower valent cations, said one or more sulphides having a cubic fluorite structure, said one or more ABS.sub.3 structures with A and B tri-valent cations, said one or more ABS.sub.3 structures with A bivalent cation and B tetra-valent cation, said one or more A.sub.2B.sub.2S.sub.7 structures with A trivalent cation and B tetra-valent cation being at least partially substituted with lower valent cations also means that the same element, being a high-valent cation, can be reduced in the lower-valent equivalent, for example, Ti(IV) can be reduced in Ti(III) and/or Co(III) can be reduced in Co(II) and/or Fe(III) can be reduced in Fe(II) and/or Cu(II) can be reduced in Cu(I).

(65) Phosphate electrolytes such as LiPO.sub.4 or LaPO.sub.4 can also be used as electrically conductive particles.

(66) Metallic carbides, transition metal nitrides and metallic phosphides can also be selected as electrically conductive particles. For example, metallic carbides are selected from iron carbide (Fe.sub.3C), molybdenum carbide (mixture of MoC and Mo.sub.2C). For example, said one or more transition metal nitrides are selected from zirconium nitride (ZrN), tungsten nitride (mixture of W.sub.2N, WN, and WN.sub.2), vanadium nitride (VN), tantalum nitride (TaN), and/or niobium nitride (NbN). For example, said one or more metallic phosphides are selected from copper phosphide (Cu.sub.3P), indium phosphide (InP), gallium phosphide (GaP), sodium phosphide Na.sub.3P), aluminium phosphide (AlP), zinc phosphide (Zn.sub.3P.sub.2) and/or calcium phosphide (Ca.sub.3P.sub.2).

(67) For example, the electrically conductive particles of the bed are or comprise silicon carbide. For example, at least 10 wt. % of the electrically conductive particles based on the total weight of the particles of the bed are silicon carbide particles and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at of 500° C.

(68) In the embodiment wherein the electrically conductive particles of the bed are or comprise silicon carbide, the person skilled in the art will have the advantage to conduct a step of pre-heating with a gaseous stream said fluidized bed reactor before conducting said endothermic reaction in the fluidized bed reactor. Advantageously, the gaseous stream is a stream of inert gas, i.e., nitrogen, argon, helium, methane, carbon dioxide or steam. The temperature of the gaseous stream can be at least 500° C., or at least 550° C., or at least 600° C., or at least 650° C., or at least 700° C. Advantageously, the temperature of the gaseous stream can be comprised between 500° C. and 700° C., for example between 525° C. and 675° C. Said gaseous stream of inert gas can also be used as the fluidification gas. The pre-heating of the said gaseous stream of inert gas is performed thanks to conventional means, including using electrical energy. The temperature of the gaseous stream used for the preheating of the bed doesn't need to reach the temperature reaction.

(69) Indeed, the resistivity of silicon carbide at ambient temperature is high, to ease the starting of the reaction, it may be useful to heat the fluidized bed by external means, as with preference the fluidized bed reactor is devoid of heating means. Once the bed is heated at the desired temperature, the use of a hot gaseous stream may not be necessary.

(70) However, in an embodiment, the electrically conductive particles of the bed are or comprise a mixture of silicon carbide particles and electrically conductive particles different from silicon carbide particles.

(71) The pre-heating step may be also used in the case wherein electrically conductive particles different from silicon carbide particles are present in the bed. For example, it may be used when the content of silicon carbide in the electrically conductive particles of the bed is more than 80 wt. % based on the total weight of the electrically conductive particles of the bed, for example, more than 85 wt. %, for example, more than 90 wt. %, for example, more than 95 wt. %, for example, more than 98 wt. %, for example, more than 99 wt. %. However, a pre-heating step may be used whatever is the content of silicon carbide particles in the bed.

(72) In the embodiment wherein the electrically conductive particles of the bed are or comprise a mixture of silicon carbide particles and electrically conductive particles different from silicon carbide particles, the electrically conductive particles of the bed may comprise from 10 wt. % to 99 wt. % of silicon carbide particles based on the total weight of the electrically conductive particles of the bed; preferably, from 15 wt. % to 95 wt. %, more preferably from 20 wt. % to 90 wt. %, even more preferably from 25 wt. % to 80 wt. % and most preferably from 30 wt. % to 75 wt. %.

(73) For example, the electrically conductive particles of the bed are or comprise a mixture of silicon carbide particles and electrically conductive particles different from silicon carbide particles and the electrically conductive particles of the bed comprises at least 40 wt. % of silicon carbide particles based on the total weight of the electrically conductive particles of the bed; preferably at least 50 wt. %, more preferably at least 60 wt. %, even more preferably at least 70 wt. % and most preferably at least 80 wt. %.

(74) In an embodiment, the electrically conductive particles of the bed may comprise from 10 wt. % to 90 wt. % of electrically conductive particles different from silicon carbide particles based on the total weight of the electrically conductive particles of the bed; preferably, from 15 wt. % to 95 wt. %, more preferably from 20 wt. % to 90 wt. %, even more preferably from 25 wt. % to 80 wt. % and most preferably from 30 wt. % to 75 wt. %.

(75) However, it may be interesting to keep the content of electrically conductive particles different from silicon carbide particles quite low in the mixture. Thus, in an embodiment, the electrically conductive particles of the bed comprise a mixture of silicon carbide particles and electrically conductive particles different from silicon carbide particles and electrically conductive particles of the bed comprises from 1 wt. % to 20 wt. % of electrically conductive particles different from silicon carbide based on the total weight of the electrically conductive particles of the bed; preferably, from 2 wt. % to 15 wt. %, more preferably, from 3 wt. % to 10 wt. %, and even more preferably, from 4 wt. % to 8 wt. %.

(76) For example, the electrically conductive particles of the bed are or comprise a mixture of silicon carbide particles and electrically conductive particles different from silicon carbide particles and the said electrically conductive particles different from silicon carbide particles are particles selected from graphite, carbon black, coke, petroleum coke and/or any mixture thereof. For example, the said electrically conductive particles different from silicon carbide particles are or comprise graphite.

(77) Thus, in an embodiment, the electrically conductive particles are a combination of silicon carbide particles and graphite particles. Such electrically conductive particles, upon the electrification of the fluidized bed reactor, will heat up and because of their fluidification, will contribute to the raise and/or to the maintaining of the temperature within the reactor. The Joule heating of such electrically conductive material allows accelerating the heating of the reactant and/or of the catalyst that is present within the fluidized bed reactor.

(78) When graphite is selected, it can preferably be flake graphite. It is also preferable that the graphite has an average particle size ranging from 1 to 400 μm as determined by sieving according to ASTM D4513-11, preferably from 5 to 300 μm, more preferably ranging from 10 to 200 μm and most preferably ranging from 20 to 200 μm or from 30 to 150 μm.

(79) The presence of electrically conductive particles different from silicon carbide particles in the bed allows applying the process according to the disclosure with or without the pre-heating step, preferably without the pre-heating step. Indeed, the electrically conductive particles, upon the electrification of the fluidized bed reactor, will heat up and because of their fluidification, will contribute to raising and/or maintaining the desired temperature within the reactor.

(80) The Silicon Carbide Particles

(81) For example, the silicon carbide is selected from sintered silicon carbide, nitride-bounded silicon carbide, recrystallised silicon carbide, reaction bonded silicon carbide and any mixture thereof.

(82) Sintered SiC (SSiC) is a self-bonded material containing a sintering aid (typically boron) of less than 1% by weight.

(83) Recrystallized silicon carbide (RSiC), a high purity SiC material sintered by the process of evaporation-condensation without any additives.

(84) Nitride-bonded silicon carbide (NBSC) is made by adding fine silicon powder with silicon carbide particles or eventually in the presence of a mineral additive and sintering in a nitrogen furnace. The silicon carbide is bonded by the silicon nitride phase (Si.sub.3N.sub.4) formed during nitriding.

(85) Reaction bonded silicon carbide (RBSC), also known as siliconized silicon carbide or SiSiC, is a type of silicon carbide that is manufactured by a chemical reaction between porous carbon or graphite with molten silicon. The silicon reacts with the carbon forming silicon carbide and bonds the silicon carbide particles. Any excess silicon fills the remaining pores in the body and produces a dense SiC—Si composite. Due to the left-over traces of silicon, reaction bonded silicon carbide is often referred to as siliconized silicon carbide. The process is known variously as reaction bonding, reaction sintering, self-bonding, or melt infiltration.

(86) In general, high purity SiC particles have a resistivity above 1000 Ohm.Math.cm, whereas sintered, reaction bonded and nitride-bonded can exhibit resistivities of about 100 to 1000 depending on the impurities in the SiC phase. Electrical resistivity of bulk polycrystalline SiC ceramics shows a wide range of resistivity depending on the sintering additive and heat-treatment conditions (Journal of the European Ceramic Society, Volume 35, Issue 15, December 2015, Pages 4137; Ceramics International, Volume 46, Issue 4, March 2020, Pages 5454). SiC polytypes with high purity possess high electrical resistivity (>10.sup.6 Ω.Math.cm) because of their large bandgap energies. However, the electrical resistivity of SiC is affected by doping impurities. N and P act as n-type dopants and decrease the resistivity of SiC, whereas Al, B, Ga, and Sc act as p-type dopants. SiC doped with Be, O, and V are highly insulating. N is considered the most efficient dopant for improving the electrical conductivity of SiC. For N doping of SiC (to decrease resistivity) Y.sub.2O.sub.3 and Y.sub.2O.sub.3-REM.sub.2O.sub.3 (REM=rare earth metal=Sm, Gd, Lu) have been used as sintering additives for efficient growth of conductive SiC grains containing N donors. N-doping in SiC grains was promoted by the addition of nitrides (AlN, BN, Si.sub.3N.sub.4, TiN, and ZrN) or combinations of nitrides and REM.sub.2O.sub.3 (AlN—REM.sub.2O.sub.3 (REM=rare earth metal=Sc, Nd, Eu, Gd, Ho, and Er) or TiN—Y.sub.2O.sub.3).

(87) The Catalytic Composition

(88) The choice of the catalytic composition is dependent on the reaction performed.

(89) For example, the process to perform a dehydrogenation and/or aromatisation of hydrocarbons having at least two carbons to produce olefins and/or aromatics is selected from paraffin dehydrogenation, alkyl-aromatic dehydrogenation, naphtha reforming, or paraffin aromatisation.

(90) Examples of commercially available catalysts to perform propane dehydrogenation are DeH-26 (UOP) and CATOFIN™ (Clariant).

(91) Paraffin Dehydrogenation:

(92) In one or more embodiments, the paraffin dehydrogenation catalyst may include gallium, zinc, chromium, iron and/or group VIII metal or mixtures thereof, carried on a refractory oxide support, and may optionally comprise silicon, tin, germanium, lead, indium, gallium, thallium and mixtures of alkali or alkaline earth metal compounds.

(93) In a preferred embodiment, the catalyst for the paraffin dehydrogenation reaction comprises essentially gallium (values are on dry final catalyst composition basis, balance to 100 wt. % being the carrier, like alumina with gamma, delta, theta or alpha phase): (i) from 0.1 to 25 wt. %, preferably 0.2 to 3.0 wt. %, of gallium oxide (Ga.sub.2O.sub.3); (ii) from 1 to 300 weight parts per million (wppm), preferably 50 to 300 wppm of platinum; (iii) from 0 to 4 wt. %, preferably 0.01 to 1 wt. %, of an alkali metal and/or alkaline earth metal such as potassium; (iv) from 0.1 to 4 wt. % silicon oxide;

(94) In another preferred embodiment, the catalyst for the paraffin dehydrogenation reaction is based on chromium and comprises (values are on dry final catalyst composition basis, balance to 100 wt. % being the carrier, like alumina with gamma, delta, theta or alpha phase): (i) from 1 to 30 wt. %, preferably, from 10 to 25 wt. %, of chromium oxide (Cr.sub.2O.sub.3); (ii) optionally, from 0.1 to 3.5 wt. %, most preferably, from 0.2 to 2.5 wt. %, of tin oxide (SnO); (iii) from 0.2 to 3 wt. %, most preferably, from 0.5 to 2.0 wt. %, of an alkali or alkaline earth metal oxide, for example, potassium oxide; (iv) from 0.1 to 4 wt. % silicon oxide;

(95) In another preferred embodiment, the catalyst for the paraffin dehydrogenation reaction may comprise essentially iron (values are on dry final catalyst composition basis, balance to 100 wt. % being the carrier, like alumina with gamma, delta, theta or alpha phase): (i) from 1 to 50 wt. %, preferably from 2 to 30 wt. %, of iron oxide; (ii) from 0.1 to 20 wt. %, preferably from 0.5 to 10 wt. %, of at least one alkali or alkaline earth metal oxide, more preferably, potassium oxide; (iii) from 0 to 10 wt. %, preferably, from 0.1 to 5 wt. %, of at least one rare earth oxide, preferably selected from the group comprising cerium oxide, lanthanum oxide, praseodymium oxide, and mixtures thereof;

(96) In another preferred embodiment, the catalyst for the paraffin dehydrogenation reaction may comprise essentially group VIII metals (values are on dry final catalyst composition basis, balance to 100 wt. % being the carrier, like alumina with gamma, delta, theta or alpha phase): (i) 0.01 to 5.0 wt. % Group VIII noble metal, preferably 0.05 to 3.0 wt. %, especially about 0.1 to about 2.0 wt. % selected from the group comprising platinum, palladium, iridium, rhodium, osmium, ruthenium, or mixtures thereof. Platinum is the preferred Group VIII noble metal component; (ii) The alkali or alkaline earth component (as oxide or carbonate) preferably comprise between 0.7 and 1.5 wt. %, or between 0.8 to 1.2 wt. %. They may be selected from the group comprising caesium, rubidium, potassium, sodium, and lithium or from the group comprising barium, strontium, calcium, and magnesium or mixtures of metals. Potassium is the preferred second catalytic component; (iii) 0.01 to about 10 wt. %, preferably 0.1 to 5 wt. % of metal components selected from the group comprising tin, germanium, lead, indium, gallium, thallium, and mixtures thereof. This third metal component of the present disclosure preferably is tin; (iv) A halogen component comprising from 0.01 wt. % to about 15 wt. % of the group fluorine, chlorine, bromine, or iodine, or mixtures thereof. Chlorine is the preferred halogen components.

(97) Other suitable particulate catalyst carriers are refractory oxides such as alumina (gamma, delta, theta or alpha phase), titania, zirconia, hafnia, lanthania, magnesia, ceria, preferably zirconia stabilized with magnesia, lanthania, yttria or ceria; metal-aluminates such as calcium aluminate and magnesium aluminate; and mixtures thereof. Particularly preferred particulate catalyst supports comprise alumina and/or stabilized zirconia, e.g. lanthania-stabilized alumina, ceria-zirconia-alumina, ceria-titania-alumina and ceria-magnesia-alumina materials. Preferred support materials are those common materials (mentioned above) that can be used for resistive heating at the same time and which can be subdivided into two main groups: (1) Metallic alloys and (2) non-metallic resistors like Silicon carbide (SiC) and Molybdenum disilicide (MoSi.sub.2), several mixed oxides with variable temperature optima and carbons like graphite. This latter option results in intimate contact between the catalytic active metal and the resistor particulate material.

(98) Alkyl-Aromatic Dehydrogenation:

(99) The alkyl-aromatic dehydrogenation is selected from ethylbenzene dehydrogenation, ethylnaphthalene dehydrogenation, isopropylbenzene dehydrogenation or diethylbenzene dehydrogenation

(100) Ethylbenzene, ethylnaphthalene, isopropylbenzene or diethylbenzene dehydrogenation catalysts comprise the following components, based on the total weight of the catalyst: (i) from 50 to 85 wt. % Fe.sub.2O.sub.3, preferably from 60 to 80 wt. % (ii) from 3 to 25 wt. % K.sub.2O, preferably from 4 to 20 wt. % (iii) Optionally from 0.1 to 5 wt. % MoO.sub.3, preferably from 0.5 to 4 wt. % (iv) from 3 to 30 wt. % CeO.sub.2, preferably from 5 to 25 wt. % (v) from 0.1 to 5 wt. % CaO, preferably from 0.5 to 4 wt. % (vi) from 0.1 to 5 wt. % Na.sub.2O, preferably from 0.5 to 4 wt. % (vii) Optionally from 0.1 to 5 wt. % MnO.sub.2, preferably from 0.5 to 4 wt. % (viii) from 0.1 to 150 ppm of at least one element of Pb, Pt, Os, Ir, Ru, Re, Pd, Ag, Au, Sn; (ix) Optionally from 0.1 to 40 wt. % solid carbon, like graphite, carbon black, petcoke or graphene (x) Furthermore, as an additional promoter, it contains from 0.001 to 5.0 wt. % of at least one oxide selected from the group comprising magnesium, titanium, zirconium, vanadium, niobium, chrome, tungsten, cobalt, nickel, copper, zinc, boron, aluminum, gallium, indium, silicon, germanium, tin, phosphorus, antimony, bismuth, yttrium, lanthanum, praseodymium, neodymium, dysprosium and samarium.

(101) Alkyl-aromatic dehydrogenation catalysts are generally binderless and composed of the elements listed above. Examples of commercially available catalysts are FlexiCat Gold®-2 S3 (BASF) and StyroMax® (Clariant).

(102) In a particular embodiment of the present disclosure binderless composition can also be mixed with electrically conducting materials to form particulate material, being those common materials (mentioned above) that can be used for resistive heating at the same time and which can be subdivided into two main groups: (1) Metallic alloys and (2) non-metallic resistors like Silicon carbide (SiC) and Molybdenum disilicide (MoSi.sub.2), several mixed oxides with variable temperature optima and carbons like graphite. This latter option results in intimate contact between the catalytic active metal and the resistor particulate material.

(103) Naphtha Reforming:

(104) Naphtha reforming catalysts are bifunctional catalysts comprising of a hydrogenation-dehydrogenation function and an acid function. The acid function, which is important for isomerization reactions, is generally associated with the porous refractory oxide which serves as the support for the metal component, usually a Group VIII noble metal, to which is generally attributed the hydrogenation-dehydrogenation function. The reforming catalysts comprise the following components (values are on dry final catalyst composition basis, balance to 100 wt. % being alumina (gamma, delta, theta or alpha phase): (i) 0.01 to about 3 wt. % Group VIII noble metal (palladium, platinum, iridium, rhodium, osmium, ruthenium and mixtures thereof) of the final catalytic composition, more preferably 0.1 to about 2 wt. %, especially about 0.1 to 1 wt. % platinum; (ii) 0.1 to about 3.5 wt. %, preferably about 0.5 to about 1.5 wt. % of halogen (fluoride, chloride, iodide, bromide, or mixtures thereof), particularly preferred is chloride; (iii) 0.01 to about 5 wt. %, preferably 0.1 to about 3 wt. % of one or more promoter metals selected from metals of Groups IIIA, IVA, IB, VIB, and VIIB, can be present as metal or oxide compound, especially about 0.07 to 1.5 wt. % of rhenium and/or 0.07 to 1.0 wt. % of tin; (iv) Optionally 0.1-40 wt. % solid carbon, like graphite, carbon black, petroleum coke or graphene; (v) Optionally 1 to about 30 wt. % of crystalline molecular sieves (i.e. one or more zeolites, silicoaluminophosphates), preferably 10 or 12 membered ring molecular sieves. For example, the one or more zeolites are selected from the group of AFI, AFO, AEL, FAU, LTL, MFI, MEL, FER, MTT, MWW, MOR, TON, EUO, MFS, CON, MRE, MAZ, BEA and MTW families. With preference, a zeolite from the AFI family is SAPO-5. With preference, a zeolite from the AFO family is SAPO-41. With preference, a zeolite from the AEL family is SAPO-11. With preference, zeolites from the FAU family are SAPO-37, zeolite X, zeolite Y. With preference, a zeolite from the LTL family is L-zeolite. With preference, zeolites from the MFI family are ZSM-5, silicalite-1, boralite C, TS-1 With preference, zeolites from the MEL family are ZSM-11, silicalite-2, boralite D, TS-2, SSZ-46. With preference, zeolites from the FER family are ferrierite, FU-9, ZSM-35. With preference, a zeolite from the MTT family is ZSM-23. With preference, zeolites from the MWW family are MCM-22, MCM-56, UZM-8, PSH-3, ITQ-1, MCM-49. With preference, a zeolite from the MOR family is UZM-14. With preference, zeolites from the TON family are ZSM-22, Theta-1, NU-10. With preference, zeolites from the EUO family are ZSM-50, EU-1. With preference, a zeolite from the MFS family is ZSM-54. With preference, a zeolite from the CON family is CIT-1. With preference, a zeolite from the MRE family is ZSM-48. With preference, a zeolite from the MAZ family is omega zeolite. With preference, a zeolite from the BEA family is beta zeolite. With preference, a zeolite from the MTW family is ZSM-12.

(105) The components (i), (ii) and (iii) are essential parts of naphtha reforming catalysts, the above-mentioned catalyst components can be mixed with electrically conducting materials to form the particulate catalyst material, being those common materials (mentioned above) that can be used for resistive heating at the same time and which can be subdivided into two main groups: (1) Metallic alloys and (2) non-metallic resistors like silicon carbide (SiC) and molybdenum disilicide (MoSi.sub.2), several mixed oxides with variable temperature optima and carbons like graphite. This latter option results in intimate contact between the catalytic active metal and the resistor particulate material.

(106) Paraffin Aromatisation:

(107) Paraffin aromatisation catalyst comprises a formulated zeolite support wherein the formulated zeolite support comprises one or more zeolite crystals that are joined together by a binder. The term “zeolite” generally refers to crystalline metal aluminosilicates. These zeolites exhibit a network of tetravalent and trivalent metal oxide tetrahedra in which tetravalent and trivalent atoms are crosslinked in a three-dimensional framework by sharing oxygen atoms.

(108) The paraffin aromatisation catalysts comprise the following components (values are on dry final catalyst composition basis, balance to 100 wt. % is the binder): (i) from 5.0 to 90.0 wt. % of one or more zeolites comprising at least one 10-membered ring channel and based on the total weight of the catalyst composition, preferably from 20.0 to 80.0 wt. %, more preferably from 25.0 to 75.0 wt. % and/or from 5.0 to 90.0 wt. % of one or more zeolites comprising pores with a diameter of at least 0.5 nm as determined by argon adsorption and based on the total weight of the catalyst composition. For example, large pore crystalline zeolites include without limitation one or more zeolites selected from the group of FAU, MAZ, BEA, LTL, MFI, MOZ, MTW, NES, AFI, STO, CON, STF, IFR, SFF, and MOR families. With preference, zeolites from the FAU family are zeolite X, zeolite Y, ZSM-20, USY, faujasite, REY, RE-USY, LZ-210-A, LZ-210-M, LZ-210-T. With preference, zeolites from the MAZ family are omega zeolite, ZSM-4. With preference, a zeolite from the BEA family is beta zeolite. With preference, a zeolite from the LTL family is L-zeolite. With preference, a zeolite from the MFI family is ZSM-5. With preference, a zeolite from the MOZ family is ZSM-10. With preference, a zeolite from the MTW family is ZSM-12. With preference, a zeolite from the NES family is SSZ-37. With preference, zeolites from the AFI family are ZSM-12, SSZ-24. With preference, a zeolite from the STO family is SSZ-31. With preference, a zeolite from the CON family is SSZ-33. With preference, a zeolite from the STF family is SSZ-35. With preference, zeolites from the IFR family are SSZ-42, MCM-58. With preference, a zeolite from the SFF family is SSZ-44. With preference, a zeolite from the MOR family is mordenite. Another zeolite can be SSZ-41. In an aspect, the large pore zeolite has an isotypic framework structure. In a preferred embodiment, the formulated zeolite support comprises L-zeolite:
M.sub.2/nO.Math.Y.sub.2O.sub.3.Math.xZO.sub.2.Math.yH.sub.2O wherein “Y” designates aluminium, gallium or boron or mixtures thereof, “Z” designates silicon or germanium or mixtures thereof, “M” designates at least one exchangeable cation such as barium, calcium, cerium, lithium, magnesium, potassium, sodium, strontium and zinc or mixtures thereof. The “n” in the formula represents the valence of “M”, “x” is 2 or greater; and “y” is the number of water molecules contained in the channels or interconnected voids with the zeolite. (ii) The dehydrogenation activity is provided by one or more Group VIII metals added to the formulated zeolite in the range of 0.005 to 1 wt. %, preferably in the range of 0.05 to 0.5 wt. %. The metal is a Group VIII metal, Pt, Pd, Rh, Ir, Ru, Os, or combinations thereof; preferably platinum. (iii) Or the dehydrogenation activity is provided by one or more of Ga, In, Zn, Cu, Re, Mo, and W or mixtures thereof, in the range of 0.05 to 10 wt. %, preferably 0.1 to 5 wt. %. The metal may be added to the formulated zeolite by employing any suitable methodology, like ion-exchange, incipient wetness impregnation, or pore fill impregnation. (iv) a halide in the range of 0.1 to 5 wt. %, preferably 0.2 to 3 wt. % including without limitation chloride, fluoride, bromide, iodide, or combinations thereof. (v) Optionally, a rare earth element, including without limitation lanthanides, like cerium (Ce), praseodymium (Pr), neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), Lutetium (Lu), and the like (Scandium and yttrium), or combinations thereof. The rare earth element is present at about 0.1 to about 15 wt. %, preferably from about 0.2 to about 10 wt. %. Other suitable particulate catalyst binders are refractory oxides such as clays, silica, alumina (gamma, delta, theta or alpha phase), titania, zirconia, hafnia, lanthania, magnesia, ceria, preferably zirconia stabilized with magnesia, lanthania, yttria or ceria; metal-aluminates such as calcium aluminate and magnesium aluminate; and mixtures thereof. Particularly preferred particulate catalyst binders comprise alumina and/or stabilized zirconia, e.g. lanthania-stabilized alumina, ceria-zirconia-alumina, ceria-titania-alumina and ceria-magnesia-alumina materials. Preferred binder materials are those common materials (mentioned above) that can be used for resistive heating at the same time and which can be subdivided into two main groups: (1) Metallic alloys and (2) non-metallic resistors like Silicon carbide (SiC) and Molybdenum disilicide (MoSi2), several mixed oxides with variable temperature optima and carbons like graphite. This latter option results in intimate contact between the catalytic active metal and the resistor particulate material.

(109) The particulate catalyst support particles preferably have a particle size ranging from 5 to 300 μm, more preferably ranging from 10 to 200 μm and most preferably from 30 to 150 μm. The catalytic metal or metal precursors may be dispersed over the surface of the particulate catalyst support by conventional impregnation of soluble metal compounds onto the particulate catalyst support followed by drying and calcination to convert the catalytic metal compound or compounds to their respective oxides. Alternatively, the catalytic metal or metal precursors may be dispersed over the surface of the particulate catalyst support material by adsorption, precipitation, using metals sols, by mixing or by deposition-precipitation methods employing metal salts that deposit insoluble metal compounds on the particulate catalyst support from solution upon heating or combination thereof. Further, metal salts can be ion-exchanged with counter cations on the support material. The metal precursors are reduced, if required, into the metallic state at elevated temperature by using hydrogen, carbon monoxide or hydrocarbons as reductants. This can be done before loading the catalyst in the fluidised bed reactor or in situ in the fluidised bed before feeding the feedstock or during feeding the feedstock.

(110) Dehydrogenation or Aromatisation Process:

(111) The hydrocarbon stream, to be fed to the fluidized bed reactor, is vaporized in a vaporizer, which advantageously may be heated using heat contained in the reactor effluent. Before dehydrogenation and/or aromatisation, the feed gas stream is desulfurized, to prevent poisoning of the metal catalyst. For this purpose, the feed gas stream is passed through a desulfurization reactor containing NiO, CuO or ZnO as absorbent, in which H.sub.2S is converted to NiS, CuS or ZnS and H.sub.2O at temperatures of 200 to 400° C. In the case of liquid hydrocarbon feedstock, like naphtha-like feedstock (including hexane, heptane etc) catalytic desulfurization can be applied to decompose the organic sulphur compounds into inorganic sulphur with the help of hydrogen. The feed gas stream substantially free of sulfur, subsequently is mixed with steam and/or hydrogen, and preheated to a temperature of 300 to 700° C., preferably 450 to 600° C. The steam may be added to the vaporized hydrocarbon stream by direct injection or by use of a saturator. Subsequently, the feedstock mixture is heated to a temperature of 480 to 700° C. at pressures below 10 atmospheres by passing through the electrothermal fluidised bed dehydrogenation and/or aromatisation vessel containing the dehydrogenation and/or aromatisation catalyst. The gas stream leaving the fluidised bed reactor contains olefins, single-ring aromatics, H.sub.2, unconverted steam and hydrocarbons as well as possibly inert gas constituents of the feed gas stream.

(112) Dehydrogenation or aromatisation conditions include a temperature of from about 480° to about 700° C., a pressure of from about 0.01 to 10 atmospheres absolute, and a liquid hourly space velocity (LHSV) of from about 0.1 to 100 hr.sup.−1. Generally, for normal paraffins, the lower the molecular weight, the higher the temperature required for comparable conversion. The pressure in the dehydrogenation zone is maintained as low as practicable, consistent with equipment limitations, to maximize the chemical equilibrium advantages. The dehydrogenatable or aromatisizable hydrocarbons may be admixed with a diluent material before, while, or after being passed to the dehydrogenation zone. The diluent material may be hydrogen, steam, methane, ethane, carbon dioxide, nitrogen, argon, and the like or a mixture thereof. Hydrogen and steam are the preferred diluents. When utilizing a diluent, it is utilized in a diluent-to-hydrocarbon mole ratio of about 0.1/1 to about 40/1, preferably about 0.4/1 to about 10/1. The diluent stream passed to the dehydrogenation zone will typically be recycled diluent separated from the effluent from the dehydrogenation zone in a separation zone.

(113) For example, solid materials that exhibit only sufficiently low resistivity at high temperature that they can be heating by external means before reaching the high enough temperature where resistive heating with electricity overtakes or by mixing with a sufficiently low resistivity solid at a low temperature so that the combined resulting resistivity allows to heat the fluidized bed to the desired reaction temperature.

(114) It is a preferred embodiment of the present disclosure to withdraw continuously or intermittently solid particulate material and particulate catalyst, containing carbonaceous depositions, from the electrothermal fluidised bed vessel, transporting it to a fluidised bed regeneration vessel, burning the carbonaceous depositions with a stream containing oxygen and optionally carbon dioxide and/or steam, transporting the at least partially regenerated solid particulate material and particulate catalyst back into the electrothermal fluidised bed reformer vessel.

(115) It is a preferred embodiment of the present disclosure to recover the sensible and latent heat in the reactor effluent product to preheat the dehydrogenation and/or aromatisation feedstock (both the hydrocarbons, hydrogen and/or steam).

(116) The Installation

(117) The terms “bottom” and “top” are to be understood in relation to the general orientation of the installation or the fluidized bed reactor. Thus, “bottom” will mean greater ground proximity than “top” along the vertical axis. In the different figures, the same references designate identical or similar elements.

(118) FIG. 1 illustrates a prior art fluidized bed reactor 1 comprising a reactor vessel 3, a bottom fluid nozzle 5 for the introduction of a fluidizing gas and a reaction fluid, an optional inlet 7 for the material loading, an optional outlet 9 for the material discharge and a gas outlet 11 and a bed 15. In the fluidized bed reactor 1 of FIG. 1 the heat is provided by pre-heating the reaction fluid by combustion of fossil fuels using heating means 17 arranged for example at the level of the line that provides the reactor with the fluidizing gas and the reaction fluid.

(119) The installation of the present disclosure is now described with reference to FIGS. 2 to 5. For sake of simplicity, internal devices known by the person in the art that are used in fluidized bed reactors, like bubble breakers, deflectors, particle termination devices, cyclones, ceramic wall coatings, thermocouples, etc. . . . are not shown in the figures.

(120) FIG. 2 illustrates a first installation with a fluidized bed reactor 19 where the heating and reaction zone are the same. The fluidized bed reactor 19 comprises a reactor vessel 3, a bottom fluid nozzle 21 for the introduction of a fluidizing gas and a reaction fluid, an optional inlet 7 for the material loading, an optional outlet 9 for the material discharge and a gas outlet 11. The fluidized bed reactor 1 of FIG. 19 shows two electrodes 13 submerged in bed 25.

(121) FIG. 3 illustrates an embodiment wherein at least one fluidized bed reactor 19 comprises a heating zone 27 and a reaction zone 29 with the heating zone 27 is the bottom zone and the reaction zone 29 is on top of the heating zone 27. One or more fluid nozzles 23 to provide a reaction fluid to the reaction zone from a distributor 33. As it can be seen in FIG. 3, the one or more fluid nozzles 23 can be connected to a distributor 33 to distribute the reaction fluid inside the bed 25.

(122) FIG. 4 illustrates an installation wherein at least one fluidized bed reactor 18 comprises at least two lateral zones with the outer zone being the heating zone 27 and the inner zone being the reaction zone 29. The heated particles of the bed 25 from the outer zone are transferred to the inner zone by one or more openings 41 and mixed with the reaction fluid and optionally steam. At the end of the reaction zone, the particles are separated from the reaction product and transferred to the heating zone.

(123) FIG. 5 illustrates the installation that comprises at least two fluidized bed reactors (37, 39) connected one to each other wherein at least one fluidized bed reactor is the heating zone 27 and one at least one fluidized bed reactor is the reaction zone 29.

(124) The present disclosure also provides for an installation for a process to perform an endothermic dehydrogenation and/or aromatisation reaction, according to the first aspect, said installation comprising a vaporizer and at least one fluidized bed reactor (18, 19, 37, 39) arranged downstream the vaporizer, wherein the at least one fluidized bed reactor (18, 19, 37, 39) comprises: at least two electrodes 13; a reactor vessel 3; one or more fluid nozzles (21, 23) for the introduction of a fluidizing gas and/or of a reaction fluid within at least one fluidized bed reactor (18, 19, 37, 39); and a bed 25 comprising particles;
the installation is remarkable in that the particles of bed 25 comprise electrically conductive particles and particles of a catalytic composition, wherein at least 10 wt. % of the particles based on the total weight of the particles of bed 25 are electrically conductive particles and have a resistivity ranging from 0.001 Ohm.Math.cm to 500 Ohm.Math.cm at 500° C.; wherein the catalytic composition comprises one or more metallic compounds; with preference, the installation further comprises a desulfurization reactor arranged between the vaporizer and the fluidized bed reactor (18, 19, 37, 39).

(125) For example, the electrically conductive particles of the bed are or comprise one or more particles selected from one or more metallic alloys, one or more non-metallic resistors, one or more metallic carbides, one or more transition metal nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides being doped with one or more lower-valent cations, one or more mixed sulphides being doped with one or more lower-valent cations, and any mixture thereof.

(126) In an embodiment, from 50 wt. % to 100 wt. % of the electrically conductive particles of the bed based on the total weight of the electrically conductive particles of the bed are one or more particles selected from one or more metallic alloys, one or more non-metallic resistors, one or more metallic carbides, one or more transition metal nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, one or more mixed oxides being doped with one or more lower-valent cations, one or more mixed sulphides being doped with one or more lower-valent cations, and any mixture thereof; preferably, from 60 wt. % to 100 wt. %; more preferably from 70 wt. % to 100 wt. %; even more preferably from 80 wt. % to 100 wt. % and most preferably from 90 wt. % to 100 wt. %.

(127) With preference, the catalytic composition comprises: one or more catalyst materials selected from gallium, zinc, chromium, iron, metal of the group VIII or mixtures thereof, and one or more catalytic supports; or from 50 to 85 wt. % of Fe.sub.2O.sub.3 based on the total weight of the catalyst composition; from 3 to 25 wt. % of K.sub.2O; from 3 to 30 wt. % of CeO.sub.2; from 0.1 to 5 wt. % of CaO; from 0.1 to 5 wt. % of Na.sub.2O and from 0.1 to 150 ppm of at least one element selected from Pb, Pt, Os, Ir, Ru, Re, Pd, Ag, Au, Sn or any mixture thereof; or from 0.01 to 3.0 wt. % of one or more metals of the group VIII based on the total weight of the catalyst composition, from 0.1 to 3.5 wt. % of a halide; and from 0.01 to 5.0 wt. % of one or more metals selected from groups IIIA, IVA, IB, VIB and/or VIIB; or from 5.0 to 90.0 wt. % of one or more zeolites comprising at least one 10-membered ring channel and based on the total weight of the catalyst composition, from 0.1 to 5.0 wt. % of a halide; and from 0.05 to 10.0 wt. % of one or more catalyst materials selected from Ga, In, Zn, Cu, Re, Mo, W; or from 0.005 to 1.0 wt. % of one or more metals of the group VIII or mixtures thereof based on the total weight of the catalyst composition.

(128) For example, one electrode is a submerged central electrode or two electrodes 13 are submerged within the reactor vessel 3 of at least one reactor (18, 19, 37).

(129) For example, the fluidizing gas is one or more diluent gases.

(130) In a preferred embodiment, the at least one fluidized bed reactor (18, 19, 37, 39) is devoid of heating means. For example, at least one fluidized bed reactor is devoid of heating means selected from ovens, gas burners, hot plates, or any combination thereof. For example, all the fluidized bed reactors are devoid of heating means selected from ovens, gas burners, hot plates, or any combination thereof.

(131) In a preferred embodiment, the at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles is devoid of packing.

(132) For example, reactor vessel 3 has an inner diameter of at least 100 cm, or at least 200 cm; or at least 400 cm. Such large diameter allows to carry out the chemical reaction at an industrial scale, for example at a weight hourly space velocity of said reaction stream comprised between 0.1 h.sup.−1 and 100 h.sup.−1, preferably comprised between 1.0 h.sup.−1 and 50 h.sup.−1, more preferably comprised between 1.5 h.sup.−1 and 10 h.sup.−1, even more preferably comprised between 2.0 h.sup.−1 and 6.0 h.sup.−1. The weight hourly space velocity is defined as the ratio of mass flow of reaction stream to the mass of solid particulate material in the fluidized bed.

(133) The at least fluidized bed reactor (18, 19, 37) comprises at least two electrodes 13. For example, one electrode is in electrical connection with the outer wall of the at least one fluidized bed reactor, while one additional electrode is submerged into the fluidized bed 25, or both electrodes 13 are submerged into the fluidized bed 25. Said at least two electrodes 13 are electrically connected and can be connected to a power supply (not shown). It is advantageous that said at least two electrodes 13 are made of carbon-containing material. The person skilled in the art will have an advantage that the electrodes 13 are more conductive than the particle bed 25.

(134) For example, at least one electrode 13 is made of or comprises graphite; preferably, all or the two electrodes 13 are made of graphite. For example, one of the electrodes is the reactor vessel, so that the reactor comprises two electrodes, one being the submerged central electrode and one being the reactor vessel 3.

(135) For example, the at least one fluidized bed reactor comprises at least one cooling device arranged to cool at least one electrode.

(136) During use of the at least one fluidized bed reactor, an electric potential of at most 300 V is applied; preferably of at most 250 V; more preferably of at most 200 V, even more preferably of at most 150 V, most preferably at most 100 V, even most preferably of at most 90 V, or at most 80 V.

(137) Thanks to the fact that the power of the electric current can be tuned, it is easy to adjust the temperature within the reactor bed.

(138) One of the electrodes can be the reactor tube.

(139) The reactor vessel 3 can be made of graphite. In an embodiment, it can be made of electro-resistive material that is silicon carbide or a mixture of silicon carbide and one or more carbon-containing materials.

(140) With preference, reactor vessel 3 comprises reactor wall made of materials that are corrosion-resistant materials and advantageously said reactor wall materials comprise nickel (Ni), SiAlON ceramics, yttria-stabilized zirconia (YSZ), tetragonal polycrystalline zirconia (TZP) and/or tetragonal zirconia polycrystal (TPZ). SiAlON ceramics are ceramics based on the elements silicon (Si), aluminium (Al), oxygen (O) and nitrogen (N). They are solid solutions of silicon nitride (Si.sub.3N.sub.4), where Si—N bonds are partly replaced with Al—N and Al—O bonds.

(141) For example, reactor vessel 3 is made of an electro-resistive material that is a mixture of silicon carbide and one or more carbon-containing materials; and the electro-resistive material of reactor vessel 3 comprises from 10 wt. % to 99 wt. % of silicon carbide based on the total weight of the electro-resistive material; preferably, from 15 wt. % to 95 wt. %, more preferably from 20 wt. % to 90 wt. %, even more preferably from 25 wt. % to 80 wt. % and most preferably from 30 wt. % to 75 wt. %.

(142) For example, reactor vessel 3 is made of an electro-resistive material that is a mixture of silicon carbide and one or more carbon-containing materials; and the one or more carbon-containing materials are selected from graphite, carbon black, coke, petroleum coke and/or any mixture thereof; with preference, the carbon-containing material is or comprises graphite.

(143) For example, reactor vessel 3 is not conductive. For example, reactor vessel 3 is made of ceramic.

(144) For example, the at least one fluidized bed reactor (18, 19, 37, 39) comprises a heating zone 27 and a reaction zone 29, one or more fluid nozzles 23 to provide a reaction fluid to the reaction zone, and means 41 to transport the particles from the heating zone 27 to the reaction zone 29 when necessary, and optional means 35 to transport the particles from the reaction zone 29 back to the heating zone 27.

(145) For example, as illustrated in FIG. 3, the at least one fluidized bed reactor is a single one fluidized bed reactor 19 wherein the heating zone 27 is the bottom part of the fluidized bed reactor 19 while the reaction zone 29 is the top part of the fluidised bed reactor 19; with preference, the installation comprises one or more fluid nozzles 23 to inject a reaction fluid between the two zones (27, 29) or in the reaction zone 29. The fluidized bed reactor 19 further comprises optionally an inlet 7 for the material loading, optionally an outlet 9 for the material discharge and a gas outlet 11. With preference, the fluidized bed reactor 19 is devoid of heating means. For example, electrodes 13 are arranged at the bottom part of the fluidized bed reactor 19, i.e. in the heating zone 27. For example, the top part of the fluidised bed reactor 19, i.e. the reaction zone 29, is devoid of electrodes. Optionally, the fluidized bed reactor 19 comprises means 35 to transport the particles from the reaction zone 29 back to the heating zone 27; such as by means of a line arranged between the top part and the bottom part of the fluidized bed reactor 19.

(146) For example, as illustrated in FIG. 4, the installation comprises at least two lateral fluidized bed zones (27, 29) connected one to each other wherein at least one fluidized bed zone 27 is the heating zone and at least one fluidized bed zone 29 is the reaction zone. For example, the heating zone 27 is surrounding the reaction zone 29. With preference, the installation comprises one or more fluid nozzles 23 arranged to inject a reaction fluid and optionally steam to the at least one reaction zone 29 by means of a distributor 33. The fluidized bed zones (27, 29) further comprise optionally an inlet 7 for the material loading and a gas outlet 11. With preference, the at least one fluidized bed zone being the heating zone 27 and/or the at least one fluidized bed zone being the reaction zone 29 is devoid of heating means. For example, the at least one fluidized bed zone being the reaction zone 29 shows optionally an outlet 9 for the material discharge. One or more fluid nozzles 21 provide a fluidizing gas to at least the heating zone from a distributor 31. With one or more inlet devices 41, heated particles are transported from the heating zone 27 to the reaction zone 29, and with one or more means 35 comprising downcomers, the separated particles are transported from the reaction zone 29 back to the heating zone 27. The fluidization gas for the heating zone 27 can be an inert diluent, like one or more selected from steam, hydrogen, carbon dioxide, methane, ethane, argon, helium and nitrogen. In such a configuration, the fluidization gas for the heating zone can also comprise air or oxygen to burn deposited coke from the particles.

(147) For example, as illustrated in FIG. 5, the installation comprises at least two fluidized bed reactors (37, 39) connected one to each other wherein at least one fluidized bed reactor 37 is the heating zone 27 and at least one fluidized bed reactor 39 is the reaction zone 29. With preference, the installation comprises one or more fluid nozzles 23 arranged to inject a reaction fluid and optionally steam to the at least one fluidized bed reactor 39 being the reaction zone 29. The fluidized bed reactors (37, 39) further comprise optionally an inlet 7 for the material loading and a gas outlet 11. With preference, the at least one fluidized bed reactor 37 being the heating zone 27 and/or the at least one fluidized bed reactor 39 being the reaction zone 29 is devoid of heating means. For example, the at least one fluidized bed reactor 39 being the reaction zone 29 shows optionally an outlet 9 for the material discharge. By means of the inlet device 41 heated particles are transported from the heating zone 27 to the reaction zone 29 when necessary, and by means of device 35 the separated particles after the reaction zone are transported from the reaction zone back to the heating zone. The fluidization gas for the heating zone can be an inert diluent, like one or more selected from steam, hydrogen, carbon dioxide, methane, ethane, argon, helium, and nitrogen. In such a configuration, the fluidization gas for the heating zone can also comprise air or oxygen to burn deposited coke from the particles.

(148) For example, the at least one fluidized bed reactor 37 being the heating zone 27 comprises at least two electrodes 13 whereas the at least one fluidized bed reactor 39 being the reaction zone 29 is devoid of electrodes.

(149) For example, the at least two fluidized bed reactors (37, 39) are connected one to each other by means 41 suitable to transport the particles from the heating zone 27 to the reaction zone 29, such as one or more lines.

(150) For example, the at least two fluidized bed reactors (37, 39) are connected one to each other by means 35 suitable to transport the particles from the reaction zone 29 back to the heating zone 27, such as one or more lines.