Electrification process for the conversion of alcohols to the corresponding olefins in a fluidized bed reactor

Abstract

The present disclosure relates to a process for the catalytic dehydration of an alcohol having at least two carbon atoms to an alkene, said process comprising the steps of: a) providing a fluidized bed reactor and a bed comprising particles; b) bringing said particles in a fluidized state to obtain a fluidized bed; c) heating said fluidized bed to a temperature in the range of 200°C to 500°C; characterized in that said particles of said bed comprise electrically conductive particles and particles of one or more solid acid catalysts, wherein at least 10 wt% of the particles, based on the total weight of said particles of said bed, are electrically conductive particles and have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C; and the step c) of heating said fluidized bed is carried out by passing an electric current through said fluidized bed.

Description

Field of the invention

[0001] The present disclosure relates to a process for the catalytic dehydration of alcohols having at least two carbon atoms to the corresponding olefins in a fluidized bed reactor, wherein the reaction is carried out in said fluidized bed reactor without the need of external heating means. The present disclosure aims at facilitating the replacement of the use of fossil carbon-based fuel heating means. The present disclosure relates to the electrification of the chemical industry. BACKGROUND

[0002] Climate change and the ongoing energy transition make it necessary to replace fossil carbon-based fuels in chemical production and recycling processes with more environmentally friendly decarbonized energy sources. In this context, alcohols appear to be a promising platform molecule: indeed, dehydration to the corresponding olefins leads to the same monomers as those obtained via the conventional petroleum route, and at the same time to lower carbon emissions. The conversion of alcohols to olefins therefore appears to be a key process to facilitate carbon neutrality.

[0003] Among the technologies claiming to convert alcohols to olefins, most of them consider the use of conventional fixed bed reactors. A fluidized bed process for the dehydration of ethanol is described in US 4,134,926, but does not avoid the use of a burner, an oven or any other conventional heating means, and subsequently contributes to the emission of greenhouse gases.

[0004] The present disclosure aims at providing a large-scale solution to one or more of the problems encountered in the prior art, suitable for application in industry, for example in the chemical industry. The present disclosure aims at facilitating the replacement of the use of fossil carbon-based fuel heating devices in fluidized bed reactors. The present disclosure provides a solution for the catalytic dehydration of alcohols to olefins using electricity as the only energy source. SUMMARY

[0005] According to a first aspect, the present disclosure provides a process for the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins, said process comprising the steps of:

[0006] a) providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles;

[0007] b) bringing said particles of said bed in a fluidized state by flowing a fluid upwards through said bed to obtain a fluidized bed; and

[0008] c) heating said fluidized bed to a temperature in the range of 200 °C to 500 °C to carry out the catalytic dehydration of an alcohol-containing feedstock to one or more olefins, wherein said alcohol-containing feedstock comprises one or more alcohols having at least two carbon atoms;

[0009] 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 are electrically conductive particles and have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C, based on the total weight of the particles of the bed; wherein the catalytic composition comprises one or more solid acid catalysts; step c) of heating the fluidized bed is performed by passing an electric current through the fluidized bed.

[0010] Surprisingly, it has been found that the use of electrically conductive particles, such as silicon carbide and / or graphite, in one or more electrically energized fluidized bed reactors allows to maintain a temperature sufficient to perform the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins having the same number of carbon atoms as the alcohol, which reaction requires conditions such as a reaction temperature in the range of 200°C to 500°C, without the need for any external heating means. The use of at least 10 wt% of electrically conductive particles within the particles of the bed allows to minimize heat losses when a voltage is applied. Due to the Joule effect, most, if not all, of the electrical energy is converted into heat for heating the reactor medium.

[0011] For example, the electrically conductive particles are or comprise one or more selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and / or any mixture thereof.

[0012] In a preferred embodiment, the electrically conductive particles are or comprise one or more selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, and any mixture thereof.

[0013] Advantageously, the process further comprises a step (d) of recovering one or more olefins. Step (d) is performed after step (c).

[0014] In one embodiment, step (d) is performed and the process further comprises a step (e) of oligomerizing the one or more olefins recovered in step (d).

[0015] In an alternative embodiment, step (d) is performed and the process further comprises a step (f) of providing one or more aromatic compounds, and a step (g) of alkylating the one or more aromatic compounds with the one or more olefins recovered in step (d).

[0016] In an alternative embodiment, the step (d) is performed and the process comprises a step (e) of oligomerizing a portion of the one or more olefins recovered in step (d), the process further comprising a step (f) of providing one or more aromatic compounds, and a step (g) of alkylating the one or more aromatic compounds with another portion of the one or more olefins recovered in step (d), the step (g) being performed simultaneously with the step (e). Regardless of the embodiment chosen, the process further comprises an optional step (h) of hydrogenating the olefins after the step (e) and / or (g) has been performed.

[0017] The oligomerization step (e) and / or the alkylating step (g) of the aromatic compounds provided at step (f) and the optional hydrogenation step (h) are performed after the step (d) of recovering the one or more olefins, thus allowing the production of jet fuel and the decarbonization of the aviation industry.

[0018] In a preferred embodiment, the volumetric heat generation rate is greater than 0.1 MW / m3 3 the fluidized bed, more preferably greater than 1 MW / m3 3 , in particular greater than 3 MW / m3 3 The volumetric heat comes from the electrically conductive particles.

[0019] In a preferred embodiment, the at least one fluidized bed reactor is free of heating means. For example, the at least one fluidized bed reactor comprises a vessel and is free of heating means located around or inside the vessel. For example, the at least one fluidized bed reactor is free of heating means selected from the group consisting of an oven, a gas burner, a hot plate, or any combination thereof. For example, all the fluidized bed reactors are free of heating means selected from the group consisting of an oven, a gas burner, a hot plate, or any combination thereof.

[0020] For example, the content of the electrically conductive particles is in the range of 15 wt% to 95 wt%, more preferably 20 wt% to 90 wt%, even more preferably 25 wt% to 80 wt%, and most preferably 30 wt% to 75 wt%.

[0021] For example, the content of the electrically conductive particles is at least 12 wt% based on the total weight of the particles of the bed; preferably, at least 15 wt%, more preferably, at least 20 wt%; even more preferably at least 25 wt%, and most preferably at least 30 wt% or at least 40 wt% or at least 50 wt% or at least 60 wt%, based on the total weight of the particles of the bed.

[0022] For example, the electrically conductive particles have an electrical resistivity at 400°C in the range of 0.005 to 400 Ohm.cm, preferably in the range of 0.01 to 300 Ohm.cm at 400°C, more preferably in the range of 0.05 to 150 Ohm.cm at 400°C, and most preferably in the range of 0.1 to 100 Ohm.cm at 400°C.

[0023] For example, the electrically conductive particles have an electrical resistivity at 400°C of at least 0.005 Ohm.cm; preferably at least 0.01 Ohm.cm at 400°C, more preferably at least 0.05 Ohm.cm at 400°C; even more preferably at least 0.1 Ohm.cm at 400°C, and most preferably at least 0.5 Ohm.cm at 400°C.

[0024] For example, the electrically conductive particles have an electrical resistivity at 400°C of at most 400 Ohm.cm; preferably at most 300 Ohm.cm at 400°C, more preferably at most 200 Ohm.cm at 400°C; even more preferably at most 150 Ohm.cm at 400°C, and most preferably at most 100 Ohm.cm at 400°C. The content of electrically conductive particles based on the total weight of the particles of the bed and the selection of electrically conductive particles of a given electrical resistivity influence the temperature reached by the fluidized bed. Thus, in case the target temperature is not reached, the person skilled in the art can increase the density of the bed of particles, the content of electrically conductive particles based on the total weight of the particles of the bed, and / or select electrically conductive particles having a lower electrical resistivity to increase the temperature reached by the fluidized bed.

[0025] For example, the content of particles of the catalytic composition is in the range of 15 wt.% to 95 wt.%, more preferably 20 wt.% to 90 wt.%, even more preferably 25 wt.% to 80 wt.%, and most preferably 30 wt.% to 75 wt.%.

[0026] For example, the density of the bed of particles is expressed as voidage. Voidage or bed porosity is the volume of voids between the particles divided by the total volume of the bed. At incipient fluidization velocity, the voidage is typically 0.4 to 0.5. In a fast fluidized bed, the voidage can increase up to 0.98, with a lower value of about 0.5 at the bottom of the bed and higher than 0.9 at the top of the bed. The voidage can be controlled by the linear velocity of the fluidizing gas and can be reduced by recycling solid particles picked up at the top and sent back to the bottom of the fluidized bed, which compensates for the solid particles entrained out of the bed.

[0027] The voidage VF is defined as the volume fraction of voids in the bed of particles and is determined according to the following formula:

[0028]

[0029] where Vt is the total volume of the bed, and is determined by the formula

[0030] Vt = AH (2)

[0031] where A is the cross-sectional area of the fluidized bed, and H is the height of the fluidized bed; and

[0032] where Vp is the total volume of the particles within the fluidized bed.

[0033] For example, the bed has a void fraction in the range of 0.5 to 0.8; preferably in the range of 0.5 to 0.7, more preferably 0.5 to 0.6. To increase the density of the bed of particles, the void fraction is to be decreased.

[0034] For example, the particles of the bed have an average particle size in the range of 5 to 300 pm, preferably in the range of 10 to 200 pm, and more preferably in the range of 20 to 200 pm or 30 to 150 pm, when determined by sieving according to ASTM D4513-11.

[0035] Determination by sieving according to ASTM D4513-11 is preferred. In case the particles have an average size of 20 pm or less, determination of the average size can also be performed by laser scattering according to ASTM D4464-15.

[0036] For example, the electrically conductive particles of the bed have an average particle size in the range of 5 to 300 pm, preferably in the range of 10 to 200 pm, and more preferably in the range of 30 to 150 pm, when determined by sieving according to ASTM D4513-11.

[0037] In one embodiment, 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 to 100 wt.-% of the electrically conductive particles of the bed are selected from one or more of a metal alloy, one or more non-metallic resistors, one or more metallic carbides, one or more metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, based on the total weight of the electrically conductive particles of the bed.

[0038] Preferably, the electrically conductive particles of the bed are or comprise one or more selected from the group consisting of a metal alloy, one or more non-metallic resistive bodies, one or more metallic carbides, one or more metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors; preferably in an amount of 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 to 100 wt.-%, based on the total weight of the electrically conductive particles of the bed.

[0039] Preferably, the electrically conductive particles of the bed are or comprise one or more selected from the group consisting of a non-metallic resistive body, one or more metallic carbides, one or more metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, and any mixture thereof; preferably in an amount of 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 to 100 wt.-%, based on the total weight of the electrically conductive particles of the bed.

[0040] As an alternative, the electrically conductive particles of the bed are one or more particles selected from the group consisting of one or more metal alloys, one or more non-metallic resistive bodies (with the proviso that the non-metallic resistive body is not silicon carbide), one or more metallic carbides, one or more metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof; preferably in an amount of 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 to 100 wt.-%, based on the total weight of the electrically conductive particles of the bed.

[0041] For example, the electrically conductive particles of the bed are or comprise one or more selected from the group consisting of one or more metal alloys, one or more non-metallic resistive bodies, one or more carbon-containing particles, and any mixture thereof; preferably in an amount of 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 to 100 wt.-%, based on the total weight of the electrically conductive particles of the bed.

[0042] For example, the electrically conductive particles of the bed are or comprise one or more selected from the group consisting of one or more non-metallic resistors, one or more carbon-containing particles, and any mixture thereof; preferably in an amount of 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 to 100 wt.-%, based on the total weight of the electrically conductive particles of the bed.

[0043] For example, the one or more metal alloys are selected from the group consisting of Ni-Cr, Fe-Ni-Cr, Fe-Ni-Al, or mixtures thereof. Preferably, when the metal alloy comprises at least chromium, the chromium content is at least 15 mole-%, more preferably at least 20 mole-%, even more preferably at least 25 mole-%, most preferably at least 30 mole-%, based on the total mole content of the metal alloy comprising at least chromium. Also advantageously, the iron content in the metal alloy is at most 2.0%, preferably at most 1.5 mole-%, more preferably at most 1.0 mole-%, even more preferably at most 0.5 mole-%, based on the total mole content of the metal alloy.

[0044] For example, the non-metallic resistors are silicon carbide (SiC), molybdenum disilicide (MoSi2), nickel silicide (NiSi), sodium silicide (Na2Si), magnesium silicide (Mg2Si), platinum silicide (PtSi), titanium silicide (TiSi2), tungsten silicide (WSi2), or mixtures thereof, preferably silicon carbide.

[0045] For example, the one or more metal carbides are selected from the group consisting of iron carbide (Fe3C) and / or molybdenum carbide (e.g. a mixture of MoC and Mo2C).

[0046] For example, the one or more metal nitrides are selected from the group consisting of zirconium nitride (ZrN), tungsten nitride (e.g. a mixture of W2N, WN and WN2), vanadium nitride (VN), tantalum nitride (TaN), and / or niobium nitride (NbN).

[0047] For example, the one or more metal phosphides are selected from the group consisting of copper phosphide (Cu3P), indium phosphide (InP), gallium phosphide (GaP), sodium phosphide (Na3P), aluminum phosphide (AlP), zinc phosphide (Zn3P2), and / or calcium phosphide (Ca3P2).

[0048] For example, the one or more carbon-containing particles are selected from the group consisting of graphite, carbon black, petroleum coke, coke, or any combination thereof.

[0049] For example, the one or more superionic conductors are selected from the group consisting of LiAlSi04, Li10 GeP2S 12 , L i3.6 Si 0.6 P 0.4 O4, sodium super ion conductor (NaSICON) such as Na3Zr2PSi2O 12 , or sodium beta alumina such as NaAl 11 O 17 , Na 1.6 Al 11 0 17.3 , and / or Na 1.76 Li 0.38 Al 10.62 0 17 .

[0050] For example, the one or more phosphate electrolytes are selected from LiPO4or LaPO4.

[0051] For example, the electrically conductive particles of the bed are or comprise a non-metallic resistor that is a silicon carbide.

[0052] For example, the electrically conductive particles of the bed are or comprise a mixture of a non-metallic resistor that is a silicon carbide and electrically conductive particles that are different from silicon carbide. The presence of electrically conductive particles that are different from silicon carbide in the bed is optional. It can be present as a starting material for heating the bed, as the silicon carbide is found to have too high an electrical resistivity at room temperature to start heating the bed. As an alternative to the presence of electrically conductive particles that are different from silicon carbide, heat can be provided to the reactor for a defined time to start the reaction.

[0053] For example, the silicon carbide is selected from sintered silicon carbide, nitride-bonded silicon carbide, recrystallized silicon carbide, reaction-bonded silicon carbide, and any mixture thereof. The type of silicon carbide material is selected according to the required heating power necessary for the reaction heat of the supply alcohol catalytic dehydration to one or more olefins.

[0054] For example, the electrically conductive particles of the bed are or comprise a mixture of a non-metallic resistor that is a silicon carbide and electrically conductive particles that are different from silicon carbide, and the electrically conductive particles of the bed comprise from 10 wt% to 99 wt%; 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% of silicon carbide, based on the total weight of the electrically conductive mass of the bed.

[0055] For example, the electrically conductive particles of the bed are or comprise one or more metal alloys; preferably, the one or more metal alloys are selected from Ni-Cr, Fe-Ni-Cr, Fe-Ni-Al, or a mixture thereof.

[0056] Preferably, when the metal alloy comprises at least chromium, the chromium content is at least 15 mol-%, more preferably at least 20 mol-%, even more preferably at least 25 mol-%, most preferably at least 30 mol-%, based on the total molar content of the metal alloy comprising at least chromium. Advantageously, the iron content in the metal alloy is at most 2.0 mol-%, preferably at most 1.5 mol-%, more preferably at most 1.0 mol-%, even more preferably at most 0.5 mol-%, based on the total molar content of the metal alloy.

[0057] For example, the electrically conductive particles of the bed are or comprise a mixture of a non-metallic resistive body being a silicon carbide and particles different from silicon carbide, wherein the particles different from silicon carbide are or comprise molybdenum disilicide; preferably, the molybdenum disilicide is molybdenum disilicide particles having an average particle size in the range of 5 to 300 pm, more preferably 10 to 200 pm, and most preferably 30 to 150 pm, when determined by sieving according to ASTM D4513-11.

[0058] For example, the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins is carried out at a temperature in the range of 200 °C to 500 °C, preferably 240 °C to 490 °C, more preferably 260 °C to 480 °C.

[0059] For example, the catalytic dehydration of one or more alcohols having at least two carbon atoms to olefins is carried out at a pressure in the range of 0.05 MPa to 3 MPa, preferably 0.05 MPa to 1.5 MPa, more preferably 0.12 MPa to 0.8 MPa or 0.12 MPa to 0.5 MPa. This pressure is considered as medium pressure.

[0060] For example, the partial pressure of the alcohol-containing feedstock is in the range of 0.12 MPa to 0.7 MPa.

[0061] In an embodiment, the process comprises the step of preheating the fluidized bed reactor with a gaseous stream prior to the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins in the fluidized bed reactor; preferably, the gaseous stream is a stream of one or more inert gases and / or has a temperature comprised between 100°C and 300°C. This embodiment is meaningful to bring energy into the system and / or when the particles of the bed have too high an electrical resistivity at room temperature to be able to start the electrical heating of the bed. For example, the one or more inert gases are gases that do not provide any detrimental effect to the catalyst. For example, the one or more inert gases are selected from nitrogen, argon, helium, saturated hydrocarbons having up to 10 carbon atoms, or any combination thereof. More preferably, the one or more inert gases are or comprise saturated hydrocarbons having up to 10 carbon atoms, even more preferably saturated hydrocarbons having 3 to 7 carbon atoms, or 4 to 6 carbon atoms. For example, the one or more inert gases are or comprise butane, pentane, naphtha, or any combination thereof.

[0062] In an embodiment, the process comprises the step of diluting the alcohol-containing feedstock with one or more diluents. For example, the one or more diluents are selected from steam, hydrogen, methane, carbon dioxide, or any combination thereof. The one or more diluents allow managing the selectivity of the reaction.

[0063] The alcohol-containing feedstock comprises one or more alcohols having at least two carbon atoms, and optionally one or more inert gases, and / or one or more diluents. By specifying that the alcohol-containing feedstock comprises one or more alcohols having at least two carbon atoms, it is meant that methanol cannot be converted to olefins even if still present in the alcohol-containing feedstock. Preferably, the alcohol-containing feedstock does not comprise methanol. For example, the amount of the one or more alcohols having at least two carbon atoms in the alcohol-containing feedstock is in the range of 5 wt.% to 100 wt.% based on the total weight of the alcohol-containing feedstock. For example, the one or more alcohols of the alcohol-containing feedstock are or comprise one or more alcohols having 2 to 10 carbon atoms. For example, the one or more alcohols of the alcohol-containing feedstock are or comprise ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, hexan-1-ol, hexan-2-ol, hexan-3-ol, 2-methylpentan-1-ol, 3-methylpentan-1-ol, 4-methylpentan-1-ol, 2-methylpentan-2-ol, 3-methylpentan-2-ol, 4-methylpentan-2-ol, 2-methylpentan-3-ol, 3-methylpentan-3-ol, 2,2-dimethylbutan-1-ol, 2-3-dimethylbutan-1-ol, 3,3-dimethylbutan-1-ol, 2,3-dimethylbutan-2-ol, 3,3-dimethylbutan-2-ol, 2-ethylbutan-1-ol, or any combination thereof. For example, the amount of the one or more inert gases in the alcohol-containing feedstock is in the range of 0 wt.% to 95 wt.% based on the total weight of the alcohol-containing feedstock. For example, the amount of the one or more diluents in the alcohol-containing feedstock is in the range of 0 wt.% to 95 wt.% based on the total weight of the alcohol-containing feedstock.

[0064] For example, the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins is carried out at a weight hourly space velocity of the reaction stream comprised between 0.1 h -1 and 100 h -1 , preferably comprised between 1.0 h -1 and 50 h -1 , more preferably comprised between 1.5 h -1 and 10 h -1 , even more preferably comprised between 2.0 h -1 and 6.0 h -1 . The weight hourly space velocity is defined as the ratio of the mass flow of the reaction stream to the mass of the solid particulate material in the fluidized bed.

[0065] In particular, the product(s) obtained in the process of the application can comprise one or more of an olefin, water, unconverted alcohol (if any), one or more inert gas (if any), and one or more diluent (if any). For example, the olefin(s) are withdrawn through a fractionation device, and / or the inert gas(es) (if any) are recycled at the inlet of the reactor. For example, the unconverted alcohol (if any) is recycled at the inlet of the reactor.

[0066] In a preferred embodiment, the residence time of the alcohol-containing feedstock in the fluidized bed section of the reactor, wherein the temperature is comprised between 260 and 500°C, can range from 0.1 to 10 seconds.

[0067] For example, 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 optionally comprises one or more inert gas and / or one or more diluent gas, the step c) of heating the fluidized bed to a temperature ranging from 200°C to 500°C for carrying out the step c) of endothermic catalytic dehydration of an alcohol-containing feedstock into one or more olefins (wherein the alcohol-containing feedstock comprises one or more alcohol having at least two carbon atoms) comprises the following sub-steps:

[0068] - heating the fluidized bed to a temperature ranging from 200°C to 500°C by passing an electric current through the heating zone of the at least one fluidized bed,

[0069] - transporting the heated particles from the heating zone to the reaction zone,

[0070] - in the reaction zone, putting the heated particles in a fluidized state by passing a fluid stream comprising an alcohol-containing feedstock and optionally one or more inert gas and / or one or more diluent gas upward through the bed of the reaction zone, to obtain a fluidized bed and to carry out the endothermic catalytic dehydration of an alcohol-containing feedstock into one or more olefins,

[0071] - optionally, withdrawing the particles from the reaction zone and recycling them to the heating zone.

[0072] For example, the step of heating the fluidized bed is carried out by passing an electric current through the fluidized bed at a voltage of at most 300 V, 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.

[0073] The fluid stream can be a gaseous stream and / or a vaporized stream.

[0074] The step c) provides for the catalytic dehydration of an alcohol-containing feedstock into one or more olefins, which implies that an alcohol-containing feedstock is provided.

[0075] for example, wherein the heating zone and the reaction zone are mixed (i.e. the same zone); the fluid stream provided in step b) comprises an alcohol-containing feedstock.

[0076] for example, wherein the heating zone and the reaction zone are separate (separate) zones, the fluid stream provided in step b) to the heating zone does not comprise an alcohol-containing feedstock. For example, wherein the process comprises providing at least one fluidized bed reactor as a heating zone and at least one fluidized bed reactor as a reaction zone, the fluid stream provided in step b) to the heating zone does not comprise an alcohol-containing feedstock, and the fluid stream provided in step b) to the reaction zone comprises an alcohol-containing feedstock.

[0077] It will be understood that an alcohol-containing feedstock is provided to the reaction zone, and that when the heating zone is separate from the reaction zone, no alcohol-containing feedstock is provided to the heating zone. It will be understood that in addition to the alcohol-containing feedstock provided to the reaction zone, steam can also be provided to the reaction zone to achieve the recommended steam to hydrocarbon ratio in the reaction zone as described above.

[0078] for example, the at least one fluidized bed reactor provided in step a) comprises a heating zone and a reaction zone, and wherein the step c) of heating the fluidized bed comprises the following sub-steps:

[0079] - preheating the fluidized bed to a temperature in the range of 100°C to 300°C by passing a fluidizing flow upwards through the particles of the bed, the fluidizing flow being a gaseous flow having a temperature in the range of 100°C to 300°C;

[0080] - heating the fluidized bed to a temperature in the range of 200°C to 500°C by passing an electric current through the heating zone of the at least one fluidized bed reactor,

[0081] - transporting the heated particles from the heating zone to the reaction zone,

[0082] - in the reaction zone, bringing the heated particles in a fluidized state by passing a fluid stream comprising an alcohol-containing feedstock upwards through the bed of the reaction zone, to obtain a fluidized bed and to perform endothermic catalytic dehydration of one or more alcohols having at least two carbon atoms into one or more olefins,

[0083] - optionally, withdrawing particles from the reaction zone and recycling them to the heating zone.

[0084] To carry out the catalytic reaction, the bed particles further comprise a catalyst, which is one or more solid acid catalysts. For example, the content of the particles of the catalytic composition is in the range of 15% to 90% by weight, more preferably 20% to 85% by weight, even more preferably 25% to 80% by weight, and most preferably 30% to 75% by weight of the particles of the bed.

[0085] For example, the one or more solid acid catalysts have a 50 m 2 / g to 800m 2 / g, preferably 100m 2 / g to 750m 2 / g, more preferably 150m 2 / g to 700m 2 Surface area in the range of / g.

[0086] For example, the one or more solid acid catalysts are one or more oxides. Preferably, the one or more oxides are selected from γ-Al2O3, β-Al2O3, η-Al2O3, δ-Al2O3, amorphous Al2O3, chlorine-containing aluminum oxide, fluorine-containing aluminum oxide, phosphorus-containing aluminum oxide, ZrO2, acid-treated zirconium oxide, acid-treated titanium dioxide, niobium oxide, tungsten oxide, or any combination thereof.

[0087] For example, the one or more solid acid catalysts are one or more mixed oxides. Preferably, the one or more mixed oxides are selected from SiO2-Al2O3, SiO2-TiO2, SiO2-SnO2, SiO2-ZrO2, SiO2-BeO, SiO2-MgO, SiO2-CaO, SiO2-SrO, SiO2-ZnO, SiO2-Ga2O3, SiO2-Y2O3, SiO2-La2O3, SiO2-WO3, SiO2-ThO2, Al2O3-MgO, Al2O3-ZnO, Al2O3-ThO2, Al2O3-TiO2, Al2O3-ZrO2, Al2O3-MoO3 ... SiO2-Y2O3, SiO2-La2O3, SiO2-WO3, SiO2-ThO2, Al2O3-MgO, Al2O3-ZnO, Al2O3-ThO2, Al2O3- O3-WO3, Al2O3-Cr2O3, Al2O3-Mn2O3, Al2O3-Fe2O3, TiO2-MgO, TiO2-ZnO, TiO2-ZrO2, TiO2-SnO2, TiO2-Sb2O5, TiO2-V2O5, TiO2-Cr2O 3. TiO2-MoO3, TiO2-WO3, WO3-son2, WO3-ZrO2, Nb2O5-Al2O3, Nb2O5-WO3, Nb2O5-MoO3, Nb2O5-ZrO2, Nb2O5-TiO2, TiO2-Fe2O3, and any combination thereof.

[0088] For example, the one or more solid acid catalysts are one or more phosphates. Preferably, the one or more phosphates are one or more phosphates selected from titanium phosphate, zirconium phosphate, iron phosphate, or any combination thereof.

[0089] For example, the one or more solid acid catalysts are one or more zeolites selected from the MFI, MEL, MOR, FER, MTT, MWW, TON, EUO, HEU, MFS, and MRE families, and any combination thereof.

[0090] For example, the one or more solid acid catalysts are one or more zeolites having a Si / Al ratio of at least 10 when determined by X-ray fluorescence spectroscopy.

[0091] For example, the one or more solid acid catalysts are one or more silicoaluminophosphate molecular sieves selected from the AEI, CHA, and AEL families, and any combination thereof.

[0092] With respect to the measurement of the acid sites of the catalyst, it can be defined as the ability to give up a proton (as defined by Bronsted) or to accept an electron pair (as defined by Lewis). The measurement of the acidity is performed via ammonia temperature programmed desorption or by infrared spectroscopy. Such processes are described in “Studies in Surface Science and Catalysis”, Kozo TANABE, Makoto MISONO, Yoshio ONO, Hideshi HATTORI, Volume 51, NEW SOLID ACIDS AND BASES - THEIR CATALYTIC PROPERTIES, KODANSHA LTD., and in “Solid Acid Catalysis - From Fundamentals to Applications”, Hideshi Hattori & Yoshio Ono, by Taylor & Francis Group, 2015.

[0093] For example, prior to use in step (c), the one or more zeolites are steamed and then optionally leached in order to dealuminate the one or more zeolites. In other words, the one or more zeolites comprise at least 10 wt.% of aluminum, based on the one or more non-dealuminated zeolites.

[0094] For example, the one or more zeolites comprise a structure having at least one 10-membered ring.

[0095] For example, the one or more zeolites are selected from the MFI, MEL, MOR, FER, MTT, MWW, TON, EUO, HEU, MFS, and MR families, and any combination thereof; preferably, the one or more zeolites are selected from the MFI, MEL families, and any combination thereof.

[0096] For example, the one or more zeolites further comprise boron.

[0097] For example, the one or more zeolites are one or more phosphorus-modified zeolites.

[0098] Advantageously, the one or more zeolites are in the H-form. In other words, less than 50 wt.%, preferably less than 45 wt.% or less than 40 wt.% comprise one or more metal ions, based on the total weight of the one or more zeolites, the metal ions preferably being selected from Na, Mg, Ca, La, Ni, Ce, Zn, Co, or any combination thereof.

[0099] According to a second aspect, the disclosure provides a plant for carrying out the endothermic catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins according to the first aspect, the plant comprising

[0100] i) an electrically energized fluidized bed unit having at least one fluidized bed reactor, the fluidized bed reactor comprising:

[0101] - at least two electrodes;

[0102] - a reactor vessel;

[0103] - one or more fluid nozzles for introducing an alcohol-containing feedstock comprising one or more alcohols having at least two carbon atoms and, optionally, one or more inert gases and / or one or more dilution gases into the at least one fluidized bed reactor; and

[0104] - a bed comprising particles;

[0105] ii) a product take-off unit;

[0106] (iii) an olefin-conversion unit, wherein the olefin-conversion unit is selected from an olefin oligomerization unit, or an aromatic alkylation unit, or an olefin oligomerization and aromatic alkylation unit,

[0107] wherein the product take-off is downstream of the electrically energized fluidized bed unit and upstream of the olefin-conversion unit;

[0108] (iv) an optional hydrogenation unit, wherein the hydrogenation unit, when present, is downstream of the olefin-conversion unit;

[0109] The device 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 of the bed are electrically conductive, have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at a temperature of 400°C, and wherein the catalytic composition comprises one or more solid acid catalysts, based on the total weight of the particles of the bed.

[0110] Preferably, the at least two electrodes comprise or are made of tantalum.

[0111] For example, the electrically conductive particles are or comprise one or more selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0112] Advantageously, the at least one fluidized bed reactor is free of heating means. For example, the at least one fluidized bed reactor is free of heating means located around or inside the reactor vessel. For example, all fluidized bed reactors are free of heating means. When it is stated that the at least one fluidized bed reactor is free of "heating means", it is meant "classic" heating means such as ovens, gas burners, hot plates, etc. In addition to the at least two electrodes of the fluidized bed reactor itself, there are no other heating means. For example, the at least one fluidized bed reactor is free of heating means selected from the group consisting of ovens, gas burners, hot plates, or any combination thereof. For example, all fluidized bed reactors are free of heating means selected from the group consisting of ovens, gas burners, hot plates, or any combination thereof.

[0113] In a preferred embodiment, the at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles is free of packing material.

[0114] For example, the fluidization gas is one or more dilution gases.

[0115] For example, the at least one reactor vessel has an inner diameter of at least 100 cm, preferably at least 200 cm, more preferably at least 300 cm.

[0116] Preferably, the reactor vessel comprises reactor walls made of a material that is a corrosion-resistant material, and advantageously, the reactor wall material comprises nickel (Ni), SiAlON ceramic, yttria-stabilized zirconia (YSZ), tetragonal polycrystalline zirconia (TZP), and / or tetragonal zirconia polycrystal (TPZ).

[0117] Preferably, one of the electrodes is the reactor vessel or the gas distributor, and / or the at least two electrodes are made of a stainless steel material or a nickel-chromium alloy or a nickel-chromium-iron alloy.

[0118] For example, the at least one fluidized bed reactor comprises a heating zone and a reaction zone, one or more fluid nozzles to provide the alcohol-containing feedstock to the reaction zone, and optional means to transport the particles of the bed from the reaction zone back to the heating zone.

[0119] For example, the apparatus comprises at least two fluidized bed reactors connected to each other, wherein at least one of the at least two fluidized bed reactors is a heating zone and at least another of the at least two fluidized bed reactors is a reaction zone. Preferably, the apparatus comprises one or more fluid nozzles arranged to inject the alcohol-containing feedstock into at least one fluidized bed reactor that is a reaction zone; means to transport the particles of the bed from the heating zone to the reaction zone, if necessary; and optional means to transport the particles from the reaction zone back to the heating zone. The advantage of this configuration is that a given bed of particles is common to at least two fluidized bed reactors.

[0120] For example, the at least one fluidized bed reactor is a single fluidized bed reactor, wherein the heating zone is a bottom portion of the fluidized bed reactor and the reaction zone is a top portion of the fluidized bed reactor. Preferably, the apparatus comprises one or more fluid nozzles to inject the alcohol-containing feedstock between the two zones. The diameters of the heating zone and the reaction zone can be different to achieve optimal conditions for heating in the bottom zone and optimal conditions for the dehydration reaction in the top zone. The particles can move from the heating zone to the reaction zone by entrainment and from the reaction zone back to the heating zone by gravity in the opposite direction. Optionally, the particles can be collected from the upper heating zone and transported back to the bottom heating zone through a separate transport line.

[0121] For example, the at least one fluidized bed comprises at least two lateral zones, the at least two lateral zones being an outer zone and an inner zone, wherein the outer zone surrounds the inner zone and the outer zone is a heating zone and the inner zone is a reaction zone. In a less preferred configuration, the outer zone is a reaction zone and the inner zone is a heating zone. Preferably, the apparatus comprises one or more fluid nozzles to inject the alcohol-containing feedstock into the reaction zone.

[0122] In an embodiment, 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 to 100 wt.-% of the electrically conductive particles of the bed, based on the total weight of the particles of the bed, are one or more 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 metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0123] According to a third aspect, the disclosure provides the use of a bed comprising particles for the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins according to the first aspect in at least one fluidized bed reactor, which use 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 of the bed, based on the total weight of the particles of the bed, are electrically conductive, have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at a temperature of 400 °C, and wherein the catalytic composition comprises one or more solid acid catalysts.

[0124] For example, the electrically conductive particles are or comprise one or more 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 metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0125] For example, the use comprises heating a bed comprising particles to a temperature in the range of 200 °C to 500 °C in a first reactor, transporting the heated bed of particles from the first reactor to a second reactor, and providing an alcohol-containing feedstock to the second reactor; preferably, at least the second reactor is a fluidized bed reactor and / or at least the second reactor is free of heating means; more preferably, the first reactor and the second reactor are fluidized bed reactors, and / or the first and the second reactor are free of heating means. For example, the second reactor is free of electrodes.

[0126] In one embodiment, 50 to 100 wt.-%; preferably 60 to 100 wt.-%; more preferably 70 to 100 wt.-%; even more preferably 80 to 100 wt.-%, and most preferably 90 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 selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0127] According to a fourth aspect, the disclosure provides the use of an apparatus comprising at least one fluidized bed reactor for carrying out the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins, which is remarkable in that the apparatus is according to the second aspect. Preferably, the apparatus using at least one fluidized bed reactor is used for carrying out the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins in the process according to the first aspect.

[0128] Certain features, structures, characteristics or embodiments can be combined in any suitable way in one or more embodiments, as will be apparent from this disclosure to those skilled in the art. BRIEF DESCRIPTION OF DRAWINGS

[0129] - Figure 1 An apparatus according to the prior art is shown.

[0130] - Figure 2 An apparatus according to the disclosure with one reactor is shown, wherein the heating zone and the reaction zone are identical.

[0131] - Figure 3 An apparatus according to the disclosure with one reactor is shown, wherein one of the heating zone and the reaction zone is arranged above the other.

[0132] - Figure 4 An apparatus according to the disclosure with one reactor is shown, wherein the heating zone and the reaction zone are arranged laterally to each other.

[0133] - Figure 5 An apparatus according to the disclosure with two reactors is shown.

[0134] - Figure 6 An example of a setup of a temperature programmed desorption (TPD) method is shown. DETAILED DESCRIPTION

[0135] For the present disclosure, the following definitions are given:

[0136] As used herein, the terms "comprising" and "comprised of" are synonymous with "including" or "containing," and are inclusive or open-ended and do not exclude additional, unrecited members, elements, or method steps. The terms "comprising" and "comprised of" also include the term "consisting of."

[0137] Numerical ranges expressed in a "to" notation include all the integers within the recited range. For example when a range is expressed as 1 to 5, this includes 1, 2, 3, 4, and 5. The endpoints of the ranges are included in the ranges themselves. Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed

[0138] Zeolite codes (e.g. CHA...) are defined according to the "Atlas of Zeolite Framework Types", 6thRevised Edition, 2007, Elsevier, which is also cited in the present application.

[0139] The SAR of a zeolite is considered to be the ratio of the amount of SiO2to the amount of Al2O3, taking into account the fact that there are two aluminum atoms for one silicon atom. Si / Al atomic ratio The amount of SiO2corresponding to the amount of Al2O3. Silica alumina ratio The amount of SiO2corresponding to the amount of Al2O3, regardless of the ratio of Si atoms to Al atoms in the chemical formula of the zeolite. Thus, the value of the SAR is always twice the value of the Si / Al atomic ratio. SAR The amount of SiO2corresponding to the amount of Al2O3, regardless of the ratio of Si atoms to Al atoms in the chemical formula of the zeolite. Thus, the value of the SAR is always twice the value of the Si / Al atomic ratio.

[0140] The present disclosure provides a process for catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins, the process comprising the steps of:

[0141] a) providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles;

[0142] b) bringing the particles of the bed into a fluidized state by flowing a fluid upward through the bed to obtain a fluidized bed;

[0143] c) heating the fluidized bed to a temperature in the range of 200°C to 500°C to catalytically dehydrate an alcohol-containing feedstock to one or more olefins, wherein the alcohol-containing feedstock comprises one or more alcohols having at least two carbon atoms; and

[0144] d) optionally recovering one or more olefins;

[0145] 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 are electrically conductive and have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C, based on the total weight of the particles of the bed; wherein the catalytic composition comprises one or more solid acid catalysts; and the step c) of heating the fluidized bed is performed by passing an electric current through the fluidized bed.

[0146] For example, the one or more olefins have the same number of carbons as the one or more alcohols. This is why if methanol is present in the alcohol-containing feedstock, the methanol cannot be converted to an olefin. Preferably, the alcohol-containing feedstock does not comprise methanol.

[0147] For example, the electrically conductive particles of the bed are or comprise one or more selected from the group consisting of one or more carbon-containing particles, one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0148] In one embodiment, from 50 wt% to 100 wt%, 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% 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 selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0149] The fluid stream can be a gaseous stream and / or a vaporized stream.

[0150] For example, the step of heating the fluidized bed is performed by passing an electric current through the fluidized bed at a voltage of at most 300 V, preferably at most 200 V, more preferably at most 150 V, even more preferably at most 120 V, most preferably at most 100 V, and even most preferably at most 90 V.

[0151] Solid particulate material in a fluidized bed reactor is typically supported by perforated plates, plates with nozzles or chimneys, called distributors. Fluid is then forced upwards through the distributors and travels through the interstices between the solid particulate material. At lower fluid velocities, the solids remain settled as the fluid passes through the interstices in the material, called a packed bed reactor. As the fluid velocity increases, the particulate solids will reach a stage where the force of the fluid on the solids is sufficient to counterbalance the weight of the particulate material. This stage is called incipient fluidization and occurs at this minimum fluidization velocity. Once this minimum velocity is exceeded, the contents of the reactor bed begin to expand and become fluidized. Depending on the operating conditions and the properties of the solid phase, various flow regimes can be observed in such reactors. The minimum fluidization velocity required to achieve bed expansion depends on the size, shape, porosity and density of the particles and the density and viscosity of the fluid flowing upwards.

[0152] P.R. Gunjal, V.V. Ranade, in Industrial Catalytic Processes for Fine and Specialty Chemicals, (2016) read that Geldart based on average particle size distinguishes four different categories of fluidization, which determine the fluidization regime:

[0153] - Type A, aeratable fluidization (easily fluidizable medium-sized medium-density particles; typically 30-100 pm, density ~ 1500 kg / m 3 of particles);

[0154] - Type B, sandy fluidization (difficult to fluidize heavier particles; typically 100-800 pm, density 1500 to 4000 kg / m 3 of particles);

[0155] - Type C, cohesive fluidization (typical of powdered solid particles; fine-sized particles (~ 20 pm), interparticle forces or cohesion dominate); and

[0156] - Type D, spoutable fluidization (large density and larger particles ~ 1-4 mm, dense and spoutable).

[0157] Fluidization can be broadly divided into two flow regimes (Fluid Bed Technology in Materials Processing, 1999, CRC Press): homogeneous fluidization and heterogeneous fluidization. In homogeneous or particulate fluidization, the particles are uniformly fluidized without any significant voids. In heterogeneous or bubbling fluidization, voids of no solids can be observed distinctly. These voids behave like bubbles in a gas-liquid flow and exchange gas of varying size and shape with the surrounding homogeneous medium as they rise in the medium. In particulate fluidization, the bed expands smoothly with the movement of a large number of particles and the bed surface is well defined. Particulate fluidization is observed only for Geldart-A type particles. The bubbling fluidization regime is observed at much higher velocities than homogeneous fluidization, where the distinct bubbles that grow from the distributor can coalesce with other bubbles and eventually break at the surface of the bed. These bubbles enhance the mixing of solids with gas and the bubble size increases further with increasing fluidization velocity. When the bubble diameter increases up to the diameter of the reactor, the slugging regime is observed. In the turbulent fluidization regime, the bubbles grow and start breaking as the bed expands. Under these conditions, the top surface of the bed is no longer distinguishable. In fast fluidization or aerodynamic fluidization, the particles are transported out of the bed and need to be recirculated back into the reactor. No distinct bed surface is observed.

[0158] Fluidized bed reactors have the following advantages:

[0159] Uniform particle mixing : Due to the inherent fluid-like behavior of the solid particulate material, the fluidized bed does 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 critical for reaction efficiency and quality.

[0160] Uniform temperature gradient : Many chemical reactions require the addition or removal of heat. Local hot or cold spots within the reaction bed are avoided in the case of fluidization.

[0161] Ability to operate the reactor continuously : The fluidized bed nature of these reactors allows the ability to continuously withdraw product and introduce new reactants into the reactor vessel. In addition to the continuous operation of chemical reactions, due to the flowable solid particulate material, the fluidized bed also allows for the continuous or given frequency withdrawal of solid material or the continuous or given frequency addition of fresh solid material.

[0162] Heat can be generated by passing an electric current through an electrically conductive material (resistor) of sufficiently high resistivity to convert electrical energy into heat. Resistivity (also known as specific resistance or volume resistivity, an intrinsic property independent of shape and size) and its inverse (conductivity) are fundamental properties of a material quantifying how strongly the material resists or conducts an electric current (SI unit of resistivity is ohm-meters (Ω-m), and conductivity is Siemens / m (S / m)).

[0163] When electricity is passed through a fixed bed of electrically conductive particulate solids of sufficient resistivity, the bed provides electrical resistance to the flow of current; this resistance depends on a number of parameters, including the properties of the solids, the properties of the connections between the particles in the bed, the bed voidage, the bed height, the electrode geometry, etc. If the same fixed bed is fluidized via a passing gas, the electrical resistance of the bed increases; the electrical resistance provided by the electrically conductive particles generates heat within the bed, and can maintain the bed at isothermal conditions (known as an electrothermal fluidized bed or electrohydrodynamic reactor). In many high temperature reactions, electrohydrodynamic reactors provide in-situ heating during the reaction, and are particularly useful for operating endothermic reactions, and thus save energy, since no external heating or heat transfer is required. The prerequisite is that at least part of the solid particulate material is electrically conductive, but non-conductive solid particles can be mixed and still result in sufficient heat generation. Such non-conductive or very high resistivity solids can play a catalytic role in the chemical conversion. The properties of the bed material determine the electrical resistance of the electrothermal fluidized bed furnace; since this is a type of heat generation by charging resistors, the specific resistance of the particles influences the bed resistance. The size, shape, composition, and size distribution of the particles also influence the magnitude of the bed resistance. Furthermore, when the bed is fluidized, the voids created between the particles increase the bed resistance. The total resistance of the bed is the sum of two components, for example the electrode contact resistance (i.e. the resistance between the electrode and the bed) and the bed resistance. A large contact resistance will cause a large amount of local heating near the electrode, while the rest of the bed remains relatively cool. The following factors determine the contact resistance: current density, fluidization velocity, type of bed material, electrode size, and type of material used for the electrode. The electrode composition can advantageously be a metal such as iron, cast iron or other steel alloys, copper or copper-based alloys, nickel or nickel-based alloys, or refractory-type metals, intermetallic compounds, or alloys of Zr, Hf, V, Nb, Ta, Cr, Mo, W, or cermet carbides or nitrides. The contact area between the bed material and the electrode can be adjusted depending on the electrode submersion and the amount of particulate material in the fluidized bed. Thus, the resistance and power level can be manipulated by adjusting these variables. Advantageously, to prevent overheating of the electrode compared to the fluidized bed, the resistivity of the electrode (and thus the Joule heating) should be lower than that of the particulate material of the fluidized bed. In a preferred embodiment, the electrode can be cooled by a cooler fluid passing inside or outside the electrode. Such a fluid can be any liquid, a gas stream that evaporates upon heating, or can be a portion of the cooler feedstock that is first passed through the electrode before entering the fluidized bed.

[0164] Bed resistance can be predicted by Ohm's law The mechanism of current transfer in a fluidized bed is believed to occur by current flow along continuous chains of conducting particles at low operating voltages. At high voltages, current transfer occurs by a combination of chains of conducting particles, and arcing between the electrodes and the bed, and between particles that can ionize the gas, thus reducing the bed resistance. In principle, arcing within the bed is undesirable because it reduces electrical and thermal efficiency. Gas velocity strongly affects the bed resistance, which increases sharply from a settled bed as the gas flow rate increases; a maximum occurs near the incipient fluidization velocity, followed by a decrease at higher velocities. At gas flow rates sufficient to induce slugging, the resistance increases again. The average particle size and shape affect the resistance because they affect the points of contact between particles. Generally, the bed resistivity increases 2 to 5 times from a settled bed (e.g., 20 Ohm.cm for graphite) to incipient fluidization (60 Ohm.cm for graphite), and 10 to 40 times from a settled bed to twice the incipient fluidization velocity (300 Ohm.cm for graphite). Non-conducting or less conducting particles can be added to the conducting particles. If the fraction of conducting solids is small, the bed resistivity will increase due to the breaking of connections in the chains of conducting solids between the electrodes. If the fraction of non-conducting solids is small in size, it will fill the interstices or voids of the larger conducting solids and thus increase the bed resistance.

[0165] Generally, for high heating power desired, high current at low voltage is preferred. The power source can be AC or DC. The voltage applied in an electrothermal fluidized bed is typically less than 100 V to achieve sufficient heating power. The electrothermal fluidized bed can be controlled in three ways as follows:

[0166] 1. Adjusting the gas flow rate: Since the electrical conductivity of the bed depends on the degree of voids or gas bubbles within the bed, any change in the gas flow rate will change the power level; thus, the temperature can be controlled by adjusting the fluidizing gas flow rate. The flow rate required for optimum performance corresponds to a velocity equal to or slightly above the minimum fluidization velocity.

[0167] 2. Adjusting the electrode submersion: The power level can also be controlled by changing the electrode submersion level within the bed, since the electrical conductivity of the bed depends on the contact area between the conducting particles and the electrodes: the surface area of the electrodes available for current increases with electrode submersion, resulting in a decrease in the total resistance.

[0168] 3. Adjusting the applied voltage: Although changing the power level by using the first two methods is often more affordable or more economical than increasing the applied voltage, in an electrothermal fluidized bed, all three variables can be used to control the heating power produced.

[0169] The walls of the reactor are typically made of a ceramic (e.g., SiC), a high melting point metal or alloy, as it is versatile and compatible with many high temperature reactions of interest in industry. The atmosphere used for the reaction is often limited to neutral or reducing types, as oxidizing atmospheres can either burn the carbon material or produce an electrically non-conductive layer of metal oxides on top of the metal or alloy. The walls and / or the distributor plate can themselves act as electrodes for the reactor. The fluidized solids can be molybdenum disilicide, silicon carbide, or any other high melting point electrically conductive particles. Other electrodes that are typically immersed in the bed can also be high melting point metals, intermetallic compounds, or alloys.

[0170] The desired heat of reaction can be advantageously generated by heating the electrically conductive particles and / or the catalyst particles in separate zones of the reactor in which little or substantially no feedstock hydrocarbon is present, but only dilution gas. The benefit is that the proper fluidization conditions for generating heat by passing an electric current through the bed of electrically conductive particles can be optimized, while the best reaction conditions during hydrocarbon conversion can be selected for the other zones of the reactor. Such conditions of optimal void fraction and linear velocity can be different for the heating purpose and for the chemical conversion purpose.

[0171] In one embodiment of the disclosure, the apparatus comprises two zones arranged in series, i.e., a first zone is a heating zone and a second zone is a reaction zone, wherein the electrically conductive particles and the catalyst particles are continuously moved or transported from the first zone to the second zone or vice versa. The first and the second zones can be different parts of a single fluidized bed, or can be located in separate fluidized bed reactors connected to each other.

[0172] In said embodiment, a process of catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins is carried out, said process comprising the steps of:

[0173] a) providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles;

[0174] b) bringing the particles in a fluidized state by flowing a fluid upward through the bed to obtain a fluidized bed;

[0175] c) heating the fluidized bed to a temperature in the range of 200°C to 500°C to carry out a catalytic dehydration of an alcohol-containing feedstock to one or more olefins, wherein the alcohol-containing feedstock comprises one or more alcohols having at least two carbon atoms; and

[0176] d) optionally recovering the one or more olefins;

[0177] wherein at least 10 wt% of the particles are electrically conductive particles having an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C, based on the total weight of the particles of the bed; 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 optionally one or more dilution gases and / or one or more inert gases, and heating the fluidized bed to a temperature in the range of 200°C to 500°C to carry out step c) of endothermic catalytic dehydration of an alcohol-containing feedstock to one or more olefins comprises the following sub-steps:

[0178] - heating the fluidized bed to a temperature in the range of 200°C to 500°C by passing an electric current through the heating zone of the at least one fluidized bed,

[0179] - transporting the heated particles from the heating zone to the reaction zone,

[0180] - in the reaction zone, bringing the heated particles in a fluidized state by passing a fluid stream comprising an alcohol-containing feedstock and optionally a dilution gas upward through the bed of the reaction zone to obtain a fluidized bed and to carry out endothermic catalytic dehydration of an alcohol-containing feedstock to one or more olefins,

[0181] - optionally, withdrawing particles from the reaction zone and recycling them to the heating zone.

[0182] For example, the electrically conductive particles are or comprise one or more selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and / or any mixture thereof.

[0183] For example, the one or more inert gases are selected from the group consisting of nitrogen, carbon dioxide, argon, helium, a saturated hydrocarbon having up to 10 carbon atoms, or any combination thereof. More preferably, the one or more inert gases are or comprise a saturated hydrocarbon having up to 10 carbon atoms, even more preferably a saturated hydrocarbon having 3 to 7 carbon atoms, or 4 to 6 carbon atoms. For example, the one or more inert gases are or comprise butane, pentane, naphtha, or a combination thereof.

[0184] For example, the one or more diluents are selected from the group consisting of steam, hydrogen, methane, or any combination thereof.

[0185] The fluid stream can be a gaseous stream and / or a vaporized stream.

[0186] For example, the at least one fluidized bed reactor is at least two fluidized bed reactors connected to each other, wherein at least one of the at least two fluidized bed reactors is a heating zone and at least one other of the at least two fluidized bed reactors is a reaction zone. Preferably, the at least one fluidized bed reactor that is a heating zone comprises a gravitational or pneumatic transport device to transport particles from the heating zone to the reaction zone, and / or the apparatus comprises a device arranged to inject alcohol-containing feedstock into the at least one fluidized bed reactor that is the reaction zone. The apparatus is devoid of a device to inject alcohol-containing feedstock into the at least one fluidized bed reactor that is the heating zone.

[0187] For example, the at least one fluidized bed reactor is a single fluidized bed reactor, wherein the heating zone is a bottom portion of the fluidized bed reactor and the reaction zone is a top portion of the fluidized bed reactor. Preferably, the apparatus comprises a device to inject alcohol-containing feedstock and / or diluent between the two zones. The diameters of the heating zone and the reaction zone can be different to achieve optimal conditions for heating in the bottom zone and optimal conditions for hydrocarbon conversion in the top zone. Particles can move from the heating zone to the reaction zone by entrainment and from the reaction zone back to the heating zone by gravity from the opposite direction. Optionally, particles can be collected from the upper heating zone and transported back to the bottom heating zone through a separate transport line.

[0188] Step c) provides for catalytic dehydration of the alcohol-containing feedstock to one or more olefins having at least two carbon atoms, which implies that an alcohol-containing feedstock is provided. It will be understood that the alcohol-containing feedstock is provided to the reaction zone and, when the heating zone is separate from the reaction zone, then preferably no alcohol-containing feedstock is provided to the heating zone. When the heating zone and the reaction zone are combined (i.e. the same zone); the fluid stream provided in step b) comprises the alcohol-containing feedstock.

[0189] Bed comprising particles - catalyst particles

[0190] To perform the catalytic reaction, the bed particles further comprise a catalyst, which is one or more solid acid catalysts. For example, the content of the catalyst particles is in the range of 15 wt% to 90 wt%, more preferably 20 wt% to 85 wt%, even more preferably 25 wt% to 80 wt%, and most preferably 30 wt% to 75 wt%, based on the total weight of the particles of the bed.

[0191] For example, the one or more solid acid catalysts have a specific surface area in the range of 50 m2 / g to 800 m2 / g, preferably 100 m2 / g to 750 m2 / g, more preferably 150 m2 / g to 650 m2 / g, when measured by N2adsorption. 2 / g to 800 m 2 / g, preferably 100 m 2 / g to 750 m 2 / g, more preferably 150 m 2 / g to 700 m 2 / g to 700 m

[0192] The catalyst employed in the bed can be any one of a variety of dehydration catalysts. Such catalysts are generally known in the art, and the details in this respect are not deemed essential to a full understanding of the present application. As exemplary dehydration catalysts, mention can be made of alumina, silica-alumina, activated clays, zeolites, modified zeolites.

[0193] More specifically, the catalyst composition comprises one or more zeolites and / or one or more silicoaluminophosphate molecular sieves. Preferably, the one or more zeolites have a Si / Al ratio of at least 10, more preferably at least 15, even more preferably at least 50, most preferably at least 100, even most preferably at least 150, or at least 180, or at least 200, when determined by XRF spectroscopy. Preferably, the one or more zeolites have a Si / Al ratio of at most 1000, when determined by XRF spectroscopy. For example, the one or more zeolites have a Si / Al ratio in the range of 10 to 1000, or 15 to 1000, or 50 to 1000, or 100 to 1000, or 180 to 1000, or 200 to 1000, when determined by XRF spectroscopy. In the present specification, the term "Si / Al ratio", or "silicon / aluminum atomic ratio", or "silicon / aluminum ratio" is intended to mean the Si / Al atomic ratio of the overall material, which can be determined by elemental analysis upon dissolution of the material or by X-ray fluorescence (XRF) spectroscopy. In particular, for crystalline silicate materials, the stated Si / Al ratio applies not only to the Si / Al framework of the crystalline silicate, but also to the overall material.

[0194] Preferably, the one or more zeolites have a relatively low acidity. The acidity of the catalyst or of the one or more zeolites can be determined by temperature programmed desorption (TPD) of ammonia, wherein after contacting the catalyst with ammonia, which is adsorbed onto the acid sites on the catalyst, followed by desorption of the ammonium at elevated temperature, the amount of residual ammonia on the catalyst is measured by differential thermogravimetric analysis.

[0195] For example, prior to use in step (c), the one or more zeolites are steamed and then optionally leached to dealuminate the one or more zeolites. In other words, the one or more zeolites comprise less than 10% of aluminum, based on the one or more non-dealuminated zeolites. Preferably, the one or more zeolites are steamed at a temperature in the range of 425 °C to 870 °C, more preferably in the range of 540 °C to 815 °C, and / or at atmospheric pressure (i.e., about 0.1 MPa) and / or at a water partial pressure in the range of 13 kPa to 200 kPa. Preferably, the steaming is performed in an atmosphere comprising 5 to 100 vol.% steam, based on the total volume of the atmosphere. The steam preferably comprises 5 to 100 vol.% steam and 0 to 95 vol.% of an inert gas, based on the total volume of the steam. For example, the inert gas is nitrogen. A more preferred atmosphere comprises 72 vol.% steam and 28 vol.% nitrogen, based on the total volume of the atmosphere, i.e., 72 kPa steam at one atmosphere. The steaming is preferably performed for a period in the range of 1 to 200 hours, more preferably in the range of 20 hours to 100 hours. As mentioned above, steam treatment tends to reduce the amount of tetrahedral aluminum in the crystalline silicate framework by forming alumina.

[0196] For example, the one or more zeolites comprise a structure having at least one 10-membered ring.

[0197] For example, the one or more zeolites are selected from the MFI, MEL, MOR, FER, MTT, MWW, TON, EUO, HEU, MFS, and MRE families, and any combination thereof; preferably, the one or more zeolites are selected from the MFI, MEL, FER, MTT, MWW, TON, EUO, MFS, and MRE families, and any combination thereof; more preferably, the one or more zeolites are selected from the MFI, MEL, and any combination thereof.

[0198] For example, when the zeolite is MFI, it is preferred that the MFI zeolite has a Si / Al ratio of at least 100, when the one or more zeolites are determined by X-ray fluorescence spectroscopy in their solid form.

[0199] For example, when the zeolite is FER, it is preferred that the FER zeolite has a Si / Al ratio of at least 10, more preferably at least 15, when the one or more zeolites are determined by X-ray fluorescence spectroscopy in their solid form.

[0200] At Si / Al ratios higher than the values mentioned here, the alcohol is essentially dehydrated to an olefin, and there are virtually no side reactions that can lead to aldehydes, saturated hydrocarbons, or any undesired components.

[0201] Preferably, the zeolite from the MFI family is one or more selected from ZSM-5, silicalite-1, boralite C, or TS-1; more preferably, the zeolite from the MFI family is one or more selected from ZSM-5 or silicalite-1; even more preferably, the zeolite from the MFI family is ZSM-5.

[0202] Preferably, the zeolite from the MEL family is one or more selected from ZSM-11, silicalite-2, boralite D, TS-2, or SSZ-46; more preferably, the zeolite from the MEL family is ZSM-11.

[0203] Preferably, the zeolite from the MOR family is UZM-14.

[0204] Preferably, the zeolite from the FER family is one or more selected from ferrierite, FU-9, or ZSM-35.

[0205] Preferably, the zeolite from the MTT family is ZSM-23.

[0206] Preferably, the zeolite from the MWW family is one or more selected from MCM-22, PSH-3, ITQ-1, or MCM-49.

[0207] Preferably, the zeolite from the TON family is one or more selected from ZSM-22, Theta-1, or NU-10.

[0208] Preferably, the zeolite from the EUO family is selected from ZSM-50, or EU-1.

[0209] Preferably, the zeolite from the HEU family is clinopilotite.

[0210] Preferably, the zeolite from the MFS family is ZSM-57.

[0211] Preferably, the zeolite from the MRE family is ZSM-48.

[0212] For example, the one or more zeolites further comprise boron.

[0213] For example, the one or more zeolites are one or more phosphorus-modified zeolites.

[0214] For example, the one or more zeolites are dealuminated zeolites.

[0215] Advantageously, the one or more zeolites are in the H-form. In other words, less than 50 wt.%, preferably less than 45 wt.% or less than 40 wt.% comprises one or more metal ions, preferably selected from Na, Mg, Ca, La, Ni, Ce, Zn, Co, or any combination thereof, based on the total weight of the one or more zeolites.

[0216] The following description gives more details about the one or more zeolites (i.e. about one or more crystalline silicates).

[0217] The one or more zeolites are microporous crystalline inorganic polymers based on XO4tetrahedral frameworks connected to each other by sharing oxygen ions, wherein X can be trivalent (e.g. Al, B,...) or tetravalent (e.g. Ge, Si,...). The crystal structure of crystalline silicates is defined by the specific order in which the network of tetrahedral units is connected together. The size of the crystalline silicate pore opening is determined by the number of tetrahedral units or alternatively oxygen atoms required to form the pore and the nature of the cations present in the pore. They have a unique combination of properties: high internal surface area; uniform pores of one or more discrete sizes; ion exchange properties; good thermal stability; and the ability to adsorb organic compounds. Because the pores of these crystalline silicates are similar in size to many practically interesting organic molecules, they control the access of reactants and products, leading to specific selectivities in catalytic reactions. Crystalline silicates with MFI structure have a bivariant intersecting pore system with straight channels along

[010] : 0.53-0.56 nm, and sinusoidal channels along

[100] : 0.51-0.55 nm. Crystalline silicates with MEL structure have a bivariant intersecting straight pore system with straight channels along

[100] with a pore size of 0.53-0.54 nm.

[0218] In a more specific embodiment, the crystalline silicate catalyst is dealuminated by heating the catalyst in steam to remove aluminum from the crystalline silicate framework and extracting the aluminum from the catalyst by contacting the catalyst with a complexing agent for aluminum to remove the aluminum oxide deposited in the pores of the framework during the steaming step, thereby increasing the silicon to aluminum atomic ratio of the catalyst. The catalyst having a high silicon to aluminum atomic ratio for use in the catalytic process of the present disclosure is manufactured by removing aluminum from a commercially available crystalline silicate. As an example, a typical commercially available silicalite has a silicon to aluminum atomic ratio of about 120. According to the present disclosure, the commercially available crystalline silicate is modified by a steaming process that reduces the tetrahedral aluminum in the crystalline silicate framework and converts the aluminum atoms to octahedral aluminum in the form of amorphous aluminum oxide. While in the steaming step, aluminum atoms are chemically removed from the crystalline silicate framework structure to form aluminum oxide particles, those particles can cause partial obstruction of the pores or channels in the framework. This can inhibit the dehydration process of the present disclosure. Therefore, after the steaming step, the crystalline silicate can be subjected to leaching (i.e., an extraction step) in which the amorphous aluminum oxide is removed from the pores and the micropore volume is at least partially restored. The overall effect of dealuminating the crystalline silicate is achieved by the leaching step physically removing the amorphous aluminum oxide from the pores by forming a water-soluble aluminum complex. In this way, by removing aluminum from the crystalline silicate framework and then removing the aluminum oxide formed thereby from the pores, the process aims to achieve a substantially uniform dealumination over the entire pore surface of the catalyst. This reduces the acidity of the catalyst. The reduction in acidity ideally occurs substantially uniformly throughout the pores defined in the crystalline silicate framework. After steaming, the extraction process is carried out to dealuminate the catalyst by leaching. The aluminum is preferably extracted from the crystalline silicate by a complexing agent that tends to form a soluble complex with aluminum oxide. The complexing agent is preferably in an aqueous solution thereof. The complexing agent can comprise an organic acid, such as citric acid, formic acid, oxalic acid, tartaric acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, phthalic acid, isophthalic acid, fumaric acid, nitrilotriacetic acid, hydroxyethylenediaminetriacetic acid, ethylenediaminetetraacetic acid, trichloroacetic acid, trifluoroacetic acid, or a salt (e.g., sodium salt) of such an acid, or a mixture of two or more such acids or salts. The complexing agent can comprise an inorganic acid, such as nitric acid, a halogen acid, sulfuric acid, phosphoric acid, or a salt of such an acid, or a mixture of such acids. The complexing agent can also comprise a mixture of such organic and inorganic acids or their respective salts. The complexing agent for aluminum preferably forms a water-soluble complex with aluminum and in particular removes the aluminum oxide formed during the steam treatment step from the crystalline silicate. A particularly preferred complexing agent can comprise an amine, preferably ethylenediaminetetraacetic acid (EDTA) or a salt thereof, in particular the sodium salt thereof. In a preferred embodiment, the framework silicon to aluminum ratio is increased to a value of about 150 to 1000, more preferably at least 200 to 1000 by the process.

[0219] Following the aluminum leaching step, the crystalline silicate can be subsequently washed, for example, with distilled water, and then dried, preferably at an elevated temperature (e.g., about 110 °C).

[0220] Additionally, if an alkali or alkaline earth metal has been used during the preparation of the catalyst of the present disclosure, the molecular sieve can be subjected to an ion exchange step. Conventionally, ion exchange is carried out using an ammonium salt or mineral acid in aqueous solution.

[0221] Following the dealumination step, the catalyst can be subsequently calcined, for example, at a temperature of 400 to 800 °C, and / or at atmospheric pressure, and / or for a period in the range of 1 to 10 hours.

[0222] The crystalline silicate can be subjected to various treatments prior to use in dehydration, including ion exchange, modification with metals (in a non-limiting manner, alkali, alkaline earth, transition, or rare earth elements), external surface passivation, modification with phosphorous compounds, steaming, acid treatment, or other dealumination methods, or combinations thereof.

[0223] For example, the one or more silicoaluminophosphate molecular sieves are selected from the AEI, CHA, and AEL families, and any combination thereof.

[0224] Preferably, one silicoaluminophosphate molecular sieve selected from the AEI family is SAPO-18.

[0225] Preferably, one silicoaluminophosphate molecular sieve selected from the CHA family is SAPO-34.

[0226] Preferably, one silicoaluminophosphate molecular sieve selected from the AEL family is SAPO-11.

[0227] SAPO molecular sieves are based on ALPO, with an Al / P ratio essentially 1 atom / atom. During synthesis, a silicon precursor is added, and the insertion of silicon in the ALPO framework leads to acid sites at the microporous surface of the 10-membered ring sieve. The silicon content ranges from 0.1 to 10 atom% (Al+P+Si is 100).

[0228] In another embodiment, the one or more solid acid catalysts and, preferentially, the one or more zeolites are mixed with a binder, preferably an inorganic binder, and shaped into a desired shape, for example pellets. The binder is chosen so as to be resistant to the temperatures and other conditions employed in the dehydration process of the present disclosure. The binder is an inorganic material selected from clays, silicas, metal silicates, metal oxides such as Zr02and / or metals, or gels, including mixtures of silica and metal oxides. If the binder used in conjunction with the crystalline silicate is itself catalytically active, this can alter the conversion and / or selectivity of the catalyst. The non-active material used for the binder can suitably act as a diluent to control the amount of conversion so that the product can be obtained economically and in an orderly fashion without the need to employ other means of controlling the rate of reaction. It is desirable to provide a catalyst with good crush strength. This is because in commercial use, it is desirable to prevent the catalyst from breaking down into a powdery material. Such clay or oxide binders are often used only for the purpose of improving the crush strength of the catalyst. A particularly preferred binder for the catalyst of the present disclosure comprises silica. The relative proportions of finely divided crystalline silicate material to the inorganic oxide matrix of the binder can vary widely. Typically, the binder content is in the range of 5 to 95% by weight, based on the total weight of the composite catalyst, which is the mixture between the one or more solid acid materials and the binder, more typically 20 to 50% by weight, based on the weight of the composite catalyst. Such mixtures of crystalline silicate and inorganic oxide binder are also referred to as formulated crystalline silicates. In mixing the catalyst with the binder, the catalyst can be formulated into spheres or spray-dried powders.

[0229] The spherical shape can be manufactured in a rotary granulator or by the oil drop technique. Small spheres can be further manufactured by spray-drying a catalyst-binder suspension. Thereafter, the formulated crystalline silicate is typically calcined at a temperature of 200 to 900 °C in air or an inert gas for a period of 1 to 48 hours.

[0230] The binder is preferably free of any aluminium compounds, such as alumina. This is because, as mentioned above, the preferred catalysts for use in the present invention are dealuminated to increase the silicon / aluminium ratio of the crystalline silicate. If the cementation step is performed prior to the aluminium extraction step, the presence of alumina in the binder creates additional excess alumina. If an aluminium-containing binder is mixed with the crystalline silicate catalyst after the aluminium extraction, this re-aluminates the catalyst.

[0231] Furthermore, the mixing of the catalyst with the binder can be performed prior to or after the steaming and extraction steps.

[0232] In another embodiment, the catalyst is a crystalline silicate catalyst having a monoclinic structure, which is produced, for example, by a process comprising: providing a MFI-type crystalline silicate having a silicon / aluminum atomic ratio below 80; treating the crystalline silicate with steam, after which aluminum is leached from the zeolite by contact with an aqueous solution of a leachant to provide a silicon / aluminum atomic ratio in the catalyst of at least 180, whereby the catalyst has a monoclinic structure. Preferably, in the steam treatment step, the temperature is 425 to 870 °C, more preferably 540 to 815 °C, and / or the water partial pressure is 13 to 200 kPa. Preferably, the aluminum is removed by leaching to form a water-soluble compound by contacting the zeolite with an aqueous solution of a complexing agent for aluminum which tends to form a soluble complex with aluminum oxide.

[0233] According to this preferred process for producing a monoclinic crystalline silicate, the MFI-type starting crystalline silicate catalyst has an orthorhombic symmetry and a relatively low silicon / aluminum atomic ratio, which can be synthesized without any organic template molecules, and due to the successive steam treatment and aluminum removal, the final crystalline silicate catalyst has a relatively high silicon / aluminum atomic ratio and a monoclinic symmetry. After the aluminum removal step, the crystalline silicate can be ion-exchanged with ammonium ions. Such MFI-type crystalline silicates exhibiting an orthorhombic symmetry belong to the space group Pnma in the art. The X-ray diffraction pattern of such orthorhombic structure has one peak at d = about 0.365 nm, d = about 0.305 nm, and d = about 0.300 nm (see EP 0 146 524).

[0234] The starting crystalline silicate has a silicon / aluminum atomic ratio below 80. A typical ZSM-5 catalyst has 3.08 wt% Al203, 0.062 wt% Na20, based on the total weight of the ZSM-5 catalyst, and is 100% orthorhombic. Such a catalyst has a silicon / aluminum atomic ratio of 26.9.

[0235] The steaming step is carried out as explained above. The steaming tends to reduce the amount of tetrahedral aluminum in the crystalline silicate framework by forming aluminum oxide. The aluminum leaching or extraction step is carried out as explained above. In the aluminum leaching step, the crystalline silicate is immersed in an acidic solution or a solution containing a complexing agent, and then preferably heated, for example under reflux conditions (at the boiling point temperature, wherein the condensed steam is all returned), for an extended period of time, for example 18 hours. After the aluminum leaching step, the crystalline silicate is subsequently washed, for example with distilled water, and then preferably dried at an elevated temperature, for example about 110 °C. Optionally, the crystalline silicate is subjected to ion exchange with ammonium ions, for example by immersing the crystalline silicate in an aqueous solution of NH4CI.

[0236] Finally, the catalyst is calcined at an elevated temperature, for example at a temperature of at least 400°C. The calcination period is typically about 3 hours.

[0237] The resulting crystalline silicate has monoclinic symmetry, belonging to the space group P21 / n. The x-ray diffraction pattern of the monoclinic structure exhibits three doublets at d = about 0.36, 0.31 and 0.19 nm. The presence of such doublets is unique for monoclinic symmetry. More particularly, the doublet at d = about 0.36 comprises two peaks, one at d = 0.362 nm and one at d = 0.365 nm. In contrast, the orthorhombic structure has a single peak at d = 0.365 nm.

[0238] The presence of the monoclinic structure can be quantified by comparing the x-ray diffraction line intensities at d = about 0.36 nm. When a mixture of MFI crystalline silicates having pure orthorhombic and pure monoclinic structure is prepared, the composition of the mixture can be expressed as a monoclinicity index (in %). The x-ray diffraction pattern is recorded and the peak heights at d = 0.362 nm (for monoclinicity) and d = 0.365 nm (for orthorhombicity) are measured and expressed as I m and I o , respectively. A linear regression line between the monoclinicity index and I m / I o gives the relationship needed to measure the monoclinicity of an unknown sample. Thus, the monoclinicity index % = (a x I m / I o - b) x 100, wherein a and b are the regression parameters.

[0239] Such monoclinic crystalline silicates having a relatively high Si / Al atomic ratio of at least 100, preferably more than about 200, can be produced, preferably without using organic template molecules during the crystallization step. Furthermore, the crystal size of the monoclinic crystalline silicates can remain relatively low, typically less than 1 micron, more typically about 0.5 micron, because the starting crystalline silicates have a lower crystal size which does not increase with subsequent process steps. Thus, since the crystal size can remain relatively small, this can result in a corresponding increase in the activity of the catalyst. This is an advantage over known monoclinic crystalline silicate catalysts, in which the crystal size is typically more than 1 micron, because they are produced in the presence of organic template molecules and directly have a high Si / Al ratio, which inherently leads to a larger crystal size.

[0240] As far as the one or more phosphorus modified zeolites that are catalysts are concerned, they can advantageously be made from MFI, MOR, MEL, HEU, or FER crystalline aluminosilicate molecular sieves having an initial Si / Al ratio of 4 to 500. The P modified zeolite of the formulation can be obtained from inexpensive crystalline silicates having a low Si / Al ratio (less than 30).

[0241] As an example, the P modified zeolite is made by a process comprising in order:

[0242] - introducing P under conditions effective to advantageously introduce at least 0.05 wt% P based on the total weight of the selected zeolite; + or NH4 + - selecting a zeolite (advantageously having a Si / Al ratio of 4 to 500) of the MFI, MEL, FER, MOR, HEU type;

[0243] - introducing P under conditions effective to advantageously introduce at least 0.05 wt% P based on the total weight of the selected zeolite;

[0244] - separating the solid from the liquid, if any;

[0245] - an optional washing step, or an optional drying step, or an optional drying step followed by a washing step;

[0246] - a calcination step.

[0247] Zeolites having a low Si / Al ratio have been previously made with or without direct addition of organic templates.

[0248] Optionally, the process of making the P modified zeolite comprises a steaming step, preferably followed by a leaching step. The method comprises steaming followed by leaching. It is generally known to the person skilled in the art that steaming of a zeolite results in the removal of aluminium from the zeolite framework and its presence as alumina within and outside the pores of the zeolite. This transformation is known as dealumination of the zeolite. Treatment of the steamed zeolite with an acid solution results in the dissolution of the extra-framework alumina. This transformation is known as leaching. The zeolite is then advantageously separated by filtration and optionally washed. Between the filtration and washing steps, a drying step can be envisaged. The solution after washing can be separated from the solid, for example by filtration or evaporation.

[0249] The phosphorus can be introduced by any means, or for example according to the formulations described in US3911041, US5573990 and US6797851.

[0250] The catalyst made from the P modified zeolite can be the P modified zeolite itself, or it can be the P modified zeolite formulated into a catalyst by combination with other materials that provide additional hardness or catalytic activity to the finished catalyst product.

[0251] The separation of the liquid from the solid is advantageously performed by filtration at a temperature between 0 and 90°C, centrifugation at a temperature between 0 and 90°C, evaporation or equivalent.

[0252] Optionally, the zeolite can be dried after separation before washing. Advantageously, the drying is performed at a temperature between 40 and 600°C and / or advantageously performed during 1 to 10 hours. The drying can be performed under static conditions or in a gas stream. Air, nitrogen or any inert gas can be used.

[0253] The washing step can be performed during the filtration (separation step) with a part of cold water (< 40°C) or hot water (> 40 but < 90°C) or the solid can be submitted to an aqueous solution (1 kg of solid / 4 liters of aqueous solution) and treated under reflux conditions during 0.5 to 10 hours followed by evaporation or filtration.

[0254] The final calcination step is advantageously performed at a temperature between 400 and 700°C under static conditions or in a gas stream. Air, nitrogen or any inert gas can be used.

[0255] According to a particular embodiment, the phosphorus modified zeolite is manufactured by a process comprising in order:

[0256] - a zeolite of the MFI, MEL, FER, MOR, HEU type is selected (advantageously with a Si / Al ratio between 4 and 500, in a particular embodiment between 4 and 30); + or NH4 + - the zeolite is steamed at a temperature ranging from 400 to 870°C and / or during a period ranging from 0.01 hours to 200 hours;

[0257] - the zeolite is leached with an aqueous acid solution under conditions effective to remove a significant portion of Al from the zeolite;

[0258] - P is introduced with an aqueous solution containing a source of P under conditions effective to advantageously introduce at least 0.05% by weight of P based on the total weight of the selected zeolite;

[0259] - the solid is separated from the liquid;

[0260] - an optional washing step, or an optional drying step, or an optional drying step followed by a washing step;

[0261] - a calcination step.

[0262] - a calcination step.

[0263] Optionally, there is an intermediate step between the steaming step and the leaching step, as an example, for instance a contact with a silica powder and drying.

[0264] Advantageously, the selected MFI, MEL, FER, MOR, HEU (or H + or NH4 + - type MFI, MEL, FER, MOR, HEU) has an initial atomic ratio Si / Al of 100 or less, and in a particular embodiment, of 4 to 30. The H + or NH4 + - type conversion is known per se and described in US 3911041 and US 5573990.

[0265] Advantageously, the final P content is at least 0.05 wt.%, and preferably 0.3 wt.% to 7 wt.% based on the total weight of the phosphorus-modified zeolite. Advantageously, the phosphorus-modified zeolite comprises at least 10% less Al relative to the parent zeolite MFI, MEL, FER, MOR and HEU, as it has been extracted and removed from the zeolite by leaching.

[0266] The zeolite is then separated from the washing solution, or dried without separation from the washing solution. The separation is advantageously performed by filtration. The zeolite is then calcined, for example at 400°C for 2-10 hours.

[0267] In the steaming step, the temperature is preferably 420 to 870°C, more preferably 480 to 760°C. The pressure is preferably atmospheric pressure, and / or the water partial pressure can be in the range of 13 to 100 kPa. The steam atmosphere preferably contains 5 to 100 vol.% steam and 0 to 95 vol.% inert gas based on the total volume of the steam atmosphere. For example, the inert gas is nitrogen. The steaming is preferably performed in a period of 0.01 to 200 hours, advantageously 0.05 to 200 hours, more preferably 0.05 to 50 hours. The steaming tends to reduce the amount of tetrahedral aluminum in the crystalline silicate framework by forming aluminum oxide.

[0268] The leaching can be performed with an organic acid, for example citric acid, formic acid, oxalic acid, tartaric acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, phthalic acid, isophthalic acid, fumaric acid, nitrilotriacetic acid, hydroxyethylenediaminetriacetic acid, ethylenediaminetetraacetic acid, trichloroacetic acid, trifluoroacetic acid, or a salt (e.g. sodium salt) of such an acid, or a mixture of two or more such acids or salts. Other inorganic acids can comprise inorganic acids such as nitric acid, hydrochloric acid, methanesulfonic acid, phosphoric acid, phosphonic acid, sulfuric acid, or a salt (e.g. sodium or ammonium salt) of such an acid, or a mixture of two or more such acids or salts.

[0269] The residual P content is adjusted by the P concentration in the aqueous acid solution containing the P source, the drying conditions, and the washing procedure, if any. Between the filtration and washing steps, a drying step can be envisaged.

[0270] The P-modified zeolite can be used as a catalyst by itself. In another embodiment, it can be formulated into a catalyst by combining it with other materials that provide additional hardness or catalytic activity to the finished catalyst product. The materials that can be blended with the P-modified zeolite can be various inert or catalytically active materials, or various binder materials. These materials include compositions such as kaolin and other clays, various forms of rare earth metals, phosphates, alumina or alumina sols, titania, zirconia, quartz, silica or silica sols, and mixtures thereof. These components are effective in densifying the catalyst and increasing the strength of the formulated catalyst. The catalyst can be formulated into spheres or formed into spray-dried granules. The amount of P-modified zeolite contained in the final catalyst product is in the range of 10 to 90 wt% of the total catalyst, preferably 20 to 70 wt% of the total catalyst.

[0271] Bed comprising particles - conductive particles

[0272] To achieve the desired temperature necessary to perform the catalytic dehydration of one or more alcohols to one or more olefins, at least 10 wt% of the particles of the bed are electrically conductive, having an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C, based on the total weight of the particles of the bed.

[0273] For example, the electrically conductive particles of the bed are or comprise one or more selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0274] For example, 50 wt% to 100 wt%; preferably 60 wt% to 100 wt%; more preferably 70 wt% to 100 wt%; even more preferably 80 wt% to 100 wt%, and most preferably 90 wt% to 100 wt% of the electrically conductive particles of the bed are one or more selected from the group consisting of one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof, based on the total weight of the electrically conductive particles of the bed.

[0275] In one embodiment, 50 wt% to 100 wt%; preferably 60 wt% to 95 wt%; more preferably 70 wt% to 90 wt%; and even more preferably 75 wt% to 85 wt% of the electrically conductive particles of the bed are free of graphite and / or carbon black, based on the total weight of the electrically conductive particles of the bed.

[0276] For example, the content of the electrically conductive particles is in the range of 10 to 100 wt.%, preferably 15 to 95 wt.%, more preferably 20 to 90 wt.%, even more preferably 25 to 80 wt.%, and most preferably 30 to 75 wt.%, based on the total weight of the particles of the bed.

[0277] For example, the content of the electrically conductive particles is at least 12 wt.%, preferably at least 15 wt.%, more preferably at least 20 wt.%, even more preferably at least 25 wt.%, and most preferably at least 30 wt.% or at least 40 wt.% or at least 50 wt.% or at least 60 wt.%, based on the total weight of the bed.

[0278] For example, the electrically conductive particles have an electrical resistivity in the range of 0.005 to 400 Ohm.cm at 400°C, preferably in the range of 0.01 to 300 Ohm.cm at 400°C, more preferably in the range of 0.05 to 150 Ohm.cm at 400°C, and most preferably in the range of 0.1 to 100 Ohm.cm at 400°C.

[0279] For example, the electrically conductive particles have an electrical resistivity of at least 0.005 Ohm.cm at 400°C, preferably at least 0.01 Ohm.cm at 400°C, more preferably at least 0.05 Ohm.cm at 400°C, even more preferably at least 0.1 Ohm.cm at 400°C, and most preferably at least 0.5 Ohm.cm at 400°C.

[0280] For example, the electrically conductive particles have an electrical resistivity of at most 400 Ohm.cm at 400°C, preferably at most 300 Ohm.cm at 400°C, more preferably at most 200 Ohm.cm at 400°C, even more preferably at most 150 Ohm.cm at 400°C, and most preferably at most 100 Ohm.cm at 400°C.

[0281] For example, the particles of the bed have an average particle size in the range of 300 pm, preferably in the range of 10 to 200 pm, and more preferably in the range of 30 to 150 pm, when determined by sieving according to ASTM D4513-11.

[0282] For example, the electrically conductive particles of the bed have an average particle size in the range of 5 to 300 pm, preferably in the range of 10 to 200 pm, and more preferably in the range of 30 to 150 pm, when determined by sieving according to ASTM D4513-11.

[0283] The electrical resistance is measured by the four-probe DC method using an ohmmeter. The densified powder sample is shaped into a cylindrical pellet and placed between the probe electrodes. The electrical resistivity is determined from the measured resistance value R by applying the known expression r = R x A / L, where L is the distance between the probe electrodes (typically a few millimeters) and A is the electrode area.

[0284] The electrically conductive particles of the bed can exhibit electronic, ionic, or mixed electronic-ionic conductivity. The ionic bonding of many refractory compounds allows for ion diffusion and, correspondingly, for ionic conduction under the influence of an electric field and appropriate temperature conditions.

[0285] The electrical conductivity s (proportionality constant between the current density j and the electric field E) is given by

[0286] s = j / E =∑c i x Z i q x m i

[0287] where c i is the carrier density (number / cm 3 ), μ i is the mobility (cm 2 / Vs), and Z i q is the charge of the i-th charge carrier (q = 1.6 x 10 -19 C). The several orders of magnitude difference in s between metals, semiconductors, and insulators is generally caused by differences in c rather than μ. On the other hand, the higher electrical conductivity of electronic conductors relative to ionic conductors is generally due to the much higher mobility of electronic species relative to ionic species.

[0288] The most common materials that can be used for resistance heating are subdivided into nine groups:

[0289] (1) metal alloys, up to temperatures of 1200-1400°C,

[0290] (2) non-metallic resistors, such as silicon carbide (SiC), molybdenum disilicide (MoSi2), nickel silicide (NiSi), sodium silicide (Na2Si), magnesium silicide (Mg2Si), platinum silicide (PtSi), titanium silicide (TiSi2), and tungsten silicide (WSi2), up to 1600-1900°C,

[0291] (3) carbon-containing materials,

[0292] (4) metal carbides,

[0293] (5) metal nitrides,

[0294] (6) metal phosphides,

[0295] (7) superionic conductors, and

[0296] (8) phosphate electrolytes.

[0297] For temperatures up to 1150-1250°C, the first group of metal alloys can consist of Ni-Cr alloys with low Fe content (0.5-2.0%), preferably the alloys Ni-Cr (80% Ni, 20% Cr) and (70% Ni, 30% Cr). Increasing the Cr content increases the oxidation resistance of the material at high temperatures. The second group of metal alloys with three components is Fe-Ni-Cr alloys, with a maximum operating temperature in oxidizing atmospheres of 1050-1150°C, but which can be used conveniently in reducing atmospheres, or Fe-Cr-Al (chemical composition 15-30% Cr, 2-6% Al and the balance Fe) protected from corrosion by a surface layer of oxides of Cr and Al, which can be used in oxidizing atmospheres up to 1300-1400°C. Silicon carbide as a non-metallic resistor can exhibit a wide range of resistivities, which can be controlled by the way they are synthesized and by the presence of impurities (such as aluminum, iron, oxides, nitrogen or additional carbon or silicon) that result in non-stoichiometric silicon carbide. In general, silicon carbide has a high resistivity at low temperatures, but a good resistivity in the range of 500 to 1200°C. In an alternative embodiment, the non-metallic resistor can not contain silicon carbide, and / or can comprise molybdenum disilicide (MoSi2), nickel silicide (NiSi), sodium silicide (Na2Si), magnesium silicide (Mg2Si), platinum silicide (PtSi), titanium silicide (TiSi2), tungsten silicide (WSi2), or mixtures thereof.

[0298] A number of sublattice-disordered oxides or sulfides have high ionic transport capacity at elevated temperatures. These are superionic conductors, such as LiAlSiO4, Li 10 GeP2S 12 , L i3.6 Si 0.6 P 0.4 O4, with the general formula Na 1+x Zr2P 3-x Si x O 12 NaSICON (sodium (Na) superionic conductor) with the general formula Na3Zr2PSi2O 12 (x = 2), or sodium beta alumina, such as NaAl 11 O 17 , Na 1.6 Al 11 0 17.3 , and / or Na 1.76 Li 0.38Al 10.62 0 17 .

[0299] Phosphate electrolytes such as LiP04or LaP04may also be used as electrically conductive particles.

[0300] Metal carbides, metal nitrides and metal phosphides can also be selected as electrically conductive particles. For example, the metal carbide is selected from iron carbide (Fe3C), molybdenum carbide (e.g. a mixture of MoC and Mo2C). For example, the one or more transition metal nitrides are selected from zirconium nitride (ZrN), tungsten nitride (e.g. a mixture of W2N, WN and WN2), vanadium nitride (VN), tantalum nitride (TaN) and / or niobium nitride (NbN). For example, the one or more metal phosphides are selected from copper phosphide (Cu3P), indium phosphide (InP), gallium phosphide (GaP), sodium phosphide (Na3P), aluminum phosphide (AlP), zinc phosphide (Zn3P2) and / or calcium phosphide (Ca3P2).

[0301] In a preferred embodiment of the present disclosure, electrically conductive particles that exhibit sufficiently low electrical resistivity only at high temperatures can be heated by an external device and then resistively heated using electrical overload to reach sufficiently high temperatures, or can be mixed with solids that have sufficiently low electrical resistivity at low temperatures, such that the resulting electrical resistivity of the mixture allows the fluidized bed to be heated to the desired reaction temperature.

[0302] 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 are silicon carbide particles, based on the total weight of the electrically conductive particles of the bed, and have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C.

[0303] In embodiments where the electrically conductive particles of the bed are or comprise silicon carbide, the person skilled in the art will have the advantage of carrying out a step of preheating the fluidized bed reactor with a gaseous stream before carrying out the endothermic reaction in the fluidized bed reactor. Advantageously, the gaseous stream is a stream of inert gas, i.e. nitrogen, argon, helium, methane, hydrogen, or steam. The temperature of the gaseous stream can be at least 300°C, or at least 350°C, or at least 400°C, or at least 450°C, and / or at most 500°C. Advantageously, the temperature of the gaseous stream can be comprised between 300°C and 500°C. The gaseous stream of inert gas can also be used as fluidizing gas. The preheating of the gaseous stream of inert gas is carried out by conventional means, including the use of electrical energy. The temperature of the gaseous stream used to preheat the bed does not need to reach the reaction temperature.

[0304] Indeed, silicon carbide has a relatively high electrical resistivity at ambient temperature, and in order to facilitate the start of the reaction, it can be useful to heat the fluidized bed by external means, as it is preferred that the fluidized bed reactor does not have heating means. Once the bed is heated at the desired temperature, it can not be necessary to use a hot gaseous stream.

[0305] 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.

[0306] In case electrically conductive particles different from silicon carbide particles are present in the bed, a pre-heating step can also be used. For example, it can be used when the content of silicon carbide in the electrically conductive particles of the bed is greater than 80 wt.%, for example greater than 85 wt.%, for example greater than 90 wt.%, for example greater than 95 wt.%, for example greater than 98 wt.%, for example greater than 99 wt.%, based on the total weight of the particles of the bed. However, the pre-heating step can be used regardless of the content of silicon carbide particles in the bed.

[0307] In an 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 can comprise from 10 wt.% to 99 wt.%; 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.% of silicon carbide particles, based on the total weight of the electrically conductive particles of the bed.

[0308] 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 comprise at least 40 wt.%; 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.% of silicon carbide particles, based on the total weight of the electrically conductive particles of the bed.

[0309] In an embodiment, the electrically conductive particles of the bed can comprise from 10 wt.% to 90 wt.%; 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.% of electrically conductive particles different from silicon carbide particles, based on the total weight of the electrically conductive particles of the bed.

[0310] However, it can be of interest to keep the content of electrically conductive particles different from silicon carbide particles in the mixture rather low. Thus, 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, and the electrically conductive particles of the bed comprise from 1 to 20 wt.%, preferably from 2 to 15 wt.%, more preferably from 3 to 10 wt.%, and even more preferably from 4 to 8 wt.% of electrically conductive particles different from silicon carbide, based on the total weight of the electrically conductive particles of the bed.

[0311] For example, the electrically conductive particles of the bed are or comprise a mixture of silicon carbide particles and particles different from silicon carbide particles, and the particles different from silicon carbide particles are or comprise molybdenum disilicide particles.

[0312] Thus, in an embodiment, the electrically conductive particles are a combination of silicon carbide particles and molybdenum disilicide particles. Such electrically conductive particles will heat up when the fluidized bed reactor is powered on and will contribute to raise and / or maintain the temperature within the reactor due to their fluidization. The Joule heating of the molybdenum disilicide allows to accelerate the heating of the reactants and / or other particles present within the fluidized bed reactor.

[0313] It is also preferred that the molybdenum disilicide has an average particle size ranging from 1 to 400 pm, preferably from 5 to 300 pm, more preferably from 10 to 200 pm, and most preferably from 30 to 150 pm, when determined by sieving according to ASTM D4513-11.

[0314] The presence of molybdenum disilicide particles in the bed allows to apply the process according to the present disclosure with or without a preheating step, preferably without a preheating step. Indeed, molybdenum disilicide particles will heat up when the fluidized bed reactor is powered on and will contribute to raise and / or maintain the desired temperature within the reactor due to their fluidization.

[0315] Silicon carbide particles

[0316] For example, the silicon carbide is selected from the group consisting of sintered silicon carbide, nitride-bonded silicon carbide, recrystallized silicon carbide, reaction-bonded silicon carbide, and any mixture thereof.

[0317] Sintered SiC (SSiC) is a self-bonded material containing less than 1 wt.% of sintering aids, typically boron.

[0318] Recrystallized silicon carbide (RSiC) is a high purity SiC material sintered by an evaporation-condensation process without any additives.

[0319] Nitride-bonded silicon carbide (NBSC) is prepared by adding fine silicon powder with silicon carbide particles or finally sintering in the presence of mineral additives and in a nitriding furnace. Silicon carbide is bonded by silicon nitride phase (Si3N4) formed during nitriding.

[0320] Reaction-bonded silicon carbide (RBSC) (also known as siliconized silicon carbide or SiSiC) is a class of silicon carbide manufactured by a chemical reaction between porous carbon or graphite and molten silicon. Silicon reacts with carbon to form silicon carbide and bonds silicon carbide particles. Any excess silicon fills the remaining pores in the body and produces a dense SiC-Si composite. Reaction-bonded silicon carbide is often referred to as siliconized silicon carbide due to the residual traces of silicon. The process is variously known as reaction bonding, reaction sintering, self-bonding or melt infiltration.

[0321] Generally, high-purity SiC particles have an electrical resistivity above 1000 Ohm.cm, while sintered, reaction-bonded and nitride-bonded can exhibit an electrical resistivity of about 100 to 1000 depending on the impurities in the SiC phase. The electrical resistivity of bulk polycrystalline SiC ceramics shows a wide range of resistivity depending on the sintering additives and heat treatment conditions (Journal of the European Ceramic Society, Vol. 35, Issue 15, December 2015, p. 4137; Ceramics International, Vol. 46, Issue 4, March 2020, p. 5454). High-purity SiC polytypes have high electrical resistivity (> 10 6 Ω.cm) due to their large band gap energy. However, the electrical resistivity of SiC is affected by doping impurities. N and P act as n-type dopants and decrease the electrical resistivity of SiC, while Al, B, Ga and Sc act as p-type dopants. SiC doped with Be, O and V is highly insulating. N is considered the most effective dopant to improve the conductivity of SiC. For N-doping of SiC (for decreasing the electrical resistivity), Y2O3 and Y2O3-REM2O3 (REM, rare earth metal = Sm, Gd, Lu) have been used as sintering additives for effective growth of N-donor containing conductive SiC grains. N-doping in SiC grains is promoted by adding nitrides (AIN, BN, Si3N4, TiN and ZrN) or combinations of nitrides with Re2O3 (AIN-REM2O3 (REM = Sc, Nd, Eu, Gd, Ho and Er) or TiN-Y2O3).

[0322] Apparatus

[0323] The terms "bottom" and "top" are to be understood in relation to the general orientation of the apparatus or fluidized bed reactor. Thus, "bottom" will mean closer to the ground along the vertical axis than "top". In different figures, the same reference signs designate the same or similar elements.

[0324] Figure 1 A fluidized bed reactor 1 of the prior art is shown, comprising a reactor vessel 3, a bottom fluid nozzle 5 for introducing fluidization gas and alcohol-containing feedstock, an optional inlet 7 for material loading, an optional outlet 9 for material discharge, and a gas outlet 11 and a bed 15. In Figure 1 In the fluidized bed reactor 1 of the prior art, heat is provided by preheating the feedstock by combustion of fossil fuel using a heating device 17 arranged at the level of the line providing the reactor with fluidization gas and said alcohol-containing feedstock, for example.

[0325] The apparatus of the present invention is now described with reference to Figures 2 to 5 For the sake of simplicity, internal means used in the fluidized bed reactor are known to the person skilled in the art, such as bubble breakers, guide plates (deflection plates), particle terminal means, cyclones, ceramic wall coatings, thermocouples, etc... and are not shown in the illustrations.

[0326] Figure 2 A first apparatus with a fluidized bed reactor 19 is shown, wherein the heating and reaction zones are identical. The fluidized bed reactor 19 comprises a reactor vessel 3, a bottom fluid nozzle 21 for introducing fluidization gas and alcohol-containing feedstock, an optional inlet 7 for material loading, an optional outlet 9 for material discharge, and a gas outlet 11. Figure 2 The fluidized bed reactor 19 of the prior art shows two electrodes 13 immersed in the bed 25.

[0327] Figure 3 An embodiment is shown, wherein at least one fluidized bed reactor 19 comprises a heating zone 27 and a reaction zone 29, wherein the heating zone 27 is a bottom zone and the reaction zone 29 is on top of the heating zone 27. One or more fluid nozzles 23 provide the alcohol-containing feedstock to the reaction zone from a distributor 33. As can be seen in Figure 3 As can be seen in the prior art, one or more fluid nozzles 23 can be connected to a distributor 33 to distribute the alcohol-containing feedstock inside the bed 25.

[0328] Figure 4 An apparatus is shown, wherein at least one fluidized bed reactor 18 comprises at least two lateral zones, wherein the outer zone is a heating zone 27 and the inner zone is a reaction zone 29. The heated particles from the bed 25 of the outer zone are transferred to the inner zone through one or more openings 41 and mixed with alcohol-containing feedstock and / or steam. At the end of the reaction zone, the particles are separated from the reaction products and transferred to the heating zone.

[0329] Figure 5 An apparatus comprising at least two fluidized bed reactors (37, 39) connected to each other is shown, wherein at least one fluidized bed reactor is a heating zone 27 and at least one fluidized bed reactor is a reaction zone 29.

[0330] The present disclosure provides an apparatus for carrying out a process of endothermic catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins, said apparatus comprising at least one fluidized bed reactor (18, 19, 37, 39), said fluidized bed reactor comprising:

[0331] - at least two electrodes 13,

[0332] - a reactor vessel 3;

[0333] - one or more fluid nozzles (21, 23) for introducing fluidization gas and / or an alcohol- containing feedstock comprising one or more alcohols having at least two carbon atoms and, optionally, one or more inert gases and / or one or more dilution gases into the at least one fluidized bed reactor (18, 19, 37, 39); and

[0334] - a bed 25 comprising particles;

[0335] wherein the particles of the bed 25 comprise electrically conductive particles and particles of a catalytic composition, wherein at least 10 wt.-% of the particles of the bed are electrically conductive, have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400 °C, based on the total weight of the particles of the bed 25, and wherein the catalytic composition comprises one or more solid acid catalysts.

[0336] In particular, the present disclosure provides an apparatus for carrying out a process of endothermic catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins, said apparatus comprising

[0337] i) an electrically energized fluidized bed unit having at least one fluidized bed reactor (18, 19, 37, 39), said fluidized bed reactor comprising:

[0338] - at least two electrodes (13);

[0339] - a reactor vessel (3);

[0340] - one or more fluid nozzles (21, 23) for introducing an alcohol-containing feedstock comprising one or more alcohols having at least two carbon atoms and, optionally, one or more inert gases and / or one or more dilution gases into the at least one fluidized bed reactor (18, 19, 37, 39); and

[0341] - a bed (25) of particles;

[0342] ii) a product withdrawal unit;

[0343] (iii) an olefin-conversion unit, wherein the olefin-conversion unit is selected from an olefin oligomerization unit, or an aromatic alkylation unit, or an olefin oligomerization and aromatic alkylation unit,

[0344] wherein the product is withdrawn downstream of the electrically energized fluidized bed unit and upstream of the olefin-conversion unit;

[0345] The device 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 of the bed are electrically conductive, have an electrical resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at a temperature of 400 °C, based on the total weight of the particles of the bed, and wherein the catalytic composition comprises one or more solid acid catalysts.

[0346] Preferably, the at least two electrodes comprise or are made of tantalum.

[0347] Details on the oligomerization step (e) that can be performed on the one or more olefins withdrawn in step (d) and to be performed in the olefin-conversion unit (i.e. the olefin oligomerization unit) are found in the review entitled “Applications of light olefin oligomerization to the production of fuels and chemicals” (Nicholas C. P., Applied Catal. A: General, 2017, 543, 82-97) and / or in chapter 10 (page 271) of the book entitled “Hydrocarbon Biorefinery” (ISBN 978-0-12-823306-1).

[0348] Details on the alkylation step (f) of aromatic compounds that can be performed on the one or more olefins withdrawn in step (d) and to be performed in the olefin-conversion unit (i.e. the aromatic alkylation unit) are found in the review entitled “Alkylation of aromatics with ethylene and propylene: recent developments in commercial processes” (Degnan Jr. T. F., et al., Applied Catal. A: General, 2001, 221, 283-294) and / or in the review entitled “ Recent advances in the industrial alkylation of aromatics: new catalysts and new processes" (Perego C., et al., Catal. Today, 2002, 73, 3-22) of the book entitled “Hydrocarbon Biorefinery” (ISBN 978-0-12-823306-1).

[0349] The aromatic alkylation unit is designed to receive, in addition to the one or more olefins withdrawn in step (d), the one or more aromatic compound sources provided in step (f). Advantageously, the oligomerization step (e) of the one or more olefins withdrawn in step (d) and the alkylation step (g) of the one or more aromatic compounds provided in step (f) can occur simultaneously within, for example, the same olefin conversion unit as the olefin oligomerization and aromatic alkylation units.

[0350] In converting the olefins in the olefin oligomerization unit or in the aromatic alkylation unit or in the olefin oligomerization and aromatic alkylation units, and if there are remaining olefinic bonds, it is useful to hydrogenate them, especially when the oligomerization step (e) to produce compounds with olefinic moieties is effected. This is the reason why the optional hydrogenation unit can be placed downstream of the olefin conversion unit.

[0351] For example, the electrically conductive particles of the bed are or comprise one or more 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 metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0352] In an embodiment, from 50 wt% to 100 wt%; 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% 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 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 metallic nitrides, one or more metallic phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and any mixture thereof.

[0353] For example, one of the electrodes is a submerged central electrode, or both electrodes 13 are submerged within the reactor vessel 3 of at least one of the reactors (18, 19, 37).

[0354] For example, the fluidization gas is one or more dilution gases.

[0355] In a preferred embodiment, at least one fluidized bed reactor (18, 19, 37, 39) is free of heating means. For example, at least one fluidized bed reactor is free of heating means selected from the group consisting of an oven, a gas burner, a hot plate, or any combination thereof. For example, all fluidized bed reactors are free of heating means selected from the group consisting of an oven, a gas burner, a hot plate, or any combination thereof. In a preferred embodiment, at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles is free of packing.

[0356] For example, the reactor vessel 3 has an inner diameter of at least 100 cm, or at least 200 cm; or at least 400 cm. Such a large diameter allows carrying out chemical reactions on an industrial scale, for example, the weight hourly space velocity of the reaction stream is comprised between 0.1 h -1 and 100 h -1 , preferably between 1.0 h -1 and 50 h -1 , more preferably between 1.5 h -1 and 10 h -1 , even more preferably between 2.0 h -1 and 6.0 h -1 . The weight hourly space velocity is defined as the ratio of the mass flow of the reaction stream to the mass of the solid particulate material in the fluidized bed.

[0357] At least one fluidized bed reactor (18, 19, 37) comprises at least two electrodes 13. For example, one electrode is electrically connected to the outer wall of the fluidized bed reactor, while one additional electrode is immersed in the fluidized bed 25, or both electrodes 13 are immersed in the fluidized bed 25. The at least two electrodes 13 are electrically connected and can be connected to an electrical power source (not shown).

[0358] For example, at least one fluidized bed reactor comprises at least one cooling means arranged to cool at least one electrode.

[0359] During use of the fluidized bed reactor, a voltage of at most 300 V, preferably at most 250 V, more preferably at most 200 V, even more preferably at most 150 V, most preferably at most 100 V, even most preferably at most 90 V, or at most 80 V is applied.

[0360] Due to the fact that the electrical current source can be adjusted, it is easy to adjust the temperature within the reactor bed.

[0361] Preferably, the reactor vessel 3 comprises reactor walls made of a material that is a corrosion-resistant material, and advantageously, the reactor wall material comprises nickel (Ni), SiAlON ceramic, yttria-stabilized zirconium oxide (YSZ), tetragonal polycrystalline zirconium oxide (TZP), and / or tetragonal zirconium oxide polycrystal (TPZ). SiAlON ceramic is a ceramic based on the elements silicon (Si), aluminum (Al), oxygen (O), and nitrogen (N). They are solid solutions of silicon nitride (Si3N4), in which the Si-N bonds are partially replaced by Al-N and Al-O bonds.

[0362] For example, the reactor vessel 3 is made of a resistive material that is a mixture of silicon carbide and molybdenum disilicide; and the resistive material of the reactor vessel 3 comprises from 10 wt.-% to 99 wt.-%; 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.-% silicon carbide, based on the total weight of the resistive material.

[0363] For example, the reactor vessel 3 is made of a resistive material that is a mixture of silicon carbide and molybdenum disilicide.

[0364] For example, the reactor vessel 3 is not electrically conductive. For example, the reactor vessel 3 is made of ceramic.

[0365] 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 21 providing fluidization gas from a distributor 31 to at least the heating zone, one or more fluid nozzles 23 providing alcohol-containing feedstock from a distributor 33 to the reaction zone, and means 41 to transport particles from the heating zone 27 to the reaction zone 29, and optionally means 35 to transport particles from the reaction zone 29 back to the heating zone 27, if necessary.

[0366] For example, as Figure 3As shown in Fig. 1, the apparatus comprises at least one fluidized bed reactor 19, wherein the heating zone 27 is the bottom part of the fluidized bed reactor 19 and the reaction zone 29 is the top part of the fluidized bed reactor 19; preferably, the apparatus comprises one or more fluid nozzles 23 to inject alcohol-containing feedstock between the two zones (27, 29) or in the reaction zone 29. The fluidized bed reactor 19 further comprises an inlet 7, optionally for material loading, an outlet 9, optionally for material discharge, and a gas outlet 11. Preferably, the fluidized bed reactor 19 is free of heating devices. For example, the 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 fluidized bed reactor 19, i.e. the reaction zone 29, is free of electrodes. Optionally, the fluidized bed reactor 19 comprises a device 35 to transport the particles from the reaction zone 29 back to the heating zone 27; for example by means of a line arranged between the top part and the bottom part of the fluidized bed reactor 19.

[0367] For example, as shown in Fig. 1, the apparatus comprises at least one fluidized bed reactor 19, wherein the heating zone 27 is the bottom part of the fluidized bed reactor 19 and the reaction zone 29 is the top part of the fluidized bed reactor 19; preferably, the apparatus comprises one or more fluid nozzles 23 to inject alcohol-containing feedstock between the two zones (27, 29) or in the reaction zone 29. The fluidized bed reactor 19 further comprises an inlet 7, optionally for material loading, an outlet 9, optionally for material discharge, and a gas outlet 11. Preferably, the fluidized bed reactor 19 is free of heating devices. For example, the 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 fluidized bed reactor 19, i.e. the reaction zone 29, is free of electrodes. Optionally, the fluidized bed reactor 19 comprises a device 35 to transport the particles from the reaction zone 29 back to the heating zone 27; for example by means of a line arranged between the top part and the bottom part of the fluidized bed reactor 19. Figure 4 For example, as shown in Fig. 1, the apparatus comprises at least one fluidized bed reactor 19, wherein the heating zone 27 is the bottom part of the fluidized bed reactor 19 and the reaction zone 29 is the top part of the fluidized bed reactor 19; preferably, the apparatus comprises one or more fluid nozzles 23 to inject alcohol-containing feedstock between the two zones (27, 29) or in the reaction zone 29. The fluidized bed reactor 19 further comprises an inlet 7, optionally for material loading, an outlet 9, optionally for material discharge, and a gas outlet 11. Preferably, the fluidized bed reactor 19 is free of heating devices. For example, the 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 fluidized bed reactor 19, i.e. the reaction zone 29, is free of electrodes. Optionally, the fluidized bed reactor 19 comprises a device 35 to transport the particles from the reaction zone 29 back to the heating zone 27; for example by means of a line arranged between the top part and the bottom part of the fluidized bed reactor 19.

[0368] For example, as shown in Fig. 1, the apparatus comprises at least one fluidized bed reactor 19, wherein the heating zone 27 is the bottom part of the fluidized bed reactor 19 and the reaction zone 29 is the top part of the fluidized bed reactor 19; preferably, the apparatus comprises one or more fluid nozzles 23 to inject alcohol-containing feedstock between the two zones (27, 29) or in the reaction zone 29. The fluidized bed reactor 19 further comprises an inlet 7, optionally for material loading, an outlet 9, optionally for material discharge, and a gas outlet 11. Preferably, the fluidized bed reactor 19 is free of heating devices. For example, the 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 fluidized bed reactor 19, i.e. the reaction zone 29, is free of electrodes. Optionally, the fluidized bed reactor 19 comprises a device 35 to transport the particles from the reaction zone 29 back to the heating zone 27; for example by means of a line arranged between the top part and the bottom part of the fluidized bed reactor 19. Figure 5As shown in the middle, the apparatus comprises at least two fluidized bed reactors (37, 39) connected 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. Preferably, the apparatus comprises one or more fluid nozzles 23 arranged to inject alcohol-containing feedstock and / or steam into at least one fluidized bed reactor 39 being the reaction zone 29. The fluidized bed reactors (37, 39) further comprise an inlet 7, optionally for material loading, and a gas outlet 11. Preferably, at least one fluidized bed reactor 37 being the heating zone 27 and / or at least one fluidized bed reactor 39 being the reaction zone 29 are free of heating devices. For example, at least one fluidized bed reactor 39 being the reaction zone 29 shows an outlet 9, optionally for material discharge. When necessary, heated particles are transported from the heating zone 27 to the reaction zone 29 by means of inlet means 41 and particles separated after the reaction zone are transported back to the heating zone by means of means 35. The fluidizing gas for the heating zone can be an inert diluent, such as one or more selected from steam, hydrogen, carbon dioxide, methane, argon, helium and nitrogen. In such a configuration, the fluidizing gas for the heating zone can also comprise air or oxygen to burn deposited coke from the particles.

[0369] For example, the at least two fluidized bed reactors (37, 39) are connected to each other by means 41 (such as one or more lines) adapted to transport particles from the heating zone 27 to the reaction zone 29.

[0370] For example, the at least two fluidized bed reactors (37, 39) are connected to each other by means 41 (such as one or more lines) adapted to transport particles from the heating zone 27 to the reaction zone 29.

[0371] For example, the at least two fluidized bed reactors (37, 39) are connected to each other by means 35 (such as one or more lines) adapted to transport particles from the reaction zone 29 back to the heating zone 27.

[0372] Catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins

[0373] For example, the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins is carried out at a temperature in the range of 200 °C to 500 °C, preferably 240 °C to 490 °C, more preferably 260 °C to 480 °C.

[0374] For example, the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins is carried out at a pressure in the range of 0.05 MPa to 3 MPa, preferably 0.05 MPa to 1.5 MPa, more preferably 0.12 MPa to 0.8 MPa, or 0.12 MPa to 0.5 MPa. This pressure is considered as medium pressure, easy to achieve and economic.

[0375] For example, the partial pressure of the alcohol-containing feedstock is in the range of 0.12 MPa to 0.7 MPa.

[0376] For example, the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins is carried out in the presence of a reaction stream and is carried out in a reaction mixture comprising 0.1 h -1 and 100h -1 between, preferably included within 1.0h -1 and 50h -1 between, more preferably included in 1.5h -1 and 10h -1 between, and even more preferably including, 2.0h -1 and 6.0h -1 The reaction is carried out at a weight hourly space velocity between the reaction flows.

[0377] For example, the residence time of the alcohol-containing feedstock in the fluidized bed section of the reactor where the temperature is from 260°C to 500°C may be in the range of 0.1 to 10 seconds, or 1 to 10 seconds.

[0378] Test and measurement methods

[0379] X-ray diffraction XRD (XRD) is used to determine the crystal structure of the catalyst. It is performed on a powder sample of one or more zeolites synthesized and uses a CuKα monochromatic radiation ( The X-ray diffraction data were taken using a PANalytical X'PertPro diffractometer (45 kV, 40 mA). The sample was scanned in a step size of 0.02 ° within the range of 5-50 ° 2θ. The unit cell parameters of the zeolite particles were determined by X-ray diffraction data using JANA2006 software by calculating based on Le Bail profile refinement and pseudo-Voigt profile functions. In addition, in order to minimize the difference between the observed pattern and the pattern calculated using the structural model, progressive Rietveld refinement was performed using JANA2006 software to solve and quantify the framework and framework outer structure (structure type and atomic position).

[0380] Temperature programmed desorption method (TPD) is a method for observing molecules desorbing from a surface as the surface temperature increases. Figure 6 The heating sequences shown are I, II and III (corresponding to activation, saturation and analysis, respectively). Briefly, in the first step ( Figure 6In the embodiment of the present invention, the solid acid sample was activated by gradually increasing the temperature from room temperature (25°C) to 600°C at a rate of 20°C / min under a helium flow (at a rate of 50 cc / min). After 1 hour at 600°C, the solid acid sample was considered to be activated, and then the temperature was gradually decreased to 100°C at a rate of 10°C / min. Then, in the second step (at Figure 6 During the 3 hours, the temperature was maintained at 100°C and, in the first hour, 10% ammonia (NH3) was added to the helium flow (which was reduced to 30 cc / min). Thus, the surface of the solid acid was saturated with ammonia molecules that were to be adsorbed onto the surface. In the last 2 hours of the 100°C temperature threshold, the initial helium flow was restored. Then, in the third step ( Figure 6 In the embodiment of the present invention, the method for the adsorption of ammonia on the solid acid is carried out by a flow cytometry. The method comprises the steps of: (a) performing a filtration step of the filtration of the solid acid and (b) performing a filtration step of the filtration of the solid acid and (c) performing a filtration step of the filtration of the solid acid and (d) performing a filtration step of the filtration of the solid acid and (e) performing a filtration step of the filtration of the solid acid and (e) performing a filtration step of the filtration of the solid acid and (f) performing a filtration step of the filtration of the solid acid and (f) performing a filtration step of the filtration of the solid acid and (g) performing a filtration step of the filtration step of the filtration step of the solid acid and (g) performing a filtration step of the filtration step of the solid acid and (g) performing a filtration step of the filtration step of the solid acid and (h) performing a filtration step of the filtration step of the solid acid and (h) performing a filtration step of the filtration step of the solid acid and (h) performing a filtration step of the filtration step of the solid acid and (i) performing a filtration step of the filtration step of the solid acid and (ii) performing a filtration step of the filtration step of the solid acid and (ii) performing a filtration step of the filtration step of the solid acid and (iii) performing a filtration step of the filtration step of the solid acid and (ii) performing a filtration step of the filtration step of the solid acid and (iii) performing a filtration step of the filtration step of the solid acid and (iv) performing a filtration step of the filtration step of the solid acid and (v ...

[0381] X-ray fluorescence spectroscopy (XRF)

[0382] X-ray fluorescence (XRF) spectroscopy measurements were performed using an Orbis Micro-EDXRF spectrometer equipped with an Rh source (15 kV, 500 μA) and a silicon drift detector. XRF measurements were performed on the (undissolved) material as is. This is useful for determining the amounts of SiO2 and Al2O3 and, subsequently, the Si / Al atomic ratio.

[0383] N2adsorption measurements

[0384] Nitrogen adsorption / desorption isotherms were determined using N adsorption analysis using a Micrometrics ASAP 2020 volumetric adsorption analyzer. Prior to the measurements, the samples were degassed overnight at 350°C under vacuum. From these measurements, the specific surface area of ​​the solid acid catalyst was determined.

Claims

1. A process for the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins, said process comprising the following steps: a) providing at least one fluidized bed reactor comprising at least two electrodes and a bed comprising particles; b) fluidizing said particles of said bed by passing a fluid upwardly through said bed to obtain a fluidized bed; c) heating the fluidized bed to a temperature in the range of 200° C. to 500° C. to perform catalytic dehydration of an alcohol-containing feedstock to one or more olefins, wherein the alcohol-containing feedstock comprises one or more alcohols having at least two carbon atoms; and d) optionally recovering the one or more olefins; characterised 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 in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C; wherein the catalytic composition comprises one or more solid acid catalysts; and step c) of heating the fluidised bed is carried out by passing an electric current through the fluidised bed.

2. The process according to claim 1, characterized in that The conductive particles of the bed comprise one or more selected from one or more metal alloys, one or more non-metallic resistors, one or more metal carbides, one or more metal nitrides, one or more metal phosphides, one or more carbon-containing particles, one or more superionic conductors, one or more phosphate electrolytes, and / or any mixtures thereof.

3. The process according to claim 1 or 2, characterized in that The conductive particles of the bed include a mixture of a non-metallic resistor that is silicon carbide and conductive particles other than silicon carbide.

4. The process according to claim 3, characterized in that The electrically conductive particles of the bed comprise from 10% to 99% by weight of silicon carbide, based on the total weight of the electrically conductive particles of the bed; and / or The conductive particles other than silicon carbide are one or more carbon-containing particles.

5. The process according to claim 3, characterized in that The conductive particles other than silicon carbide are one or more carbon-containing particles.

6. The process according to claim 1 or 2, characterized in that The electrically conductive particles of the bed comprise one or more metal alloys; and / or one or more superionic conductors.

7. The process according to claim 1 or 2, characterized in that The conductive particles of the bed include LiAlSiO4, Li 10 GeP2S 12 、L i3.6 Si 0.6 P 0.4 O4, sodium superionic conductor, or one or more superionic conductors of sodium beta alumina.

8. The process according to claim 1 or 2, characterized in that The one or more alcohols having at least two carbon atoms are selected from ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, hexan-1-ol, hexan-2-ol, hexan-3-ol, 2-methylpentan-1-ol, 3-methylpentan-1-ol, 4-methylpentan-1-ol, 2-methylpentan-2-ol, 3-methylpentan-2-ol, 4-methylpentan-2-ol, 2-methylpentan-3-ol, 3-methylpentan-3-ol, 2,2-dimethylbutan-1-ol, 2-3-dimethylbutan-1-ol, 3,3-dimethylbutan-1-ol, 2,3-dimethylbutan-2-ol, 3,3-dimethylbutan-2-ol, 2-ethylbutan-1-ol, or any combination thereof.

9. The process according to claim 1 or 2, characterized in that A step of preheating the fluidized bed reactor with a gaseous stream prior to carrying out the catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins in the fluidized bed reactor.

10. The process according to claim 9, characterized in that The gaseous stream is a stream of one or more inert gases chosen from nitrogen, argon, helium, saturated hydrocarbons with up to 10 carbon atoms, or any combination thereof, and / or has a temperature comprised between 100°C and 300°C.

11. The process according to claim 1 or 2, 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 fluid stream provided in step b) is provided to the heating zone, and step c) of heating the fluidized bed to a temperature in the range of 200° C. to 500° C. to perform endothermic catalytic dehydration of an alcohol-containing feedstock to one or more olefins, wherein the alcohol-containing feedstock comprises one or more alcohols having at least two carbon atoms, comprises the following sub-steps: - heating said fluidized bed to a temperature in the range of 200° C. to 500° C. by passing an electric current through said heating zone of said at least one fluidized bed, - transporting heated particles from the heating zone to the reaction zone, - in said reaction zone, said heated particles are placed in a fluidized state by passing a fluid stream comprising an alcohol-containing feedstock and, optionally, one or more inert gases and / or one or more diluent gases, upwardly through said bed of said reaction zone, so as to obtain a fluidized bed and to carry out an endothermic catalytic dehydration of the alcohol-containing feedstock to one or more olefins.

12. The process according to claim 1 or 2, characterized in that The at least one fluidized bed reactor provided in step a) comprises a heating zone and a reaction zone, and wherein step c) of heating the fluidized bed comprises the following sub-steps: - preheating the fluidized bed to a temperature in the range of 100° C. to 300° C. by passing a fluidizing stream upwardly through the particles of the bed, said fluidizing stream being a gaseous stream having a temperature in the range of 100° C. to 300° C.; - heating the fluidized bed to a temperature in the range of 200° C. to 500° C. by passing an electric current through a heating zone of the at least one fluidized bed reactor, - transporting the heated particles from the heating zone to the reaction zone, - in a reaction zone, said heated particles are placed in a fluidized state by passing a fluid stream comprising an alcohol-containing feedstock upwardly through said fluidized bed of the reaction zone, so as to obtain a fluidized bed and to carry out an endothermic catalytic dehydration of one or more alcohols having at least two carbon atoms to one or more olefins, - Optionally, recovering the particles from the reaction zone and recycling them to the heating zone.

13. The process according to claim 1 or 2, characterized in that The one or more solid acid catalysts have a 50 m 2 / g to 800m 2 The present invention relates to a catalyst having a surface area in the range of 1000 Å / g and / or a content of said particles of said catalytic composition in the range of 15% to 90% by weight, based on the total weight of said particles of said bed.

14. The process according to claim 1 or 2, characterized in that The one or more solid acid catalysts are selected from one or more oxides, one or more mixed oxides, one or more phosphates, one or more zeolites, one or more silicoaluminophosphate molecular sieves, or combinations thereof.

15. The process according to claim 1 or 2, characterized in that The one or more solid acid catalysts are mixed with a binder.

16. The process according to claim 15, characterized in that The binder is an inorganic material selected from one or more clays, silica, one or more metal silicates, one or more metal oxides, one or more gels, or a combination thereof.

17. The process according to claim 1 or 2, characterized in that Said step d) is carried out, and said process comprises a step e) of oligomerizing a portion of said one or more olefins recovered in step d), said process further comprising a step f) of providing one or more aromatic compounds, and a step g) of alkylating said one or more aromatic compounds with another portion of said one or more olefins recovered in step d), said step g) being carried out simultaneously with said step e).

18. Use of a bed comprising particles for carrying out a process for the catalytic dehydration of one or more alcohols having at least two carbon atoms to olefins according to any one of claims 1 to 17 in at least one fluidized bed reactor, characterized in that at least 10% by weight of the particles of the bed, based on the total weight of the particles of the bed, are electrically conductive and have a resistivity in the range of 0.001 Ohm.cm to 500 Ohm.cm at 400°C.

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