WO2015082375A1 - Procédé pour mettre en œuvre des réactions endothermiques à catalyse hétérogène - Google Patents

Procédé pour mettre en œuvre des réactions endothermiques à catalyse hétérogène Download PDF

Info

Publication number
WO2015082375A1
WO2015082375A1 PCT/EP2014/076050 EP2014076050W WO2015082375A1 WO 2015082375 A1 WO2015082375 A1 WO 2015082375A1 EP 2014076050 W EP2014076050 W EP 2014076050W WO 2015082375 A1 WO2015082375 A1 WO 2015082375A1
Authority
WO
WIPO (PCT)
Prior art keywords
catalyst particles
particles
reaction
fed
process according
Prior art date
Application number
PCT/EP2014/076050
Other languages
English (en)
Inventor
Christoph DITTRICH
Original Assignee
Saudi Basic Industries Corporation
Sabic Global Technologies B.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Saudi Basic Industries Corporation, Sabic Global Technologies B.V. filed Critical Saudi Basic Industries Corporation
Publication of WO2015082375A1 publication Critical patent/WO2015082375A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J38/00—Regeneration or reactivation of catalysts, in general
    • B01J38/04—Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst
    • B01J38/12—Treating with free oxygen-containing gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/90—Regeneration or reactivation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/0015—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor
    • B01J8/0025—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor by an ascending fluid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/0015—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor
    • B01J8/003—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor in a downward flow
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/005—Separating solid material from the gas/liquid stream
    • B01J8/0055—Separating solid material from the gas/liquid stream using cyclones
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/005—Separating solid material from the gas/liquid stream
    • B01J8/007—Separating solid material from the gas/liquid stream by sedimentation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
    • B01J8/24—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique
    • B01J8/26—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique with two or more fluidised beds, e.g. reactor and regeneration installations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
    • B01J8/24—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique
    • B01J8/26—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique with two or more fluidised beds, e.g. reactor and regeneration installations
    • B01J8/28—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique with two or more fluidised beds, e.g. reactor and regeneration installations the one above the other
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
    • B01J8/24—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique
    • B01J8/38—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique with fluidised bed containing a rotatable device or being subject to rotation or to a circulatory movement, i.e. leaving a vessel and subsequently re-entering it
    • B01J8/384—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique with fluidised bed containing a rotatable device or being subject to rotation or to a circulatory movement, i.e. leaving a vessel and subsequently re-entering it being subject to a circulatory movement only
    • B01J8/388—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique with fluidised bed containing a rotatable device or being subject to rotation or to a circulatory movement, i.e. leaving a vessel and subsequently re-entering it being subject to a circulatory movement only externally, i.e. the particles leaving the vessel and subsequently re-entering it
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G35/00—Reforming naphtha
    • C10G35/04—Catalytic reforming
    • C10G35/06—Catalytic reforming characterised by the catalyst used
    • C10G35/095—Catalytic reforming characterised by the catalyst used containing crystalline alumino-silicates, e.g. molecular sieves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00327—Controlling the temperature by direct heat exchange
    • B01J2208/00336—Controlling the temperature by direct heat exchange adding a temperature modifying medium to the reactants
    • B01J2208/0038—Solids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00504—Controlling the temperature by means of a burner
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/02—Processes carried out in the presence of solid particles; Reactors therefor with stationary particles
    • B01J2208/023—Details
    • B01J2208/024—Particulate material
    • B01J2208/025—Two or more types of catalyst

Definitions

  • the present invention relates to a process for carrying out endothermic, heterogeneously catalyzed reactions.
  • the DHAM catalysts usually comprise a porous support and at least one metal applied thereto, i.e. at least one metal as active component and at least one further metal as dopant, wherein the active component is selected from among Mo, W, Re, Ru, Os, Rh, Ir, Pd, Pt, and the dopant is selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, V, Zn, Zr and Ga.
  • a crystalline or amorphous inorganic compound is usually used as support.
  • the mixture comprising catalyst particles and inert heat transfer particles is transferred from the reaction zone into a regeneration zone wherein both the catalyst particles and the inert heat transfer particles are regenerated in a nonoxidative atmosphere by introduction of a hydrogen-comprising regeneration gas stream.
  • WO 2009/105344 relates to a process for converting methane to higher hydrocarbons including aromatic hydrocarbons, the process comprising contacting a feed comprising methane with a dehydrocyclization catalyst in a reaction zone under conditions effective to convert said methane to aromatic hydrocarbons, said dehydrocyclization catalyst comprising molybdenum or a compound thereof dispersed on an aluminosilicate zeolite and the amount of aluminum present as aluminum molybdate.
  • the dehydrocyclization reaction tends to deposit coke on the catalyst and hence, to maintain the activity of the dehydrocyclization catalyst, at least part of the catalyst is continuously or intermittently regenerated by withdrawing a portion of the catalyst from the or each reaction zone, either on an intermittent, or a continuous basis, and then transferring the catalyst portion to a separate regeneration zone. Since the dehydrocyclization reaction is endothermic, it is necessary to supply heat to the reaction by withdrawing part of the catalyst from the reaction zone, either on an intermittent or a continuous basis, supplying heat to the catalyst and then returning the heated catalyst back to the reaction zone.
  • US 2007/0249880 discloses a process for converting methane to higher hydrocarbon(s) including aromatic hydrocarbon(s) in a reaction zone, the process comprising : (a) providing to a reaction zone a hydrocarbon feedstock containing methane; (b) providing a quantity of catalytic material within the reaction zone; (c) maintaining the reaction zone with an inverse temperature profile; and (d) operating the reaction zone under reaction conditions sufficient to convert at least a portion of methane to a first effluent having said higher hydrocarbon(s).
  • coked catalyst needs to be regenerated outside of the methane dehydroaromatization (MDA) reactor with hydrogen.
  • Coke burn-off with oxygen would convert catalytically active Mo carbide into Mo oxide being volatile at high temperature resulting in a significant loss.
  • the catalytically active Mo carbide moiety needs to be formed again during an induction period in the MDA reactor.
  • regeneration with hydrogen does not supply enough heat such that the hot regenerated catalyst recirculated to the MDA reactor could be used as heat source for the endothermic MDA reaction requiring additional heating of the recirculated catalyst, e.g. by hot flue gases, when using the regenerated catalyst as heat source for the MDA reaction.
  • Another aspect is that recirculated coarse inert heat carrier particles occupy a significant part of the MDA reactor volume without effect beyond being heat source. Additional means are necessary for regenerating coked fine bifunctional catalyst either inside the MDA reactor, or in a second external recirculation loop for fine bifunctional catalyst.
  • the denser and larger particles of the inert heat carrier may grind t e fine bifunctional catalyst particles, thereby creating dust and related problems.
  • An object of the present invention is to provide a process for carrying out endothermic, heterogeneously catalyzed reactions wherein the disadvantages of the prior art discussed above have been overcome or at least minimized.
  • Another object of the present invention is to provide a process for carrying out endothermic, heterogeneously catalyzed reactions wherein the heat necessary for the endothermic reaction is supplied by regenerated catalyst particles.
  • the process for carrying out endothermic, heterogeneously catalyzed reactions according to the present invention comprise the steps of:
  • the reactor contains two types of catalyst particles.
  • metal supported catalyst particles e.g. molybdenum (Mo)carbide, especially Mo(oxy)carbide
  • Mo molybdenum
  • aromatization catalyst particles e.g. zeolite particles catalyze the aromatization of the intermediate species. Coking of zeolite occurs as undesired side reaction of the aromatization reaction.
  • the present invention is principally based on the fact that the metal supported catalyst particles, e.g. supported Mo(oxy)carbide, stays in the reactor while the aromatization catalyst particles, e.g. partially coked zeolite particles are discharged from the reactor and decoked in a regenerator.
  • the terms "Mo carbide” and "Mo(oxy)carbide” are used interchangeably.
  • Air can be used for burning off coke because zeolites are not sensitive to oxygen.
  • the combustion heat of removed coke heats up the zeolite particles which in turn are recirculated to the reactor at a temperature higher than the reaction temperature.
  • the heated, regenerated catalyst particles supply the heat for the overall endothermic dehydroaromatization reactions.
  • the catalyst particles comprise supported metal catalyst particles and zeolite particles.
  • the catalyst particles comprise bifunctional catalysts, e.g. Mo carbide supported on zeolite particles, and zeolite particles.
  • Solid acid catalysts such as zeolites, are inorganic or organic porous solids which provide Bronsted- and/or Lewis-acidic sites capable to catalyze aromatization reactions of lower aliphatic hydrocarbons.
  • the present inventor found that the two types of catalyst particles with the two different catalytic components/functions will undergo different treatments inside the process, e.g. for coke removal. If both catalytic functions/components are located on the same type of catalyst particle like in the discussed US 2012/0022310 and WO 2009/105344, the catalyst particles need to be treated such that none of the two catalytic functions/components is damaged.
  • one type of catalyst particles comprises a metal supported catalyst, i.e. molybdenum as catalytic component for methane activation and the second type of catalyst particle comprise zeolite as catalytic component for aromatization.
  • a metal supported catalyst i.e. molybdenum as catalytic component for methane activation
  • the second type of catalyst particle comprise zeolite as catalytic component for aromatization.
  • the present inventor found that the first type (molybdenum) should not be treated with air because it will damage the catalytic function (as can be found in WO 2009/105344) while the second type (zeolite) can and should be treated with air. Since the second type (zeolite) accumulates coke much faster than the first type (molybdenum) it can be recirculated through an oxidizing regenerator, heated up during coke combustion and returned as heat carrier and regenerated second type-catalyst into the reactor.
  • the present inventor is of the opinion that the first type (molybdenum) of catalyst particles cokes much less and is regenerated, if needed, in a separate, non-oxidizing regenerator, e.g. by hydrogen.
  • the mixture of catalyst particles is not regenerated (for coke removal) and reheated (for reaction heat supply) in a single step, as is the case in both WO 2009/105344 and US 2012/0022310, but preferably the second type (zeolite) of catalyst particles is regenerated and reheated.
  • the afore mentioned reaction zone is chosen from the group of fluidized bed type reactor, fixed bed trickle flow type reactor and monolith trickle flow reactor.
  • the Mo carbide catalyst especially Mo(oxy)carbide
  • the Mo carbide catalyst on inert support forms a stationary bubbling bed and the zeolite powder is transported upwards by gas through the bubble and void volume.
  • the reactor is a fixed bed trickle flow reactor the Mo carbide catalyst on inert support forms the fixed bed and zeolite powder trickles through the void space by gravity, or is transported upwards by gas through the void space.
  • the sizes of the inert support particles for the Mo carbide catalyst and the zeolite particles are to be chosen such that the Mo carbide catalyst is fluidized in bubbling mode in the fluidized bed reactor, or forms a fixed bed in the fixed bed reactor.
  • the zeolite is either kept in bubbling or fast fluidization mode by the gas feed flow in a fluidized bed reactor, or kept in trickle flow or in fast fluidization in a fixed bed or monolith trickle flow reactor.
  • the engineer skilled in the art will be able to select the diameters of Mo carbide catalyst particles and zeolite particles accordingly.
  • the reactor is a monolith trickle flow reactor, in which the Mo carbide catalyst is immobilized on the monolith surface and the zeolite powder trickles downwards through the straight or zigzag shaped channels of the monolith, or is transported upwards by gas through the channels of the monolith.
  • reaction temperature can be chosen such that the coking rate is high enough that burning off the coke delivers the heat required by the overall endothermic dehydroaromatization reaction.
  • both types of catalysts can be fluidized in bubbling mode together in the reactor, and recirculate between the reactor and a disengagement vessel, where the fine zeolite particles and the coarse particles of supported Mo carbide are separated by elutriation of the fine zeolite particles.
  • the Mo carbide catalyst particles especially Mo(oxy)carbide, are recycled directly to the reactor, or fed to a reducing regenerator in order to remove any potential traces of coke by hydrogasification, while the elutriated zeolite particles are decoked in an oxidative regenerator by coke burn-off. In that way, the Mo carbide catalyst can be regenerated or replaced independently on the zeolite catalyst.
  • the Mo carbide catalyst may contain an acid function as well.
  • the dehydroaromatization reactor contains a mixture of bifunctional catalyst, e.g. Mo carbide supported on zeolite, and zeolite, of which the bifunctional catalyst particles are decoked in a reducing regenerator and the zeolite particles are decoked in an oxidative regenerator.
  • the Mo carbide catalyst particles are more active for methane activation.
  • the bifunctional catalyst particles have on average a larger particle size than the zeolite particles.
  • More heat additional to the combustion heat of coke burn-off can be supplied to the recirculating fine zeolite particles in an additional catalyst reheater.
  • the flue gases of a burner heat the catalyst reheater and provide part of or the complete transport gas for transporting the fine zeolite catalyst through the reheater which is essentially a riser.
  • the reactor temperature does not necessarily to be chosen such that the coking rate matches the heat requirements of the overall aromatization reaction, but can be chosen in a wider temperature range.
  • the fluidized bed reactor can be compartmented horizontally or vertically by baffles, weirs or trays in order to ensure a more uniform residence time distribution of the catalyst particles of both types, and especially of the fine zeolite particles. In that way, it is prevented that comparably fresh and not yet coked zeolite catalyst is withdrawn prematurely from the reactor.
  • the regenerated hot zeolite particles can be recirculated to the compartmented reactor to different compartments in order to ensure a more homogeneous temperature profile.
  • the regeneration zone comprises a stripper unit and an oxidative regenerator, wherein the stripper is fed with natural gas as stripping gas, and the gaseous effluent comprising mainly natural gas components, lower olefins, benzene, toluene and naphthalene is sent to further processing units.
  • the effluent comprising coked particles from said stripper is preferably fed to said oxidative regenerator, said oxidative regenerator being fed with air.
  • step b) comprises feeding the mixture of said two types of catalyst particles to a disengagement vessel, separating of the coked catalyst particles from the mixture present in said disengagement vessel and returning the other type of catalyst particles into said reaction zone, wherein said disengagement vessel is fed with natural gas.
  • the step of returning said other type of catalyst particles comprises especially feeding said other type of catalyst particles to a reducing regenerator and returning the thus regenerated other type of catalyst particles to said reaction zone, wherein said reducing regenerator is fed with a hydrogen containing gas.
  • the step of recirculating the regenerated catalyst particles comprises preferably a step of reheating the regenerated catalyst particles and returning the thus reheated, regenerated catalyst particles to said reaction zone, more preferably by passing the reheated, regenerated catalyst particles through a cyclone before returning to said reaction zone.
  • the present method further comprises positioning several reaction zones in series, wherein the oxidatively regenerated catalyst particles from a first reaction zone are fed to a second reaction zone, wherein the oxidatively regenerated catalyst particles from a second zone are fed to a third reaction zone, wherein preferably the coked catalyst particles from the third reaction zone are transferred to a regeneration zone and the thus regenerated catalyst particles are fed to the first reaction zone in order to ensure a more uniform residence time distribution of the catalyst particles of both types, and especially of the fine zeolite particles. In that way, it is prevented that comparably fresh and not yet coked zeolite catalyst is withdrawn prematurely from the dehydroaromatization reactor.
  • the oxidatively regenerated catalyst particles transferred from a first to a second reaction zone, or from a second to a third reaction zone can be reheated with flue gas before entering a second or a third reaction zone. Even more heat can be supplied to the reaction zones for the endothermic overall reaction in that way.
  • the regenerated hot zeolite particles can be recirculated to the reactor to different reaction zones in order to ensure a more homogeneous temperature profile. Such a method of positioning several reaction zones in series is however not restricted to a specific number of reaction zones.
  • Fig.1 shows an embodiment of the method according to the present invention.
  • Fig.2 shows another embodiment of the method according to the present invention.
  • Fig.3 shows an embodiment of the method according to the present invention.
  • Fig.4 shows another embodiment of the method according to the present invention.
  • Fig.5 shows another embodiment of the method according to the present invention.
  • the drawing illustrates a simplified design of a dehydroaromatization reactor system for converting methane or lower hydrocarbons into aromatics by non-oxidative dehydroaromatization according to one embodiment of this disclosure, wherein natural gas is used as feedstock.
  • the stripper natural gas is used as a stripping gas and CH4, lower olefins, lower paraffins, benzene, toluene, naphthalene are discharged from the top of the stripper.
  • the zeolite particles are in a fluidized state in the stripper and discharged to an oxidative regenerator for decoking purposes. Air is used for burning off coke because zeolites are not sensitive to oxygen. The combustion heat of removed coke heats up the zeolite particles which in turn are recirculated to the reactor at a temperature higher than the reaction temperature. The heated, regenerated catalyst particles supply the heat for the overall endothermic dehydroaromatization reactions.
  • the dehydroaromatization reactor can be a fluidized bed reactor, a fixed bed trickle flow reactor or a monolith trickle flow reactor.
  • the Mo carbide catalyst on an inert support forms the fixed bed and zeolite powder trickles through the void space, wherein the Mo carbide catalyst is fluidized in bubbling mode (fluidized bed reactor), or forms a fixed bed in the fixed bed reactor, while the zeolite is either kept in bubbling or fast fluidization mode by the gas feed flow.
  • the Mo carbide catalyst is immobilized on the monolith surface and the zeolite powder trickles through the straight or zigzag shaped channels of the monolith.
  • FIG. 2 is a schematic drawing illustrating a simplified design of a dehydroaromatization reactor system for converting methane or lower hydrocarbons into aromatics by non-oxidative dehydroaromatization according to another embodiment of this disclosure.
  • the stripping section and oxidative regenerator, as discussed in Fig 1 above, are omitted for legibility reasons, but the person skilled in the art would immediately recognize that these process units are necessary as well. This simplification of the total process is also valid for the discussion of the processes shown in Figs. 3-5.
  • Both catalysts are fluidized in bubbling mode together in the dehydroaromatization reactor, and recirculate between the reactor and a disengagement vessel, where the fine zeolite particles and the coarse particles of supported Mo carbide are separated by elutriation of the fine zeolite particles.
  • the Mo carbide catalyst particles can be recycled directly to the dehydroaromatization reactor.
  • natural gas is used as transport gas, and the coked zeolite particles, together with the natural gas, are sent to the stripping section and oxidative regenerator, as discussed in Fig. 1 above. The thus regenerated, hot zeolite particles are returned to the reactor at the bottom thereof.
  • Product gas leaves the dehydroaromatization reactor at the top and is further processed elsewhere.
  • Fig. 3 is based on the principle of Fig. 2 discussed above, but the Mo carbide catalyst particles are fed from the disengagement vessel to a reducing regenerator in order to remove any potential traces of coke by hydrogasification, while the elutriated zeolite particles are withdrawn from said disengagement vessel and decoked in an oxidative regenerator by coke burn-off, as discussed above in Fig.2. In that way, the Mo carbide catalyst can be regenerated or replaced independently on the zeolite catalyst. Hydrogen is fed to the reducing regenerator in which regenerator the Mo carbide catalyst particles are present as a bubbling fluidized bed. Hydrogen and methane is discharged from the reducing regenerator, and the thus regenerated Mo carbide catalyst particles are recycled to the bottom of the dehydroaromatization reactor with the aid of a transport gas, for example natural gas.
  • a transport gas for example natural gas.
  • Fig. 4 shows another embodiment of the present invention in which an additional catalyst reheater is used. Consequently, more heat additional to the combustion heat of coke burn-off is supplied to the recirculating fine zeolite particles in such an additional catalyst reheater.
  • the flue gases of a burner heat the catalyst reheater and provide part of or the complete transport gas for transporting the fine zeolite catalyst through the reheater which is essentially a riser.
  • the reheated catalyst particles are fed to a cyclone for separating the zeolite particles from the gaseous stream, and only the catalyst particles thus heated are fed to the dehydroaromatization reactor.
  • the reactor temperature of the dehydroaromatization reactor does not necessarily to be chosen such that the coking rate matches the heat requirements of the overall aromatization reaction, but can be chosen in a wider temperature range.
  • Fig. 5 shows another embodiment of the present invention in which the fluidized bed dehydroaromatization reactor of the type fluidized bed is compartmented vertically by trays in three different compartments in order to ensure a more uniform residence time distribution of the catalyst particles of both types, and especially of the fine zeolite particles. In that way, it is prevented that comparably fresh and not yet coked zeolite catalyst is withdrawn prematurely from the dehydroaromatization reactor.
  • the regenerated hot zeolite particles are recirculated to the top compartment of the compartmented reactor.
  • the invention is in no way limited to any number of compartments and even five, six or ten compartments may be present.
  • the bottom or third compartment receives natural gas as feedstock and the product gas leaves the dehydroaromatization reactor at the top after passing through the second or middle compartment and the top or first compartment, respectively.
  • the mixture of both zeolite particles and supported Mo catalyst is transported to a disengagement vessel in which the zeolite particles are separated from the supported Mo catalyst particles.
  • the supported Mo catalyst particles are returned to the top compartment of the dehydroaromatization reactor, whereas the zeolite particles, together with the transport gas, are fed to a separation unit, e.g. a cyclone, and separated from the transport gas.
  • the zeolite particles thus separated are fed to the middle or second compartment of the dehydroaromatization reactor.
  • the mixture of both zeolite particles and supported Mo catalyst is transported to a disengagement vessel in which the zeolite particles are separated from the supported Mo catalyst particles.
  • the supported Mo catalyst particles are returned to the middle or second compartment of the dehydroaromatization reactor, whereas the zeolite particles, together with the transport gas, are fed to a separation unit, e.g. a cyclone, and separated from t e transport gas.
  • the zeolite particles thus separated are fed to the bottom or third compartment of the dehydroaromatization reactor.
  • the mixture of both zeolite particles and supported Mo catalyst is transported to a disengagement vessel in which the zeolite particles are separated from the supported Mo catalyst particles.
  • the supported Mo catalyst particles are returned to the third or bottom compartment of the dehydroaromatization reactor, whereas the zeolite particles, together with the transport gas, are fed to a separation unit, e.g. a cyclone, and separated from the transport gas.
  • the zeolite particles thus separated are fed to a stripping section and an oxidative regenerator (both not shown), as discussed in Fig. 1 above.
  • the thus regenerated hot zeolite is returned to the top or first compartment of the dehydroaromatization reactor.
  • the coked zeolite particles coming from the third or bottom compartment of the dehydroaromatization reactor are first sent to a stripper section and an oxidative regeneration section and then to a reheating section, similar to the embodiment as discussed above in Fig. 4.
  • Fig. 5 shows that coarse particles of Mo carbide catalyst on an inert support are fluidized in bubbling mode in the different compartments of a vertically compartmented fluidized bed by upwards flowing gas feed of methane and lower hydrocarbons.
  • Regenerated hot particles of fine zeolite catalyst coming from the bottom compartment of the dehydroaromatization reactor are fed to the top compartment and fluidized in bubbling mode together with the Mo carbide catalyst particles.
  • Zeolite particles are separated from the Mo carbide catalyst particles in a disengagement vessel next to each reactor compartment and fed to the next lower reactor compartment.
  • Zeolite catalyst deactivated by coke is collected in the disengagement vessel next to the bottom zone of the reactor and interstitial product gas is removed from the deactivated zeolite catalyst in the stripper by using methane as stripping gas.
  • the deactivated zeolite catalyst is regenerated by burning off coke with oxygen or air in a bubbling fluidized bed and thereby heated up.
  • the regenerated zeolite catalyst is preferably further heated by burner flue gases in a riser to a temperature higher than the reactor gas outlet temperature and high enough to supply the heat of the endothermic overall aromatization reaction via the sensible heat of the regenerated zeolite catalyst particles.
  • Fig. 5 discloses a countercurrent flow of zeolite and feed/product gas
  • the regenerated hot zeolite is fed to the bottom compartment and coked zeolite is withdrawn from the top compartment.
  • Fig. 5 discloses the use of natural gas as transport gases to the disengagement vessels
  • hot flue gas is used as transport gas, thereby heating up the zeolite particles transferred from a previous to a subsequent compartment and supplying even more heat to the reactor compartments for the overall endothermic reactions.
  • Figs. 1 -5 clearly show that the use of two types of catalyst particles in a dehydroaromatization the reactor has a beneficial effect on the supply of the heat of reaction to the reactor.
  • the supported Mo carbide catalyst stays in the reactor while the partially coked zeolite particles are discharged from the reactor and decoked in a separate process unit, i.e. a regenerator.
  • the combustion heat of removed coke heats up the zeolite particles which in turn are recirculated to the reactor at a temperature higher than the reaction temperature.
  • the heated, regenerated catalyst particles supply the heat for the overall endothermic dehydroaromatization reactions.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Materials Engineering (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Catalysts (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

La présente invention concerne un procédé pour mettre en œuvre des réactions endothermiques à catalyse hétérogène, qui comprend les étapes a) mise en œuvre de la réaction dans une zone de réaction en présence d'un mélange comprenant deux types de particules de catalyseur, comprenant des particules de catalyseur sur support métallique et des particules de catalyseur d'aromatisation, b) séparation des particules de catalyseur d'aromatisation cokéfiées dudit mélange présent dans ladite zone de réaction, c) transfert desdites particules de catalyseur d'aromatisation cokéfiées séparées dans une zone de régénération, d) mise en œuvre d'une régénération desdites particules de catalyseur d'aromatisation cokéfiées dans ladite zone de régénération, e) recirculation, vers ladite zone de réaction, des particules de catalyseur d'aromatisation ainsi régénérées.
PCT/EP2014/076050 2013-12-03 2014-12-01 Procédé pour mettre en œuvre des réactions endothermiques à catalyse hétérogène WO2015082375A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP13195484.4 2013-12-03
EP13195484 2013-12-03

Publications (1)

Publication Number Publication Date
WO2015082375A1 true WO2015082375A1 (fr) 2015-06-11

Family

ID=49683605

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2014/076050 WO2015082375A1 (fr) 2013-12-03 2014-12-01 Procédé pour mettre en œuvre des réactions endothermiques à catalyse hétérogène

Country Status (1)

Country Link
WO (1) WO2015082375A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110434280A (zh) * 2019-09-03 2019-11-12 南阳仁创砂业科技有限公司 一种水玻璃无机旧砂再生方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009105344A2 (fr) * 2008-02-21 2009-08-27 Exxonmobil Chemical Patents Inc. Production des produits aromatiques à partir de méthane
US20120022310A1 (en) * 2010-07-21 2012-01-26 Basf Se Process for preparing aromatics from methane

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009105344A2 (fr) * 2008-02-21 2009-08-27 Exxonmobil Chemical Patents Inc. Production des produits aromatiques à partir de méthane
US20120022310A1 (en) * 2010-07-21 2012-01-26 Basf Se Process for preparing aromatics from methane

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110434280A (zh) * 2019-09-03 2019-11-12 南阳仁创砂业科技有限公司 一种水玻璃无机旧砂再生方法

Similar Documents

Publication Publication Date Title
US5858207A (en) FCC process with combined regenerator stripper and catalyst blending
EP0106052B1 (fr) Démétallisation et décarbonisation de charges de départ consistant en huiles résiduelles
CN1926080B (zh) 脱氢烃化合物的制备方法
US4840928A (en) Conversion of alkanes to alkylenes in an external catalyst cooler for the regenerator of a FCC unit
US5059305A (en) Multistage FCC catalyst stripping
JP2937479B2 (ja) アルカンを脱水素する方法及び装置
CN101939100A (zh) 由甲烷生产芳族化合物
JP2015528037A (ja) 軽質オレフィン又は中質流出物及び軽質オレフィンを最大化するための流動式接触分解方法及び装置
CN105859503A (zh) 脱氢方法和催化剂
US2730556A (en) Method for effecting endothermic dehydrogenation reactions
JP4674658B2 (ja) 触媒の還元を含む移動床での芳香族化合物の製造方法
CA1183826A (fr) Regeneration d'un catalyseur de conversion de petroles residuaires charges d'elements carbometalliques
WO2016061905A1 (fr) Procédé de production d'oléfine à faible teneur en carbone
WO2015082375A1 (fr) Procédé pour mettre en œuvre des réactions endothermiques à catalyse hétérogène
JP2002241764A (ja) 重質油の流動接触分解法
US5019353A (en) Reactor system for conversion of alkanes to alkenes in an external FCC catalyst cooler
JPH04322747A (ja) 炭素質物質を含む粒子からこのような物質を除去する方法および装置
CN114478180B (zh) 一种重质芳烃轻质化方法
JPH0272127A (ja) アルカンからの芳香族炭化水素の製造方法
US2733282A (en) Fluidized solids reactor system
CA1183825A (fr) Regeneration d'un catalyseur de conversion de petroles residuaires charges d'elements carbometalliques
JP4660834B2 (ja) 触媒の還元を含む、芳香族化合物の製造方法および装置
CN116083119B (zh) 一种废塑料油与重油共炼生产丙烯和高芳烃汽油的催化转化方法
US2464489A (en) Method for hydrocarbon conversion
JP2885876B2 (ja) 水素化脱アルキル方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14809320

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14809320

Country of ref document: EP

Kind code of ref document: A1