WO2013135668A1

WO2013135668A1 - Chemical reactor system, comprising an axial flow reactor with heating levels and intermediate levels

Info

Publication number: WO2013135668A1
Application number: PCT/EP2013/054960
Authority: WO
Inventors: Vanessa GEPERT; Alexander Karpenko; Emanuel Kockrick; Leslaw Mleczko; Albert TULKE; Daniel Gordon Duff; Ludger KASTER; Daniel Wichmann
Original assignee: Bayer Intellectual Property Gmbh
Priority date: 2012-03-13
Filing date: 2013-03-12
Publication date: 2013-09-19

Abstract

The present invention relates to a chemical reactor system, comprising a first flow reactor for reacting a fluid comprising reactants and a second flow reactor connected downstream of the first flow reactor and/or parallel thereto for reacting a fluid comprising reactants. The second flow reactor, as viewed in the direction of flow of the fluid, comprises a plurality of heating levels (100, 101, 102, 103), which are electrically heated by means of heating elements (110, 111, 112, 113), and wherein the fluid can flow through the heating levels, wherein a catalyst is arranged on at least one heating element, where it can be heated. The invention also relates to a method for operating a reactor system according to the invention.

Description

Chemical reactor system comprising an axial flow reactor with hitting and intermediate planes

The present invention relates to a chemical reactor system comprising a first flow reactor for reacting a reactant comprising fluid and a fluid downstream of the first flow reactor and / or connected in parallel with the second flow reactor for reacting a reactant comprising fluid. The second flow reactor comprises in the flow direction of the fluid seen a plurality of heating levels, which are electrically heated by heating elements and wherein the heating levels are flowed through by the fluid, wherein at least one heating element, a catalyst is arranged and is heated there. It further relates to a method for operating a reactor system according to the invention.

Due to the increased expansion of renewable energies, a fluctuating supply of energy in the power grid is created. In phases of favorable electricity prices results for the operation of reactors for carrying out endothermic reactions, preferably for the production of synthesis gas, the possibility of an economical and economically meaningful operation taking advantage of renewable energies when they are electrically heated. This is especially the case when a direct heating of a catalyst structure is possible, so that losses are significantly reduced by heat transfer resistances.

Conventionally, synthesis gas is produced by steam reforming of methane. Due to the high heat demand of the reactions involved, they are carried out in externally heated reformer tubes. Characteristic of this process is the limitation due to the reaction equilibrium, a heat transfer limitation and above all the pressure and temperature limitation of the reformer tubes used (nickel-based steels). Temperature and pressure side results in a limitation to a maximum of 900 ° C at about 10 to 40 bar. An alternative method is autothermal reforming. In this case, a portion of the fuel is burned by the addition of oxygen within the reformer, so that the reaction gas is heated and the expiring endothermic reactions are supplied with heat.

In the prior art, some proposals for internal heating of chemical reactors have become known. For example, Zhang et al., International Journal of Hydrogen Energy 2007, 32, 3870-3879, describe the simulation and experimental analysis of a coaxial axial cylindrical dumbber using an electrically heated alumite catalyst (EHAC ). DE 10 2008 027 882 A1 relates to a process for producing a low-carbon, low-methane gas (synthesis gas), wherein a hydrocarbon-containing feed (fuel) together with carbon dioxide (CO2) and / or water vapor and an oxidizing agent by catalytically assisted partial oxidation (autothermal reforming or ATR) is implemented. The synthesis gas as product gas of the autothermal reforming is obtained at a temperature of more than 1 100 ° C. Also described is an apparatus for producing a low carbon, low methane gas (syngas) comprising a refractory lined, pressure resistant reactor (ATR reactor) in which a hydrocarbon containing feed (fuel) is co-charged with carbon dioxide (CO2) and / or Steam and an oxidizing agent by catalytically assisted partial oxidation (autothermal reforming or ATR) can be implemented and a reactor burner through which the starting materials in the reaction chamber of the ATR reactor can be introduced, wherein the synthesis gas as product gas from the ATR reactor at a temperature of more than 1 100 ° C is deductible. DE 19960521 A1 discloses a device for the elimination of oineches and / or odors by oxidation on a solid catalyst, which is characterized in that the solid noble metal catalyst on a metallic conductive wire, tape or tissue-shaped tubular carrier in adhering thinly or firmly bonding by burn-in with the metallic carrier, or by first coating the metallic carrier with a substantially porous mass, anchoring it to the metallic carrier by baking and loading the porous mass by impregnation with noble metal catalysts and the metallic carrier to heat by DC or AC current to the required oxidation temperature, wherein the change of the electrical resistance is used for temperature control and the effluent gas from the converter is used to preheat the incoming gas. DE 10 2010 033316 A1 describes an exhaust gas treatment system comprising: M electrically heated substrates coated with a catalyst material and arranged in series to receive exhaust gas from a machine, M being an integer greater than one; and a heater control module that applies power to N of the M substrates to heat the N substrates for a predetermined period, where N is an integer less than M, wherein during the predetermined period the engine is off and the M electrically heated substrates are not Absorb exhaust.

DE 103 1 71 7 relates to an electrically heated reactor for carrying out gas reactions at high temperature, comprising a reactor block surrounded by an enclosure of one or more monolithic modules made of a material suitable for resistance heating or inductive heating, as a reaction space, from one to the A device for supplying and discharging a gaseous medium to / from the channels and at least two electrodes (8, 8 ') connected to a power source and the reactor block for passing a current through the reactor block or a device for the Inducing a stream in the reactor block, wherein the enclosure of the reactor block comprises a gas-tight sealing this double jacket and at least one device for supplying an inert gas in the double jacket.

The publication Guo et al., Chemical Engineering Science 2011, 66, 6287-6296 is assigned to

Steam reforming of kerosene directed.

US 2009/246118 Λ 1 discloses a process and plant for producing hydrogen in which a synthesis gas stream from the gasification of a carbonaceous substance is processed in a synthesis processing unit by reacting the carbon monoxide content with steam to form further hydrogen , which is removed by a pressure swing absorption unit. The pass-through unit is further reformed in a steam reformer by adding a hydrocarbon stream. Thus, more hydrogen is obtained. This is also separated in a Druckwechsels elabsorption unit.

WO 2007/042279 AI deals with a reformer system with a reformer for the chemical conversion of a hydrocarbon-containing fuel into a hydrogen-rich gas

Reformatgas, as well as electrical heating means by which the reformer heat energy for producing a reaction temperature required for the reaction can be supplied, wherein the reformer system further comprises a capacitor which can supply the electric heating means with electric current.

However, it would be desirable to have a more accurate control of a temperature profile in an endothermic internally heated reaction. The present invention has therefore set itself the task of providing a suitable reactor system for this purpose.

This object is achieved according to the invention by a chemical reactor system comprising a first flow reactor for reacting a fluid comprising reactants and a fluid downstream of the first flow reactor and / or a second flow stream connected in parallel therewith or in which the reactant comprises Second Str ömungsr eakt or one, seen in the flow direction of the fluid, comprises a plurality of heating levels, which are electrically heated by heating elements and wherein the heating levels are flowed through by the fluid, wherein at least one heating element, a catalyst is arranged and is heated there; where at least once an intermediate level between two Heating levels is arranged and wherein the intermediate plane is also traversed by the fluid.

The intermediate level in the second flow reactor or its contents can also be catalytically coated. This not only serves as a contact surface for the metallic conductor, but also generates a pressure loss, which is mainly due to porosity and thickness

Reactor inlet has a better flow distribution result. The combination of heat conductor and intermediate level (or support surface) can then be on a metallic support structure, which ensures the mechanical stability. It is preferred that the intermediate plane is an electrical insulation, in particular in the presence of a metallic support structure.

By the one or more located in the second flow reactor, non-heated intermediate level, a dwell of a reacting fluid can still be achieved, within which there is a more favorable heat distribution. By choosing correspondingly long or short distances of the fluid through the intermediate plane (s), the reaction can be influenced in a comparatively simple manner. Furthermore, it is possible to influence the reaction by catalytic coatings in different types or amounts in the intermediate level or their content.

A further subject of the present invention is a method for operating a chemical reactor system, comprising the steps of: a) providing an abovementioned reactor system according to the invention; b) electrically heating at least one of the heating elements in the second flow reactor, the aforementioned reactor system according to the invention; and c) passing a reactant-comprising fluid through the first and second flow reactors of the aforesaid reactor system of the invention with at least partial reaction of the reactants of the fluid.

The reactor system according to the invention is particularly suitable for the production of synthesis gas. Therefore, in the following, the invention will be described in this aspect without, however, being limited thereto.

The first flow reactor can be a (conventional) reforming reactor. Thanks to its compact and modular design, the second flow rate control is suitable for increasing the capacity of a conventional system for generating electricity. The incorporation of the second flow reactor in the overall system can, inter alia, as a post-reactor or as Backup system done. The connection of a parallel arranged second flow reactor for capacity expansion can be done quickly due to the electric heating, when an increased demand for reaction products occurs. The second flow reactor can be started up as needed and operated with fresh reaction gas. Both reactors can use the same gas purification system. Furthermore, the second flow reactor can be integrated into a suitable bypass strand in an existing combination of conventional reformers and purification (CO2 scrubbing, drying, coldbox, PSA, etc.).

A further advantage of the internal heating of the second flow reactor is that higher temperatures than in other refrigerants can be used. Prior to equilibrium limited reactions, these higher temperatures (or the ability to impose a specific temperature profile) may allow an increase in sales.

Reactions which can be carried out in the reactor system according to the invention and in particular in the second flow reactor are, for example, the dry reforming of

Methane (DR. CI L + C0 ₂ ; ± 2 CO + 2 H ₂ ), the reverse water gas shift reaction (RWGS, C0 ₂ + H ₂ 5 = £ CO + H ₂ 0), the partial oxidation of methane (POX , CH ₄ + 1/2 0 ₂ ^ CO + 2 H ₂ ), the methane steam reforming (SMR, CH ₄ + I!: · () ^ CO + 3 H ₂ ) and the reaction of methane with

Ammonia for the production of hydrocyanic acid (BMA, CI I i + NH ₃ HCN + 3 H ₂ ). Mixed forms of

Reactions SMR, RWGS and DR are also possible.

In the use of the second flow reactor as a post-reactor in the synthesis gas production enters the reformer (first flow reactor) with temperatures of preferably below 900 ° C leaving reformate or fission gas in the Nachre actuator. In other words, if the inlet temperature is high, unwanted side reactions such as carbon formation or methanation are largely suppressed. An additional preheating is then obsolete. In the secondary reactor, a continuation of the equilibrium reaction at higher temperatures can be realized. This is accompanied by an increase in sales and an increase in the CO yield and thus enables a capacity increase based on the target products, especially CO. Especially in equilibrium reactions with strong pressure dependence, a continuation of the reaction towards higher temperatures can once again increase the conversion.

The system according to the invention is characterized by a high flexibility with regard to the energy input. Thus, it is possible to respond flexibly to the degree of the respective prevailing endothermy. This makes it possible to operate the postreactor both with pure RWGS operation (+ 38 kJ / mol) and with pure dry reforming (+247 kJ / mol). This opens up a wide window of possible input compositions and also includes a mixed operation the aforementioned reactions, especially SMR and the mixed operation with CI I H2O and CO2. Furthermore, a reaction to demand-changed ratios of H2 / CO is possible.

Because of this and the fact that the electrical heating in the second reactor is usually characterized by a very rapid heating behavior, the second reactor can also be used as a backup system for demand-controlled additional syngas production in a composite of conventional reformers. It is therefore possible to flexibly set up the system capacity if the second reactor is switched on as required. Conventional reformers show very little tolerance to frequent startup and shutdown procedures. The present invention, including preferred embodiments thereof, is illustrated in conjunction with the following drawings and examples, without being limited thereto. The embodiments can be combined as desired, unless clearly the opposite results from the context.

In the drawings: FIG. 1 -4 schematically second flow reactors according to the invention in an expanded representation FIG. 5-10 Results of Simulation Calculations for Two Flow Reactors

The in FIG. 1 schematically flows through a fluid comprising reactants from top to bottom, as shown by the arrows in the drawing. The fluid may be liquid or gaseous and may be single-phase or multi-phase. Preferably, also in view of the possible reaction temperatures, the fluid is gaseous. It is conceivable that the oil contains exclusively reactants and reaction products, but also that additionally inert components such as inert gases are present in the fluid.

As seen in the flow direction of the fluid, the reactor has a plurality of (four in the present case) heating levels 100, 101, 102, 103, which are electrically heated by means of corresponding heating elements 110, 111, 112, 113. The heating levels 100, 101, 102, 103 are in operation of the

Flowed through the reactor by the fluid and the heating elements 1 10, 1 1 1, 1 12, 1 13 are contacted by the fluid.

At least one heating element 1 10, 1 1 1. 1 12, 1 13 a catalyst is arranged and is heated there. The catalyst can directly or indirectly with the heating elements 1 10, 1 1 1. 1 12, 1 13 be connected, so that these heating elements represent the catalyst support or a support for the catalyst support. In the reactor, therefore, the heat supply of the reaction takes place electrically and is not introduced from the outside by means of radiation through the walls of the reactor, but directly into the interior of the reaction space. It is realized a direct electrical heating of the catalyst.

For the heating elements 1 10, 1 1 1, 1 12, 1 13 are preferably Heizleiterlegierungen such as FeCrAl alloys used. As an alternative to metallic materials, it is also possible to use electrically conductive Si-based materials, particularly preferably SiC, and / or carbon-based materials.

In the present invention the second flow reactor is also at least once a, for example, ceramic intermediate layer 200, 201, 202 (which is preferably of a ceramic or metallic support frame / ^'is plane worn) between two heating zones 100, 101, 102, 103 are disposed, wherein the intermediate plane ( n) 200, 201, 202 or the contents 210, 21 1, 212 of an intermediate level 200, 201, 202 are likewise flowed through by the fluid during operation of the reactor. This has the effect of homogenizing the fluid flow. It is also possible that additional catalyst is present in one or more intermediate levels 200, 201, 202 or other isolation elements in the reactor. Then an adiabatic reaction can take place.

When using FeCrAl heating conductors, the fact can be exploited that the material forms an AhCh protective layer by temperature acting in the presence of air / oxygen. This passivation layer can serve as the basis of a washcoat which acts as a catalytically active coating. Thus, the direct resistance heating of the catalyst or the heat supply of the reaction is realized directly via the catalytic structure. It is also, when using other 1 lei leiier. the formation of other protective layers such as Si-O-C systems possible.

The pressure in the reactor can take place via a pressure-resistant steel jacket. Using suitable ceramic insulation materials it can be achieved that the pressure-bearing steel is exposed to temperatures of less than 200 ° C and, if necessary, less than 60 ° C. By means of appropriate devices, it can be ensured that, when the dew point is undershot, there is no condensation of water on the steel jacket.

The electrical connections are shown in FIG. 1 only shown very schematically. They can be conducted in the cold region of the reactor within an insulation to the ends of the reactor or laterally from the heating elements 1 1 0, 1 1 1. 1 12, 1 1 3 are performed so that the di e actual electrical connections can be provided in the cold region of the reactor. The electrical heating is done with direct current or alternating current. Against the background of conventional heat recovery and heat integration in the overall process and / or plant composite reactor inlet temperatures are often reached by 600 ° C, which are often below the desired inlet temp eratur which reduce the formation of carbon black / carbon in reforming reactions. The connection of one or more of the described electrically heated elements as a gas heater allows a rapid heating of the educt gases to temperatures higher than usual in the prior art, without an oxygen-containing atmosphere is required.

The use of the electrically heated elements in the inlet region of the reactor also has a positive effect with regard to the cold start and starting behavior, in particular with regard to rapid heating to the reaction temperature and better controllability.

By means of suitable shaping, it is possible to achieve an increase in performance. It is possible that in the second flow reactor in the heating levels 100, 101, 102, 103 heating elements 1 10, 1 1 1, 1 12, 1 13 are arranged, which are helical, meandering, lattice-shaped and / or net-shaped. It is also possible that in the second flow reactor at least one heating element 1 10, 1 1 1, 1 12, 1 13 one of the remaining heating elements 1 10, I I I, 1 12, 1 13 different amount and / or type of catalyst is present. Preferably, the heating elements 1 10, I I I, 1 12, 1 13 are arranged so that they can each be electrically heated independently.

In the final result, the individual heating levels can be individually controlled and regulated. As required, a catalyst in the heating levels can also be dispensed with in the reactor inlet area, so that only the heating and no reaction take place in the inlet area.

This is particularly advantageous in terms of starting the reactor. When the heating levels 100, 101, 102, 103 are in power input, catalyst loading and / or

Different catalyst type, a matched for the particular reaction temperature profile can be achieved. With regard to the application for endothermic equilibrium reactions this is for example a Temperaturpr il. the highest temperatures and therefore the highest

Sales achieved at the reactor outlet.

The (for example ceramic) intermediate levels 200, 201, 202 or their contents 210, 21 1, 212 comprise a material resistant to the reaction conditions, for example a ceramic foam. They serve for mechanical support of the heating levels 100, 101, 102, 103 and for mixing and distribution of the gas stream. At the same time is such an electrical

Insulation between two heating levels possible. It is preferred that in the second flow reactor the material of the content 210, 21 1, 212 of an intermediate level 200, 201, 202 oxides, carbides, nitrides, Phosphides and / or borides of aluminum, silicon and / or zirconium. An example of this is SiC. Further preferred is cordierite.

The intermediate level 200, 201, 202 in the second flow reactor can comprise, for example, a loose bed of solids. These solids themselves may be porous or solid, so that the fluid flows through gaps between the solids. It is preferred that the material of the solid bodies comprises oxides, carbides, nitrides, phosphides and / or borides of aluminum, silicon and / or zirconium. An example of this is SiC. Further preferred is cordierite.

It is also possible that in the second flow reactor, the intermediate level 200, 201, 202 comprises a one-piece porous solid. In this case, the fluid flows through the intermediate plane via the pores of the solid. This is shown in FIG. 1 shown. Preference is given to honeycomb monoliths, as used for example in the exhaust gas purification of internal combustion engines.

With regard to the structural dimensions, it is preferred that the average length of a plane 100, 101, 102, 103 seen in the flow direction of the fluid and the average length of an intermediate level 200, 201, 202 in the flow direction of the fluid in a ratio of> 0 , 01: 1 to <100: 1 to each other. Even more advantageous are ratios of> 0, 1: 1 to <10: 1 or 0.5: 1 to <5: 1.

Suitable catalysts in the second flow reactor may for example be selected from the group consisting of: (I) mixed metal oxides of the formula A (i _-w -x) A _'w A _"x B (Iy _z) B' _y B" _z 03-Deita where:

A, A 'and A "are independently selected from the group: Mg, Ca, Sr, Ba, Li, Na, K. Rh. Cs, Sn, Sc, Y, La, Ce, Pr, Nd, Pm, Sm , Eu, Gd, Tb. Dy, Ho, Er, Tm, Yb, Tl, Lu, Ni, Co, Pb, Bi and / or Cd, and B, B 'and B "are independently selected from the group: Cr , Mn, Fe. Bi Cd,

Co, Cu, Ni, Sn, Al, Ga, Sc, Ti, V, Nb, Ta, Mo, Pb. I i f. Zr. Tb.W. (id.Yb.Mg, Li, Na, K. Ce and / or Zn; and

0 <w <0.5; 0 <x <0.5; 0 <y <0.5; 0 <z <0.5 and - 1 <delta <1; (II) mixed metal oxides of the formula A (i _-w -x) A _'w A _"x B (IYZ) B' _y B" _z 03-Deita which applies here: A, A 'and A "are independently selected from the group: Mg, Ca, Sr, Ba, Li, Na, Rh. Cs, Sn, Sc, Y, La, Ce, Pr, Nd. Sm, Eu, Gd, Tb. Dy. Ho, Er, Tm. Yb. Tl, Lu, Ni,

Co, Pb and or Cd; and

B is selected from the group: Cr, Mn, Fe, Bi, Cd, Co, Cu, Ni, Sn, Al, Ga, Sc, Ti, V, Nb, Ta, Mo, Pb, I I f. Zr, Tb. W. Gd. Yb. Mg, Cd, To. Re. Ru. Rh. Pd, Os, Ir and / or Pt;

B 'is selected from the group: Re, Ru, Rh, Pd, Os, Ir and / or Pt;

B "is selected from the group: Cr, Mn, Fe, Bi. Cd, Co, Cu, Ni, Sn, Al, Ga, Sc, Ti, V, Nb. Ta, Mo, Pb I II ^" . Zr. Tb. W. Gd. Yb. Mg, Cd and Zn; and

0 <w <0.5; 0 <x <0.5; 0 <y <0.5; 0 <z <0.5 and -1 <delta <1; (III) mixtures of at least two different metals M 1 and M2 on a support comprising an oxide of Al, Ce and / or Zr doped with a metal M 3; where:

Ml and M2 are independently selected from the group: Re. Ru. Rh. Ir, Os, Pd and / or Pt; and M3 is selected from the group: Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm,

Yb and / or Lu;

(IV) mixed metal oxides of the formula LOx (M ( _y / _z ) Al (2-y / z) 03) z; where:

L is selected from the group: Na, K. Rb. Cs, Mg, Ca, Sr, Ba. Sc, Y. Sn, Pb. Pd. Mn. In. Tl, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and / or Lu; and

M is selected from the group: Ti, Zr. Hf, V, Nb. Ta, Cr, Mo, W, Mn, Re. Fe. Ru. Os, Co, Rh. Ir, Ni, Pd. Pt, Zn. Cu, Ag and / or Au; and l <x <2; 0 <y <12; and 4 <z <9;

(V) mixed metal oxides of the formula L0 (Al ₂ O ₃ ) _Z ; where:

I is selected from the group: Na, K. Rb. Cs, Mg, Ca, Sr, Ba, Sc, Y. Sn, Pb. Mn, In, Tl, La, Ce, Pr. Nd. Sm, Eu. Gd. Tb. Dy. Ho, He, Tin. Yb and / or Lu; and 4 <z <9;

(VI) Oxide catalyst comprising Ni and Ru.

(VII) metal Mi and / or at least two different metals M1 and M2 on and / or in a carrier, wherein the carrier is a carbide, oxycarbide, carbonitride, nitride, boride, silicide, germanide and / or selenide of the metals A and / or 6 is; where:

Ml and M2 are independently selected from the group: Cr, Mn, Fe, Co, Ni,

Re, Ru, Rh, Ir, Os, Pd, Pt, Zn, Cu, La. Ce, Pr, Nd, Sm, Eu, Gd, Tb. Dy, Ho, Er. Tm, Yb, and / or Lu; and

A and 6 are independently selected from the group: Be, Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr. Nb, Mo, I I f. Ta, W. La. Ce, Pr, nd. Sm, Eu, Gd. Tb, Dy. Ho, Er, Tm, Yb. and / or Lu; and or

Reaction products of (I), (II), (III), (IV), (V), (VI) and / or (VII) in the presence of carbon dioxide, hydrogen, carbon monoxide and / or water at a temperature of> 700 ° C.

The term "reaction products" includes the catalyst phases present under reaction conditions.

Preferred are for:

(I) LaNiÜ3 and / or

(especially

(II) LaNio, 9-o, 99Ruo, o1 -O, 103 and / or LaNio, 9-o, 99Rho, oi-o, i03 (especially LaNio ^ Ruo.osC and / or LaNio.gsRho.osC).

(III) Pt-Rh on Ce-Zr-Al oxide, Pt-Ru and / or Rh-Ru on Ce-Zr-Al oxide

(IV) BaNiAlnOi9, C a N i A I11O19, BaNio, 975Ruo, o25Ali 1019,

1O19,

BANIO, 92Ruo, o8AlnOi9,

and / or BaRuo.osAln.gsOig

(V) BaAlizOw, SrAli ₂ 0i ₉ and / or CaAli ₂ 0i ₉

(VI) Ni and Ru on Ce-Zr-Al oxide, on an oxide of the class of perovskites and / or on an oxide of the class of hexaaluminates (VII) Cr, Mn, Fe, Co, Ni, Re, Ru, Rh. Ir, Os, Pd, Pt, Zn, Cu, La, Ce, Pr, Nd, Sm, Eu, Cid. Tb, Dy. Ho, Er, Tm, Yb, and / or Lu on M02C and / or WC.

The second flow reactor according to the invention can have a modular design. A module may include, for example, a heating level, an intermediate level, the electrical contact and the corresponding further insulation materials and thermal insulation materials.

In the inventive method in the provided second flow reactor is an electrical heating of at least one of the heating elements 110, III, 1 12, 113. This may, but not in time prior to the passage of a reactant comprising fluid through the flow stream or at least partially reacting the reactants the fluid take place. As already mentioned in connection with the reactor, it is advantageous if the individual heating elements 1 10, 11, 112, 13 are operated in the second flow reactor or in each case with different heating power.

With regard to the temperature, it is preferred that in the first and / or second flow reactor, the reaction temperature in the reactor is at least in places> 700 ° C to <1300 ° C. More preferred ranges are> 800 ° C to <1200 ° C and> 900 ° C to <1100 ° C, especially> 850 ° C to <1050 ° C.

The average (average) contact time of the fluid to a heating element 1 10, 1 1 1, 1 12, 1 13 in the second flow reactor, for example,> 0.01 seconds to <1 second and / or the average contact time of the fluid to an intermediate level. 1 10, III. For example, 1 12, 1 13 may be> 0.001 seconds to <5 seconds. Preferred contact times are> 0.005 to <1 second, more preferably> 0.01 to <0.9 second.

The reaction in the first and / or second flow reactor may take place at a pressure of> 1 bar

<200 bar are performed. Preferably, the pressure is> 2 bar to <50 bar, more preferably> 6 bar to <30 bar. It is possible that additional reactants are added to the fluid between the first and second flow reactors. In particular, it may be CO2, for example, from a return of a CO2 scrubber act. With hydrogen present in the cracked gas, the H2 / CO ratio is then reduced by means of an RWGS reaction taking place in the second flow reactor or this ratio can be adapted flexibly to the respective requirement. Furthermore, hydrogen or hydrogen gas, which is contaminated with CO and / or methane, for example (purge, PSA exhaust gas, etc.) can also be supplied and converted into the desired product CO together with CO.sub.2. It is also preferred that the reactants in the fluid are selected from the group comprising alkanes, alkenes, alkynes, alkanols, alkenols, alkynols, carbon monoxide, carbon dioxide, water, ammonia, hydrogen and / or oxygen. Among the alkanes, methane is particularly suitable, among the alkanols methanol and / or ethanol are preferred. The following figures 2-4 show second flow reactors, which are optimized for certain reactions, further a mixed operation with various above-mentioned reactions is expressly possible. In the use of the second flow reactor as a slow-reacting or as a gas-to-gas product, the equilibrium ends with the equilibrium composition corresponding to the exit tem- perature of the first reactor. This can then be added to other streams.

FIG. 2 shows a further second flow reactor according to the invention, which can preferably be used for the RWGS reaction. The first heating level 100 with heating element 1 10 is not yet provided with a catalyst and serves as a gas heater. The subsequent intermediate level 200 contains a monolithic shaped catalyst body 210, which is catalytically coated. Alternatively, it may also be a catalyst bedding. This is followed by a heating level 101 with heating element 1 1 1, an intermediate level 201 with a porous support layer 21 1 (optionally catalytically coated) and a further 1 leizebene 102 with heating element 1 12 at. Downstream of this heating level 102 is again an intermediate level 202 with a monolithic catalytic converter body or catalyst inlet 212, a heating level 103 with a heating element 13 and an intermediate level 203 with a monolithic shaped catalyst body or catalyst feed 213. At least one of the heating elements 11 1 1, I 12 and I 13 also includes a catalyst.

Also, the individual catalyst-supporting elements of the reactor may be different in the type and amount of the catalyst, and the heating elements may be controlled and controlled individually or in groups.

The characteristics of the RWGS reaction lie in a comparatively moderate heat requirement and in the fact that it is an equilibrium reaction. As a side reaction, a Metlianisierung especially at elevated pressure and at temperatures below 800 ° C occur. Therefore, a high gas inlet temperature is preferably selected in order to thermodynamically suppress the side reactions and in particular the methanation. In turn, a high outlet temperature ensures high sales.

The catalytic reaction takes place here for the most part adiabatically to the monolithic catalyst moldings and to a lesser extent to the catalyst provided with I lei / elements. FIG. 3 shows a further second flow reactor according to the invention, which can preferably be used for dry reforming. The first heating level 100 with heating element 1 10 can not yet be provided with a catalyst and then serves as a pure gas heater. In order to avoid unwanted side reactions, however, a (weakly) catalytically active layer may already be applied to the heating element 110. The subsequent intermediate level 200 contains an orotic support layer 210, which may optionally be catalytically coated. This is followed by a heating level 101 with a catalytically coated heating element 11 1, an intermediate level 201 with a porous supporting layer 211 (optionally catalytically coated) and a further heating level 102 with a catalytically coated heating element 1 12. Downstream of this heating level 102 is again an intermediate level 202 with a porous support layer 212 (optionally catalytically coated), a heating level 103 with catalytically coated heating element 11 and an intermediate level 203 with a porous support layer 213 (optionally catalytically coated).

Again, the individual catalyst-carrying elements of the reactor can differ in the type and amount of the catalyst and the heating elements can be controlled and regulated individually or in groups.

The main feature of the Dry Reforming lies in a high heat demand, which prevails locally limited, especially in the first third of the reactor. It is an equilibrium reaction with a soot formation as a side reaction. Therefore, it is preferred to choose high gas inlet temperatures to thermodynamically suppress the side reaction. High outlet temperatures ensure high sales. The reaction takes place essentially in the catalytically coated heating elements.

FIG. 4 shows a further second flow reactor according to the invention, which can preferably be used for methane steam reforming. The first heating level 100 with heating element 1 10 can not yet be provided with a catalyst and then serves as a pure gas heater. In order to avoid unwanted side reactions, however, a (weakly) catalytically active layer may already be applied to the heating element 110. The subsequent intermediate level 200 contains a porous support layer 210, which may optionally be catalytically coated. This is followed by a heating level 101 with a catalytically coated heating element 11 1, an intermediate level 201 with a porous supporting layer 2 1 1 (optionally catalytically coated) and a further heating level 102 with a catalytically coated heating element 1 12. Downstream of this heating level 102 is again an intermediate level 202 with a porous support layer 212 (optionally catalytically coated), a heating level 103 with catalytically coated heating element 13 and an intermediate level 203 with monolithic shaped catalyst body or catalyst bed 213. Again, the catalyst supporting elements of the reactor may differ in the type and amount of catalyst and the heating elements may be controlled and controlled individually or in groups.

The main feature of methane steam reforming is a high heat requirement. It is an equilibrium reaction with a soot formation as a side reaction. Therefore, it is preferable to select high gas inlet temperatures to thermodynamically suppress the side reaction. High outlet temperatures ensure high sales. The reaction is carried out essentially in the first reactor segment on the catalytically coated heating elements. The first segment is characterized by the fact that the reactant concentration and the heat requirement of the reaction are very high. In the second segment of the reactor, which is characterized by the fact that the reactant methane is already largely implemented and the volume-specific heat demand is significantly lower, the further reaction of the starting materials can be carried out on catalytically coated moldings. The heating elements then act as an intermediate heater as needed.

EXAMPLES In the following, simulation studies for two different methods of a second flow reactor according to the invention ("driving style I" and "driving style II") are described.

The simulation studies were based on the following:

• The mathematical model equations were derived on the basis of the mass and energy balancing on the differential volume element. · The model contains a solid phase and a gas phase

• The mass transfer between gas and catalyst is taken into account (linear instinct of propulsion)

• Changes in the states large are only considered in the axial flow direction (ID model) · The temperature and pressure dependence of the substance sizes is taken into account The simulation studies refer to a) the dry reforming b) the reactor type based on FIG. 3, that is, the heating levels are catalytically coated and the reaction takes place on these catalytically active 1 lei / conductors Driving instructions:

FIG. Figure 5 shows the conversion (XCH4, XCCG) over the normalized reactor length. The "spikes" in the sales profile result from the consideration of a bypass stream that is added behind each heating element.The turnover rises steadily and reaches 90% after the first half of the reactor, then the sales level flattens out and approaches the corresponding equilibrium value at the exit at.

FIG. 6 shows the temperature profile of the gas and solid phase. In the mode of operation shown, the maximum power of the heating elements is given up in the inlet area (corresponds to 100% in the power profile). Much of the electrical energy is consumed by the heat of reaction. The power input is selected such that the solid-state temperature (including the catalysis) is in the range around 1 100 ° C. The reaction gas enters the reactor at 800.degree. C., and the temperature of the gas phase rises above the reactor length through heat exchange with the solid. The reaction takes place on the solid, reactions in the gas phase are not taken into account. FIG. 7 shows the relative heating power per heating element. The profile of heat input per element (in percent based on the maximum power of a single element) shows that the highest power is introduced in the first third of the reactor. At the rear of the reactor, sales level off and only a small input of power is required. This is where the concepts derive. which provide monolithic shaped bodies or catalyst charge in the area.

Fahi-wise II:

In contrast to driving mode I, the advantage of the reactor concept is clarified here

Reaction to impose a desired temperature profile can. The gas temperature in the inlet is 800 ° C and the power input per heating element is chosen so that a continuous ramp over the reactor length is impressed with the highest temperature at the reactor outlet is reached. In contrast to the procedure I, a longer reactor is required in this procedure, but the heating elements are significantly less burdened, which can lead to longer service life. FIG. 8 shows the conversion (XCH4, XCCC) over the normalized reactor length, FIG. 9 shows the temperature profile of the gas and solid phase and FIG. 10 shows the relative heating power per heating element.

Claims

claims

A chemical reactor system comprising a first flow reactor for reacting a reactant comprising fluid and a fluid downstream of the first flow reactor and / or connected in parallel therewith second flow reactor for reacting a reactant, characterized in that the second flow reactor, viewed in the flow direction of the fluid , a plurality of heating levels (100, 101, 102, 103), which are electrically heated by means of heating elements (1 10, 11 1, 1 12, 1 13) and wherein the heating levels (100, 101, 102, 103) of the Fluid can be flowed through, wherein at least one heating element (1 10, III, 1 12, 113), a catalyst is arranged and is heated there; wherein at least once an intermediate level (200, 201, 202) between two heating levels (100, 101, 102, 103) is arranged and wherein the intermediate level (200, 201, 202) can also be traversed by the fluid.

2. Reactor system according to claim 1, wherein in the second flow direction or in the heating levels (100, 101, 102, 103) heating elements (110, 111, 112, 113) are arranged which form a spiral, meandering shape are constructed erförmig and / or net-shaped.

3. Reactor system according to claim 1 or 2, wherein in the second flow reactor at least one heating element (1 10, III, 1 12, 1 13) one of the other heating elements (1 10, I ii, 112, 113) different amount and / or Type of catalyst is present.

4. Reactor system according to one of claims I to 3, wherein in the second flow reactor, the heating elements (1 10, 1 1 1, 1 12, 1 13) are arranged so that they can each be electrically heated in each case independently.

5. Reactor system according to one of claims 1 to 4, wherein in the second flow reactor, the material of the content (210, 211, 212) of an intermediate level (200, 201, 202) oxides, carbides, nitrides, phosphides and / or borides of aluminum, silicon and / or zirconium.

6. Reactor system according to one of claims 1 to 5, wherein in the second flow reactor the

Intermediate level (200, 201, 202) comprises a loose bed of solids.

7. Reactor system according to one of claims 1 to 5, wherein in the second flow reactor, the intermediate level (200, 201, 202) comprises a one-piece porous Festk body.

8. Reactor system according to one of claims 1 to 7, wherein in the second flow reactor, the average length of a 1 Iegebene (100, 101, 102, 103) seen in the flow direction of the fluid and the average length of an intermediate level (200, 201, 202) in Seen flow direction of the fluid in a ratio of> 0.01: 1 to <100: 1 to each other.

Reactor system according to one of claims 1 to 8, wherein in the second flow reactor, the catalyst is selected from the group consisting of:

(I) mixed metal oxides of the formula A (i _-w -x) A _'w A _"x B (Iy _z) B' _y B" _z 03-Deita which applies here:

A, A 'and A "are independently selected from the group: Mg, Ca, Sr,

Ba, Li, Na, K, Rb, Cs, Sn, Sc, Y, La, Ce, Pr, Nd, Pm, Sin, Eu, Gd, Tb, Dy, Ho, Er. Tin, Yb, Tl, Lu, Ni, Co, Pb, Bi and / or Cd; and

B, B 'and B "are independently selected from the group: Cr, Mn, Fe, Bi, Cd, Co, Cu, Ni, Sn, Al, Ga, Sc, Ti, V, Nb, Ta, Mo, Pb , II for Zr Tb, W, Gd, Yb, Mg, Li, Na, K. Ce and / or Zn;

0 <w <0.5; 0 <x <0.5; 0 <y <0.5; 0 <z <0.5 and -1 <delta <1;

(II) mixed metal oxides of the formula A (i _-w -x) A _'w A _"x B (Iy _z) B' _y B" _z 03-Deita which applies here:

A, A 'and A "are independently selected from the group: Mg, Ca, Sr, Ba, Li, Na, K. Rb. Cs, Sn, Sc, Y. La, Ce, Pr. Nd, Sm, Eu Ho, Er, Tm, Yb, Tl, Lu, Ni, Co, Pb, and / or Cd, and Gd, Tb

B is selected from the group: Cr, Mn, Fe, Bi, Cd, Co, Cu, Ni, Sn, Al, Ga, Sc, Ti, V, Nb, Ta, Mo, Pb, Hf, Zr. Tb, W. Gd. Yb, Mg, Cd, Zn, Re. Ru. Rh. Pd. Os, Ir and / or Pt; and

B 'is selected from the group: Re, Ru, Rh, Pd, Os, Ir and / or Pt; and

B "is selected from the group: Cr, Mn, Fe, Bi. Cd, Co, Cu, Ni, Sn, Al, Ga. Sc, Ti, V, Nb, Ta. Mo, Pb. Hf, Zr. Tb. W. Gd. Yb. Mg, Cd and / or Zn; and

0 <w <0.5; 0 <x <0.5; 0 <y <0.5; 0 <z <0.5 and -1 <delta <1;

(III) mixtures of at least two different metals M 1 and M2 on a support comprising an oxide of Al, Ce and / or Zr doped with a metal M 3; where:

Ml and M2 are independently selected from the group: Re, Ru. Rh. Ir, Os, Pd and / or Pt; and

M3 is selected from the group: Sc, Y, La, Ce, Pr. Nd, Sm, Eu, Gd. Tb. Dy, Ho, Er, Tin, Yb and / or Lu;

(IV) mixed metal oxides of the formula LO _x (M ( _y / _z ) Al (2-y / z) 03) z; where:

I. is selected from the group: Na, K, Rh, Cs, Mg, Ca, Sr, Ba, Sc, Y, Sn, Pb, Pd, Mn, In, Tl, La, Ce, Pr. Nd. Sm, Eu, Gd, Tb, Dy. Ho, he. Tin, Yb and / or Lu; and M is selected from the group: Ti, Zr, Hf, V, Nb. Ta, Cr, Mo. W. Mn, Re. Fe, Ru.

Os, Co, Rh. Ir, Ni, Pd. Pt. Zn, Cu, Ag and / or Au; and

0 <x <2; 0 <y <12; and 4 <z <9;

(V) mixed metal oxides of the formula LO (Al ₂ O ₃ ) _z ; where:

1. is selected from the group: Na, K. Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y. Sn, Pb. Mn,

In, T1, La, Ce, Pr. Nd, Sm, Eu. Gd, Tb. Dy. Ho, he. Tm, Yb and / or Lu; and

4 <z <9;

(VI) Oxide catalyst comprising Ni and Ru.

(VII) metal Ml and / or at least two different metals Ml and M2 on and / or in a carrier, wherein the carrier comprises a carbide, oxycarbide, carbonitride, nitride, boride,

Silicide, germanide and / or selenide of metals A and / or B; where:

MI and M2 are independently selected from the group: Cr, Mn, Fe, Co, Ni, Re. Ru. Rh. Ir. Os, Pd. Pt, Zn. Cu, La, Ce, Pr. Nd. Sm, Eu. Gd, Tb, Dy. Ho. He, Tm. Yb. and / or Lu; and

A and B are independently selected from the group: Be, Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y. Zr. Nb. Mo. Hf, Ta. W. La, Ce, Pr, Nd. Sm, Eu, Gd. Tb, Dy. Ho, Er, Tm, Yb, and / or Lu; and or

Reaction products of (I), (II), (III), (IV), (V), (VI) and / or (VII) in the presence of carbon dioxide, hydrogen, carbon monoxide and / or water at a temperature of> 700 ° C. 10. A method / operation of a chemical reactor system, comprising the steps of: a) providing a reactor system according to one or more of claims 1 to

9; b) electrically heating at least one of the heating elements (110, 111, 112, 113) in the second flow reactor; and c) passing a reactant comprising fluid through the first and second fluid

Flow reaction or at least partial reaction of the reactants of the fluid.

1 1. A method according to claim 10, wherein in the second flow reactor, the individual heating elements (110, 111, 112, 113) are operated with a respective different heating power. 12. The method according to claim 10 or 11, wherein in the first and / or second flow reactor, the reaction temperature in the reactor at least in places> 700 ° C to <1300 ° C.

13. The method according to any one of claims 10 to 12, wherein in the second flow reactor, the average contact time of the fluid to a heating element (110, 11, 112, 113) is> 0.01 second to <1 second and / or the average Contact time of the fluid to the content (210, 211, 212) of an intermediate level (200, 201, 201)> 0.001 seconds to <5

Seconds.

14. The method of claim 10, wherein additional reactants are added to the fluid between the first and second flow reactors.

15. The method according to any one of claims 10 to 14, wherein the reactants in the fluid are selected from the group comprising alkanes, alkenes, alkynes, alkanols, alkenols, alkynols, carbon monoxide, carbon dioxide, water, ammonia, hydrogen and / or oxygen.