THERMAL INTEGRATION OF AN ELECTRICALLY HEATED REACTOR

Abstract

The present invention proposes a plant (110) for producing reaction products. The plant (110) comprises at least a preheater (114). The plant (110) comprises at least one raw material supply (118) which is adapted for supplying at least one raw material to the preheater (114). The preheater (114) is adapted for preheating the raw material to a predetermined temperature. The plant (110) comprises at least one electrically heatable reactor (122). The electrically heatable reactor (122) is adapted for at least partially converting the preheated raw material into reaction products and byproducts. The plant (110) comprises at least one heat integration apparatus (132) which is adapted for at least partially supplying the byproducts to the preheater (114). The preheater (114) is adapted for at least partially utilizing energy required for preheating the raw material from the byproducts.

Claims

1.-16. (canceled)

17. A plant (110) for producing reaction products, wherein the plant (110) comprises at least one preheater (114), wherein the plant (110) comprises at least one raw material supply (118) which is adapted for supplying at least one raw material to the preheater (114), wherein the preheater (114) is adapted for preheating the raw material to a predetermined temperature, wherein the plant (110) comprises at least one electrically heatable reactor (122), wherein the electrically heatable reactor (122) is an electrically operated reactor, wherein the electrically heatable reactor (122) is adapted for heating a fluid present in the reactor (122) using electric current, wherein the electrically heatable reactor (122) is adapted for at least partially converting the preheated raw material into reaction products and byproducts, wherein the plant (110) comprises at least one heat integration apparatus (132) which is adapted for at least partially supplying the byproducts to the preheater (114), wherein the preheater (114) is adapted for at least partially utilizing energy required for preheating the raw material from the byproducts, wherein the plant (110) comprises at least one safety device (182) which is adapted for allowing a return stream of the raw material from the electrically heatable tube system of the reactor (122) to the preheater (114).

18. The plant (110) according to claim 17, wherein the plant (110) comprises at least one raw material integration apparatus (144) which is adapted for supplying raw material not converted by the electrically heatable reactor (122) to the preheater (114).

19. The plant (110) according to claim 17, wherein the plant (110) comprises at least one ventilation apparatus (176), wherein the ventilation apparatus (176) is adapted for supplying ambient air to the preheater (114), wherein the ventilation apparatus (176) is further adapted for cooling a power supply for heating the electrically heatable reactor (122).

20. The plant (110) according to claim 17, wherein the electrically heatable reactor (122) is heatable by electric current.

21. The plant (110) according to claim 17, wherein the electrically heatable reactor (122) is electrically heatable through the use of a multi-phase alternating current and/or a 1-phase alternating current and/or a direct current and/or radiation and/or induction.

22. The plant (110) according to claim 17, wherein the electrically heatable reactor (122) is adapted for heating the raw material to a temperature in the range from 200° C. to 1700° C., preferably to a temperature in the range from 300° C. to 1400° C., particularly preferably to a temperature in the range from 400° C. 875° C.

23. The plant (110) according to claim 17, wherein the plant (110) comprises at least one atmosphere-side connection which is adapted for allowing atmospheric exchange from the electrically heatable reactor (122) to the preheater (114).

24. The plant (110) according to claim 17, wherein the plant (110) comprises at least one process steam supply (120) which is adapted for supplying at least one process steam to the preheater (114), wherein the electrically heatable reactor (122) is adapted for converting the raw material into a cracked gas in the presence of the process steam, wherein the preheater (114) is adapted for at least partially utilizing energy required for preheating the raw material from the byproducts.

25. The plant (110) according to claim 17, wherein the raw material supply (118) is adapted for supplying the at least one raw material to the preheater (114), wherein the raw material comprises at least one element selected from the group consisting of: methane, ethane, propane, butane, naphtha, ethylbenzene, gas oil, condensates, bioliquids, biogases, pyrolysis oils, waste oils and liquids from renewable raw materials.

26. The plant (110) according to claim 17, wherein the electrically heatable reactor (122) is adapted for at least partially converting the preheated raw material into reaction products, wherein the reaction product comprises at least one element selected from the group consisting of: acetylene, ethylene, propylene, butene, butadiene, benzene, styrene, synthesis gas.

27. The plant (110) according to claim 17, wherein the electrically heatable reactor (122) is adapted for at least partially converting the preheated raw material into byproducts, wherein the byproduct comprises at least one element selected from the group consisting of: hydrogen, methane, ethane, propane.

28. The plant (110) according to claim 17, wherein the plant (110) is selected from the group consisting of: a plant for performing at least one endothermic reaction, a plant for heating, a plant for preheating, a steam cracker, a steam reformer, an apparatus for alkane dehydrogenation, a reformer, an apparatus for dry reforming, an apparatus for styrene production, an apparatus for ethylbenzene dehydrogenation, an apparatus for cracking ureas, isocyanates, melamine, a cracker, a catalytic cracker, an apparatus for dehydrogenation.

29. The plant (110) according to claim 17, wherein the plant (110) comprises a plurality of electrically heatable reactors (122) and/or wherein the plant (110) additionally comprises at least one reactor having an integrated convection zone.

30. The plant (110) according to claim 17, wherein the plant (110) comprises at least one steam system (148).

31. The plant (110) according to claim 30, wherein the steam system (148) comprises at least one steam drum (150), wherein the steam system (148) is adapted for preheating boiler feed water in the preheater (114) and introducing it into the steam drum (150), wherein the plant (110) comprises at least one heat exchanger (136) which is adapted for terminating chemical reactions of reaction products and/or byproducts that are in progress, wherein the steam system (148) comprises at least one connection between the steam drum (150) and the heat exchanger (136) such that the boiler feed water from the steam drum (150) can be introduced into the heat exchanger (136), wherein the heat exchanger (136) is adapted for returning the boiler feed water and saturated steam to the steam drum (150), wherein the steam system (148) comprises at least one connection between the steam drum (150) and the preheater (114) such that saturated steam from the steam drum (150) can be passed into the preheater (114), wherein the preheater is adapted for superheating the saturated steam at least for a short time.

32. A process for heat integration in a production of reaction products using a plant (110) according to claim 17 relating to a plant, wherein the process comprises the steps of: providing at least one raw material to a preheater (114) via at least one raw material supply; preheating the raw material to a predetermined temperature with the preheater (114); at least partially converting the preheated raw material into reaction products and byproducts with at least one electrically heatable reactor (122), wherein the electrically heatable reactor (122) is an electrically operated reactor, wherein the electrically heatable reactor (122) is adapted for heating a fluid present in the reactor (122) using electric current, wherein the plant (110) comprises at least one safety device (182) which is adapted for allowing a return stream of the raw material from the electrically heatable tube system of the reactor (122) to the preheater (114); at least partially supplying the byproducts to the preheater (114) with at least one heat integration apparatus; and producing the required energy for preheating the raw material with the preheater (114) at least partially from the byproducts.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0102] Further details and features of the invention are apparent from the following description of preferred exemplary embodiments, in particular in conjunction with the subsidiary claims. The respective features may be realized by themselves alone or as a plurality in combination with one another. The invention is not limited to the exemplary embodiments. The exemplary embodiments are represented in schematic form in the figures. Identical reference numerals in the individual figures describe identical or functionally identical or functionally corresponding elements.

[0103] In particular:

[0104] FIGS. 1 to 4 shows schematic representations of exemplary embodiments of a plant according to the invention; and

[0105] FIG. 5 shows a schematic representation of a further exemplary embodiment of the plant according to the invention in the form of a steam cracker.

EXEMPLARY EMBODIMENTS

[0106] FIG. 1 shows a schematic representation of an exemplary embodiment of an inventive plant 110 for producing reaction products which are represented schematically by arrow 112 in FIG. 1. The plant 110 may be a chemical production plant. The plant 110 may for example be selected from the group consisting of: a plant for performing at least one endothermic reaction, a plant for heating, a plant for preheating, a steam cracker, a steam reformer, an apparatus for alkane dehydrogenation, a reformer, an apparatus for dry reforming, an apparatus for styrene production, an apparatus for ethylbenzene dehydrogenation, an apparatus for cracking ureas, isocyanates, melamine, a cracker, a catalytic cracker, an apparatus for dehydrogenation. The plant 110 may for example be adapted for performing at least one process selected from the group consisting of: at least one endothermic reaction, a preheating, steam cracking, steam reforming, dehydrogenation, a reforming, dry reforming, a styrene production, an ethylbenzene dehydrogenation, cracking of ureas, isocyanates, melamine, a cracking, a catalytic cracking, a dehydrogenation.

[0107] The plant 110 comprises at least one preheater 114. The preheater 114 is adapted for preheating the raw material to a predetermined temperature. The raw material may have a first temperature upon being supplied. The first temperature may be 100° C. for example. The preheater 114 may be adapted for heating the raw material to a second temperature, wherein the second temperature is higher than the first temperature. The predetermined temperature may be 500° C. to 750° C. for example. The predetermined temperature may depend on the raw material, the intended chemical reaction and/or the reaction product to be produced. The preheater 114 may comprise at least one burner 116 which is shown in FIG. 5. The preheater 114 may be adapted for producing an energy demand for preheating the raw material by combustion of gases, for example of methane. Byproducts likewise generated during production of the reaction products and recycled may be burnt in the preheater 114 and at least partially provide the energy required for heating in the preheater 114.

[0108] The raw material may in particular be a reactant with which the chemical reaction is to be performed. The raw material may be a liquid or a gaseous raw material. The raw material may comprise at least one element selected from the group consisting of: methane, ethane, propane, butane, naphthenic, ethylbenzene, gas oil, condensates, bioliquids, pyrolysis oils, waste oils and liquids from renewable raw materials. The plant 110 comprises at least one raw material supply 118 which is represented schematically as an arrow in FIG. 1. The raw material supply 118 is adapted for supplying at least one raw material to the preheater 114. The raw material supply 118 may comprise at least one tube conduit or a tube conduit system.

[0109] The plant 110 may comprise at least one process steam supply 120 which is adapted for supplying at least once process steam to the preheater 114. The process steam supply 120 is likewise represented as an arrow in FIG. 1. The process steam may in particular be steam in whose presence the raw material may be converted into reaction products and byproducts. The process steam may be a hot process steam, for example having a temperature of 180° C. to 200° C. The process steam supply 120 may be adapted for providing the process steam to the preheater 114. The process steam supply 120 may comprise at least one tube conduit or a tube conduit system.

[0110] The plant 110 comprises the at least one electrically heatable reactor 122. The electrically heatable reactor 122 is adapted for converting the preheated raw material at least partially into reaction products and byproducts. The electrically heatable reactor 122 may be adapted for converting the raw material into a cracked gas in the presence of the process steam.

[0111] The plant 110 may comprise at least one feed conduit 124, see for example FIGS. 4 and 5, which is adapted for supplying a fluid preheated, in particular superheated, by the preheater 114 to the electrically heatable reactor 122. In particular, the raw material preheated by the preheater 114 and/or the preheated mixture of raw material and process steam may be supplied to the electrically heatable reactor 122 via the feed conduit 124. The fluid may be a gaseous and/or liquid medium.

[0112] The fluid may in particular be a mixture of raw material and process steam superheated by the preheater 114. The fluid may for example be a hydrocarbon to be thermally cracked, in particular a mixture of hydrocarbons to be thermally cracked. The fluid may for example be water or steam and additionally comprise a hydrocarbon to be thermally cracked, in particular a mixture of hydrocarbons to be thermally cracked. The fluid may for example be a preheated mixture of hydrocarbons to be thermally cracked and steam.

[0113] The plant 110 may be adapted for allowing the proceeding of a chemical reaction in which main products and byproducts are produced. The reaction product may comprise at least one element selected from the group consisting of acetylene, ethylene, propylene, butene, butadiene, benzene, styrene, synthesis gas. The byproduct may be a further product of the chemical reaction which is generated in addition to the reaction products. The byproduct may comprise at least one element selected from the group consisting of: hydrogen, methane, ethane, propane.

[0114] The electrically heatable reactor 122 may be adapted for allowing the proceeding therein of at least one chemical process and/or allowing the performing therein of at least one chemical reaction. The electrically heatable reactor 122 may be an electrically operated reactor. The electrically heatable reactor 122 may be adapted for heating a fluid present in the reactor using electric current. The electrically heatable reactor 122 may be heatable by electric current. The supply of electric current is represented with arrow 130 in FIG. 1. Electricity from any desired electricity source may in principle be used for heating the reactor 122. Electricity from renewable energy sources may advantageously be used, thus further increasing the climate compatibility of the plant 110. Furthermore, the use of a preheater 114 for producing the reaction products can result in only partial powering for processes in the electrically heatable reactor being required. This makes it possible to limit the electricity demand. An electricity and transformer concept independent of the remaining elements of the plant 110 may be possible for the electrically heatable reactor 122.

[0115] The electrically heatable reactor 122 may comprise at least one apparatus adapted for accommodating the preheated raw material. The electrically heatable reactor 122 may comprise at least one reaction tube 126, see FIG. 5, also referred to as a tube conduit, in which the chemical reaction can proceed. The reaction tube 126 may comprise for example at least one tube conduit 128 and/or at least one tube conduit segment for accommodating the fluid. The reaction tube 126 may further be adapted for transporting the fluid preheated by the preheater 114 through the electrically heatable reactor 122. The geometry and/or surface areas and/or material of the reaction tube 126 may be independent of a fluid to be transported.

[0116] The electrically heatable reactor 122 may comprise a plurality of tube conduits 128. The electrically heatable reactor 122 may comprise L tube conduits 128, wherein L is a natural number of not less than two. The electrically heatable reactor 122 may comprise for example at least two, three, four, five or more tube conduits 128. The electrically heatable reactor 122 may comprise for example up to 100 tube conduits 128. The tube conduits 128 may be identical or different.

[0117] The tube conduits 128 may comprise symmetrical and/or asymmetrical tubes and/or combinations thereof. In the case of a purely symmetrical configuration the electrically heatable reactor 122 may comprise tube conduits 128 of identical tube type. The tube type may be characterized by at least one feature selected from the group consisting of: a horizontal configuration of the tube conduit 128; a vertical configuration of the tube conduit 128, a length in the entrance (l1) and/or exit (l2) and/or transition (l3); a diameter in the entrance (d1) and exit (d2) and/or transition (d3); a number n of passes; a length per pass; a diameter per pass; a geometry, a surface area; and a material. The electrically heatable reactor 122 may comprise a combination of at least two different tube types which are connected in parallel and/or in series. The electrically heatable reactor 122 may comprise for example tube conduits 128 of different lengths in the entrance (l1) and/or exit (l2) and/or transition (l3). The electrically heatable reactor may comprise for example tube conduits having an asymmetry of diameters in the entrance (d1) and/or exit (d2) and/or transition (d3). The electrically heatable reactor may comprise for example tube conduits 128 having a different number of passes. The electrically heatable reactor 122 may comprise for example tube conduits 128 having passes with different lengths per pass an/or different diameters per pass. Any desired combinations in parallel and/or in series of any tube types are in principle conceivable.

[0118] The electrically heatable reactor 122 may comprise a plurality of inlets and/or outlets and/or production streams. The tube conduits 128 of different or identical tube type may be arranged in parallel and/or in series with a plurality of inlets and/or outlets. Tube conduits 128 may be present in different tube types in the form of a modular system and selected and combined as desired depending on an intended use. A use of tube conduits 128 of different tube types can make it possible to achieve more precise temperature management and/or adaptation of the reaction in case of varying feed and/or a selective yield of the reaction and/or optimized process engineering. The tube conduits 128 may comprise identical or different geometries and/or surface areas and/or materials.

[0119] The tube conduits 128 may be continuously connected and thus form a tube system for accommodating the fluid. The tube system may comprise supplying and discharging tube conduits. The tube system may comprise at least one inlet for admitting the fluid. The tube system may comprise at least one outlet for discharging the fluid. The tube conduits 128 may be arranged and connected such that the fluid flows through the tube conduits 128 successively. The tube conduits 128 may be connected to one another in parallel such that the fluid can flow through at least two tube conduits 128 in parallel. The tube conduits 128, in particular the tube conduits 128 connected in parallel, may be adapted to transport different fluids in parallel. The tube conduits 128 connected in parallel may in particular have different geometries and/or surface areas and/or materials to one another for transport of different fluids. In particular, for the transport of a fluid a plurality or all of the tube conduits 128 may be configured in parallel, thus allowing the fluid to be divided over said tube conduits 128 configured in parallel. Combinations of serial and parallel connection are also conceivable.

[0120] The reaction tube 126 may for example comprise at least one electrically conductive tube conduit 128 for accommodating the fluid. However, embodiments as electrically nonconducting tube conduits 128 or poorly conducting tube conduits 128 are also conceivable.

[0121] The tube conduits 128 and corresponding supplying and discharging tube conduits 128 may be in fluid connection with one another. When using electrically conductive tube conduits 28 the supplying and discharging tube conduits 128 may be galvanically separated from one another. The electrically heatable reactor 122 may comprise at least one insulator, not shown in the figures, in particular a plurality of insulators. The galvanic separation between the respective tube conduits 128 and the supplying and discharging tube conduits 128 may be ensured by the insulators. The insulators may ensure free passage of the fluid.

[0122] The electrically heatable reactor 122 may be electrically heatable through the use of a multi-phase alternating current and/or a 1-phase alternating current and/or a direct current and/or radiation.

[0123] The electrically heatable reactor 122 may comprise at least one alternating current source and/or at least one alternating voltage source. The alternating current source and/or alternating voltage source may be 1-phase or multi-phase. The alternating current may be a sinusoidal alternating current for example. The alternating voltage may be a sinusoidal alternating voltage for example. The voltage produced by the alternating voltage source brings about a current flow, in particular a flow of an alternating current. The electrically heatable reactor 122 may comprise a plurality of single-phase or multi-phase alternating current or alternating voltage sources. Each of the tube conduits 128 may have a respective alternating current and/or alternating voltage source assigned to it which is connected to the respective tube conduit 128, especially electrically via at least one electrical connection. Also conceivable are embodiments in which at least two tube conduits 128 share an alternating current and/or alternating voltage source. To connect the alternating current or alternating voltage source and the respective tube conduits 128 the electrically heatable reactor 122 may comprise 2 to N feed conductors and 2 to N return conductors, wherein N is a natural number of not less than three. The respective alternating current and/or alternating voltage source may be adapted for producing an electric current in the respective tube conduit 128. The alternating current and/or alternating voltage sources may be either controlled or uncontrolled. The alternating current and/or alternating voltage sources may be configured with or without an option to control at least one electrical starting value. The electrically heatable reactor 122 may comprise 2 to M different alternating current and/or alternating voltage sources, wherein M is a natural number of not less than three.

[0124] The alternating current and/or alternating voltage sources may be electrically controllable independently of one another. It is thus possible for example to achieve a different current in the respective tube conduits 128 and different temperatures in the tube conduits 128. The electrically heatable reactor 122 may for example be configured as described in WO 2015/197181 A1, WO 2020/035574 A1 or as in EP 20 157 516.4, filed on 14 Feb. 2020, the contents of which are hereby incorporated by reference.

[0125] The electrically heatable reactor 122 may comprise at least one direct current and/or at least one direct voltage source. The direct current source and/or the direct voltage source are configured for producing a direct current in the respective tube conduit 128. The electrically heatable reactor 122 may comprise a plurality of direct current and/or direct voltage sources. Each tube conduit 128 may have a respective direct current and/or direct voltage source assigned to it which is connected to the respective tube conduit 128, in particular electrically via at least one electrical connection. To connect the direct current and/or direct voltage sources and the respective tube conduit 128 the electrically heatable reactor 122 may comprise 2 to N positive terminals and/or conductors and 2 to N negative terminals and/or conductors, wherein N is a natural number not less than three.

[0126] The respective direct current and/or direct voltage sources may be adapted for producing an electric current in the respective tube conduit 128. The current produced can heat the respective tube conduit 128 through Joule heat formed upon passage of the electric current through conductive tube material to heat the fluid.

[0127] The electrically heatable reactor 122 may for example be configured as described in WO 2020/035575 A1, the contents of which are hereby incorporated by reference.

[0128] The electrically heatable reactor 122 may for example be electrically heatable through the use of radiation, in particular through the use of induction, infrared radiation and/or microwave radiation.

[0129] The electrically heatable reactor 122 may be heatable for example through the use of at least one current-conducting medium. The current or voltage source, alternating current, alternating voltage or direct current, direct voltage, may be adapted for producing an electric current in the current-conducting medium which heats the electrically heatable reactor 122 through Joule heat formed upon passage of the electric current through the current-conducting medium. The current-conducting medium and the electrically heatable reactor 122 may be arranged relative to one another such that the current-conducting medium at least partially surrounds the electrically heatable reactor 122 and/or that the electrically heatable reactor 122 at least partially surrounds the current-conducting medium.

[0130] The current-conducting medium may exhibit a solid, liquid and/or gaseous state of matter selected from the group consisting of solid, liquid and gaseous and mixtures such as for example emulsions and suspensions. The current-conducting medium may for example be a current-conducting granulate or a current-conducting fluid.

[0131] The current-conducting medium may comprise at least one material selected from the group consisting of: carbon, carbides, silicides, electrically conductive oils, salt melts, inorganic salts and solid/liquid mixtures. The current-conducting medium may have a specific resistance ρ of 0.1 Ωmm.sup.2/m≤ρ≤1000 Ωmm.sup.2/m, preferably of 10 Ωmm.sup.2/m≤ρ≤1000 Ωmm.sup.2/m.

[0132] The electrically heatable reactor 122 may be adapted for heating the raw material to a temperature of 200° C. to 1700° C. The reactor 122 may in particular be adapted for further heating the preheated fluid to a predetermined or prespecified temperature value through the heating. The temperature range may be independent of an application. The fluid may be heated for example to a temperature in the range from 200° C. to 1700° C., preferably from 300° C. to 1400° C., particularly preferably from 400° C. to 875° C.

[0133] The electrically heatable reactor 122 may for example be part of a steam cracker as shown in FIG. 5. “Steam cracking” is to be understood as meaning a process where through thermal cracking relatively long-chain hydrocarbons, for example naphtha, propane, butane and ethane as well as gas oil and hydro-wax, biooil, biodiesel, liquids from renewable raw materials, pyrolysis oil, waste oil, are converted into short-chain hydrocarbons in the presence of steam. Steam cracking can afford ethylene, propylene, butenes and/or butadiene and benzene as reaction product. Methane, ethane, propane and/or hydrogen may be produced as byproducts for example. The electrically heatable reactor 122 may be adapted for a use in a steam cracker to heat the preheated fluid to a temperature in the range from 550° C. to 1700° C. Raw materials, also referred to as starting materials, that may be employed include biooil, biodiesel, liquids from renewable raw materials, pyrolysis oil, waste oil. The main product formed may be butenes and the byproducts formed may be ethane or propane.

[0134] The plant 110 comprises at least one heat integration apparatus 132 which is adapted for at least partially supplying the byproducts to the preheater 114. The preheater is adapted for at least partially utilizing energy required for heating the raw material and the process steam from the byproducts. The heat integration apparatus 132 may be for using, in particular reusing or further-using, generated byproducts for heat recovery to produce reaction products. Fractions of the cracked gas which are not desired as reaction product, in particular methane and hydrogen, ethane and propane, may be recycled to the preheater 114. In particular, excess amounts of the methane fraction produced by the electrically heatable reactor 122 may be recycled to the preheater. The heat integration apparatus 132 is adapted for at least partially supplying the byproducts to the preheater 114. The heat integration apparatus 132 may comprise at least one conduit which is adapted for at least partially conducting and/or transporting the byproducts from the electrically heatable reactor to the preheater 114. The byproducts produced may be entirely supplied to the preheater 114 or a portion of the byproducts produced may be supplied to the preheater 114. The preheater 114 is adapted for at least partially utilizing energy required for preheating the raw material from the byproducts. The preheater 114 may be adapted for at least partially utilizing energy required for heating the raw material and the process steam from the byproducts. The recycled byproducts may be burnt in the preheater 144 and at least partially cover an energy demand of the process in the preheater. Excess amounts of the methane fraction from the cracked gas may be utilized for firing the preheater 114 and superheating.

[0135] The preheater may be supplied with further gases for combustion, for example from another plant, a conventional reactor based on combustion furnaces and/or a further electrically heatable reactor. The supply of further gases is indicated by arrow 134 in FIG. 5. Byproducts not supplied may be discharged, for example into a further plant or a further region of the plant 110, for example for production of further products or as a semifinished product.

[0136] FIG. 2 shows a further embodiment of the plant 110 in schematic representation. Having regard to the description of the embodiment shown in FIG. 2, reference may be made to the description of FIG. 1. In the embodiment shown in FIG. 2 the plant 110 comprises at least one heat exchanger 136 which is adapted for terminating chemical reactions of reaction products and/or byproducts that are in progress. The heat exchanger 136 is arranged in the plant 110 downstream of the electrically heatable reactor 122 in the direction of transport of the fluid. The plant 110 may comprise at least one conduit 138 which is adapted for conducting the cracked gas from the reactor 122 to the heat exchanger 136. The heat exchanger 136 may be adapted for cooling the hot cracked gas produced by the electrically heatable reactor 122, in particular to a temperature of 350° C. to 400° C. The heat exchanger 136 may comprise for example a heat cooler, in particular a high-pressure boiler feed water cooler.

[0137] The plant 110 may comprise at least one separation section 140 which is adapted for separating reaction products and byproducts. The separation section 140 may be adapted for separating substances present in the cracked gas from one another.

[0138] The cracked gas may be supplied to the separation section 140 via a further conduit 142. The separation section 140 may be adapted for performing at least one separating step, for example at least one distillation, in particular a rectification. The separation section 140 may moreover comprise an absorption and/or extraction and a compressor adapted for compressing the cracked gas.

[0139] Such separating steps and processes are known to those skilled in the art. The separation section 140 may be adapted such that the main products to be produced are in pure form after passing through the separation section 140.

[0140] The plant 110 may comprise at least one raw material integration apparatus 144, shown schematically as arrow in FIG. 2, which is adapted for supplying raw material not converted by the electrically heatable reactor 122 to the preheater 114. The raw material integration apparatus 144 may be adapted for using, in particular reusing or further-using, unconverted raw material as raw material for producing reaction products. The raw material integration apparatus 144 may comprise at least one conduit, shown for example in FIG. 3, which is adapted for at least partially conducting and/or transporting the unconverted raw material from the electrically heatable reactor 122, in particular from the separation section 140, to the preheater 114.

[0141] FIG. 3 shows a further embodiment of the plant 110 in schematic representation. Having regard to the description of the embodiment shown in FIG. 3, reference may be made to the description of FIGS. 1 and 2. As set out above, the raw material and the process steam may in each case be supplied to and passed through the preheater 114 in tube conduits and heated by said preheater. The preheater 114 may in particular be adapted to superheat the raw material, as represented by reference 146 in FIG. 3. The plant 110 may be adapted for mixing the preheated raw material and the preheated process steam. The raw material mixed with the process steam may, for example via a further conduit, be passed into a zone of the preheater 114 close to the burner 116 and superheated. For example the raw material mixed with the process steam may be superheated to a temperature somewhat below a cracking temperature. The superheated fluid may subsequently be passed into the electrically heatable reactor 122 and cracked therein.

[0142] The plant 110 may further comprise at least one steam system 148. The steam system 148 may comprise at least one steam separator, also known as a steam drum 150, shown for example in FIGS. 4 and 5. The steam system 148 may be adapted for preheating boiler feed water 152 in the preheater 114 and introducing it into the steam drum 150. The steam system 148 may comprise at least one connection 154 between the steam drum 150 and the heat exchanger 136 such that the boiler feed water from the steam drum 150 can be introduced into the heat exchanger 136. The heat exchanger 136 may be adapted for returning the boiler feed water and the saturated steam to the steam drum 150, for example via at least one conduit 156. The steam system 148 may further comprise at least one connection 158 between the steam drum 150 and the preheater 114 such that saturated steam from the steam drum 150 can be passed into the preheater 114.

[0143] The preheater 114 may be adapted for superheating the saturated steam at least for a short time. The resulting superheated high-pressure steam may be passed out of the preheater 114 and utilized for driving turbines, for example for electricity generation, represented with arrow 160.

[0144] The plant 110 may further comprise at least one cooling circuit 162 shown in FIG. 3. A cooling circuit 162, also referred to as a refrigeration circuit, may be an open or closed circuit comprising one or more suitable refrigerants. In addition the refrigerant circuit may comprise one or more condensation and evaporation steps.

[0145] Individual different process stages may after condensation of the refrigerant be supplied with liquid refrigerant at the end pressure of the compressor. The refrigerant may be evaporated in individual process stages and, through evaporation to different pressure levels in the process stages, provides the required refrigeration power. The refrigerant evaporated in the refrigeration consumers can be recompressed to the required end pressure by a multistage compressor.

[0146] FIG. 4 shows a further embodiment of the plant 110 in schematic representation. Having regard to the description of the embodiment shown in FIG. 4, reference may be made to the description of FIGS. 1 to 3. FIG. 4 shows different zones of the preheater 114 with decreasing temperature from bottom to top. In a region 164 furthest from the burner 116 the boiler feed water 152 may be heated. Admittance of the raw material and a preheating of the raw material may be effected in a region 166 arranged therebelow. Region 168 indicates the admittance of the saturated steam introduced from the steam drum 150 which may be superheated in region 170. In a region 172 closest to the burner 116 the raw material mixed with the process steam may be superheated to a temperature somewhat below a cracking temperature. The preheater 114 may comprise a chimney through which offgas 174 from the preheater 114 may be discharged.

[0147] For a cracking of, for example, naphtha as raw material, energy utilization of the methane fraction may be as follows: the production process provides the energy of the methane fraction. This may be utilized for example to an extent of 20% or up to 20% partially for heating the boiler feed water 152 and for producing the superheated steam in the region's 168 and 170. For example 80% or up to 80% of the energy of the methane fraction may be utilized for the preheating and superheating of the raw material.

[0148] FIG. 5 shows a schematic representation of a further exemplary embodiment of the inventive plant in the form of a steam cracker. Having regard to the description of the embodiment shown in FIG. 5, reference may be made to the description of FIGS. 1 to 4. The electrically heatable reactor 122 may be completely integrated into existing plants, such as conventional steam crackers, although the electrically heatable reactor 122 does not comprise a convection zone. Complete integration is in particular possible through utilization of excess amounts of methane fraction and the presence of the separation section 140. This makes it possible to use conventional technology in known dimensions outside the reactor space.

[0149] In the embodiment shown in FIG. 5 the tube conduit 128 in the electrically heatable reactor 122 may be heated by alternating current for example. Three conductors L1, L2, L3, which are connected to the tube conduit 128, are shown.

[0150] The plant 110 may comprise at least one ventilation apparatus 176. The ventilation apparatus 176 may be adapted for cooling any desired element of the plant 110.

[0151] The ventilation apparatus 176 may be adapted for cooling a power supply for heating the electrically heatable reactor 122. The ventilation apparatus 176 may be adapted for ensuring an operating temperature, in particular a temperature range, of the power supply. This makes it possible to avoid overheating of the power supply. The ventilation apparatus 176 may be adapted for cooling the power supply using air, in particular ambient air 178. During and/or as a result of the cooling process the ambient air may be heated. The ventilation apparatus 176 may be adapted for supplying the ambient air, in particular the ambient air heated by the power supply cooling, to the preheater 114, for example using conduit 180. The heated ambient air may be used directly in the preheater 114 without any need for additional heating of the ambient air. The plant 110 may comprise at least one atmosphere-side connection which is adapted for allowing atmospheric exchange, in particular of reaction space atmosphere from the reaction space of the reactor 122 into the preheater 114. This especially allows discharging of a reaction space atmosphere with the flue gas stream of the preheater 114. The plant 110 may comprise at least one safety device 182 which is adapted for allowing a return stream of the raw material from the electrically heatable reactor 122 to the preheater 114. The safety device 182 may be adapted for allowing evacuation of the electrically heatable reactor 122 in the case of a failure.

LIST OF REFERENCE NUMERALS

[0152] 110 Plant [0153] 112 Reaction product [0154] 114 Preheater [0155] 116 Burner [0156] 118 Raw material supply [0157] 120 Process steam supply [0158] 122 Electrically heatable reactor [0159] 124 Feed conduit [0160] 126 Reaction tube [0161] 128 Tube conduit [0162] 130 Supply of electric current [0163] 132 Heat integration apparatus [0164] 134 Supply of further gases [0165] 136 Heat exchanger [0166] 138 Conduit [0167] 140 Separation section [0168] 142 Conduit [0169] 144 Raw material integration apparatus [0170] 146 Raw material superheating [0171] 148 Steam system [0172] 150 Steam drum [0173] 152 Boiler feed water [0174] 154 Connection [0175] 156 Conduit [0176] 158 Connection [0177] 160 High-pressure steam [0178] 162 Cooling circuit [0179] 164 Region [0180] 166 Region [0181] 168 Region [0182] 170 Region [0183] 172 Region [0184] 174 Offgas [0185] 176 Ventilation apparatus [0186] 178 Ambient air [0187] 180 Conduit [0188] 182 Safety device