Method and plant for producing vinyl chloride from 1,2-dichloroethane
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- THYSSENKRUPP UHDE GMBH
- Filing Date
- 2023-08-21
- Publication Date
- 2026-08-04
Smart Images
Figure 0007900601000001 
Figure 0007900601000002
Abstract
Description
Technical Field
[0001] The present invention relates to a method for producing vinyl chloride by catalytic thermal cracking of 1,2-dichloroethane, wherein the heat required for thermal cracking is supplied through a liquid heat transfer medium or a condensing heat transfer medium. The present invention further provides a plant for producing vinyl chloride by catalytic thermal cracking of 1,2-dichloroethane, wherein the heat required for thermal cracking is supplied through a liquid heat transfer medium or a condensing heat transfer medium, and the plant includes at least one reactor where thermal cracking occurs, at least one first heating device for heating the heat transfer medium, and a conduit system for supplying the heated heat transfer medium (4) to the reactor (1). The at least one first heating device is preferably operated by a fuel that burns without the formation of carbon dioxide, such as hydrogen or ammonia or a mixture of hydrogen and ammonia, more preferably hydrogen, i.e., the heat transfer medium is heated in the at least one first heating device by the thermal energy generated by the oxidation of hydrogen or the oxidation of another fuel that burns without the formation of carbon dioxide.
[0002] In particular, the thermal cracking of 1,2-dichloroethane for producing vinyl chloride required for the production of polyvinyl chloride follows the reaction formula shown below.
[0003] C2H4Cl2 → C2H3Cl + HCl (1) This is an endothermic reaction that can be carried out in the gas phase without a catalyst under a high pressure of 1 to 3 MPa and a temperature of 450 to 600 °C with thermal decomposition, or an endothermic reaction in a method where a catalyst that enables thermal decomposition to be carried out at a lower temperature acts.
Background Art
[0004] For example, European Patent Application Publication No. 0264065 describes a method for producing vinyl chloride by catalyst-free thermal cleavage of 1,2-dichloroethane, where 1,2-dichloroethane is heated in a first vessel and then transferred to a second vessel by vaporization at a lower pressure than in the first vessel without further heating, supplying the gaseous 1,2-dichloroethane to a cracking furnace where cleavage into vinyl chloride and hydrogen chloride occurs. The temperature of the 1,2-dichloroethane when it exits the second vessel is 220°C to 280°C. In the cracking furnace, the tubes in which the 1,2-dichloroethane undergoes thermal cleavage are heated by fossil fuels. In the radiant zone of the cracking furnace, the gaseous 1,2-dichloroethane is heated to 525°C and 533°C, respectively.
[0005] European Patent Application Publication No. 0264065 also mentions that a temperature-controlled medium may be used to preheat new 1,2-dichloroethane in liquid form, wherein the temperature-controlled medium is sequentially heated within the convection zone of the cracking furnace by flue gas generated by a burner heating the cracking furnace. Suitable temperature-controlled mediums include heated high-boiling-point liquids such as mineral oil, silicone oil, and molten biphenyl. However, this only achieves preheating to temperatures of 150 to 220°C, while the pyrolysis itself takes place at approximately 530°C. Therefore, this known method does not result in the execution of pyrolysis in the range of 200 to 400°C and all heating using a liquid heat transfer medium, as required herein.
[0006] A complex plant for manufacturing polyvinyl chloride generally consists of the following:
[0007] - A plant for producing 1,2-dichloroethane from ethene and chlorine ("direct chlorination"), or - A plant for producing 1,2-dichloroethane from ethene, hydrogen chloride, and oxygen ("oxychlorination"), Plant for distillation and purification of -1,2-dichloroethane, - A plant for thermal cleavage of distilled and purified 1,2-dichloroethane into vinyl chloride and hydrogen chloride, and - A plant for the distillation removal of hydrogen chloride and unreacted 1,2-dichloroethane and the purification of vinyl chloride.
[0008] The hydrogen chloride obtained by the thermal cleavage of 1,2-dichloroethane can be returned to an oxychlorination plant, where it can be reacted again with ethene and oxygen to produce 1,2-dichloroethane.
[0009] The above-described complex plant may further include a plant for incinerating liquid and / or gaseous chlorinated hydrocarbons. These are produced as by-products in the vinyl chloride manufacturing process and are removed primarily by distillation and purification of 1,2-dichloroethane. The hydrogen chloride produced by the incineration of these substances is supplied to other manufacturing processes as an aqueous hydrochloric acid solution or similarly returned to the oxychlorination plant. The waste heat from the incineration is used in existing steam generation processes.
[0010] The method for the cleavage of 1,2-dichloroethane into vinyl chloride and hydrogen chloride, as described in German Patent Application Publication No. 10252891, utilizes a catalyst that allows for a reduction in the operating temperature during endothermic cleavage. However, even in this method, the tubular reactor is burned by a primary energy carrier such as oil or gas, and the furnace is divided into a radiant zone and a convective zone. In the radiant zone, the heat required for pyrolysis is transferred to the reaction tubes primarily by radiation from the furnace walls heated by the burner. In the convective zone, the energy contained in the high-temperature flue gas leaving the radiant zone is utilized by convective heat transfer, thereby allowing 1,2-dichloroethane to be preheated, vaporized, or superheated as a reactant in the pyrolysis reaction.
[0011] Various means for energy saving and / or heat recovery in plants for producing 1,2-dichloroethane are known by the prior art. Such means result in a significant reduction in operating costs and therefore greatly contribute to the economic efficiency of the plant and the reduction of the plant's CO2 emissions. These include, for example, means of utilizing the heat of reaction from exothermic reaction steps to heat heat sinks in the process. International Publication 2014 / 108159 details various known means for heat recovery in plants for producing polyvinyl chloride, citing the corresponding references.
[0012] European Patent Application Publication No. 0225617 describes a method for producing vinyl chloride by thermal cleavage of 1,2-dichloroethane, and states that the implementation of this method may, in some cases, result in the recovery of waste heat from the flue gas of a burnt cracking furnace by steam generation. However, the relatively low flue gas temperature means that such a method is not very economical. Thermal cleavage of 1,2-dichloroethane also occurs at relatively high temperatures in this method. First, the reactants are preheated to about 243°C, then partially vaporized by releasing the pressure and partially vaporized by pressurizing with steam, and then thermal cleavage occurs in a cracking furnace at a temperature of 435°C to 497°C without the use of a catalyst. Heating with heat transfer oil is not described and is not possible at these temperatures.
[0013] European Patent Application Publication No. 0002021 describes a method for catalytic dehalogenation of 1,2-dichloroethane to vinyl chloride using a Lewis acid-treated zeolite catalyst. When using such a catalyst, the reaction can be carried out under high pressure and at temperatures in the range of 200°C to 400°C, and therefore at significantly lower temperatures than the conventional thermal decomposition of 1,2-dichloroethane. [Prior art documents] [Patent Documents]
[0014] [Patent Document 1] European Patent Application Publication No. 0264065 [Patent Document 2] German Patent Application Publication No. 10252891 [Patent Document 3] International Publication No. 2014 / 108159 [Patent Document 4] European Patent Application Publication No. 0225617 [Patent Document 5] European Patent Application Publication No. 0002021 [Overview of the project] [Problems that the invention aims to solve]
[0015] An object of the present invention is to provide an improved method for producing vinyl chloride by thermal cleavage of 1,2-dichloroethane, which reduces operating costs. A further object of the present invention is to improve the CO2 balance of the production method for producing vinyl chloride. [Means for solving the problem]
[0016] The above objective is achieved by a method for producing vinyl chloride by catalytic thermal cleavage of a type of 1,2-dichloroethane having the characteristics of claim 1, as described at the beginning.
[0017] According to the present invention, a liquid heat transfer medium or a condensed heat transfer medium is heated at least partially, and at least temporarily, by the thermal energy produced in the oxidation of hydrogen, ammonia, or an ammonia-hydrogen mixture. Such a mode of operation is CO2 neutral. The use of a catalyst for the thermal cleavage of 1,2-dichloroethane makes it possible to shift the temperature range in which the reaction occurs to sufficiently low temperatures, more specifically to a range of about 200°C to about 400°C, and as a result the reactor can be heated by the heat transfer medium instead of direct combustion with fossil fuels used in existing methods. Instead of a tubular cracking furnace, it is possible to use, for example, a shell-and-tube heat exchanger as the reactor, in which tubes are filled with a catalyst bed and the heat transfer medium flows through a shell space, preferably in a loop.
[0018] According to a preferred development of the method of the present invention, at least some or all of the hydrogen to be oxidized is produced in an upstream electrolysis unit. The electrolysis unit can preferably be configured to perform chlorine-alkali electrolysis. The resulting chlorine gas can then be used for direct chlorination in the vinyl chloride manufacturing process. Alternatively, the electrolysis unit may be configured for hydroelectrolysis. In this case, the resulting oxygen can be used for oxychlorination. Finally, the electrolysis unit may be configured for hydrogen chloride electrolysis. Preferably, the hydrogen chloride produced by the thermal cleavage of 1,2-dichloroethane is electrochemically cleaved, and / or the resulting chlorine gas is reused in the chlorination of ethene in the manufacturing process.
[0019] Furthermore, heating the heat transfer medium by the combustion of hydrogen and / or ammonia has the advantage of providing at least partially, temporarily, the heat required for the reaction. In this case, it is possible to obtain all of the heat required for the reaction by the oxidation of hydrogen and / or ammonia.
[0020] The heat transfer medium can also be heated at least temporarily, in part by the thermal energy generated by the oxidation of hydrogen and / or ammonia, and in part by the combustion of a fuel different from these fuels. In this preferred variant of the method, most of the heat required for the reaction is provided by a first heating device that can be heated by hydrogen and / or ammonia, but at least one second heating device operating with a fuel different from the above fuel is provided and can be used at least temporarily. In these cases, the first heating device can be throttled, or can be completely stopped for a certain period as required, or the heat transfer medium can be directed so that its flow bypasses the first heating device.
[0021] For example, at least one second heating device may be designed as an incineration plant for incinerating liquid and / or gaseous chlorinated hydrocarbons such as those produced as by-products in a vinyl chloride production plant.
[0022] The use of a liquid heat transfer medium or a condensing heat transfer medium to provide the entire heat of reaction required for the thermal cracking of 1,2-dichloroethane enables the reaction to be carried out in the presence of a suitable catalyst that allows a significant reduction in the reaction temperature compared to conventional methods without using a catalyst. When using such a catalyst, the reaction temperature can be reduced, for example, from a temperature of about 430°C to about 530°C typically used in conventional methods to a temperature in the range of particularly about 200°C to 400°C. Heating to a temperature in this range is possible, for example, when using a heat transfer oil, or molten salts may also be used. Suitable catalysts include, for example, substances such as those listed in the above European Patent Application Publication No. 0002021.
[0023] Methods for pure thermal EDC cracking (catalyst-free in a pyrolysis furnace) or thermal catalytic EDC cracking (involving heat supply and use of a catalyst) usually consist of the following sub-steps.
[0024] - Preheating liquid 1,2-dichloroethane to its vaporization temperature at a given pressure, - To vaporize preheated 1,2-dichloroethane, -1,2-dichloroethane vapor may be superheated to the reaction temperature range (if the previous vaporization did not occur within the reaction temperature range). - Carrying out a cleavage reaction (either purely thermally or thermally using a catalyst) while supplying heat.
[0025] The present invention provides a method that allows heating for catalytic thermal cleavage reactions using a liquid heat transfer medium or a condensed heat transfer medium, as well as heating upstream of 1,2-dichloroethane for preheating, vaporization, or superheating using the heat transfer medium. It is not necessarily required that all of these steps be heated by a heat transfer medium. The method of the present invention includes heating from at least one of the above substeps to any desired combination, and each substep can be successively subdivided into individual steps (with respect to the apparatus).
[0026] For the purposes of the method of the present invention, "heating" means the transfer of heat to the starting material 1,2-dichloroethane and / or the reaction mixture by a heat transfer medium. This allows the starting material 1,2-dichloroethane to be heated, vaporized, and / or superheated. The heat can be supplied to the reaction mixture in the reactor at a constant temperature level (isothermal reaction control). The reaction mixture can also be further heated, and the heat supplied by heating is used partly to supplement the heat required for the reaction and partly to further heat the reaction mixture. Finally, the supply of heat to the reaction mixture by heating can be adjusted so that the sensible heat contained in the reaction mixture is used at least in part to supplement the heat requirement for the reaction, and the reaction mixture in the reactor is cooled compared to the reactor inlet temperature. Heating, and further heat transfer to the starting material 1,2-dichloroethane, is carried out by a liquid heat transfer medium with cooling of the heat transfer medium / reduction of its sensible heat contained, and / or by a condensed heat transfer medium pre-vaporized by a heating device.
[0027] For the purposes of the method of the present invention, the heating device for the heat transfer medium may be a device (heater and / or evaporator or a device combining the functions of a heater and an evaporator) that can be heated by hydrogen, ammonia or an ammonia-hydrogen mixture (first heating device) or by fossil fuels, such as heating oil or preferably natural gas (second heating device). Alternatively, they may be heat transfer devices (heater and / or evaporator or a device combining the functions of a heater and an evaporator) that are heated by waste heat from a plant for incinerating by-products of a chemical plant, preferably a plant for incinerating by-products of a complex plant for the production of polyvinyl chloride. Such devices are well known to those skilled in the art.
[0028] Generally, the thermal requirements of a plant for catalytic thermal cleavage of 1,2-dichloroethane can only be partially met by the incineration of by-products in a composite plant for vinyl chloride production. Therefore, in a preferred mode of operation, the heat transfer medium is first heated by waste heat from the combustion of by-products, and the remaining heat required is supplied by the combustion of hydrogen, ammonia, or a hydrogen-ammonia mixture in a first heating unit.
[0029] According to a preferred development of the method of the present invention, a liquid heat transfer medium or a condensed heat transfer medium is circulated within a loop, the loop comprising at least one first heating device operating by the oxidation of hydrogen, ammonia, or a hydrogen-ammonia mixture, and a reactor for catalytic thermal cleavage of 1,2-dichloroethane, where heat exchange occurs between the reaction medium and the heat transfer medium within the reactor. The loop also preferably comprises at least one second heating device operating by the combustion of at least one fuel different from the fuels described above.
[0030] According to a preferred development of the method of the present invention, at least one first heating device and at least one second heating device are connected in series within a loop. In this case, the heat transfer medium flows through the conduit loop, first through the second heating device and then through the first heating device located downstream thereof. Alternatively, the flow through these two heating devices may be in opposite directions. Alternatively, the two heating devices may be arranged in a quasi-parallel connection, i.e., the connection of the conduit loop containing the heating devices is such that the associated conduit can be closed, for example, via a valve, so that the heat transfer medium can flow through the second heating device without flowing through the first heating device, or vice versa if necessary.
[0031] According to a preferred development of the method of the present invention, the heat transfer medium circulates within the loop in a countercurrent to the flow of the reaction medium through the reactor. This modification is advantageous for effective heat transfer. Alternatively, the heat transfer medium can be flowed in a parallel flow to the flow of the reaction medium.
[0032] According to a preferred development of the method of the present invention, the second heating device is at least temporarily powered by waste heat from the plant for incinerating by-products of the vinyl chloride manufacturing plant. This modification has the advantage that the waste heat used is essentially derived from plant components within the same complex plant, which means that the energy balance of the method can be improved.
[0033] According to a preferred development of the method of the present invention, the second heating device operates permanently at full load. The remaining energy required for thermal cleavage can be supplied to the heat transfer medium by the first heating unit, which is heated by hydrogen and / or ammonia. In this variation of the method, the second heating device is preferably at a permanent operating temperature.
[0034] According to a preferred development of the method of the present invention, the thermal cleavage of 1,2-dichloroethane is carried out within a temperature range of 200°C to 400°C. This is a preferred temperature range that can be easily achieved with a liquid heat transfer medium, such as a heat transfer oil.
[0035] The present invention further provides a plant for producing vinyl chloride by catalytic thermal cleavage of 1,2-dichloroethane, wherein the heat required for the thermal cleavage of 1,2-dichloroethane, and preferably further for preheating, vaporizing and / or superheating of 1,2-dichloroethane, is supplied via a liquid heat transfer medium or a condensed heat transfer medium, the plant comprising at least one reactor in which thermal cleavage occurs, at least one first heating device for heating the liquid heat transfer medium, and a conduit system for supplying the heated heat transfer medium to the reactor, the at least one first heating device being designed for the oxidation of hydrogen and / or ammonia, i.e., heat can be generated by the oxidation, preferably by combustion, of one of the fuels described above.
[0036] In this case, it is particularly preferable that the plant includes at least one electrolysis unit, in particular for performing chlorine-alkali electrolysis, hydroelectrolysis, or hydrogen chloride electrolysis, upstream of at least one first heating device, in which case the generated hydrogen is supplied to at least one first heating device, and may also be supplied after being mixed with ammonia.
[0037] Furthermore, the plant may also include at least one second heating device for heating the reaction medium, designed for the combustion of at least one fuel other than hydrogen and ammonia, such as methane, natural gas, and / or liquid and / or gaseous waste from a chemical plant. In this case, it is preferable that the heat transfer medium flows through the second heating device first. The remaining heat necessary for the cleavage of 1,2-dichloroethane and further for preheating to vaporize and / or superheat the 1,2-dichloroethane can be supplied by the first heating unit. The first heating unit can preferably be designed to be adjustable to reach a predetermined final temperature in the heat transfer medium.
[0038] In a preferred evolution of the present invention, the conduit system forms a loop of heat transfer medium, comprising a reactor and at least one first heating device operated by hydrogen, ammonia, or a hydrogen-ammonia mixture.
[0039] According to a preferred modification of the present invention, the loop of the heat transfer medium also includes at least one second heating device. In this case, the flow order is preferably such that the medium flows first through the second heating device. Thus, the terms “first” or “second” heating devices as used herein simply refer to functionally different types of heating devices and do not define the order in which the heat transfer medium flows through them.
[0040] In a preferred evolution of the present invention, the first heating device and the second heating device are arranged in series or in parallel within a loop of heat transfer medium.
[0041] In a preferred modification of the present invention, means are provided for transferring heat from a heat transfer medium to a reaction medium that flows through or is present within the reactor.
[0042] In a preferred evolution of the present invention, the reactor comprises a shell-and-tube heat exchanger, the tubes of which are filled with a catalyst bed and preferably have a shell space through which a heat transfer medium circulates within a loop.
[0043] The present invention will be described in more detail below based on exemplary embodiments with reference to the accompanying drawings. [Brief explanation of the drawing]
[0044] [Figure 1] A schematic, simplified diagram of the plant according to the present invention for producing vinyl chloride by catalytic thermal cleavage of 1,2-dichloroethane is shown. [Figure 2] A schematic diagram of a reactor equipped with a shell-and-tube heat exchanger is shown, with the tubes filled with a catalyst bed. [Modes for carrying out the invention]
[0045] The following references are made to the drawings used to illustrate exemplary embodiments and variations of the method of the present invention in more detail. The depictions in Figures 1 and 2 are substantially simplified in general terms, and only those plant components relevant to the context of the present invention are shown. The plant comprises a reactor 1 supplied with a reactor inlet flow 2 of 1,2-dichloroethane (EDC) via at least one conduit, the 1,2-dichloroethane being thermally decomposed into vinyl chloride monomer (VCM) in the reactor 1 under the influence of heat, the formation of vinyl chloride accompanied by the generation of hydrogen chloride. The enumerated products of the method exit the reactor 1 in a reactor discharge flow 3.
[0046] The reactor 1 is incorporated into a loop 18 of a heat transfer medium 4 formed by a conduit system 8, so that heat is supplied to the reactor 1 via a liquid heat transfer medium, such as a heat transfer oil, which flows countercurrently to the reaction medium, thereby heating the reaction medium 13 (see Figure 2) flowing through the reactor 1 to a temperature of, for example, 300°C to 400°C, at which catalytic thermal cleavage of 1,2-dichloroethane to vinyl chloride occurs within the reactor 1.
[0047] The loop 18 of the heat transfer medium 4 is described in more detail below. The loop 18 of the heat transfer medium 4 includes a pump 5 for circulating the heat transfer medium 4 within the loop 18, downstream of the pump 5, the heat transfer medium first flows through an optional second heating device 7 as taught in the present invention, and when the second heating device 7 is operating, the heat transfer medium 4 can be heated by at least one fuel other than hydrogen and / or ammonia, e.g., methane, natural gas and / or by combustion of liquid and / or gaseous waste from a chemical plant, or by thermal energy from waste heat of a chemical plant, e.g., from a polyvinyl chloride manufacturing plant.
[0048] Downstream of the second heating device 7, the heat transfer medium 4 flows through the first heating device 6, which is burned with hydrogen 10, ammonia 11, or an ammonia-hydrogen mixture to heat the heat transfer medium 4. As shown in Figure 1, the hydrogen 10 used for heating can be produced, for example, in an upstream electrolysis unit 9. The electrolysis unit 9 can preferably be configured to perform chlorine-alkali electrolysis, hydroelectrolysis, or hydrogen chloride electrolysis.
[0049] In an exemplary embodiment, the second heating device 7 and the first heating device 6 are arranged one behind the other in the direction of flow within the conduit system 8 of the loop 18, and are therefore connected in series. However, alternatively, the two heating devices can also be connected in parallel with each other, i.e., unlike in Figure 1, the two heating devices are incorporated into the conduit system 8 so that the heat transfer medium 4 flows through at least one or the other of the two heating devices, while bypassing the other heating device.
[0050] In the variant shown in Figure 1, in which the two heating devices 6 and 7 are arranged in series, and in the variant having a parallel connection (not shown), valves (not shown in Figure 1) may be provided for switching the heating devices on and off, or for blocking the conduit in the loop 18 at appropriate locations. In addition, one or more adjustment devices (also not shown in Figure 1) may be provided to adjust the heat output supplied by the first and / or second heating devices 6 and 7 according to the heating requirements of the reaction medium in reactor 1.
[0051] A modified version of the present invention shown in Figure 1 may further include a device 19 capable of preheating, vaporizing, and superheating the reactor inlet flow 2 by the heat contained in the flow of the heat transfer medium 4. These options do not necessarily have to be realized, and can be realized in any combination. The device 19 is located in the loop of the heat transfer medium, preferably downstream of the reactor 1. [Explanation of symbols]
[0052] 1 Reactor 2. Reactor inflow 3. Reactor effluent 4 Heat transfer medium 5. Recirculation pump 6. First heating device 7. Second heating device 8. Conduit System 9. Electrolysis Unit 10 Hydrogen 11 Ammonia 12 Heat transfer means 13 Reaction medium 14. Shell-and-tube heat exchanger 15 tubes 16 Catalyst bed 17 Shell Space 18 loops 19 Apparatus for preheating and / or vaporization and / or superheating
Claims
1. A method for producing vinyl chloride by catalytic thermal cleavage of 1,2-dichloroethane, characterized in that the heat required for the catalytic thermal cleavage is supplied via a heat transfer medium which is a liquid heat transfer medium or a condensed heat transfer medium (4), and the heat transfer medium (4) is heated at least somewhat, at least temporarily, by the thermal energy generated in the oxidation of hydrogen (10), ammonia (11), or a hydrogen-ammonia mixture.
2. The method according to claim 1, characterized in that at least a portion or all of the hydrogen (10) to be oxidized is generated in the upstream electrolysis unit (9).
3. The method according to claim 1 or 2, characterized in that the oxidation of the hydrogen (10) and / or the ammonia (11) is carried out by the combustion of the hydrogen (10) and / or the ammonia (11).
4. The method according to claim 1, characterized in that the 1,2-dichloroethane is preheated and / or vaporized and / or superheated by the heat transfer medium (4).
5. The method according to claim 1, characterized in that the heat transfer medium (4) is heated at least temporarily, to some extent by the thermal energy generated by the oxidation of hydrogen (10) and / or ammonia (11), and to some extent by the combustion of a fuel other than hydrogen and ammonia, or the heat transfer medium is heated completely by the thermal energy generated by the oxidation of hydrogen (10) and / or ammonia (11).
6. The method according to claim 1, characterized in that at least one first heating device (6) operating by the oxidation of hydrogen (10) and / or ammonia (11), and at least one second heating device (7) operating by the combustion of at least one fuel different from hydrogen and ammonia, are used to heat the liquid heat transfer medium (4).
7. The method according to claim 6, characterized in that the heat transfer medium (4) is circulated within a loop (18), the loop (18) includes the at least one first heating device (6) and a reactor (1) for the catalytic thermal cleavage of 1,2-dichloroethane, and the heat exchange takes place between the reaction medium (13) in the reactor (1) and the heat transfer medium (4).
8. The method according to claim 7, characterized in that the loop (18) includes the second heating device (7).
9. The method according to claim 7, characterized in that the at least one first heating device (6) and the at least one second heating device (7) are connected in series within the loop (18).
10. The method according to claim 7, characterized in that the heat transfer medium (4) circulates within the loop (18) in a countercurrent to the flow of the reaction medium (13) through the reactor (1).
11. The method according to claim 1, characterized in that the catalytic thermal cleavage of the 1,2-dichloroethane is carried out within a temperature range of 200°C to 400°C.
12. A plant for producing vinyl chloride by catalytic thermal cleavage of 1,2-dichloroethane, wherein the heat required for the catalytic thermal cleavage of 1,2-dichloroethane is supplied via a heat transfer medium which is a liquid heat transfer medium or a condensed heat transfer medium (4), the plant comprising at least one reactor (1) in which the catalytic thermal cleavage occurs, at least one first heating device (6) for heating the heat transfer medium (4), and a conduit system (8) for supplying the heated heat transfer medium (4) to the reactor (1), wherein the at least one first heating device (6) is configured to oxidize hydrogen (10) and / or ammonia (11).
13. The plant according to claim 12, wherein the heat is further used for preheating, vaporizing and / or superheating the 1,2-dichloroethane.
14. The plant according to claim 12 or 13, characterized in that the at least one first heating device (6) is configured to burn hydrogen (10) and / or ammonia (11).
15. The plant according to claim 12 or 13, characterized in that the plant includes at least one electrolysis unit (9) upstream of the at least one first heating device (6), and hydrogen (10) produced in the electrolysis unit (9) is supplied to the at least one first heating device (6).
16. The plant according to claim 12 or 13, further comprising at least one second heating device (7) for the combustion of at least one fuel different from hydrogen and ammonia in order to heat the heat transfer medium (4).
17. The plant according to claim 16, wherein the at least one fuel includes methane, natural gas, and / or liquid and / or gaseous waste from a chemical plant.
18. The plant according to claim 16, characterized in that the conduit system (8) circulates the heat transfer medium (4) within a loop (18) including the reactor (1) and the at least one first heating device (6).
19. The plant according to claim 18, characterized in that the loop (18) includes at least one second heating device (7).
20. The plant according to claim 16, characterized in that the at least one first heating device (6) and the at least one second heating device (7) are arranged in series or in parallel within the loop (18) of the heat transfer medium (4).
21. The plant according to claim 12 or 13, characterized in that means (12) for transferring heat from the heat transfer medium (4) to a reaction medium (13) flowing through the reactor (1).
22. The plant according to claim 12 or 13, characterized in that the reactor (1) comprises a shell-and-tube heat exchanger (14) and houses a catalyst bed (16) through which the tubes (15) flow.
23. The plant according to claim 22, characterized in that the heat transfer medium (4) flows through the shell space (17) of the reactor (1).
24. The plant according to claim 12 or 13, characterized in that at least one device (19) for preheating and / or vaporizing and / or superheating the 1,2-dichloroethane is incorporated into the conduit system (8) of the heat transfer medium (4).