System of thermally coupled process devices

Abstract

The invention relates to a system (1) of thermally coupled processes, wherein the system (1) has: at least one heat-emitting process device (P1) which is designed to carry out a technical process and thereby emit waste heat at a temperature T1; at least one heat-absorbing process device (P2) which is designed to carry out a technical process and thereby absorb heat at a temperature T2 which is higher than T1; a heat pump (10) which is designed to increase the waste heat of the heat-emitting process device (P1) from T1 to T2; and a T1 store (20), which is a thermal store, arranged between the heat-emitting process device (P1) and the heat pump (10) and designed to store the waste heat of the heat-emitting process device (P1), preferably at the temperature T1, and / or a T2 store (30), which is a thermal store, arranged between the heat pump (10) and the heat-absorbing process device (P2) and designed to store the heat to be absorbed by the heat-absorbing process device (P2), preferably at the temperature T2.

Description

SYSTEM OF THERMALLY COUPLED PROCESS DEVICES BACKGROUNDThe application relates to a system of thermally coupled process devices and to a method for operating such a system.In the sectors of chemical, energy and process engineering, it is known to couple processes thermally. In this case, one process emits process waste heat which is then not discarded but supplied to another process for use, as a result of which the total energy input can be optimized. A multiplicity of examples of such process coupling are known, for instance electrolysis, thermocatalytic processes, drying, pyrolysis and the like. These are generally processes which run continuously (24 / 7). If waste heat is available at a higher temperature level, it can be used continuously to supply other processes at a lower temperature level (temperature cascade). In the context of the decarbonization of chemical and food technology processes, in particular petrochemical processes, there is a desire to operate processes with renewable energy. However, this energy is not necessarily available continuously (24 / 7), so it may be necessary to operate the processes intermittently according to the availability of the volatile energy. Some processes are in principle unsuitable for such intermittent operation, for example many thermocatalytic processes in refineries, for instance for producing ammonia, methane, methanol, gasoline or diesel. For some processes, the capital expenditure is very high, so that a limited machine utilization ("load factor") makes the product very expensive. This can lead to situations in which it is most economical to operate only certain processes intermittently, and to supply other processes with conventional energy and allow them to run continuously. Examples of intermittent processes generally include very energy-intensive processes, which are operated and generate waste heat only when renewable energies are directly available (electrolysis, compression, etc.). Continuous processes include, for example, chemical-technical processes for obtaining CO2 from the ambient air (direct air CO2 capture), water treatment by distillation / evaporation, thermocatalytic processes, drying, sterilization, food preparation (cooking, baking), plastic melts for extrusion and others. In the case of continuous processes, if these processes are supplied with renewable energies, there is no continuity - which is absolutely essential - of the waste heat transfer. As a result, if for example the waste heat from an intermittently operated process is intended to be used for thermal coupling with a continuously operated process, the problem exists of different operating times of the two processes (fluctuating provision of the waste heat versus continuous operation of the process engineering procedure). Furthermore, the temperatures of the waste heat source may be too low. To solve these problems, all processes could be operated with continuously available energy from the power grid, but this results in a correspondingly high CO2 emission. Alternatively, the processes could be operated only when renewable energy is available. However, this is often not possible since many processes have to be operated continuously for technical reasons or are not economic, in particular in the case of CAPEX-intensive processes with a low load factor. The use of batteries to provide electrical energy in the event of non-availability of renewables is generally not economic, since the storage of electrical energy is very resource-intensive and costly. Alternatively, in the event of non-availability of renewable energy, electricity could be drawn from the grid; however, as a rule this does not meet the criterion of a supply of purely renewable energy due to the electricity mix in the networks, and prevents the use of temporarily cheaper renewable energy. It is an object of the invention to provide an improved system of thermally coupled process devices and an improved method for operating such a system. This object is achieved by a system having the features of claim 1 and by a method having the features of the associated method claim. Advantageous refinements arise from the dependent claims, the following description of the invention and the description of preferred exemplary embodiments. SUMMARY OF THE INVENTIONThe invention relates to a system of thermally coupled processes. These are technical industrial processes, in particular from chemical, energy and / or process engineering sectors, including for example electrolysis and / or DAC (Direct Air Capture). The system comprises at least one heat-emitting process device which is configured to carry out a technical process and thereby emit waste heat at a temperature T1, and at least one heat-absorbing process device which is configured to carry out a technical process and thereby absorb and utilize heat at a temperature T2 which is higher than T1. The system has a heat pump which is configured to heat the waste heat of the heat-emitting process device from T1 to T2. The heat pump thermally couples the two processes, i.e. it provides a heat flow from the heat-emitting process to the heat-absorbing process, and modifies it to heat the waste heat of the one process to a suitable level for the heat-absorbing process. The heat is transported by means of a suitable heat medium, which may be liquid or gaseous. The system furthermore comprises a T1 store, which is a thermal store, arranged between the heat-emitting process device and the heat pump and configured to store the waste heat of the heat-emitting process device, preferably at the temperature T1 or in a temperature range around T1, and / or a T2 store, which is a thermal store, arranged between the heat pump and the heat-absorbing process device and configured to store the heat to be absorbed by the heat-absorbing process device, preferably at the temperature T2 or in a temperature range around T2. It should be noted that the preposition "between" and the like in the present context refers to the heat flow and does not necessarily define a spatial relationship. Furthermore, for the sake of linguistic simplicity, reference is usually made to one heat-emitting process device and one heat-absorbing process device. However, the invention similarly comprises the thermal coupling of a plurality of process devices or processes on the heat-emitting side and / or the heat-absorbing side. The system makes use of the fact that, in contrast to electricity, heat and / or process gases can be stored in a substantially more cost-effective and resource-conserving manner. As a result, the processes of the process devices can advantageously be coupled, in particular if they run at different times, without burdening the overall process with excessively high costs or resource consumption. The system thus permits the coupling of processes operated at different times if the temperature level of the heat-emitting process is below the temperature level of the heat-absorbing process. The system also allows the thermal coupling of continuously operated and intermittently operated processes. As a result, it is possible to adjust the system flexibly to the use of temporarily available or volatile energy, such as renewable energy. The system allows an adaptation of the temperature levels between the heat-emitting process and the heat-absorbing process by means of an energy-efficient heat pump, the operating time of which can in turn be adapted to the availability of electrical energy. As a result, the system allows an ideal utilization of waste heat, for example in the production of synthetic fuels or energy carriers. The heat pump is preferably configured to emit cold at a temperature T3 and supply it to the heat-emitting process device. This usually takes place via an evaporator of the heat pump. In this case, a T3 store, which is a thermal store, can be arranged between the heat pump and the heat-emitting process device and be configured to store the cold emitted by the heat pump, preferably at the temperature T3. The low temperature T3 emitted by the heat pump can be supplied to the heat-emitting process as actively generated cold. This utilization of the cooling power of the heat pump is particularly advantageous at high ambient temperatures, as it eliminates a cooling device (air cooling, water cooling) and often also improves the efficiency of the heat-emitting process. The effects can be intensified by a cooling apparatus which is arranged between the heat pump and the heat-emitting process device or the T3 store, and is configured to cool the cold emitted by the heat pump at the temperature T3 to a lower temperature T3'. The cooling apparatus is realized, for example, by air cooling, cooling with ambient water, or a further heat pump which is used for cooling. This allows an even more effective cooling of the heat-emitting process. It is possible to utilize the waste heat of the heat-absorbing process. In this case, the heat-absorbing process absorbs heat at a temperature T2 and emits heat at a colder temperature level T4. Preferably, the heat-absorbing process device is thus configured to emit waste heat at a temperature T4 and to supply it to the heat pump, wherein a T4 store, which is a thermal store, can be arranged between the heat-absorbing process device and the heat pump and be configured to store the waste heat emitted by the heat-absorbing process, preferably at the temperature T4. If the temperature T4 is below the temperature level emitted by the heat pump, then a circuit arrangement is advantageous in which the colder temperature T4 (possibly via the T4 store) is used for cooling the heat-generating process. The temperature level T3 emitted by the heat pump or its evaporator is preferably used to generate the heat supply at T2. Possible examples of heat-absorbing processes with very low output temperature T4 include drying or also DAC technologies with amine-based capture molecules. The system is thus preferably configured to supply the waste heat, preferably at temperature T4, to the heat-absorbing process device or the T4 store of the heat-emitting process device, or to the T3 store, bypassing the heat pump, for cooling. Preferably, the cold at T3 from the heat pump can be supplied to the T4 store. The circuit can preferably be switched between different configurations, comprising those mentioned above, by means of a changeover valve. The technical processes of the process devices often provide starting materials which are then converted into the actual target substances in an industrial-scale synthesis process (for example methanol synthesis, reverse water gas shift reaction with subsequent Fischer-Tropsch process). In this case, it may be expedient to provide one or more product buffer stores which are configured to store a respective starting product of the corresponding process device. Pressure vessels made of metal or plastic, in particular fiber-reinforced plastic, can be used as product buffer stores, which are preferably dimensioned such that process interruptions of hours to days can occur before the starting product runs out. Preferably, the heat-emitting process device and / or the heat-absorbing process device and / or the heat pump draw electrical energy for regular operation. In particular for renewable or otherwise volatile electrical energy, the present system provides an economically advantageous solution. Thus, for example, when electrical energy is present, the heat pump can be operated in order to heat the waste heat from the T1 store to a higher temperature level and supply it to the T2 store. In this way, the thermally coupled processes and the heat pump can be operated independently within a certain framework and thus react to the availability of volatile energy forms. The heat-emitting process device and / or the heat-absorbing process device and / or the heat pump preferably work intermittently, i.e. not continuously. In particular, the processes of the process devices and of the heat pump need not necessarily run simultaneously, owing to the thermal stores. The system preferably has a control device for controlling and / or regulating the processes and heat flows. In particular, the control device is configured to obtain information about the fill states of the thermal stores and to activate the heat pump in such a way that sufficient process heat is always available for the heat-absorbing process device. The processes of the process devices and their coupling via the heat pump and the thermal stores are controlled and / or regulated via the control device. In particular, the control device controls / regulates the times at which the processes are operated. In addition to system parameters, for this the control device evaluates, for example, information about the available renewable energy, prices and also availability forecasts, and about the fill states of the thermal stores. One aim of the control device is preferably to activate the heat pump in such a way that sufficient process heat is always available for the heat-absorbing process, as far as possible at the lowest costs or with maximum utilization of renewable energies. In addition, the control device can evaluate the essential system parameters for monitoring, by checking the interplay of the system parameters for plausibility. The control device is connected to the system components which are to be controlled or regulated and / or read out as signals with any integrated sensors, for example for temperatures, fill levels and / or throughput quantities, and thus in particular connected to the process devices, the heat pump and the thermal stores. The communication between the control device and the components to be controlled or regulated and / or read out can be wired or wireless, digital or analog. The control device can accordingly receive and / or transmit signals (control signals, data, etc.), wherein signal transport in one direction and also in both directions falls under the term "communication" in this context. In this case, the control device need not necessarily be implemented by a central computing device or electronic control system, but rather comprises decentralized and / or multi-stage systems, control networks, cloud systems and the like. The control device can moreover be an integral component of or communicate with a superordinate installation controller. The heat-emitting process device is preferably an electrolyzer for generating H2 or directly reducing CO2. Alternatively or additionally, the heat-absorbing process device may be configured to perform a DAC process to provide CO2. The above-mentioned object is furthermore achieved by a method for operating a system of thermally coupled processes, wherein the method comprises: carrying out a technical process which emits waste heat at a temperature T1 by means of a heat-emitting process device; carrying out a further technical process which absorbs heat at a temperature T2, which is higher than T1, by means of a heat-absorbing process device; heating the waste heat of the heat-emitting process from T1 to T2 by means of a heat pump; storing the waste heat of the heat-emitting process in a T1 store, which is a thermal store and is arranged between the heat-emitting process device and the heat pump, and / or storing the heat to be absorbed by the heat-absorbing process in a T2 store, which is a thermal store and is arranged between the heat pump and the heat-absorbing process device. The features, technical effects, advantages and exemplary embodiments which have been described in relation to the system apply similarly to the method. For the reasons mentioned above, the heat-emitting process and the heat-absorbing process are preferably not carried out simultaneously for at least part of the time. Preferably, for the reasons mentioned above, the heat pump emits cold at a temperature T3 and supplies it to the heat-emitting process device, wherein preferably a T3 store, which is a thermal store, is arranged between the heat pump and the heat-emitting process device and stores the cold emitted by the heat pump, preferably at the temperature T3. Preferably, for the reasons mentioned above, the heat-absorbing process device emits waste heat at a temperature T4 and supplies this to the heat pump, wherein preferably a T4 store, which is a thermal store, is arranged between the heat-absorbing process device and the heat pump and stores the waste heat emitted by the heat-absorbing process, preferably at the temperature T4. Further advantages and features of the present invention are apparent from the following description of preferred exemplary embodiments. The features described therein can be implemented alone or in combination with one or more of the features set out above, insofar as the features do not contradict one another. The following description of preferred exemplary embodiments is given with reference to the accompanying drawings. Preferred further embodiments of the invention are explained in more detail by the following description of the figures. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows schematically a system with thermally coupled process devices and thermal stores;Figure 2 shows schematically a system with thermally coupled process devices and thermal stores, according to a further exemplary embodiment;Figure 3 shows schematically a system with thermally coupled process devices and thermal stores, according to a further exemplary embodiment;Figure 4 shows schematically a system with thermally coupled process devices, thermal stores and an additional cooling apparatus, according to a further exemplary embodiment;Figure 5 shows schematically a system with thermally coupled process devices, thermal stores and additional utilization of cold output temperatures of the heat-absorbing process, according to a further exemplary embodiment;Figure 6 shows schematically a system with thermally coupled process devices, thermal stores and variable use of low temperatures, with switching facility, according to a further exemplary embodiment; andFigure 7 shows schematically a system with thermally coupled process devices, thermal stores and product buffer stores, according to a further exemplary embodiment.Preferred exemplary embodiments are described hereinafter with reference to the figures. Identical, similar or equivalent elements in the different figures are given identical reference numerals, and repeated description of these elements has been omitted to some extent in order to avoid redundancy. In the figures, electrically supplied power provided by corresponding devices E is represented by arrows with a single line. The arrows with a double line indicate flows of a heat medium.DETAILED DESCRIPTIONFigure 1 shows schematically a system 1 having two thermally coupled process devices P1 and P2 and a plurality of thermal stores 20, 30, 40, 50. The process devices P1, P2 are configured to each carry out a technical process, for example electrolysis in the case of process device P1, and DAC (Direct Air Capture) in the case of process device P2. In this case, the process device P1 carries out a heat-emitting process, while the process device P2 carries out a heat-absorbing process. The terms "process device" and "process" are used partially synonymously herein. Figure 1 shows a heat flow in the system 1 by means of double arrows. The heat is transported by means of a suitable heat medium, which may be liquid or gaseous. The heat medium in the system 1 is preferably water, optionally under pressure. However, other heat carriers, such as alcohols, thermal oils or also gases, are also suitable. The system 1 has a heat pump 10, by means of which the two process devices P1, P2 are thermally coupled. The heat pump 10 is configured to transform supplied heat at a temperature T1 (waste heat from the heat-emitting process device) into a heat at a higher temperature level T2 (supply heat for the heat-absorbing process device P2) using technical work, for instance by means of an electrically driven compressor, and thereby emit cold at a temperature level T3. For this purpose, the heat pump 10, comprising an evaporator 11 and a condenser 12, works with a heat carrier which is selected such that the temperature level of the waste heat is transformed into the desired high temperature level as economically as possible. In this case, in addition to the suitable selection of the working medium, the pressure levels of the heat pump process are also optimally adapted as far as possible. During the operation of the heat-emitting process P1, its waste heat at the temperature T1 is introduced into a thermal store 20, also referred to herein as "T1 store". The heat pump 10 uses the T1 store 20 at a suitable time as a heat source in order to generate heat at a higher temperature level T2 > T1 and store it in a second thermal store 30, also referred to herein as "T2 store". The heat-absorbing process P2 can then be supplied from the T2 store 30. The heat T4 emitted thereby can be supplied to the condenser 12 of the heat pump 10. In particular, if renewable electrical energy is present, the heat pump 10 can be operated in order to heat the waste heat from the T1 store 20 to the higher temperature level T2 and supply it to the T2 store. In this way, the thermally coupled processes P1, P2 and the heat pump 10 can be operated independently to a certain extent and thus react to the availability of volatile energy. The low temperature T3 emitted by the evaporator 11 of the heat pump 10 can be supplied to the heat-emitting process P1 as actively generated cold. Such utilization of the cooling power of the heat pump 10 is particularly advantageous at high ambient temperatures, as it eliminates a cooling apparatus (air cooling, water cooling) and often also improves the efficiency of the heat-emitting process P1. The system preferably comprises further thermal stores 40, 50, accordingly for the intermediate storage of the cold temperature level T3 of the heat pump 10 and the waste heat T4 of the heat-absorbing process P2. The thermal store 40 for supplying cold to the heat-emitting process P1 is also referred to herein as "T3 store". The thermal store 50 for the waste heat of the heat-absorbing process P2 is also referred to herein as "T4 store". The system 1 allows the use of the waste heat of the process P1 which is too cold for the heat-absorbing process P2. Furthermore, the two processes P1, P2 and the heat pump 10 can be operated independently of one another. The processes P1, P2 and their coupling via the heat pump 10 and the thermal stores 20, 30, 40, 50 are controlled and / or regulated via a control device 100. In particular, the control device 100 controls / regulates the times at which the processes P1, P2 are operated. In addition to system parameters, for this the control device 100 evaluates, for example, information about the available renewable energy, prices and also availability forecasts, and about the fill states of the thermal stores 20, 30, 40, 50. One aim of the control device 100 is to activate the heat pump 10 such that sufficient process heat is always available for the heat-absorbing process P2, as far as possible at the lowest costs or with maximum utilization of renewable energies. In addition, the control device 100 can use the essential system parameters for monitoring, by checking the interplay of the system parameters for plausibility. The control device 100 is connected for signaling purposes to the components of the system 1 to be controlled or regulated and / or read out, thus in particular to the processes P1, P2, the heat pump 10 and the thermal stores 20, 30, 40, 50. The communication between the control device 100 and the components to be controlled or regulated and / or read out can be wired or wireless, digital or analog. The control device 100 can accordingly receive and / or transmit signals (control signals, data, etc.), wherein signal transport in one direction and also in both directions falls under the term "communication" in this context. In this case, the control device 100 need not necessarily be implemented by a central computing device or electronic control system, but rather comprises decentralized and / or multi-stage systems, control networks, cloud systems and the like. The control device 100 can moreover be an integral component of or communicate with a superordinate installation controller. If the heat pump 10 is operated simultaneously with the heat-absorbing process P2, the thermal stores 30, 50 can be omitted. Figure 2 shows such an exemplary embodiment in which the process P1 is operated when energy, for example renewable energy, is present, while the heat pump 10 and the process P2 run continuously. Alternatively, the thermal stores 20, 40 on the other side can be omitted if the heat pump 10 is operated simultaneously with the heat-emitting process P1. Figure 3 shows such an exemplary embodiment in which the process P2 is operated when energy, for example renewable energy, is present, while the heat pump 10 and the process P1 run continuously. The thermal stores 20, 30, 40, 50 are preferably configured as thermally insulated devices, such as insulated containers which are made of steel, concrete or also of temperature-resistant plastics, and filled with water or thermal oil, for example. Thermal stores 20, 30, 40, 50 with a phase change are also possible, or for example the salt stores commonly used in concentrated solar power (CSP), or also water-conducting pipes in solid concrete or bulk material (such as e.g. sand), wherein the concrete or the bulk material assumes the function of the thermal store. The heat T1 emitted by the process P1 for the system 1 proposed here preferably lies in the range from 30 to 140°C, in particular in the range from 50 to 80°C. The required process heat T2 lies preferably in the range from 70 to 250°C, in particular in the range from 90 to 140°C. Higher final temperatures are also possible, wherein in this case further components may perhaps be necessary, such as steam compressors or electrical heating elements. Figure 4 shows a further exemplary embodiment of the system 1, in which an additional cooling of the cold emitted by the evaporator 11 of the heat pump 10 is implemented. The heat pump 10 receives the waste heat at temperature T1, emits heat at the higher temperature T2 and at the same time cold at the temperature T3, i.e. T2 > T1 > T3. The emitted cold thus lies below the temperature of the coolant output of the heat-emitting process P1. Depending on the design of the processes, further cooling of the cooling emitted at T3 by the evaporator 11 of the heat pump 10, to a temperature T3' < T3, may be expedient here. In the present exemplary embodiment, this is achieved by a cooling apparatus 60 which is installed between the evaporator 11 and the thermal store 40. The cooling apparatus 60 comprises, for example, air cooling, cooling with ambient water or a further heat pump which is used for cooling. This allows an even more effective cooling of the heat-emitting process P1. In addition, the cold generated by the cooling apparatus 60 can in principle also be used for other applications with a corresponding cooling requirement, such as for example data centers. Figure 5 shows a further exemplary embodiment of the system 1, which allows an alternative use of cold output temperatures of the heat-absorbing process P2. The heat-absorbing process P2 absorbs heat at a temperature T2 and emits heat at a colder temperature level T4. If T4 lies below the temperature level which is emitted by the evaporator 11 of the heat pump 10, then a circuit as illustrated in Figure 5 is advantageous, in which the colder temperature T4 is used for cooling the heat-generating process P1 (optionally via the thermal store 40). The temperature level T3 emitted by the evaporator 11 is used to generate the heat supply at T2. Possible examples of heat-absorbing processes P2 with very low output temperature T4 include drying or also DAC technologies with amine-based capture molecules. A lower starting level is available for efficient cooling of the heat-emitting process P1, and a higher starting level is available for heat generation, whereby the temperature change to be achieved by means of the heat pump 10 can be limited. In this way, advantageously, operating energy can be saved. In the configuration of Figure 5, the same heat medium must be used in both circuits. Different flows (volumes per time) of the heat carriers through the evaporator 11 and condenser 12 may be used in the design. This leads to different fill levels in the thermal stores 20, 50 and 30, 40, so that in this case measures should be carried out to equalize the quantity of the thermal stores. This can be achieved by means of the control device 100 using a suitable regulated pumped circulation of heat medium between the thermal stores 20, 30, 40, 50. Here again, the control device 100 performs the control and / or regulation of the relevant sequences. The control device 100 preferably also obtains information about the actual values of T4 and T3 and, in a further exemplary embodiment, can change the circuit configuration between those of Figures 1 and 5. For this purpose, a corresponding changeover valve 70 can be implemented, as shown in the exemplary embodiment of Figure 6. A separation of the thermal coupling between intermittent and continuously operated processes P1, P2 has been described, or in other words processes P1, P2 operated at different time patterns. An example of this is an intermittently operated electrolysis process P1, for instance an electrolyzer for generating H2 or directly reducing CO2, and a DAC process for providing CO2. The processes P1, P2 often provide starting materials which are then converted into the actual target substances in an industrial-scale synthesis process (for example methanol synthesis, reverse water gas shift reaction with subsequent Fischer-Tropsch process). These industrial-scale synthesis processes usually proceed continuously, but the preceding processes P1, P2 run intermittently for part of the time. In this case, it may be expedient to provide product buffer stores 80, 90 before transfer to the subsequent synthesis process, as shown in the exemplary embodiment of Figure 7. Preferably, such a product buffer store 80, 90 for a subsequent continuously operated process is provided for each intermittent process P1 and / or P2. The product buffer store 80, 90 should be dimensioned such that it can bridge downtimes of the volatile energies (a few hours to a few days). In the case of only one intermittently operated process P1 or P2, only one gas store is required. A continuously operated process P1, P2 requires no product buffer store 80, 90, or not a significantly large product buffer store. Depending on the sensitivity of the process P1, P2, a direct coupling is also possible, or the use of a very small product buffer store 80, 90 in order to compensate for process fluctuations (bridging times of, for example, 10 min to 1 h). Pressure vessels made of metal or plastic, in particular fiber-reinforced plastic, are preferably used as product buffer stores 80, 90, which are preferably dimensioned such that process interruptions of hours to days can occur before the starting product runs out. The control device 100 can additionally be supplied with information about the fill level of the product buffer stores 80, 90, so that the run times of the intermittently operated heat-emitting / heat-absorbing processes P1, P2 can be controlled so as to ensure the continuous supply to permanently operated subsequent processes via a sufficient fill level of the product buffer stores 80, 90. The above-described exemplary embodiments of the system 1 of thermally coupled processes P1, P2 can be applied to various industrial processes, including, for example, the process of generating synthetic fuels or energy carriers, which could be dimensioned as follows:The starting point is the coupling of an industrial water electrolyzer, with 17.5 MW electrically supplied power, the waste heat of which is supplied to a DAC plant with the aim of producing corresponding amounts of H2 and CO2 which can subsequently be used for the synthesis of hydrocarbons (gasoline, methane, etc.). Water electrolyzer: Intermittent operation (load factor 30%); 17.5 MW, 75% efficiency -> approx. 4.4 MWh waste heat at 65°C per hour; in 1 h running time generates approx. 335 kg H2. Using this amount of hydrogen, about 2,300 kg of CO2 is required for the synthesis of gasoline (approximate formula C8H18). About 2,460 kg of CO2 is required for the synthesis of methanol (formula CH3OH). DAC: Continuous operation; about 2.78 MWh heat is required for the release of 1t CO2; this results in the following amounts of heat for the provision of the respective CO2 requirement: about 6.39 MWh heat supply for gasoline production; about 6.84 MWh heat supply for methanol production. The drive power of the compressor must be added to the heat quantity of the waste heat. With a COP = 4, approximately 5.5 MWh heat is thus present at the high temperature level. COP (Coefficient of Performance) is defined as COP = generated heat at T2 [kWh] / electrical current required therefor [kWh]. This gives a well-adapted system since it is very close to the amount of heat required by the DAC system. The smaller amount of heat additionally required can be provided by other waste heat sources or also by direct generation (electricity, gas, etc.). This gives a highly efficient overall system which ideally utilizes the fluctuating presence of waste heat in the overall process. The process P1 for providing the waste heat source can also be realized in another way, in addition to the electrolyzer mentioned: for example via a data center, thermal power plant or a fuel cell. In order to further minimize the operating costs of the system 1, a battery store should suitably be incorporated. This is charged during peak times, in which the demand of the heat pump 10 or of the system 1 is lower than the generated volatile energy, in order to deliver the current to the heat pump 10 (or other units), for example, in times when insufficient energy is generated. Thus, for example in a solar PV system, the midday peak can be used to operate the units in the morning and evening hours via the battery store. The system 1 makes use of the fact that, in contrast to electricity, heat and / or process gases can be stored more cost-effectively and with less use of resources. As a result, processes P1, P2 running at different times (operated continuously and intermittently) can advantageously be coupled without burdening the overall process with excessively high costs or resources. The system 1 enables the thermal coupling of continuously operated and intermittently operated processes P1, P2. This allows flexible adaptation to the use of temporarily available energies, such as renewable energies. The system 1 allows an adaptation of the temperature levels between the heat-emitting process P1 and the heat-absorbing process P2 by means of an energy-efficient heat pump 10, the operating time of which can in turn be adapted to the availability of energy. The operating behavior can be optimized by a control logic implemented by the control device 100. The control device 100 can additionally implement monitoring functions. The system 1 allows an ideal utilization of waste heat, for example in the production of synthetic fuels or energy carriers. Where applicable, all individual features shown in the exemplary embodiments can be combined with one another and / or exchanged without leaving the scope of the invention.List of reference signs1 System10 Heat pump11 Evaporator12 Condenser20 Thermal store / T1 store30 Thermal store / T2 store40 Thermal store / T3 store50 Thermal store / T4 store60 Cooling apparatus70 Changeover valve80 Product buffer store90 Product buffer store100 Control deviceP1 Heat-emitting process deviceP2 Heat-absorbing process deviceE Device for providing electrical energyT1 Waste heat of the heat-emitting processT2 Supply heat for the heat-absorbing processT3 Temperature level of the cold outputT4 Waste heat of the heat-absorbing process

Claims

 1.A system (1) of thermally coupled processes, wherein the system (1) comprises:at least one heat-emitting process device (P1) which is configured to carry out a technical process and thereby emit waste heat at a temperature T1;at least one heat-absorbing process device (P2) which is configured to carry out a technical process and thereby absorb heat at a temperature T2 which is higher than T1;a heat pump (10) which is designed to heat the waste heat of the heat-emitting process device (P1) from T1 to T2; anda T1 store (20), which is a thermal store, arranged between the heat-emitting process device (P1) and the heat pump (10) and configured to store the waste heat of the heat-emitting process device (P1), preferably at the temperature T1, and / ora T2 store (30), which is a thermal store, arranged between the heat pump (10) and the heat-absorbing process device (P2) and configured to store the heat to be absorbed by the heat-absorbing process device (P2), preferably at the temperature T2.  2.The system (1) as claimed in claim 1, characterized in that the heat pump (10) is configured to emit cold at a temperature T3 and supply it to the heat-emitting process device (P1), wherein preferably a T3 store (40), which is a thermal store, is arranged between the heat pump (10) and the heat-emitting process device (P1) and is configured to store the cold emitted by the heat pump (10), preferably at the temperature T3.  3.The system (1) as claimed in claim 2, characterized in that the system (1) has a cooling apparatus (60) which is arranged between the heat pump (10) and the heat-emitting process device (P1) or the T3 store (40), and is configured to cool the cold emitted at T3 by the heat pump (10) to a lower temperature T3'.  4.The system (1) as claimed in one of the preceding claims, characterized in that the heat-absorbing process device (P2) is configured to emit waste heat at a temperature T4 and to supply it to the heat pump (10), wherein preferably a T4 store (50), which is a thermal store, is arranged between the heat-absorbing process device (P2) and the heat pump (10), and is configured to store the waste heat emitted by the heat-absorbing process (P2), preferably at the temperature T4.  5.The system (1) as claimed in claim 4, characterized in that the waste heat at T4 from the heat-absorbing process device (P2) or the T4 store (50) can be supplied to the heat-emitting process device (P1) or the T3 store, bypassing the heat pump (10), for cooling purposes, preferably in switchable fashion by means of a changeover valve (70).  6.The system (1) as claimed in claim 5, characterized in that the cold at T3 from the heat pump (10) can be supplied to the T4 store, preferably in switchable fashion by means of the changeover valve (70).  7.The system (1) as claimed in one of the preceding claims, characterized in that at least one product buffer store (80, 90) is provided which is configured to store a starting product of at least one of the process devices (P1, P2).  8.The system (1) as claimed in one of the preceding claims, characterized in that the heat-emitting process device (P1) and / or the heat-absorbing process device (P2) and / or the heat pump (10) draw electrical energy for regular operation.  9.The system (1) as claimed in one of the preceding claims, characterized in that the heat-emitting process device (P1) and / or the heat-absorbing process device (P2) and / or the heat pump (10) work intermittently.  10.The system (1) as claimed in one of the preceding claims, characterized in that a control device (100) is furthermore provided for control and / or regulation of the system (1), wherein the control device (100) is preferably configured to obtain information about the fill states of the thermal stores (20, 30, 40, 50) and to activate the heat pump (10) such that sufficient process heat is always available for the heat-absorbing process device (P2).  11.The system (1) as claimed in any of the preceding claims, characterized in that the heat-emitting process device (P1) is an electrolyzer for generating H2 or directly reducing CO2, and / or the heat-absorbing process device (P2) is configured to carry out a DAC process for providing CO2.  12.A method for operating a system (1) of thermally coupled processes, wherein the method comprises:carrying out a technical process which emits waste heat at a temperature T1 by means of a heat-emitting process device (P1);carrying out a technical process which absorbs heat at a temperature T2, which is higher than T1, by means of a heat-absorbing process device (P2);heating the waste heat of the heat-emitting process from T1 to T2 by means of a heat pump (10);storing the waste heat of the heat-emitting process in a T1 store (20), which is a thermal store and is arranged between the heat-emitting process device (P1) and the heat pump (10), and / orstoring the heat to be absorbed by the heat-absorbing process in a T2 store (30), which is a thermal store and is arranged between the heat pump (10) and the heat-absorbing process device (P2).  13.The method as claimed in claim 12, characterized in that the heat-emitting process and the heat-absorbing process are not carried out simultaneously for at least part of the time.  14.The method as claimed in claim 12 or 13, characterized in that the heat pump (10) emits cold at a temperature T3 and supplies it to the heat-emitting process device (P1), wherein preferably a T3 store (40), which is a thermal store, is arranged between the heat pump (10) and the heat-emitting process device (P1) and stores the cold emitted by the heat pump (10), preferably at the temperature T3.  15. The method as claimed in any of claims 12 to 14, characterized in that the heat-absorbing process device (P2) emits waste heat at a temperature T4 and supplies it to the heat pump (10), wherein preferably a T4 store (50), which is a thermal store, is arranged between the heat-absorbing process device (P2) and the heat pump (10) and stores the waste heat emitted by the heat-absorbing process (P2), preferably at the temperature T4. 

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