Arrangement and method for producing starting materials of electric current and water vapour in a hybrid power plant

Abstract

For water electrolysis, a hybrid power plant is arranged in which at least one power plant (6m, 60) produces only the reactant, electricity, and at least one additional power plant produces electricity (8i) and / or steam (8c, 8k) from thermal energy (100). In an ammonia / water-based absorption power cycle, a two-phase mixture (20p) is generated by heat input and separated in a desorber (13) into aqueous ammonia vapor (19) and a low-absorption solution (16). Following a combined heat and power (CHP) process, superheated aqueous ammonia vapor (19a) is used in a turbine (14) for electricity production, and the low-absorption solution (16) is used in a steam generator (13b) for steam production (8k) for electrolysis. In variant A, the hybrid power plant is preferably formed from photovoltaic systems (6m) and a closed-loop gas turbine (6) with precooling.In variant B, a circulating LOHC transport system (20a, 20b) is added, wherein thermal energy is transferred to a two-phase mixture (21p) of the absorption power cycle in its hydrogenator (20d). In variant C, the input of thermal energy to a two-phase mixture takes place exclusively in the hydrogenator (20d) of the circulating LOHC transport system (20a, 20b). This variant is preferably suitable for a hybrid power plant with wind turbines (60).

Description

[0001] The invention relates to a hybrid power plant for the production of electricity and steam for the provision of hydrogen and a corresponding method for this.

[0002] It is known that the production costs of hydrogen can be significantly reduced using a hybrid power plant consisting of a closed-loop gas turbine and photovoltaic systems, by increasing the full-load hours of the electrolysis plants considerably above those of the photovoltaic systems. A disadvantage is that the concept is currently only designed for electrolysis plants based on water. A technical challenge lies in developing a concept for energy-efficient steam electrolysis.

[0003] A project called HyGen, launched in 2023 and involving, among others, the Hamburg University of Technology and the University of Erlangen-Nuremberg, is developing a floating hydrogen production plant for conventional offshore wind farms. The wind turbine generates electricity for the electrolysis of desalinated seawater directly on a floating platform to produce hydrogen. The seawater desalination process is powered by the heat generated during hydrogenation, which is produced by loading a liquid organic hydrogen carrier (LOHC) with hydrogen. The hydrogen can be stored at low pressure in the LOHC, allowing for transport using slightly modified tankers. On land, the hydrogen is separated from the LOHC and is available as pure (green) hydrogen.

[0004] German patent application DE 10 2021 002 893 B3 describes a closed-loop gas turbine with pre-cooling coupled to an absorption combined heat and power (CHP) cycle. Heat is supplied to the closed-loop gas turbine by means of concentrated solar radiation absorbed by heat-storing ceramic spheres in a solar tower. Waste heat from the closed-loop gas turbine is fed into the absorption CHP cycle for electricity and cooling generation. Additionally, steam can be generated from a temperature range above approximately 200 °C for steam electrolysis. An advantage is that this steam heat replaces electricity; a disadvantage is that only a narrow temperature range can be provided by CHP. A technical challenge lies in increasing the width of this temperature range.

[0005] The object of the invention is to provide a hybrid power plant and a method for operating the hybrid power plant in which steam is generated for steam electrolysis in an energy-saving manner from an economic point of view.

[0006] The solution to the problem is found in a main claim and a further associated dependent claim. The dependent claims formulate further preferred embodiments of the invention.

[0007] The invention describes a method and an arrangement for producing reactants of electric current and steam in a hybrid power plant for the provision of hydrogen using renewable energy.

[0008] The hybrid power plant comprises at least one electricity-generating power plant and at least one system from which thermal energy is extracted and which, as a power plant, produces electricity and / or steam. The following process steps are then added: Providing at least one water electrolysis plant, including a high-temperature steam electrolysis plant, wherein electricity from the at least one power-generating power plant is fed at least as a subset into the steam electrolysis plant; arranging an ammonia / water-based absorption power cycle, which is supplied from the at least one plant from which thermal energy is extracted.

[0009] The absorption force cycle is equipped with common and well-known components and features additional equipment: a steam turbine for electricity generation, wherein water-rich ammonia vapor is expanded and drives the steam turbine, a first steam generator heated by poor absorption circuit solution, with a desorber having height-graded surfaces that serve only for mass and heat exchange between rising water-containing ammonia vapor and descending partial stream of enriched ammonia solution, the absorption force cycle is carried out with the following process steps: Ammonia vapor containing water is extracted from the desorber, superheated, and then directed to the steam turbine of the absorption power cycle. The generated steam is temporarily stored in a steam storage tank and later or directly fed into the steam electrolysis plant. Hot water extracted from a condenser of the steam electrolysis plant is fed to the first steam generator for steam generation. The poor absorption cycle solution is drawn from a sump of the desorber and directed to the first steam generator for heat input. The poor absorption cycle solution, along with any remaining heat that can be extracted, is then transferred to at least one first solution heat exchanger.

[0010] The electrolysis is carried out using a high-temperature electrolysis plant with steam and capillary electrolysis equipment, whereby 100% of the total power of the electrolysis equipment is divided between 40% and 60% for high-temperature electrolysis and 40% and 60% for low-temperature electrolysis.

[0011] High-temperature electrolysis is performed at atmospheric pressure.

[0012] The at least one power plant generating electricity is designed as a wind turbine and / or a photovoltaic system. Furthermore, the at least one system from which thermal energy is extracted can be designed as a geothermal power plant and / or a steam power plant driven by solar thermal energy.

[0013] Furthermore, a closed gas turbine powered by solar thermal energy and equipped with pre-cooling is arranged both as a power-generating power plant and for the input of thermal energy into the absorption power cycle, thereby extending the latter to the absorption power-cooling cycle.

[0014] In the closed gas turbine cycle, intermediate heating is carried out and an additional utility turbine is inserted for this purpose, whereby a pressure ratio of at least 6.5 to 8 is provided for in the closed gas turbine.

[0015] The amount of water vapor production in the absorption power cycle should be measured under the following three conditions: (A) according to the size of the electrical current generated in the hybrid power plant for hydrogen production, (B) according to the ratio in energy equivalent of the reactant steam to the reactant electrical current in the steam electrolysis plant, where the ratio steam to electricity is assumed to be between 1 to 4.75 and 5.25, and (C) reduced by the size of the reactant steam generated in the hybrid power plant.

[0016] The hybrid power plant can be oversized to produce steam for a seawater desalination plant.

[0017] The hydrogen produced in electrolysis can be transferred into liquid organic hydrogen carriers, which are handled by a transport system. This transport system can be integrated into the hybrid power plant in such a way that thermal energy transferred to a dehydrogenator within the transport system is released again in a hydrogenator.

[0018] Ultimately, the absorption-force cycle can be designed as an absorption-force-cold cycle, with the following process steps being provided. A rich absorption loop solution is raised to high pressure by a second solution pump and directed to a second solution heat exchanger for heat absorption. The rich absorption loop solution is introduced into a waste heat boiler heated by a low-pressure gas from the closed gas turbine and converted into a first two-phase mixture by means of external heat input. A second partial stream of poor absorption loop solution is introduced into the developing first two-phase mixture of the absorption loop. Subsequently, the first two-phase mixture is introduced from the waste heat boiler into the sump of the desorber. A first partial stream of enriched absorption loop solution is taken from a low-pressure absorber and raised to high pressure by a fourth solution pump and heated in a third solution heat exchanger.then the first partial stream of enriched absorption solution is divided into a second and third partial stream of enriched absorption solution, and the second partial stream of enriched absorption solution is introduced into the head of the desorber, and the energy released in a hydrogenator of the transport system is supplied to the third partial stream of enriched absorption solution, whereby this is converted into a second two-phase mixture of ammonia and water, subsequently the second two-phase mixture is introduced into the desorber, in the desorber the process step rectification is arranged by separating the introduced first two-phase mixture and the introduced second two-phase mixture into vapor phase and liquid phase in the sump of the desorber,According to an equilibrium existing in the wet steam range between steam and liquid, a water fraction of the aqueous ammonia vapor exiting the desorber head is determined via the first partial stream of enriched absorption solution; poor absorption solution is discharged from the desorber sump and directed to the first steam generator for heat transfer; and a steam pressure of 3.5 to 5.5 bar is maintained. From the poor absorption solution discharged from the first steam generator, a first and a second partial stream of poor absorption solution are separated; the remaining main stream of poor absorption solution is directed to the first solution heat exchanger for heat transfer, so that the first partial stream of enriched absorption solution is heated to boiling temperature.and subsequently, the main flow of poor absorption circuit solution is reduced to low pressure by means of a first throttle and introduced into the low-pressure absorber for absorption, the first partial flow of the poor absorption circuit solution is reduced to medium pressure by means of a second throttle and is passed through the second solution heat exchanger with poor compression circuit solution for heat transfer, and then reduced to low pressure by means of a third throttle and introduced into the low-pressure absorber for absorption.

[0019] The Figure 1 essentially shows the state of the art according to Figure 7from DE 102021002893 B3. It shows cooling generation and transfer to the circulating medium air of a closed gas turbine (6) with a recuperative counterflow heat exchanger (6c) and heat input from its low-pressure gas (9c) to a first partial flow (28e) of rich absorption solution, as well as a compression circuit with rich (38) and poor (36) compression solution and a resorption circuit with rich (48) and poor (46) resorption solution for cooling generation by means of a deaerator (43). The cooling serves to pre-cool the closed gas turbine (6). The reference numerals of the figure are largely taken from DE 102021 002 893 B3.

[0020] In DE 10 2021 002 893 B3, the absorption cycle is used to generate electricity (15a) via a steam turbine (14). The absorption cycle and the thermal compression cycle are linked in shared low-pressure absorber (1) and low-pressure absorber (2). The thermal compression cycle will be referred to as the compression cycle in the following.

[0021] Accordingly Fig. 8According to DE 10 2021 002 893 B3, solar radiation (6j) is focused by means of mirrors (6k) onto a particle receiver (6i) located on a solar tower. Ceramic spheres are generally used for this purpose. The particles are heated there to high temperatures (500 to 1000 °C). At least some of the high-temperature heat is temporarily stored. The particles are conveyed by means of a particle transport device (6h) into a thermal high-temperature storage unit (6f). From there, the particles are conveyed to the heater (6e) of a closed gas turbine (6).

[0022] After heat removal, the particles are directed into a thermal medium-temperature storage unit (6g). The temperature of this storage unit is between 450 and 620 °C. From this medium-temperature storage unit (6g), the particles are directed to the particle receiver (6i) for solar radiation harvesting.

[0023] The high-pressure gas (9b) from the closed-loop gas turbine (6) is heated and fed to its power turbine (6a) and expanded to low pressure. The low-pressure gas (9c) is first passed through a recuperative counterflow heat exchanger (6c) and then through a heat recovery steam generator (5) for heat transfer. The low-pressure gas (9c) is then supercooled and fed to the compressor (6b) of the closed-loop gas turbine, where it is raised to high pressure. The high-pressure gas (9b) is then passed through the heater (6e) to input heat, thus closing the gas turbine cycle. The power output of the closed-loop gas turbine (6) is converted into electricity in a generator (15).

[0024] Heat from the low-pressure gas (9c) is transferred to the absorption chiller cycle in a waste heat boiler (5). This cycle includes a very low-pressure absorber (1), a low-pressure absorber (2), and a medium-pressure absorber (3).

[0025] Enriched solution from the absorption circuit and the compression circuit (29) is drawn from the low-pressure absorber (1). This combined flow is raised to low pressure by means of the first solution pump (21) and introduced into the low-pressure absorber (2) for absorption. In both absorbers (1, 2), heat of absorption is transferred to a cooling medium.

[0026] Rich absorption solution (28) and rich compression solution (38) are drawn from the low-pressure absorber (2). The rich absorption solution (28) is pressurized to high pressure by a second solution pump (21a), and then a first partial stream (28e) of rich absorption solution is separated. The remaining main stream of rich absorption solution (28d) is passed through a second solution heat exchanger (22) for heat transfer. Subsequently, the main stream of rich absorption solution (28d) is directed to a waste heat boiler (5) through which the low-pressure gas (9c) from the closed gas turbine (6) flows. There, the main stream of rich absorption solution (28d) is first heated to boiling temperature and then converted into a first two-phase mixture (20p) by partial evaporation. A second partial stream (16c) of poor absorption solution is then introduced into the already partially formed two-phase mixture (20p).The first two-phase mixture (20p) is taken from the waste heat boiler (5) and introduced into a dual-function desorber (13a). There, the first two-phase mixture (20p) is separated into water-rich ammonia vapor and poor absorption solution (16). In this arrangement, the second partial stream (16c) of poor absorption solution is predominantly heated only in the waste heat boiler, and the absorbed heat is released again in the dual-function desorber (13a).

[0027] The first partial stream (28e) of rich absorption loop solution is heated in a first solution heat exchanger (12). Subsequently, this first partial stream (28e) of rich absorption loop solution is introduced into the head of the dual-function desorber (13a).

[0028] In the dual-function desorber (13a), two process steps take place simultaneously. First, the rising water-rich ammonia vapor is reduced to aqueous ammonia vapor (19) by heat and mass transfer with a descending first partial stream (28e) of rich absorption solution, and a lean solution is formed. For heat and mass transfer, several trough-like surfaces are arranged in a known manner at different heights. Second, aqueous ammonia vapor (19) is driven off from the first partial stream (28e) of rich absorption solution by means of indirectly heat-transferring lean absorption solution (16), and additional lean solution is formed. The lean solutions formed during rectification and drive-off flow into the sump of the dual-function desorber (13a). There, they are combined with the liquid phase of the phase separation to form the lean absorption solution (16). This lean solution (16) is passed from bottom to top through the trough-like surfaces.

[0029] The water-containing ammonia vapor (19) exits from the head of the two-function desorber (13a), the water content of which is determined at least approximately to a water content of approximately 6% via an equilibrium line of the introduced first partial stream (20e) of rich absorption circuit solution.

[0030] The poor absorption loop solution (16) is withdrawn from the head of the dual-function desorber (13a) after heat transfer. First, the second partial stream (16c) of the poor absorption loop solution is separated, followed by a first partial stream (16a) of poor absorption loop solution. The remaining main stream (16b) of poor absorption loop solution is passed through the first solution heat exchanger (12) for heat transfer, the volume of the main stream (16b) being dimensioned to be large enough to heat the first partial stream (16e) of rich absorption loop solution to its boiling temperature. Subsequently, the main stream (16b) of poor absorption loop solution is reduced to a low-pressure level by means of a first throttle (17) and introduced into the low-pressure absorber (1) for absorption.

[0031] The separated first partial flow (16a) of poor solution from the absorption circuit is reduced to medium pressure by means of a second throttle (17a) and combined with the poor compression circuit solution (36) for heat transfer through the second solution heat exchanger (22). The mixed flow (26) of poor solutions from the absorption and compression circuits is reduced to very low pressure by means of a third throttle (27) and introduced into the very low pressure absorber (1) for absorption.

[0032] Hydrogenated ammonia vapor (19) exits the head of the dual-function desorber (13a) and is directed to the waste heat boiler (5), where it is superheated. The superheated hydrogenated ammonia vapor (19a) is directed to a steam turbine (14) and expanded to the wet steam range. The mechanical work is converted into electricity by a generator (15). Low-pressure steam (19b), expanded to extremely low pressure, is extracted from the steam turbine (14) and directed to the low-pressure absorber (1) for absorption.

[0033] For refrigeration, a compression circuit and an absorption circuit are arranged, both of which are also operated with the binary mixture of ammonia and water. A rich compression circuit solution (38) is drawn from the low-pressure absorber (2) and raised to medium pressure by means of a fifth solution pump (31). It is then fed to a medium-pressure trickling extractor (33) operating at medium pressure and introduced into its head for extraction. The extraction process takes place in the medium-pressure trickling extractor (33): By means of an indirectly heat-transferring circulating water stream (7), nearly pure medium-pressure ammonia vapor (39) is driven out of the rich compression circuit solution (38), and a lean compression circuit solution (36) is formed. The lean compression circuit solution (36) collects at the bottom of the medium-pressure trickling extractor (33) and is drawn off.The medium-pressure ammonia vapor (39) exits the head of the medium-pressure trickling extractor (33) and is directed to a medium-pressure absorber (3) at the same pressure for absorption. A poor absorption cycle solution (46) is introduced into this medium-pressure absorber (3). After absorption, a rich absorption cycle solution (48) is withdrawn and reduced to low pressure by means of a fourth throttle (47) and then introduced into a degasser (43). In the degasser (43), the process step of expulsion takes place, in which the low-pressure gas (9c) is supercooled to a temperature level below ambient temperature by its heat transfer. The rich absorption cycle solution (4) is converted into a two-phase mixture of the absorption cycle. Subsequently, the two-phase mixture of the absorption cycle is directed to a vapor separator (44) and separated into low-pressure vapor (49) of the absorption cycle and the poor absorption cycle solution (46).The medium-pressure ammonia vapor (39) is directed to a low-pressure absorber (2) at the same pressure for absorption. The poor absorption circuit solution (46) is raised to medium pressure by means of a fifth solution pump (41) and directed to the medium-pressure absorber (3) for absorption. As is known, an additional solution heat exchanger could be inserted into the absorption circuit to further subcool the rich absorption solution (48) before throttling. This is not shown here.

[0034] The water flow (7) is directed circulatingly from the medium-pressure trickle blower (33), supported by a circulation pump (11c), to the waste heat boiler (5) for heat input and then back to the medium-pressure trickle blower (33) for heat discharge.

[0035] The first steam stream (8c) generated in the waste heat boiler (5) and the electrical current (10) generated in the generators (15) are fed as reactants to a steam electrolysis plant (8d) for the production of hydrogen (8e). The fact that the electrical current (10) generated in the generators will be converted from alternating current to direct current (8i) for this purpose is not shown in this and the following figures. The known process includes the following apparatus: a first counterflow heat exchanger (8j) for heating the supplied air, a second counterflow heat exchanger (8g) for heating the supplied first steam stream (8c), and a condenser (8i). The heat of condensation is used to preheat water (8a) and direct it to a steam drum (8b).

[0036] The heat input sequence in the waste heat boiler is as follows: a second steam generator (13c), then a steam superheater (5a), followed by a preheated main stream of rich absorption solution (28d) and a second partial stream of poor absorption solution (16c) to generate the first two-phase mixture (20p). Subsequently, the rich absorption solution (28e) and the circulating water stream (7) are connected in parallel for heating, followed by a gas turbine cooler (7b), and finally a deaerator (43).

[0037] In the known process of steam electrolysis, direct current (8i) and steam (8) are supplied, and it is assumed that the steam is to be supplied under overpressure (preferably 10 bar). Therefore, an inlet temperature of 220 °C for the low-pressure gas of the closed gas turbine (6) into the heat recovery boiler is required. The objective is to increase the temperature range by approximately 30 K to improve the efficiency of the closed gas turbine (6) with its downstream absorption power-cooling cycle by generating steam. This utilizes the fact that this steam can replace electrical current, with approximately 20% of the electrical current being replaceable by steam.

[0038] The invention is illustrated in several figures, which show in detail: Fig. 2 : Apparatus and circuit design deviating from Fig. 1 , Fig. 3 : three variants of power plant types in the hybrid power plant, Fig. 4: an extended variant B, Fig. 5 : inserted water electrolyzer, Fig. 6 Closed gas turbine with reheating, Fig. 7 : Variant B and Fig. 8 Variant C.

[0039] In the Figure 2 According to the invention, the apparatus and circuit design deviate from the Figure 1The following four modifications are illustrated: Instead of the dual-function desorber (13a), a desorber (13) is arranged, from whose sump the poor absorption solution (16) is discharged. This eliminates the heat input of the poor absorption solution (16) into the desorber (13). The exchange surfaces arranged in the desorber are simplified to flat surfaces. The poor absorption solution (16) is passed through an additionally arranged first water evaporator (13b) to generate a second steam stream (8k). With this new arrangement, the supplied heat is used in an energy-saving combined heat and power (CHP) process. For evaporation, preheated water (8a) is supplied from the condenser (8I) to the steam electrolysis unit (8d).

[0040] Unlike the Figure 1The reactants, electricity and steam, are reacted in a steam electrolysis plant (8d) operated at atmospheric pressure. Steam (8) at low pressure – preferably 3.5 bar – is supplied for electrolysis. The first steam stream (8c) generated in the waste heat boiler is fed to a steam storage tank (Ruths storage tank) (8p) and supplied to the steam electrolysis plant (8d) as needed. The number of units generating the steam reactant increases by two.

[0041] The order of heat input in the waste heat boiler is changed and arranged as follows: Superheating of the aqueous ammonia vapor (19) of the absorption power refrigeration cycle; second stage of expulsion from the supplied main stream of rich absorption circuit solution (28d); first steam generator (13b); first stage of expulsion from the supplied main stream of rich absorption circuit solution (28d); circulating water stream (7); gas turbine cooler (7b); degasser (4).

[0042] In addition to the renewable electricity generation in a solar tower for the closed gas turbine (6), electricity generation using photovoltaic systems (6m) is added, thus forming a hybrid power plant.

[0043] The arrangement of the desorber (13) with a downstream first steam generator (13b) according to the invention, in combination with an LOHC transport system (20a, 20b), creates a new degree of freedom for the design of hybrid power plants: Their hydrogenation heat is approximately 30% of the heat content of the hydrogen to be introduced into the LOHC transport system, while the heat requirement for the steam of a steam electrolysis plant (8d) is only approximately 20%. When the hydrogenation heat is introduced into the absorption power cycle, the proportion remaining for water evaporation is reduced to approximately 15% – in favor of generating electricity. A third water evaporator (20e) of a hydrogenation unit of the LOHC transport system can also be arranged in a hybrid power plant. The respective proportions of the three water evaporators can also be arranged differently.

[0044] In the Figure 3Three variants are presented in which different power plant types are combined to generate the reactants electricity or electricity and steam in the hybrid power plant. In all three variants, three-phase current is converted into direct current (8i).

[0045] In variant A, photovoltaic systems (6m) and a closed-loop gas turbine (6) generate alternating current (11). Both devices are driven by solar thermal energy (6j), with the closed-loop gas turbine (6) receiving high-temperature thermal energy (99) from a particle receiver (6i). Thermal energy from the low-pressure gas (9c) of the closed-loop gas turbine is transferred to a first steam stream (8c) and, in a waste heat boiler (5), to the absorption power cycle. In this cycle, aqueous ammonia vapor (19) and low ammonia solution are separated in a desorber (13), and the reactant, electricity, is generated by a steam turbine (14), while the reactant, water vapor (8), is generated by a first steam generator (13b). These reactants are fed to a steam electrolysis plant (8d). This arrangement enables two cascaded combined heat and power (CHP) plants.

[0046] In variant B, the LOHC-based transport system is added. Heat is introduced into its dehydrogenator (20c). This heat is used to input heat into the absorption power cycle by utilizing the heat released in the hydrogenator to drive off ammonia from the ammonia-containing solution of the absorption power cycle. This generates additional electricity (8i) via the path from the desorber (13) to the steam turbine (14), and additionally, via the path from the first steam generator (13b), the reactant steam (8) is produced by means of a second steam stream (8k).

[0047] Variant C is shown for windy regions outside areas with high solar radiation. Wind turbines (60) generate only electricity. Using the heat source for heat input into the LOHC transport system, the reactants electricity and steam are used with the apparatus already described in Variant B (13b and 20d as well as 13) to produce steam and with the steam turbine (14) to produce electricity. Additionally, a hydrogenation apparatus (20e) is arranged as a third steam generator, producing a third steam stream (8m).

[0048] In the Figure 4Variant B is extended by three process steps. An additional apparatus for hydrogen hydrogenation (I) is inserted into the LOHC transport system, into which thermal energy (100) is introduced for steam generation. A portion of the steam (80) generated in the hybrid power plant is exported for freshwater production. For this purpose, the known process of multi-stage thermal seawater desalination (101) is simplified. A portion of the electricity generated in the hybrid power plant is exported as alternating current to a power grid (102).

[0049] The following figures represent those in the Figures 3 and 4 The listed process steps in different arrangements of the cycles in variants to illustrate the Figure 3 executed.

[0050] In the Figure 5 will be used to supplement the presentation of Figure 2A water electrolyzer is inserted. Preferably, a capillary electrolysis system (9) is arranged, due to its higher efficiency in producing hydrogen from the reactants water vapor and electric current. The arrangement of two different types for hydrogen production facilitates the continuous operation required for water vapor electrolysis by supplying water vapor (8) stored in the water vapor storage tank (8p) to the water vapor electrolyzer (8d) outside of the sunshine period.

[0051] In contrast to the representation in Figure 3 A first partial flow (18a) of enriched absorption circuit solution is fed to the desorber (13). For this purpose, it is taken from the low-pressure absorber (1) and raised to a high-pressure level by means of a fourth solution pump (11b) and then passed through a first solution heat exchanger (12) for heat absorption. With this, compared to the Figure 3With the modified circuit, a smaller quantity of rich absorption solution (18) is drawn from the low-pressure absorber (2). Since the quantity of low-pressure steam (49) supplied to the absorption circuit is not to be changed, the degassing range in the low-pressure absorber (2) increases, resulting in a lower ammonia content in the corresponding low-pressure absorber's enriched solution. This allows the low-pressure steam (19a) supplied by the steam turbine (14) to be absorbed at a reduced pressure level in the low-pressure absorber (1) after being expanded with increased power.

[0052] In the Figure 6The closed gas turbine (6) with reheating is depicted. For this purpose, an auxiliary turbine (6d) is inserted – in a generally known manner – and medium-pressure gas (9d) from the closed gas turbine is routed from the auxiliary turbine (6d) to the heater and reheater (6I) for heat input and then to the main turbine (6a). The pressure ratio of the closed gas turbine is designed to be at least 6.5 – preferably 7. The associated high compressor discharge temperature and the associated high outlet temperature of the low-pressure gas are optimally converted into electricity and steam by the depicted system design. The increased heat input to the closed gas turbine through reheating is almost completely converted into electricity in the overall system.

[0053] In the Figure 7 will be in the Figures 3 and 4Variant B is implemented as described. Wind turbines (60) are added as additional power generators. A dehydrogenator (20c) of the LOHC transport system is added as an additional generation unit. Heat (100) on the order of approximately 30% of the heat content of the released hydrogen is supplied to this dehydrogenator. The LOHC liquid (20b) discharged from the transported hydrogen is transported to the hydrogen loading location without heat loss. There, the heat is released again during hydrogen loading in the hydrogenator (20d). The heat is dissipated indirectly in a heat exchanger. The heat-absorbing medium must be able to dissipate the released heat of reaction; the reaction takes place under overpressure – for example, 20 bar – and no other specific requirements are necessary. At least a portion of the produced hydrogen must be compressed to this pressure level.A third partial stream (18c) of enriched absorption loop solution is arranged as a cooling medium in the hydrogenator (20d). This liquid is converted into a two-phase mixture (21p), whereby this conversion is to take place in the bubble evaporation range. For this purpose, the solution volume is adjusted according to the heat to be dissipated.

[0054] Additionally, some of the hydrogenation heat is transferred to a third water evaporator (20e). Steam generation in the waste heat boiler is therefore eliminated. This alternative to steam generation in the waste heat boiler (5) – as in the Figures 2 , 5 , 6 The configuration shown is particularly preferable for hybrid power plants with a high proportion of electricity generation from power plants without steam generation. Such a hybrid power plant is illustrated by the addition of wind turbines (60).

[0055] In contrast to the representation in Figure 2The second partial stream (18b) of enriched absorption solution is fed to the desorber (13). For this purpose, the first partial stream (18a) of enriched absorption solution is split into the second (18b) and third (18c) partial streams (18a) of enriched absorption solution after it exits the first solution heat exchanger (12). The third (18c) partial stream of enriched absorption solution is fed to the hydrogenator (20d). In contrast to the previous Figure 1 , 2 , 5 and 6 The waste heat boiler (5) is supplied with a rich absorption cycle solution (18) without prior separation of a subset.

[0056] In the Figure 8 will be in Figure 2 Variant C as described was executed. Figure 5Absorption solution is extracted from the absorber (1) and raised to a high-pressure level by means of a fourth solution pump (11b) and then passed through a first solution heat exchanger (12) for heat absorption. In contrast to the cycle designs of the Figure 1 , 2 , 5 , 6 , 7 There is a lack of poor absorption solution (39) to heat the rich absorption solution – located in the second solution heat exchanger (22). Therefore, the distribution of the enriched absorption solution (18a) is already arranged in the first solution heat exchanger (12). The third partial stream (18c) of the absorption solution is only partially heated and is fed to the hydrogenation apparatus (20d). The second partial stream (18b) of enriched absorption solution is heated to the predetermined rectification temperature in the first solution heat exchanger and introduced into the head of the desorber (13). In contrast to the representation of the Figure 5The separation of the first partial flow (16a) of the poor absorption loop solution from the poor absorption loop solution (16) is omitted. The entire poor absorption loop solution is passed through the first solution heat exchanger (12), and only this quantity is introduced into the absorber. Since no pre-cooling of a closed gas turbine is also arranged, the low-pressure absorber (2) is omitted. Reference sign

[0057] 1 Low-pressure absorber 2 Low-pressure absorber 3 Medium-pressure absorber 5 Waste heat boiler 5a Steam superheater 6 Closed gas turbine 6a Power turbine 6b Compressor 6c Recuperative counterflow heat exchanger 6d Auxiliary power turbine 6e Heater 6f High-temperature storage 6g Medium-temperature storage 6h Particle transport system 6i Particle receiver 6j Solar radiation 6k Mirror 6l Heater and reheater 6m Photovoltaic systems 6n Electrically heated heater 7 Circulating water flow 7b Gas turbine cooler 8 Steam 8a Water 8b Steam drum 8c First steam flow 8d Steam electrolysis plant 8e Hydrogen 8g Second counterflow heat exchanger 8i Direct current 8j First counterflow heat exchanger 8k Second steam flow 8l Condenser 8m Exported electricity 8p Steam storage 9 Capillary electrolysis system 9b High-pressure gas 9c Low-pressure gas 10 Electric current 11b Fourth solution pump 12 First solution heat exchanger 12a Second solution heat exchanger 13 Desorber 13aDual-function desorber 13b First steam generator 13c Second steam generator 14 Steam turbine 15 Generator 15a Electric current 16 Poor absorption loop solution 16a First partial stream of poor absorption loop solution 16b Main stream of poor absorption loop solution 16c Second partial stream of poor absorption loop solution 17 First throttle 17a Second throttle 18a First partial stream of enriched absorption loop solution 18b Second partial stream of enriched absorption loop solution 18c Third partial stream of enriched absorption loop solution 19 Hydrated ammonia vapor 19a Superheated hydrated ammonia vapor 19b Low-pressure steam 20a Hydrogen-loaded water carrier 20b Unloaded hydrogen carrier 20e Third water evaporator 20c Dehydrogenator 20d Hydrogenator 20e Third water evaporator 20p First two-phase mixture 21 First solution pump 21a Second solution pump 21p Second two-phase mixture 22 Second solution heat exchanger 26 Mixed flow of poor solutions from the absorption andCompression circuit 27 Third throttle 28 Rich absorption circuit solution 28d Main stream of rich absorption circuit solution 28e First partial stream of rich absorption circuit solution 28f Second partial stream of rich absorption circuit solution 28g Third partial stream of rich absorption circuit solution 29 Enriched solution of the absorption and compression circuits 31e Fifth solution pump 33 Medium-pressure trickle diffuser 36 Poor compression circuit solution 38 Rich compression circuit solution 39 Medium-pressure ammonia steam 41 Fifth solution pump 43 Degasser 44 Steam separator 46 Poor solution of the absorption circuit 47 Fourth throttle 48 Rich solution of the absorption circuit 49 Low-pressure steam of the absorption circuit 60 Wind turbines 80 Exported steam 99 High-temperature thermal energy 100 Thermal energy 101 Seawater desalination plant 102 Power grid

Claims

1. A method for producing reactants electricity and steam in a hybrid power plant for the provision of hydrogen using renewable energy, wherein the hybrid power plant comprises: • at least one electricity-generating power plant (6, 6m, 14, 60), • at least one plant from which thermal energy (100) is extracted and which, as a power plant, produces electricity (8i) and / or steam (8), each comprising the following process steps: • providing at least one water electrolysis plant, including a steam electrolysis plant (8d), • wherein electricity (8i) from the at least one electricity-generating power plant (6, 6m, 14, 60) is fed into the steam electrolysis plant (8d) at least as a partial quantity, • arranging an ammonia / water-based absorption power cycle, which is supplied from the at least one plant from which thermal energy (100) is extracted,with a temperature gradient with an upper limit of 290 °C and a lower limit in the interval from 150 °C to 100 °C, characterized by the fact thatThe absorption power cycle is equipped with conventional and known components and further comprises the following equipment according to the invention: • a steam turbine (14) for power generation, wherein water-rich ammonia vapor (19a) is expanded and drives the steam turbine (14), • a first steam generator (13b) heated by a poor absorption cycle solution (16), • with a desorber (13) having stepped surfaces that serve only for mass and heat exchange between rising water-containing ammonia vapor (19) and descending partial stream (18a, 18b) of enriched ammonia solution, wherein the absorption power cycle is carried out with the following process steps according to the invention: • water-containing ammonia vapor (19) is extracted from the aforementioned desorber (13) and superheated (19a) and then directed to the steam turbine (14) of the absorption power cycle,• The generated steam (8k) is temporarily stored in a steam storage tank (8p) and later or directly introduced into the steam electrolysis plant (8d), • Hot water (8a) taken from a condenser (8l) of the steam electrolysis plant (8d) is supplied to the first steam generator (13b) for steam generation, • A rich absorption loop solution (28) is converted into a first two-phase mixture (20p) by means of external heat input, and the first two-phase mixture (20p) is then introduced from the waste heat boiler (5) into the sump of the desorber (13), • A partial stream of a rich (28) or enriched (29) absorption loop solution taken from one of the absorbers (1, 2) is raised to a high-pressure level by means of a solution pump (11b, 21a) and introduced into the head of the desorber (13), • The poor absorption loop solution (16) is taken from a sump of the The desorbers (13) are discharged and directed to the first steam generator (13b) for heat input,and • furthermore, extractable residual heat from the poor absorption circuit solution (16) is transferred to at least one first solution heat exchanger (12).

2. Method according to claim 1, characterized by the fact that The electrolysis is carried out using a high-temperature electrolysis plant (8d) and capillary electrolysis apparatus (9), whereby 100% of the total power of the electrolysis apparatus is divided between 40% and 60% for high-temperature electrolysis and 40% and 60% for low-temperature electrolysis.

3. Method according to claim 2, characterized by the fact that the high-temperature electrolysis plant (8d) is operated at atmospheric pressure.

4. Method according to any one of the preceding claims, characterized by the fact that that at least one electricity-generating power plant is designed as a wind turbine (60) and / or as a photovoltaic system (6m).

5. Method according to any one of the preceding claims, characterized by the fact thatwhich at least one plant from which thermal energy (100) is extracted is designed as a geothermal power plant and / or as a steam power plant powered by solar thermal energy.

6. Method according to any one of the preceding claims, characterized by the fact that A solar thermally powered, pre-cooled closed gas turbine (6) is arranged both as a power-generating power plant and for the input of thermal energy (100) into the absorption power cycle, thereby extending the latter to the absorption power cooling cycle.

7. Method according to claim 6, characterized by the fact that An intermediate heating element (6e) is arranged in a circuit of the closed gas turbine (6) and an additional utility turbine (6d) is inserted for this purpose, wherein a pressure ratio of the closed gas turbine (6) of at least 6.5 to 8 - preferably at least 7.5 - is provided.

8. Method according to any one of the preceding claims, characterized by the fact thatThe quantity of water vapor production in the absorption power cycle is measured under the following three conditions: A) according to the quantity of electricity generated in the hybrid power plant for hydrogen production (8i), B) according to the ratio of the reactant water vapor to the reactant electricity in the water vapor electrolysis plant (8d), where the ratio of water vapor (8m, 8k) to electricity is set between 1 to 4.75 and 5.25, and C) reduced by the quantity of the reactant water vapor produced in the hybrid power plant (8c).

9. Method according to any one of the preceding claims, characterized by the fact that the hybrid power plant is designed to be oversized in order to produce steam (80) for a seawater desalination plant (101).

10. Method according to any one of the preceding claims, characterized by the fact thathydrogen produced by electrolysis (8e) is introduced into liquid organic hydrogen carriers (20a, 20b) and the liquid organic hydrogen carrier is handled in the form of a transport system.

11. Method according to the preceding claim, characterized by the fact that the transport system is integrated into the hybrid power plant in such a way that thermal energy entered into a dehydrator (20c) of the transport system is released again in a hydrogenator (20d) of the transport system.

12. Method according to claim 1, characterized by the fact thatThe absorption-power cycle is designed as an absorption-power-cooling cycle, and in this cycle the absorption loop is designed in the following process steps: • a rich absorption loop solution (28) is raised to a high-pressure level by means of a second solution pump (21a) and directed through a second solution heat exchanger (22) for heat absorption, • the rich absorption loop solution (28) is introduced into a waste heat boiler (5) heated by a low-pressure gas (9c) from the closed gas turbine (6) and converted into a first two-phase mixture (20p) by means of external heat input, • a second partial stream (16c) of poor absorption loop solution is introduced into the first two-phase mixture (20p) forming in the absorption loop, • the first two-phase mixture (20p) is then introduced from the waste heat boiler (5) into the sump of the desorber (13).• A first partial stream (18a) of enriched absorption loop solution is taken from a low-pressure absorber (1) and raised to high pressure by means of a fourth solution pump (11b) and heated in a third solution heat exchanger (12d), • the first partial stream (18a) of enriched absorption loop solution is then split into a second (18b) and third partial stream (18c) of enriched absorption loop solution, • and the second partial stream (18b) of enriched absorption loop solution is introduced into the head of the desorber (13), • and the energy released in a hydrogenator (20d) of the transport system is supplied to the third partial stream of enriched absorption loop solution (18c), whereby this is converted into a second two-phase mixture (21p) of ammonia and water, • the second two-phase mixture (21p) is then introduced into the desorber (13), • in the desorber (13) the process step rectification takes place is orderedby separating the introduced first two-phase mixture (20p) and the introduced second two-phase mixture (21p) into vapor and liquid phases in the sump of the desorber (13), • determining a water content of the aqueous ammonia vapor (19) exiting the top of the desorber (13) according to an equilibrium between vapor and liquid existing in the wet steam range via the first partial stream (18b) of enriched absorption circuit solution, • dilute absorption circuit solution (16) from the sump of the desorber (13) and passing it through the first steam generator (13b) for heat transfer, and maintaining a steam pressure of 3.5 to 5.5 bar - preferably 3.5 bar - • separating a first (16a) and a second (16c) partial stream of dilute absorption circuit solution from the dilute absorption circuit solution (16) discharged from the first steam generator (13b),• the remaining main stream (16b) of poor absorption circuit solution (16) is passed through the first solution heat exchanger (12) for heat transfer, so that the first partial stream (18a) of enriched absorption circuit solution is heated to boiling temperature, • and subsequently the main stream (16b) of poor absorption circuit solution is reduced to low pressure by means of a first throttle (17) and introduced into the low-pressure absorber (1) for absorption, • the first partial stream (18a) of the poor absorption circuit solution (16a) is reduced to medium pressure by means of a second throttle (17a) and passed through the second solution heat exchanger (22) with poor compression circuit solution (36) for heat transfer and is then reduced to low pressure by means of a third throttle (27) and introduced into the low-pressure absorber (1) for absorption.

13. Hybrid power plant for the production of reactants electricity and steam for the provision of hydrogen using renewable energy, wherein the hybrid power plant comprises: • at least one electricity-generating power plant (6, 6m, 14, 60), • at least one plant from which thermal energy (100) can be extracted, and which as a power plant produces electricity (8i) and / or steam (8), each with further elements and process steps: • at least one water electrolysis plant, including a high-temperature steam electrolysis plant (8d), • wherein electricity (8i) from the at least one electricity-generating power plant (6, 6m, 14, 60) can be fed into the steam electrolysis plant (8d), at least as a partial quantity, arranging an ammonia / water-based absorption power cycle, wherein the at least one plant extracting thermal energy (100) has a temperature gradient with a maximum upper limit of 290 °C and a lower limit ofthe temperature range is 150 to 100 °C, the absorption power cycle being equipped with conventional and known components, and further comprising the following equipment: • a steam turbine (14) for power generation, which can be driven with water-rich, expanded ammonia steam (19a), • a first steam generator (13b) that can be heated by a low-density absorption solution (16), • with a desorber (13) having stepped surfaces that serve only for mass and heat exchange between rising hydrated ammonia steam (19) and descending partial stream (18a, 18b) of enriched ammonia solution, wherein the absorption power cycle can be carried out in the following steps: • hydrated ammonia steam (19) is extracted from the desorber (13) for superheating and directed to the steam turbine (14) of the absorption power cycle, • a steam storage tank (8p) for the temporary storage of generated water vapor (8k),which can be introduced later or directly into the steam electrolysis plant (8d), • the poor absorption circuit solution (16) is drawn off from a sump of the desorber (13) and directed to the first steam generator (13b) for heat input, and • further extractable residual heat from the poor absorption circuit solution (16) can be introduced into at least one first solution heat exchanger (12).

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