Hydrogen treatment device and method

Abstract

To enable the scale of a reactor to be suppressed and furthermore to enable hydrogen to be processed stably in succession.SOLUTION: Hydrogen processing equipment 10 is provided which processes hydrogen generated in a nuclear reactor containment vessel 11 by a metal oxide (A-series metal oxide 17A, B-series metal oxide 17B). The hydrogen processing equipment 10 comprises: a plurality of reactors (A-series reactor 12A, B-series reactor 12B) that house the metal oxide and are arranged in parallel to each other; a selector valve (input selector valve 13, output selector valve 14) for selecting a discretionary reactor and supplying a reaction fluid X that includes the hydrogen to be processed; and a secondary gas supply device 15 capable of supplying a secondary gas Z that includes oxygen to a reactor which is not supplied with the reaction fluid. Hydrogen processing by the metal oxide in the reactor that is supplied with the reaction fluid and regeneration processing of the metal oxide by supply of the secondary gas in the reactor after the hydrogen processing is carried out are carried out in parallel.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a hydrogen treatment device and a hydrogen treatment method for treating hydrogen generated in a nuclear reactor containment vessel. [Background technology]

[0002] In the event of a severe nuclear accident involving significant core damage in a light water reactor, a large amount of hydrogen will be generated by the reaction between the zirconium contained in the molten core and the coolant (Metal-Water Reaction: Zr+H2O→ZrO2+H2; hereafter referred to as the MW reaction). In addition, hydrogen and oxygen will be generated over the long term by the radioactive decomposition of the coolant (H2O→H2+0.5O2), although this is slower than the MW reaction.

[0003] These reactions cause the pressure inside the reactor containment vessel to rise, and if it exceeds the design pressure, it will lead to damage to the reactor containment vessel. In order to prevent this damage to the reactor containment vessel, the reactor containment vessel is vented (gassed) through a filter vent, but due to stricter regulations since the accident, the installation of alternative circulating cooling (RHR) to supplement the reactor's cooling function has progressed, and operations that do not require reactor containment vessel venting are being considered.

[0004] On the other hand, even in an environment where the pressure rise inside the reactor containment vessel is suppressed, it is necessary to keep the hydrogen concentration below 4 vol% and the oxygen concentration below 5 vol% in order to prevent hydrogen explosions. In order to suppress this rise in hydrogen concentration, methods for treating hydrogen inside the reactor containment vessel are being considered. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-190868 A [Patent Document 2] Patent No. 3596843 [Patent Document 3] JP 2016-8839 A [Patent Document 4] JP 2018-146460 A [Patent Document 5] Patent Publication No. 2021-9099 [Patent Document 6] JP 2018-112480 A [Patent Document 7] JP 2011-12973 A Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 proposes a method of absorbing hydrogen using a hydrogen storage alloy, but this is not practical because a huge amount of hydrogen storage alloy is required to absorb hydrogen. Patent Document 2 proposes catalytic hydrogen combustion in which hydrogen and oxygen are reacted using a catalyst. However, there are problems with this method, such as a high reaction temperature, the possibility of the reactor containment vessel being pressurized at high temperatures during post-reaction treatment, the need for a large amount of catalyst due to the loss of catalytic function due to poisoning by carbon monoxide, and the need to supply oxygen from outside due to insufficient oxygen relative to the amount of hydrogen in the reactor containment vessel, which is dangerous. Patent Document 3 proposes the oxidative removal of hydrogen using metal oxides, which enables hydrogen treatment in a nitrogen atmosphere with low oxygen.

[0007] Patent Document 4 proposes a reaction control method for dealing with compositional fluctuations in the reaction fluid. Patent Document 5 proposes a method for heating the reaction fluid, and Patent Document 6 proposes a method for removing heat from the post-reaction fluid that is returned to the reactor containment vessel. Furthermore, Patent Document 7 proposes a method for oxidizing and removing hydrogen using copper oxide, in which used metallic copper or copper iodide that has become inactive in hydrogen treatment due to a reaction with cesium iodide is regenerated into copper oxide by reacting it with oxygen.

[0008] Although the reactors targeted in Patent Documents 1 to 7 are single reactors, a considerable amount of metal oxide is required to process hydrogen generated due to a severe nuclear reactor accident, and the volume of the reactor to fill with this is large, which necessitates a large scale of the device. Moreover, in a configuration in which the metal oxide is regenerated and reused multiple times as in Patent Document 7, it is possible to reduce the scale of the reactor.

[0009] On the other hand, if the reactor is made small, it is necessary to frequently regenerate the metal oxide. It is assumed that the conditions for the reaction of the metal oxide with hydrogen and the regeneration of the metal oxide are different, and it takes time to adapt to each condition, so it is difficult to continuously process hydrogen in a single reactor. In addition, from the viewpoint of controlling the reaction temperature of the metal oxide, it is necessary to control the temperature at the start-up of the device, during the reaction, and during regeneration, but the configuration and method for doing so are not disclosed in Patent Documents 1 to 7.

[0010] The embodiments of the present invention have been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a hydrogen treatment apparatus and a hydrogen treatment method that can reduce the scale of a reactor and continuously and stably treat hydrogen. [Means for solving the problem]

[0011] A hydrogen treatment device in an embodiment of the present invention is a hydrogen treatment device that treats hydrogen generated in a reactor containment vessel with a metal oxide, the hydrogen treatment device having a plurality of reactors that contain the metal oxide and are arranged in parallel with each other, a switching valve that switches and supplies a reaction fluid containing hydrogen to be treated to any of the reactors, and a secondary gas supply device that can supply a secondary gas containing oxygen to the reactor to which the reaction fluid is not supplied, and is configured so that hydrogen treatment with the metal oxide in the reactor to which the reaction fluid is supplied and regeneration treatment of the metal oxide by supplying the secondary gas to the reactor after the hydrogen treatment are performed are performed in parallel. and a branch system including a branch pipe for dividing a part of a fluid after the reaction in which hydrogen is treated by the metal oxide in the reactor and returning the part to the reaction fluid supplied to the reactor. This is characterized by the fact that In addition, a hydrogen treatment device in an embodiment of the present invention is a hydrogen treatment device that treats hydrogen generated in a reactor containment vessel with a metal oxide, the hydrogen treatment device having a plurality of reactors that contain the metal oxide and are arranged in parallel with each other, a switching valve that switches and supplies a reaction fluid containing hydrogen to be treated to any one of the reactors, and a secondary gas supply device that can supply a secondary gas containing oxygen to the reactor to which the reaction fluid is not supplied, and is configured so that hydrogen treatment with the metal oxide in the reactor to which the reaction fluid is supplied and regeneration treatment of the metal oxide by supplying the secondary gas to the reactor after the hydrogen treatment are performed are performed in parallel, and furtherThe secondary gas supply device is configured to alternately supply an oxidizing gas and a reducing gas to the reactor connected thereto before starting hydrogen treatment by the metal oxide in the reactor, thereby preheating the metal oxide with reaction heat. This is a sign.

[0012] A hydrogen processing method according to an embodiment of the present invention is a hydrogen processing method for processing hydrogen generated in a reactor containment vessel with a metal oxide, comprising the steps of: preparing a plurality of reactors each containing the metal oxide and arranged in parallel with one another; and a secondary gas supply device capable of supplying a secondary gas containing oxygen to the reactors to which a reaction fluid containing hydrogen to be processed has not been supplied; and performing hydrogen processing with the metal oxide in the reactors to which the reaction fluid has been supplied; and regenerating the metal oxide by supplying the secondary gas to the reactors after the hydrogen processing has been performed. of Alternately and in parallel Furthermore, a part of the reaction fluid in which hydrogen has been treated by the metal oxide in the reactor is branched off by a branching system having a branching pipe and refluxed to the reaction fluid supplied to the reactor. The present invention is characterized in that: Also, A hydrogen processing method in an embodiment of the present invention is a hydrogen processing method in which hydrogen generated in a reactor containment vessel is processed using a metal oxide, comprising the steps of: preparing a plurality of reactors each containing the metal oxide and arranged in parallel with one another; and a secondary gas supply device capable of supplying a secondary gas containing oxygen to the reactor to which a reaction fluid containing the hydrogen to be processed is not supplied; alternately and in parallel performing hydrogen processing using the metal oxide in the reactor to which the reaction fluid is supplied and regeneration processing of the metal oxide by supplying the secondary gas to the reactor after the hydrogen processing is performed; and further, the secondary gas supply device alternately supplies an oxidizing gas and a reducing gas to the reactor connected to it before starting hydrogen processing using the metal oxide in the reactor, thereby preheating the metal oxide with reaction heat. Effect of the Invention

[0013] According to the embodiment of the present invention, it is possible to suppress the scale of the reactor and to continuously and stably process hydrogen. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a pipeline diagram showing the hydrogen treatment device according to the first embodiment. [Diagram 2] FIG. 4 is a pipeline diagram showing a hydrogen treatment device according to a second embodiment. [Diagram 3] FIG. 11 is a partial pipeline diagram showing a part of a hydrogen treatment device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [A] First embodiment (Fig. 1) Fig. 1 is a pipeline diagram showing a hydrogen treatment device according to the first embodiment. The hydrogen treatment device 10 shown in Fig. 1 treats hydrogen generated in a reactor containment vessel 11 during, for example, a severe reactor accident, by using metal oxide, and is mainly configured with a plurality of reactors (e.g., an A-line reactor 12A and a B-line reactor 12B), switching valves (e.g., an inlet switching valve 13 and an outlet switching valve 14), a secondary gas supply device 15, and a switching valve control device 16.

[0016] The A-system reactor 12A is filled with and contains the A-system metal oxide 17A that treats hydrogen, and constitutes the A-system 20A together with the connected A-system inlet pipe 18A and A-system outlet pipe 19A. The B-system reactor 12B is filled with and contains the B-system metal oxide 17B that treats hydrogen, and constitutes the B-system 20B together with the connected B-system inlet pipe 18B and B-system outlet pipe 19B. The A-system 20A and B-system 20B are installed in parallel.

[0017] The A-system metal oxide 17A and the B-system metal oxide 17B are preferably composed of any one of copper oxide (II), nickel oxide (II), manganese oxide (IV), cobalt oxide (II, III), and iron oxide (III), or a combination thereof. The A-system metal oxide 17A and the B-system metal oxide 17B are formed by granulating the powder into a compact shape with a diameter of several mm in order to reduce the pressure loss occurring before and after the A-system reactor 12A and the B-system reactor 12B. The A-system metal oxide 17A and the B-system metal oxide 17B in the compact shape have resistance capable of maintaining their shape against the weight of the packed bed when packed in the A-system reactor 12A and the B-system reactor 12B, or against changes in density or temperature due to reduction or oxidation by hydrogen.

[0018] The inlet switching valve 13 is connected to the upstream end of the A system 20A and the B system 20B, and the outlet switching valve 14 is connected to the downstream end of the A system 20A and the B system 20B, respectively. The inlet switching valve 13 switches the reacted fluid X, which contains hydrogen to be treated and flows through the inlet piping 21, to flow into either the A system reactor 12A or the B system reactor 12B, which are optional reactors. The outlet switching valve 14 switches the reacted fluid Y, in which hydrogen has been treated by either the A system metal oxide 17A in the A system reactor 12A or the B system metal oxide 17B in the B system reactor 10B, to flow out to the outlet piping 22.

[0019] The inlet pipe 21 has an upstream end connected to the reactor containment vessel 11 and a downstream end connected to the inlet switching valve 13. On this inlet pipe 21, an inlet valve 23, a blower 24, a reaction fluid cooler 25, an inlet gas concentration meter 26, a hygrometer 27, and a reaction fluid heater 28 are sequentially arranged from the upstream end side.

[0020] The outlet piping 22 has an upstream end connected to the outlet switching valve 14 and a downstream end connected to the reactor containment vessel 11. A post-reaction fluid cooler 30, an outlet gas concentration meter 31, and an outlet valve 32 are disposed in this order from the upstream end side on the outlet piping 22.

[0021] The secondary gas supply device 15 is connected to the inlet switching valve 13 and the outlet switching valve 14. This secondary gas supply device 15 supplies a secondary gas Z containing an oxidizing gas (e.g., oxygen) to the A-line reactor 12A or the B-line reactor 12B to which the reaction fluid X of the A-line 20A or the B-line 20B is not supplied by switching the inlet switching valve 13 and the outlet switching valve 14. The A-line metal oxide 17A in the A-line reactor 12A or the B-line metal oxide 17B in the B-line reactor 12B, which has been treated with hydrogen, has been reduced by hydrogen (e.g., metal), but is oxidized and regenerated by the supply of the secondary gas Z from the secondary gas supply device 15.

[0022] The switching valve control device 16 switches the inlet switching valve 13 and the outlet switching valve 14 to simultaneously carry out hydrogen treatment using a metal oxide (e.g., A-system metal oxide 17A) in a reactor (e.g., A-system reactor 12A) to which reaction fluid X is supplied, and regeneration treatment of the metal oxide (e.g., B-system metal oxide 17B) by supplying a secondary gas Z to a reactor (e.g., B-system reactor 12B) after hydrogen treatment.

[0023] Specifically, the switching valve control device 16 inputs the hydrogen concentration measured by the inlet gas concentration meter 26 on the inlet side of a reactor (for example, the A-line reactor 12A) to which the reaction fluid X is supplied, and the hydrogen concentration measured by the outlet gas concentration meter 31 on the outlet side, and obtains the difference between these measurements. Next, the switching valve control device 16 calculates the reaction rate of the metal oxide (for example, the A-line metal oxide 17A) in the reactor (for example, the A-line reactor 12A) to which the reaction fluid X is supplied, from this difference. The switching valve control device 16 determines the reactor to which the reaction fluid X should be supplied based on the reaction rate, and controls the switching operation of the inlet switching valve 13 and the outlet switching valve 14. For example, when the reaction rate of the A-line metal oxide 17A in the A-line reactor 12A rises to a predetermined value or higher, the switching of the inlet switching valve 13 and the outlet switching valve 14 is controlled so that the reaction fluid X is supplied to the B-line reactor 12B.

[0024] Next, the operation of the hydrogen treatment device 10 will be described. By opening the inlet valve 23 and the outlet valve 32 and starting the blower 24, the reaction fluid X (mainly composed of hydrogen, water vapor, and nitrogen) remaining in the reactor containment vessel 11 is introduced into the hydrogen treatment device 10. After the water vapor is removed by condensation in the reaction fluid cooler 25, the hydrogen concentration and oxygen concentration of this reaction fluid X are measured by the inlet gas concentration meter 26, and the reaction fluid X is heated by the reaction fluid heater 28 to a temperature suitable for hydrogen treatment.

[0025] Thereafter, the reaction fluid X flows from the inlet switching valve 13 to the A-system 20A, and flows into the A-system reactor 12A through the A-system inlet piping 18A. The reaction fluid Y after being subjected to hydrogen treatment in the A-system metal oxide 17A in the A-system reactor 12A reaches the outlet piping 22 through the A-system outlet piping 19A and the outlet switching valve 14, and is cooled by the reaction fluid cooler 30 and returned to the reactor containment vessel 11.

[0026] On the other hand, the B system 20B, which exists independently of the A system 20A via the inlet switching valve 13 and the outlet switching valve 14, has the same configuration as the A system 20A and is connected to the secondary gas supply device 15. It is possible to supply a secondary gas Z containing oxygen and nitrogen gas from this secondary gas supply device 15 to the B system 20B. If hydrogen treatment is performed in the B system 20B before switching to the A system 20A, the B system metal oxide 17B filled in the B system reactor 12B is reduced. Then, the secondary gas Z containing oxygen is supplied from the secondary gas supply device 15 to the B system reactor 12B, whereby the B system metal oxide 17B is regenerated.

[0027] The A-system metal oxide 17A is reduced by the hydrogen treatment, but if this hydrogen treatment becomes insufficient, the hydrogen concentration in the outlet gas concentration meter 31 rises and becomes equal to the hydrogen concentration in the inlet gas concentration meter 26. The switching valve control device 16 then detects this and switches the inlet switching valve 13 and the outlet switching valve 14 to flow the reaction fluid X to the B-system 20B and the secondary gas Z to the A-system 20A. This allows the hydrogen treatment to continue in the B-system 20B, and the A-system metal oxide 17A used in the hydrogen treatment is regenerated by reacting with the secondary gas Z containing oxygen. As described above, the A-system 20A and the B-system 20B perform the hydrogen treatment and the regeneration treatment alternately and in parallel.

[0028] Using nickel oxide as an example, the reduction reaction of metal oxides (a general term for A-series metal oxides 17A and B-series metal oxides 17B) with hydrogen is shown below. NiO+H2→Ni+H2O ………(1) Similarly, the oxidation reaction between the metal produced by the reduction of the metal oxide and the secondary gas Z containing oxygen is as follows, taking nickel as an example. 2Ni+O2 → 2NiO ………(2)

[0029] Here, the scale of the reactor (a collective term for the A-line reactor 12A and the B-line reactor 12B) when hydrogen treatment and metal oxide regeneration are performed simultaneously according to this first embodiment will be considered. It is assumed that the total amount of hydrogen generated in the event of a severe reactor accident is approximately 580 kmol, and the hydrogen treatment period is 30 days. As shown in the reaction of formula (1), metal oxide reacts with hydrogen in a roughly 1:1 ratio, so the amount of metal oxide required is simply 580 kmol. This is equivalent to approximately 50 tons in terms of the weight of nickel oxide, and considering the volume when the molded body is packed into the reactor, it is 25 m 3 A large reactor is required.

[0030] The reactor A 12A and the reactor B 12B each have a volume of 2 m 3 Consider a configuration with a volume of 2m 3 The reactor corresponds to a cylindrical shape with a diameter of about 1.6 m and a height of about 1 m, for example, and can be filled with about 4 tons of nickel oxide moldings. Since a total amount of 50 tons corresponds to 580 kmol, 4 tons of metal oxide corresponds to about 46 kmol, which is about 1 / 12 of the amount used for total treatment. Therefore, in principle, when continuously treating hydrogen by alternately using two reactor towers filled with 4 tons of metal oxide, the A system 20A and the B system 20B are switched every 2.5 days, and each is used six times, which is the amount that can be treated.

[0031] The hydrogen processing rate required to consume the metal oxide in 2.5 days is 18 m 3 / h, and the scavenging flow rate of blower 24 is 200m 3 / h, it is sufficient to process hydrogen at an average concentration of about 9%. Under the assumed conditions, the hydrogen concentration at the beginning of the reaction is several tens of percent, and as hydrogen processing progresses, the hydrogen concentration decreases, eventually reaching about 4%. On average, the amount of hydrogen processed is 18 m 3 / h or more is expected to be satisfied.

[0032] In addition, the regeneration of metal oxides, which is carried out in conjunction with hydrogen treatment, must be performed at a switching frequency of 2.5 days or less. Secondary gas Z containing 5 vol. % oxygen is supplied from the secondary gas supply device 15 at a rate of 200 m. 3 / h and it is assumed that the total amount of oxygen (5 vol%) is consumed in the oxidation reaction of the metals, the time required to regenerate 46 mol of metal oxide packed in one tower is about 2.5 days. Therefore, it is possible to regenerate metal oxide at a rate roughly equivalent to the rate at which the metal oxide is consumed in the hydrogen treatment.

[0033] The switching method between the A system 20A and the B system 20B may be as follows. The reduction reaction of metal oxides tends to react relatively quickly up to about 60% in reaction rate, and then to react slowly. For example, when hydrogen treatment is performed in the A system 20A, a predetermined concentration of hydrogen is supplied to the A system reactor 12A until the reaction rate of the A system metal oxide 17A reaches 60%, and the hydrogen treatment is switched to the B system 20B when the reaction rate reaches 60% or more. In this case, first, the gas (hydrogen) remaining in the A system 20A is circulated between the secondary gas supply device 15, and the residual hydrogen is consumed by a gas treatment device (not shown) in the secondary gas supply device 15 to reduce the hydrogen concentration to 4 vol% or less. Next, oxygen gas is supplied from the secondary gas supply device 15 to the A system 20A so that the oxygen concentration is 5 vol% or less, which is the lower explosion limit, to oxidize the metal reduced by hydrogen in the A system reactor 12A, and regenerate the A system metal oxide 17A.

[0034] As configured as above, the first embodiment provides the following effect (1). (1) By switching the inlet switching valve 13 and the outlet switching valve 14, the reaction fluid X and the secondary gas Z are alternately supplied to the A system 20A and the B system 20B, so that hydrogen treatment by metal oxide (e.g., A system metal oxide 17A) in the reactor (e.g., A system reactor 12A) to which the reaction fluid X is supplied, and regeneration treatment of the metal oxide (e.g., B system metal oxide 17B) by supplying the secondary gas Z to the reactor (e.g., B system reactor 12B) after the hydrogen treatment are performed are performed simultaneously in parallel. Therefore, in a plurality of reactors (e.g., A system reactor 12A, B system reactor 12B), the metal oxide (e.g., A system metal oxide 17A, B system metal oxide 17B) can be regenerated a plurality of times. As a result, the total amount of the A system metal oxide 17A in the A system reactor 12 and the B system metal oxide in the B system reactor 12B can be reduced, suppressing the scale of the A system reactor 12A and the B system reactor 12B, and hydrogen can be continuously and stably processed. Therefore, the installation cost and operability of the hydrogen treatment device 10 can be improved.

[0035] [B] Second embodiment (Fig. 2) 2 is a pipeline diagram showing a hydrogen treatment device according to a second embodiment. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

[0036] The hydrogen treatment device 40 of the second embodiment differs from the first embodiment in that a reactor 41 filled with and containing a metal oxide 42 is connected to an inlet pipe 21 and an outlet pipe 22, and the hydrogen treatment device 40 has a branch system 44 equipped with a branch pipe 43 that branches off a portion of a post-reaction fluid Y in which hydrogen has been treated by the metal oxide 42 in the reactor 41 and returns it to the reaction fluid X supplied to the reactor 41.

[0037] Here, the reactor 41 is configured similarly to the A-system reactor 12A and the B-system reactor 12B in the first embodiment, and the metal oxide 42 is configured similarly to the A-system metal oxide 17A and the B-system metal oxide 17B in the first embodiment. These reactors 41 and metal oxide 42 are also the A-system reactor 12A and the A-system metal oxide 17A of the A-system 20A to which the reaction fluid X is supplied, or the B-system reactor 12B and the B-system metal oxide 17B of the B-system 20B in the first embodiment.

[0038] One end of the branch pipe 43 is connected to the inlet pipe 21 between the inlet valve 23 and the blower 24, and the other end is connected to the outlet pipe 22 between the outlet gas concentration meter 31 and the outlet valve 32. In addition, the branch pipe 43 is provided with a blower 45 and an isolation valve 46 in this order from the upstream side. Furthermore, in the reactor 41, one or more thermometers 47 are provided at any position in the packed bed of the metal oxide 42.

[0039] At least one of the blower 45 and the blower 24 is controlled by a flow rate control device 48. That is, the flow rate control device 48 adjusts at least one of the flow rate of the reaction fluid X supplied to the reactor 41 by controlling the blower 24 based on the temperature of the metal oxide 42 in the reactor 41 measured by the thermometer 47 and the hydrogen concentration of the reaction fluid X supplied to the reactor 41, and the flow rate of the post-reaction fluid Y refluxed to the reaction fluid X by controlling the floor 45.

[0040] Next, the operation will be described. The inlet valve 23 and the outlet valve 32 are opened, and the blower 24 is started, so that the reaction fluid X (mainly composed of hydrogen, water vapor, and nitrogen) remaining in the reactor containment vessel 11 is introduced into the hydrogen treatment device 40. After the water vapor contained in the reaction fluid X is condensed and removed by the reaction fluid cooler 25, the hydrogen concentration and the oxygen concentration are measured by the inlet gas concentration meter 26, and the reaction fluid X is heated by the reaction fluid heater 28 to a temperature suitable for hydrogen treatment. The reaction fluid X then flows into the reactor 41, where hydrogen treatment is performed. The reacted fluid Y reaches the outlet pipe 22, where it is cooled by the reacted fluid cooler 30, and then returned to the reactor containment vessel 11.

[0041] The reaction between metal oxide and hydrogen is generally an exothermic reaction, and the temperature of thermometer 47 rises as hydrogen treatment begins. If the temperature rise of thermometer 47 is significant, in order to prevent reactor 41 from becoming overheated, flow controller 48 reduces the output of blower 24 and reduces the flow rate of reaction fluid X supplied to reactor 41. This flow control by flow controller 48 is performed when the temperature rise exceeds 10°C / min. The upper limit temperature of reactor 41 is approximately 500°C, which is the hydrogen self-combustion temperature. If the hydrogen self-combustion temperature is exceeded, flow controller 48 stops blowers 24 and 45 and ends hydrogen treatment.

[0042] Furthermore, when the hydrogen concentration of the reaction fluid X is high, the flow rate control device 48 opens the isolation valve 46 and starts the blower 45 to perform a reflux operation of returning a constant proportion of the post-reaction fluid Y to the reaction fluid X via the branch pipe 43 in order to suppress the hydrogen concentration of the reaction fluid X supplied to the reactor 41. The reflux proportion is determined by controlling the flow rate of the blower 45 based on the hydrogen concentration of the inlet gas concentration meter 26.

[0043] As configured as above, the second embodiment provides the following effect (2). (2) A part of the reacted fluid Y that has been subjected to hydrogen gas treatment by the metal oxide 42 in the reactor 41 is returned to the reacted fluid X supplied to the reactor 41 via the branch pipe 43 of the branch system 44. As a result, even if the hydrogen concentration of the reacted fluid X is high, the hydrogen treatment can be performed in an environment in which a temperature rise in the reactor 41 caused by the reaction between the metal oxide 42 in the reactor 41 and hydrogen is suppressed.

[0044] [C] Third embodiment (FIG. 3) 3 is a partial pipeline diagram showing a part of a hydrogen treatment device according to a third embodiment. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

[0045] The hydrogen treatment device 50 of the third embodiment differs from the first embodiment in that, before hydrogen treatment is started using the metal oxide 53 filled and contained in the reactor 52, the secondary gas supply device 51 alternately supplies an oxidizing gas (e.g., oxygen) and a reducing gas (e.g., hydrogen) as a secondary gas W to the reactor 52 connected to it, thereby raising the temperature of the metal oxide 53 by the reaction heat and performing a preheating treatment.

[0046] The secondary gas supply device 51 also controls at least one of the flow rate and concentration of the oxidizing gas or reducing gas as the secondary gas W to be supplied to the reactor 52, based on a temperature measurement value by a thermometer 54 of the metal oxide 53 whose temperature has risen in the reactor 52. Furthermore, the secondary gas supply device 51 replenishes a shortage of the secondary gas W based on the difference between a concentration measurement value by an inlet gas concentration meter 55 on the inlet side of the reactor 52 and a concentration measurement value by an outlet gas concentration meter 56 on the outlet side of the reactor 52, so that the concentration of the oxidizing gas or reducing gas as the secondary gas W to be supplied to the reactor 52 becomes a predetermined concentration.

[0047] Here, the reactor 52 is configured similarly to the A-system reactor 12A and the B-system reactor 12B in the first embodiment, and the metal oxide 53 is configured similarly to the A-system metal oxide 17A and the B-system metal oxide 17B in the first embodiment. These reactors 52 and metal oxide 53 are also the A-system reactor 12A and the A-system metal oxide 17A of the A-system 20A, or the B-system reactor 12B and the B-system metal oxide 17B of the B-system 20B before the supply of the reaction fluid X is started in the first embodiment.

[0048] The hydrogen treatment device 50 of the third embodiment alternately supplies an oxidizing gas (e.g., oxygen) and a reducing gas (e.g., hydrogen) from a secondary gas supply device 51 to a reactor 52, thereby alternately causing oxidation and reduction reactions of the metal oxide 53 to occur, thereby obtaining reaction heat and thereby promoting the heating of the metal oxide 53 to the reaction initiation temperature.

[0049] Incidentally, before the hydrogen treatment device 10 (FIG. 1) of the first embodiment is started and hydrogen treatment is started, the metal oxides (A-line metal oxide 17A, B-line metal oxide 17B) are preheated to a reaction start temperature by heaters provided in the reactors (A-line reactor 12A, B-line reactor 12B) although this is not shown in FIG. 1. The reaction temperature of the metal oxide is often as high as 200°C to 400°C, and it takes several hours to several tens of hours for the metal oxide to reach the reaction start temperature by preheating. In the third embodiment, in order to shorten the time required to raise the temperature of the metal oxide 53 to the reaction start temperature, the reaction heats of the oxidation reaction of the reduced metal oxide (e.g., metal) and the reduction reaction of the metal oxide by hydrogen are used.

[0050] As shown in the first embodiment, from the viewpoint of hydrogen treatment, the metal oxide 53 is preferably copper oxide (II), nickel oxide (II), manganese oxide (IV), cobalt oxide (II, III), or iron oxide (III). In order to shorten the temperature rise time for early preheating, the metal oxide 53 is preferably cobalt oxide (II, III) or manganese oxide (IV), in which both the reduction reaction and the oxidation reaction by hydrogen tend to proceed at low temperatures and in which the reaction heat of the reduction reaction or the oxidation reaction by hydrogen is large.

[0051] Therefore, for example, when cobalt oxide (II, III) or manganese oxide (IV) is not used as the metal oxide 53 for hydrogen treatment, that is, when one or two types of metal oxides of nickel oxide (II), copper oxide (II), and iron oxide (III) are filled, at least one of cobalt oxide (II, III) and manganese oxide (IV) is also filled in an amount necessary for early preheating. Also, even when cobalt oxide (II, III) or manganese oxide (IV) is used as the metal oxide 53 for hydrogen treatment of the reaction fluid X, two or more types of other metal oxides may be mixed.

[0052] The metal oxide 53 is packed in the form of a compact obtained by granulating the powder to a diameter of several mm in order to reduce pressure loss occurring before and after the reactor 52. The metal oxide 53 in the form of this compact has resistance to maintain its shape against the weight of the packed bed, or against changes in density or temperature due to reduction or oxidation by hydrogen. In addition, the metal oxide 53 may be packed in the reactor 52 in the form of a single compact of a plurality of types, or a single compact of a plurality of compositions may be used. When a compact of a single composition is packed in the reactor 52 as the metal oxide 53, compacts of different compositions may be stacked in layers, or a packed bed of compacts of a single composition may be randomly mixed.

[0053] For early preheating, it is more efficient to utilize the oxidation reaction of reduced metal oxide (e.g., metal). Therefore, it is desirable to keep metal oxide 53 filled in reactor 52 in a reduced state with hydrogen for preheating before starting up hydrogen treatment device 50 (i.e., before hydrogen treatment starts).

[0054] The reduction of manganese(IV) oxide with hydrogen proceeds at 150°C to produce manganese(II) oxide via the following reaction: MnO2+H2→MnO+H2O………(3) The reduction temperature of the metal oxide 53 by hydrogen is 150°C, which is a low temperature, and the reduction by hydrogen of the nickel oxide (II) that is also packed in the reactor 52 is very slow, so the composition of most of the nickel oxide (II) does not change. In explaining the action of promoting the temperature rise of the metal oxide 53, it is assumed that the metal oxide 53 is nickel oxide (II) used for hydrogen treatment and manganese oxide (IV) for the purpose of promoting the temperature rise, each of which is a single-composition molded body randomly packed.

[0055] The above-mentioned hydrotreating device 50 will now be described in further detail. In the hydrogen treatment device 50, a reactor inlet pipe 57 connected to a reactor 52 is connected to a secondary gas supply device 51 via an inlet switching valve 13, and a reactor outlet pipe 58 connected to the reactor 52 is connected to the secondary gas supply device 51 via an outlet switching valve 14, and a secondary gas W is circulated between the secondary gas supply device 51 and the reactor 52. The inlet switching valve 13 can be switched to the reactor inlet pipe 18B shown in Fig. 1 by switching, and the outlet switching valve 14 can be switched to the reactor outlet pipe 19B shown in Fig. 1 by switching.

[0056] The secondary gas supply device 51 includes a secondary gas pipe 60 having both ends connected to the inlet switching valve 13 and the outlet switching valve 14. A secondary gas cooler 61, an outlet gas concentration meter 56, a blower 62, a secondary gas circulation valve 63, a pressure gauge 64, an inlet gas concentration meter 55, and a secondary gas heater 65 are arranged in this secondary gas pipe 60 in this order from the outlet switching valve 14 side.

[0057] A secondary gas supply source 67 is connected between the pressure gauge 64 and the inlet gas concentration meter 55 in the secondary gas piping 60 via a secondary gas supply system valve 66. The secondary gas supply source 67 has a hydrogen gas supply device 67A, an oxygen gas supply device 67B, and a nitrogen gas supply device 67C.

[0058] Furthermore, a gas processing system piping 68 connects between the secondary gas cooler 61 and the outlet switching valve 14 in the secondary gas piping 60 and between the blower 62 and the secondary gas circulation system valve 63. A gas processing system piping 68 is provided with a gas processing device 69, and a gas processing system inlet valve 70 is provided on the inlet side of the gas processing device 69, and a gas processing system outlet valve 71 is provided on the outlet side. Furthermore, a gas processing introduction piping 72 equipped with a gas processing introduction valve 73 is connected to the secondary gas supply source 67. The gas processing introduction piping 72 is further connected between the gas processing system inlet valve 70 in the gas processing system piping 68 and the gas processing device 69.

[0059] The secondary gas supply device 51 also includes a secondary gas control device 74. This secondary gas control device 74 receives measured values ​​from the thermometer 54, the inlet gas concentration meter 55, and the outlet gas concentration meter 56, and controls the blower 62, the secondary gas supply source 67, and various valves (secondary gas circulation system valve 63, secondary gas supply system valve 66, gas processing system inlet valve 70, gas processing system outlet valve 71, and gas processing introduction valve 73), the secondary gas cooler 61, and the secondary gas heater 65. In other words, the secondary gas control device 74 executes flow rate control of the secondary gas W by the blower 62, gas concentration control of the secondary gas W by the secondary gas supply source 67, opening and closing control of the various valves, and operation control of the secondary gas cooler 61 and the secondary gas heater 65.

[0060] Next, the operation will be described. The secondary gas control device 74 of the secondary gas supply device 51 opens the secondary gas supply system valve 66 and the secondary gas circulation system valve 63, closes the gas treatment system inlet valve 70, the gas treatment introduction valve 73, and the gas treatment system outlet valve 71, and starts the secondary gas cooler 61, the secondary gas heater 65, and the blower 62. At the stage where the secondary gas W is not supplied from the secondary gas supply source 67, the gas composition is mainly nitrogen, and the gas circulates in a closed loop consisting of the reactor inlet piping 57, the reactor 52 filled with the metal oxide 53, the reactor outlet piping 58, and the secondary gas piping 60, starting from the blower 62.

[0061] (a) Supply of secondary gas W containing oxygen While secondary gas W mainly composed of nitrogen is circulating through metal oxide 53 in reactor 52, oxygen is supplied from oxygen gas supply device 67B of secondary gas supply source 67. As a result, manganese oxide (II) in metal oxide 53 in reactor 52 is oxidized by the reaction shown below to generate manganese oxide (IV). MnO+0.5O2→MnO2…………(4)

[0062] Oxygen in the secondary gas W is consumed by the reaction in which manganese oxide (II) is oxidized to manganese oxide (IV), and the oxygen concentration in the secondary gas W at the outlet of the reactor 52 decreases. The secondary gas W passes through a secondary gas cooler 61 downstream of the reactor 52, and the oxygen concentration is measured by an outlet gas concentration meter 56. The oxygen concentration in the secondary gas W is controlled by a secondary gas control device 74, which controls the flow rate of oxygen introduced from a secondary gas supply source 67, so that the inlet gas concentration meter 55 indicates a predetermined concentration.

[0063] That is, the secondary gas control device 74 controls the blower 62 based on the measured value of the temperature rise of the metal oxide 53 due to the supply of the oxygen-containing secondary gas W measured by the thermometer 54, and adjusts the supply flow rate of the secondary gas W. Also, the secondary gas control device 74 calculates the oxygen flow rate required to make up for the shortage from the difference between the oxygen concentrations measured by the inlet gas concentration meter 55 and the outlet gas concentration meter 56, and controls the secondary gas supply source 67 to supply oxygen. Furthermore, the secondary gas control device 74 evaluates the reaction rate of the reduced metal oxide (e.g., metal) 53 with respect to oxygen from the difference between the oxygen concentrations measured by the inlet gas concentration meter 55 and the outlet gas concentration meter 56.

[0064] (b) Pretreatment When the increase in the temperature measurement by thermometer 54 stops and the oxygen concentrations measured by outlet gas concentration meter 56 and inlet gas concentration meter 55 become equal, the secondary gas control device 74 determines that the oxidation reaction has ended and moves on to pre-processing for supplying hydrogen gas.

[0065] That is, when switching to hydrogen gas, it is necessary to control the oxygen concentration in the system of hydrogen treatment device 50 to be the lower explosion limit of 5 vol% or less. Therefore, as a pretreatment for supplying hydrogen gas, in order to make the oxygen concentration in the system of hydrogen treatment device 50 5 vol% or less, blower 62 is stopped once, secondary gas supply system valve 66 and secondary gas circulation system valve 63 are closed, and gas treatment system inlet valve 70, gas treatment introduction valve 73 and gas treatment system outlet valve 71 are opened, and then blower 62 is started again, and hydrogen gas supply device 67A supplies hydrogen of 4 vol% or less to gas treatment device 69.

[0066] By this operation, oxygen in the secondary gas W remaining in the system of the hydrogen treatment device 50 including the reactor 52 reacts with hydrogen in the gas treatment device 69 to generate water vapor. The water vapor contained in the secondary gas W that has passed through the gas treatment device 69 is converted to water and removed in the secondary gas cooler 61. The secondary gas W is circulated to the gas treatment device 69 by the blower 62, whereby the oxygen is treated, and the oxygen concentration measured by the outlet gas concentration meter 56 decreases.

[0067] In addition, when oxygen is supplied from the oxygen gas supply device 67B, it is desirable to operate the secondary gas control device 74 so that, at the beginning of the reaction of the metal oxide 53 in the reactor 52, the concentration of oxygen supplied is adjusted according to the degree of temperature rise in the reactor 52 due to oxidation, and, at the end of the reaction, the amount of oxygen supplied by the secondary gas supply source 67 is adjusted so that the oxygen concentration at the time of switching to hydrogen is 5 vol% or less.

[0068] (c) Supply of secondary gas W containing hydrogen When the hydrogen concentration becomes 4 vol% or less and the oxygen concentration becomes 5 vol% or less, the secondary gas control device 74 stops the blower 62, opens the secondary gas supply system valve 66 and the secondary gas circulation system valve 63, closes the gas processing system inlet valve 70, the gas processing introduction valve 73, and the gas processing system outlet valve 71, and starts the blower 62 again to supply hydrogen from the hydrogen gas supply device 67A. That is, similar to the case of supplying oxygen gas, hydrogen is supplied from the hydrogen gas supply device 67A of the secondary gas supply source 67 to a state in which the secondary gas W mainly composed of nitrogen is circulating in the metal oxide 53 in the reactor 52.

[0069] As described above, the secondary gas W containing hydrogen is introduced into the reactor 52. The secondary gas W containing hydrogen reacts mainly with nickel oxide (II) among the metal oxides 53 in the reactor 52, which reacts at a lower temperature. The reaction follows the chemical formula shown in formula (1). Hydrogen in the secondary gas W is also consumed by the reaction of formula (3) in which manganese oxide (IV) is reduced to manganese oxide (II), and the hydrogen concentration in the secondary gas W at the outlet of the reactor 52 decreases. By passing through the secondary gas cooler 61 downstream of the reactor 52, the water vapor generated by the reaction is turned into water and removed, and the hydrogen concentration in the secondary gas W is measured by the outlet gas concentration meter 56.

[0070] The secondary gas control device 74 controls the flow rate of hydrogen introduced from the hydrogen gas supply device 67A of the secondary gas supply source 67 so that the hydrogen concentration in the secondary gas W is a predetermined concentration measured by the inlet gas concentration meter 55. That is, the secondary gas control device 74 controls the blower 62 based on the measured value measured by the thermometer 54 of the temperature rise of the metal oxide 53 due to the supply of the secondary gas W containing hydrogen, and adjusts the supply flow rate of the secondary gas W. The secondary gas control device 74 also calculates the hydrogen flow rate required to make up for the shortage from the difference between the hydrogen concentrations measured by the inlet gas concentration meter 55 and the outlet gas concentration meter 56, and controls the hydrogen gas supply device 67A of the secondary gas supply source 67 to supply hydrogen. The secondary gas control device 74 also evaluates the reaction rate of the metal oxide 53 with hydrogen from the difference between the hydrogen concentrations measured by the inlet gas concentration meter 55 and the outlet gas concentration meter 56.

[0071] (d) Pretreatment When the increase in the temperature measured by thermometer 54 stops and the oxygen concentrations measured by outlet gas concentration meter 56 and inlet gas concentration meter 55 become equal, the secondary gas control device 74 determines that the reduction reaction by hydrogen has ended and moves on to pre-processing for supplying oxygen gas.

[0072] That is, when switching to oxygen gas, it is necessary to control the hydrogen concentration in the system of hydrogen treatment device 50 to be the lower explosion limit of 4 vol% or less. Therefore, as a pretreatment for supplying oxygen gas, in order to set the hydrogen concentration in the system of hydrogen treatment device 50 to 4 vol% or less, blower 62 is stopped once, secondary gas supply system valve 66 and secondary gas circulation system valve 63 are closed, and gas treatment system inlet valve 70, gas treatment introduction valve 73 and gas treatment system outlet valve 71 are opened, and then blower 62 is started again, and oxygen gas supply device 67B supplies oxygen of 5 vol% or less to gas treatment device 69.

[0073] By this operation, hydrogen in the secondary gas W remaining in the system of the hydrogen treatment device 50 including the reactor 52 reacts with oxygen in the gas treatment device 69 to generate water vapor. The water vapor contained in the secondary gas W that has passed through the gas treatment device 69 is converted to water and removed in the secondary gas cooler 61. The secondary gas W is circulated to the gas treatment device 69 by the blower 62, whereby the hydrogen is treated, and the oxygen concentration measured by the outlet gas concentration meter 56 decreases.

[0074] (e) Supply of secondary gas W containing oxygen When the hydrogen concentration becomes 4 vol% or less and the oxygen concentration becomes 5 vol% or less, the secondary gas control device 74 stops the blower 62, opens the secondary gas supply system valve 66 and the secondary gas circulation system valve 63, closes the gas processing system inlet valve 70, the gas processing introduction valve 73, and the gas processing system outlet valve 71, starts the blower 62 again, and supplies oxygen from the oxygen gas supply device 67B of the secondary gas supply source 67. That is, similar to the case of supplying hydrogen gas, oxygen is supplied from the oxygen gas supply device 67B of the secondary gas supply source 67 to a state in which the secondary gas W mainly composed of nitrogen is circulating in the metal oxide 53 in the reactor 52.

[0075] As described above, the secondary gas W containing oxygen and the secondary gas W containing hydrogen are alternately supplied to the reactor 52 by the secondary gas supply device 51, and this operation is repeated to generate reaction heat of the metal oxide 53 in the reactor 52, which promotes the temperature rise of the metal oxide 53, causing it to reach the reaction initiation temperature early.

[0076] (f) Consideration of temperature rise of metal oxide 53 Here, we consider the effect of temperature rise due to reaction heat of metal oxide 53 when secondary gas W containing oxygen and secondary gas W containing hydrogen are alternately supplied. Of 4 tons of metal oxide 53 filled in reactor 52 (φ1.6 m × height 1.0 m) with a volume of 2 m3, 800 kg, which corresponds to 20 wt%, is nickel (II) oxide, and secondary gas W containing 20 vol% hydrogen and secondary gas W containing 10 vol% oxygen are alternately circulated at 50 m3 / h under normal pressure by blower 62, and it is assumed that 10 vol% of each react.

[0077] 50m of full flow 3 / h, 10% of the reaction volume between hydrogen and oxygen is 5m 3 / h, which is 223 mol / h when converted to moles. The reaction enthalpy of the reduction of nickel(II) oxide with hydrogen is 152 kJ / mol at 25°C, and the reaction enthalpy of the oxidation reaction of nickel is estimated to be 133 kJ / mol at 25°C. Nickel(II) oxide and hydrogen react in a 1:1 ratio, and oxygen and nickel react in a 1:2 ratio in the oxidation reaction of nickel. Taking the above into consideration, the reaction heat of the reduction of nickel(II) oxide with hydrogen is 223 mol / h x 1 x 152 kJ / mol / 3600 = 9.4 kW, and the reaction heat of the oxidation reaction of nickel is 223 mol / h x 2 x 133 kJ / mol / 3600 = 16.5 kW.

[0078] If the temperature rise when the above-mentioned reaction heat is given to 4 tons of metal oxide 53 is simply evaluated under the assumption of the conditions in the brackets below, the temperature of metal oxide 53 can rise by about 70°C by reduction with hydrogen and by about 100°C by oxidation reaction. [Weight of metal oxide 53 is 4 tons, specific heat is 0.5 J / kg°C, temperature of metal oxide 53 and its surroundings is 25°C, surface area of ​​heat dissipation part of reactor 52 is 5 m2. 2 (1.6m×3.14×1m+0.8m×0.8m×3.14×2), emissivity of object surface is 1, heat transfer coefficient by convection is 7W / m 2 K]

[0079] From the above evaluation, it is found that by alternately supplying secondary gas W containing hydrogen and secondary gas W containing oxygen, it is possible to heat (preheat) metal oxide 53 in reactor 52. Note that this evaluation is based on tentative conditions only, and in order to promote the reaction, it is effective to increase the pressure in the system of hydrogen treatment device 50, increase the concentration of hydrogen or oxygen to be supplied, preheat secondary gas W by secondary gas heater 65, or the like.

[0080] As configured as above, the third embodiment provides the following effect (3). (3) Before starting hydrogen treatment by the metal oxide 53 in the reactor 52, a secondary gas W containing oxygen and a secondary gas W containing hydrogen are alternately supplied to the reactor 52 to increase the temperature of the metal oxide 53 in the reactor 52 by the heat of reaction, thereby carrying out a preheating treatment. Therefore, the metal oxide 53 can be preheated to reach the reaction start temperature earlier than when the metal oxide 53 in the reactor 52 is preheated by a heater or the like, and the preheating can be promoted.

[0081] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, changes, and combinations can be made without departing from the spirit of the invention. Furthermore, these substitutions, changes, and combinations are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0082] For example, in the third embodiment, a catalyst may be mixed into at least one of the reactor 52 and the secondary gas heater 65, and before starting hydrogen processing using the metal oxide 53 in the reactor 52, a secondary gas W containing oxygen or a secondary gas W containing hydrogen may be supplied from the secondary gas supply device 51, and the oxygen or hydrogen may be reacted with the catalyst to raise the temperature of the secondary gas W, thereby further promoting preheating of the metal oxide 53 in the reactor 52. In addition, in the second and third embodiments, the A-line reactor was used as an example. However, in the second and third embodiments, the B-line reactor of the first embodiment can be used instead. [Explanation of symbols]

[0083] 10...hydrogen treatment device, 11...reactor containment vessel, 12A...A-line reactor, 12B...B-line reactor, 13...inlet switching valve, 14...outlet switching valve, 15...secondary gas supply device, 16...switching valve control device, 17A...A-line metal oxide, 17B...B-line metal oxide, 26...inlet gas concentration meter, 31...outlet gas concentration meter, 40...hydrogen treatment device, 41...reactor, 42...metal oxide, 43...branching piping, 44...branching system, 45...blower, 47...thermometer, 48...flow rate control device, 50...hydrogen treatment device, 51...secondary gas supply device, 52...reactor, 53...metal oxide, 54...thermometer, 55...inlet gas concentration meter, 56...outlet gas concentration meter, 62...blower, 67...secondary gas supply source, 69...gas treatment device, 74...secondary gas control device, X...reactant fluid, Y...post-reactant fluid, Z, W...secondary gas

Claims

1. In a hydrogen treatment device that treats hydrogen generated in a nuclear reactor containment vessel using a metal oxide, A plurality of reactors containing the metal oxide and arranged in parallel with each other; A switching valve that switches and supplies a reaction fluid containing hydrogen to be treated to any one of the reactors; a secondary gas supply device capable of supplying a secondary gas containing oxygen to the reactor to which the reaction fluid is not supplied, The hydrogen treatment by the metal oxide in the reactor to which the reaction fluid is supplied and the regeneration treatment of the metal oxide by supplying the secondary gas to the reactor after the hydrogen treatment are performed are performed in parallel, The hydrogen treatment device is further characterized in that it is configured with a branching system having a branching pipe that branches off a portion of the fluid after reaction in which hydrogen is treated by the metal oxide in the reactor and returns it to the reaction fluid supplied to the reactor.

2. A hydrogen treatment device that treats hydrogen generated in a nuclear reactor containment vessel with a metal oxide, comprising: A plurality of reactors containing the metal oxide and arranged in parallel with each other; A switching valve that switches and supplies a reaction fluid containing hydrogen to be treated to any one of the reactors; a secondary gas supply device capable of supplying a secondary gas containing oxygen to the reactor to which the reaction fluid is not supplied, The hydrogen treatment by the metal oxide in the reactor to which the reaction fluid is supplied and the regeneration treatment of the metal oxide by supplying the secondary gas to the reactor after the hydrogen treatment are performed are performed in parallel, The secondary gas supply device is further configured to alternately supply an oxidizing gas and a reducing gas to the reactor connected to the secondary gas supply device before starting hydrogen treatment using a metal oxide in the reactor, thereby preheating the metal oxide with reaction heat.

3. 3. The hydrogen treatment device according to claim 1, wherein the control device for controlling the switching valve is configured to calculate a reaction rate of the metal oxide in the reactor from a difference in hydrogen concentration between an inlet side and an outlet side of the reactor during supply of the reaction fluid, and to determine the reactor to which the reaction fluid should be supplied based on the reaction rate, and to control the switching valve.

4. The hydrogen treatment apparatus according to claim 1, characterized in that at least one of the flow rate of the reaction fluid and the flow rate of the post-reaction fluid returned to the reaction fluid is controlled based on the temperature of the reactor and the hydrogen concentration of the reaction fluid supplied to the reactor.

5. 3. The hydrogen treatment device according to claim 2, wherein the secondary gas supply device is configured to control at least one of a flow rate and a concentration of the oxidizing gas or the reducing gas supplied to the reactor based on a detected temperature value of the reactor.

6. 6. The hydrogen treatment device according to claim 2 or 5, wherein the secondary gas supply device is configured to replenish a shortage of the oxidizing gas or the reducing gas based on a difference between the concentrations of the oxidizing gas and the reducing gas on the inlet side and the outlet side of the reactor so that the concentration of the oxidizing gas or the reducing gas supplied to the reactor becomes a predetermined concentration.

7. 7. The hydrotreating apparatus according to claim 2, 5 or 6, wherein the metal oxide in the reactor is maintained in a reduced state in advance for a preheating treatment prior to the start of hydrotreating.

8. 8. The hydrogen treatment device according to claim 1, wherein the metal oxide in the reactor is composed of any one of copper oxide (II), nickel oxide (II), manganese oxide (IV), cobalt oxide (II, III), and iron oxide, or a combination thereof, and is formed by granulating into a molded body shape.

9. A hydrogen processing method for processing hydrogen generated in a nuclear reactor containment vessel using a metal oxide, comprising: providing a plurality of reactors each containing the metal oxide and arranged in parallel with one another; and a secondary gas supplying device capable of supplying a secondary gas containing oxygen to the reactors to which a reaction fluid containing hydrogen to be treated is not supplied; A hydrogen treatment using the metal oxide in the reactor to which the reaction fluid is supplied and a regeneration treatment of the metal oxide by supplying the secondary gas to the reactor after the hydrogen treatment are alternately and in parallel, The hydrogen processing method further comprises branching a portion of a reacted fluid obtained by treating hydrogen with a metal oxide in the reactor through a branching system having a branch pipe, and refluxing the reacted fluid to be supplied to the reactor.

10. A hydrogen processing method for processing hydrogen generated in a nuclear reactor containment vessel with a metal oxide, comprising: providing a plurality of reactors each containing the metal oxide and arranged in parallel with one another; and a secondary gas supplying device capable of supplying a secondary gas containing oxygen to the reactors to which a reaction fluid containing hydrogen to be treated is not supplied; A hydrogen treatment using the metal oxide in the reactor to which the reaction fluid is supplied and a regeneration treatment of the metal oxide by supplying the secondary gas to the reactor after the hydrogen treatment are alternately and in parallel, The hydrogen treatment method is further characterized in that the secondary gas supply device alternately supplies an oxidizing gas and a reducing gas to the reactor connected to the secondary gas supply device before starting hydrogen treatment using a metal oxide in the reactor, thereby preheating the metal oxide with reaction heat.

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