Patent Publication Number: US-2023159324-A1

Title: Hydrogen release/storage system, hydrogen release/storage method, ammonia production equipment, gas turbine, fuel cell, and steel mill

Description:
TECHNICAL FIELD 
     The present invention relates to a hydrogen release and storage system, a hydrogen release and storage method, an ammonia production apparatus, a gas turbine, a fuel cell and an steel mill. 
     Priority is claimed on Japanese Patent Application No. 2020-071759, filed in Japan on Apr. 13, 2020, the content of which is incorporated herein by reference. 
     BACKGROUND ART 
     Hydrogen energy is in use in a variety of processes such as ammonia synthesis, gas combustion, the manufacture of solid oxide fuel cells and iron making. It is known that huge effort and cost are required to supply a hydrogen gas, which serves as a raw material, and there is a demand for a technique that improves the current situation. In addition, in processes where hydrogen energy is used, a large amount of exhaust heat is generated, and thus there is a demand for a method for effectively using exhaust heat. 
     CITATION LIST 
     Patent Literature 
     Patent Document 1 
     PTC International Publication No. WO 2018/074518 
     SUMMARY OF INVENTION 
     Technical Problem 
     As a material that generates hydrogen, borohydrides are being studied. Patent Document 1 discloses a sheet containing a borohydride in a two-dimensional manner (Patent Document 1). However, when all of the hydrogen that is contained in the sheet has been generated, there is a need to supply a new sheet, and additional effort and money are required. 
     The present invention has been made in consideration of the above-described circumstances, and an objective of the present invention is to provide a hydrogen release and storage system, a hydrogen release and storage method, an ammonia production apparatus, a gas turbine, a fuel cell and a steel mill which enable the effective use of exhaust heat and suppression of the generation of additional energy necessary for hydrogen generation. 
     Solution to Problem 
     In order to solve the above-described problem, the present invention adopts the following means. 
     (1) A hydrogen release and storage system according to one aspect of the present invention includes a first hydrogen release and storage unit composed of a first hydrogen compound member, a first container that accommodates the first hydrogen compound member, a first heating apparatus configured to heat an inside of the first container, a first cooling apparatus configured to cool the inside of the first container, a first water supply apparatus configured to supply water to the first container, a second hydrogen release and storage unit composed of a second hydrogen compound member, a second container that accommodates the second hydrogen compound member, a second heating apparatus configured to heat an inside of the second container, a second cooling apparatus configured to cool the inside of the second container, and a second water supply apparatus that supplies water to the second container, wherein heating, cooling and supply of water are each independently executed on the inside of the first container and the inside of the second container. 
     (2) In the hydrogen release and storage system according to (1), the first heating apparatus and the second heating apparatus may be a same heating apparatus that is shared by the first hydrogen release and storage unit and the second hydrogen release and storage unit. 
     (3) In the hydrogen release and storage system according to any of (1) or (2), the first cooling apparatus and the second cooling apparatus may be the same cooling apparatus that is shared by the first hydrogen release and storage unit and the second hydrogen release and storage unit. 
     (4) In the hydrogen release and storage system according to any one of (1) to (3), the first water supply apparatus and the second water supply apparatus may be the same water supply apparatus that is shared by the first hydrogen release and storage unit and the second hydrogen release and storage unit. 
     (5) In the hydrogen release and storage system according to any one of (1) to (4), a stoichiometric ratio between an element other than a hydrogen element that configures each of the first hydrogen compound member and the second hydrogen compound member and the hydrogen element is preferably 1:1 to 3:4. 
     (6) In the hydrogen release and storage system according to (5), the element other than the hydrogen element may be boron. 
     (7) The hydrogen release and storage system according to any one of (1) to (6) may further include a switching apparatus configured to switch between a first state and a second state, the first state is a state where, in the first hydrogen release and storage unit, the first heating apparatus is driven and the first cooling apparatus and the first water supply apparatus are stopped, and in the second hydrogen release and storage unit, the second heating apparatus is stopped and the second cooling apparatus and the second water supply apparatus are driven and the second state is a state where, in the first hydrogen release and storage unit, the first heating apparatus is stopped and the first cooling apparatus and the first water supply apparatus are driven, and in the second hydrogen release and storage unit, the second heating apparatus is driven and the second cooling apparatus and the second water supply apparatus are stopped. 
     (8) A hydrogen release and storage method according to one aspect of the present invention is a hydrogen release and storage method in which the hydrogen release and storage system according to any one of (1) to (7) is used as a hydrogen supply source and alternately has a first step of heating the inside of the first container so as to reach 150° C. or higher, releasing hydrogen from the first hydrogen compound member, supplying water to the inside of the second container while cooling the inside of the second container so as to reach lower than 150° C. and absorbing the hydrogen into the second hydrogen compound member and a second step of supplying water to the inside of the first container while cooling the inside of the first container so as to reach lower than 150° C., absorbing the hydrogen into the first hydrogen compound member, and heating the inside of the second container so as to reach 150° C. or higher and releasing hydrogen from the second hydrogen compound member. 
     (9) An ammonia production apparatus according to one aspect of the present invention includes the hydrogen release and storage system according to any one of (1) to (7) as a hydrogen supply source. 
     (10) A gas turbine according to one aspect of the present invention includes the hydrogen release and storage system according to any one of (1) to (7) as a hydrogen supply source. 
     (11) A fuel cell according to one aspect of the present invention includes the hydrogen release and storage system according to any one of (1) to (7) as a hydrogen supply source. 
     (12) A steel mill according to one aspect of the present invention includes the hydrogen release and storage system according to any one of (1) to (7) as a hydrogen supply source. 
     Advantageous Effects of Invention 
     The hydrogen release and storage system of the present invention can be used as a hydrogen supply source in a variety of apparatuses in which hydrogen is used as a raw material. Furthermore, since hydrogen can be generated without newly adding energy by using exhaust heat that is generated in the apparatuses to heat the hydrogen compound member to generate hydrogen, it is possible to reduce the amount of natural gas used in association with the addition of energy. 
     In addition, the hydrogen release and storage system of the present invention is composed of two hydrogen release and storage units that function as hydrogen supply sources, and it is possible to independently control timings of hydrogen generation and hydrogen storage in each of the hydrogen release and storage units. Therefore, while the generation of hydrogen is stopped and hydrogen is stored in one unit, it is possible to generate hydrogen in the other unit. This makes it possible to generate hydrogen in any one of the hydrogen release and storage units at all times and makes it possible to relentlessly supply hydrogen to target apparatuses. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a view schematically showing the configuration of a hydrogen release and storage system according to one embodiment of the present invention. 
         FIG.  2    is a view schematically showing the configurations of a hydrogen compound member in a hydrogen absorption state and in a hydrogen release state. 
         FIG.  3    is a view schematically showing the configuration of a facility that is used in a hydrogen release step in a hydrogen release and storage method according to one embodiment of the present invention. 
         FIG.  4    is a graph showing the relationship between the temperature of the hydrogen compound member and the amount of hydrogen that is generated from the hydrogen compound member. 
         FIG.  5    is the flow of a process that is included in the hydrogen release step. 
         FIG.  6    is a view schematically showing the configuration of a facility that is used in a hydrogen storage step in a hydrogen release and storage method according to one embodiment of the present invention. 
         FIG.  7    is the flow of a process that is included in the hydrogen storage step. 
         FIG.  8    is a view schematically showing the configuration of an ammonia production apparatus to which the hydrogen release and storage system is applied. 
         FIG.  9    is a view schematically showing the configuration of a gas turbine to which the hydrogen release and storage system is applied. 
         FIG.  10    is a view schematically showing the configuration of a fuel cell to which the hydrogen release and storage system is applied. 
         FIG.  11    is a view schematically showing the configuration of a steel mill to which the hydrogen release and storage system is applied. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a hydrogen release and storage system according to an embodiment to which the present invention is applied will be described in detail using drawings. In some of the drawings to be used in the following description, a characteristic portion is shown in an enlarged manner for convenience in order to facilitate the understanding of the characteristic, and the dimensional ratios and the like of each configurational element are not always the same as those in actual cases. In addition, materials, dimensions, and the like in the following description are simply exemplary examples, and the present invention is not limited thereto and can be appropriately modified and carried out within the scope of the gist of the present invention. 
       FIG.  1    is a perspective view schematically showing the configuration of a hydrogen release and storage system  100  according to one embodiment of the present invention. The hydrogen release and storage system  100  includes a first hydrogen release and storage unit  100 A and a second hydrogen release and storage unit  100 B. 
     The first hydrogen release and storage unit  100 A mainly includes a first hydrogen compound member  101  ( 101 A), a first container (reaction container)  102  ( 102 A) that accommodates the first hydrogen compound member  101 , a first heating apparatus  103  ( 103 A) configured to heat the inside of the first container  102 , a first cooling apparatus  104  ( 104 A) configured to cool the inside of the first container  102  and a first water supply apparatus  105 A configured to supply water to the first container  102 . 
     The second hydrogen release and storage unit  100 B mainly includes a second hydrogen compound member  101  ( 101 B), a second container (reaction container)  102  ( 102 B) that accommodates the second hydrogen compound member  101 , a second heating apparatus  103  ( 103 B) configured to heat the inside of the second container  102 , a second cooling apparatus  104  ( 104 B) configured to cool the inside of the second container  102  and a second water supply apparatus  105 B configured to supply water to the second container  102 . 
     The first heating apparatus  103 A and the second heating apparatus  103 B may be mutually independent heating apparatuses, but may also be a same heating apparatus  103  that are shared by the first hydrogen release and storage unit  100 A and the second hydrogen release and storage unit  100 B as shown in  FIG.  1   . 
     The first cooling apparatus  104 A and the second cooling apparatus  104 B may be mutually independent cooling apparatuses, but may also be the same cooling apparatus  104  that is shared by the first hydrogen release and storage unit  100 A and the second hydrogen release and storage unit  100 B. 
     The first water supply apparatus  105 A and the second water supply apparatus  105 B may be mutually independent water supply apparatuses, but may also be the same water supply apparatus  105  that is shared by the first hydrogen release and storage unit  100 A and the second hydrogen release and storage unit  100 B. 
     Heating, cooling and supply of water are each independently executed on the inside of the first container  102 A and the inside of the second container  102 B using separate control means (apparatuses). 
     The stoichiometric ratio between an element X other than a hydrogen element that configures each of the first hydrogen compound member  101 A and the second hydrogen compound member  101 B and a hydrogen element H is 1:1 to 3:4 (for example, XH, XH 2 , XH 3 , XH 4 , X 2 H 3  or X 3 H 4 ). Examples of the element other than a hydrogen element include boron B. 
     In the side wall portion of the first container  102 A, a first hydrogen release portion  106 A ( 106 ) that releases hydrogen generated from the first hydrogen compound member  101 A to the outside of the first container  102 A and a first oxygen release portion  107 A ( 107 ) that releases oxygen that is generated from supplied water to the outside are provided apart from each other. Similarly, in the side wall portion of the second container  102 B, a second hydrogen release portion  106 B ( 106 ) that releases hydrogen generated from the second hydrogen compound member  101 B to the outside of the second container  102 B and a second oxygen release portion  107 B ( 107 ) that releases oxygen that is generated from supplied water to the outside are provided apart from each other. 
     The heating apparatus  103  (the first heating apparatus  103 A and the second heating apparatus  103 B) may be in direct contact with or may not be in contact with the hydrogen compound member  101  (the first hydrogen compound member  101 A and the second hydrogen compound member  101 B) to be heated. Here, a heating apparatus that is attached to the outsides of the containers  102  (the first container  102 A and the second container  102 B) is an exemplary example. As the heating apparatus  103 , a combustor, an electric heater, a steam heating apparatus and the like are exemplary examples. 
     The cooling apparatus  104  (the first cooling apparatus  104 A and the second cooling apparatus  104 B) may be attached to the outside of the container  102  or accommodated in the container  102  as long as the hydrogen compound member  101  (the first hydrogen compound member  101 A and the second hydrogen compound member  101 B) in the container  102  (the first container  102 A and the second container  102 B) can be cooled. As the cooling apparatus  104 , an air cooler, a water cooler and other refrigerant-type cooling apparatuses are exemplary examples. For cooling, the inside of the container  102  may be opened and left to stand in the atmosphere without using the cooling apparatus  104 . 
     The water supply apparatus  105  (the first water supply apparatus  105 A and the second water supply apparatus  105 B) supplies a fluid containing liquid or gaseous water as a main component to the inside of the container  102  (the first container  102 A and the second container  102 B). When the temperature of the fluid becomes close to the intended cooling temperature, since it is possible to make the water to be supplied function as a refrigerant, the water supply apparatus  105  is capable of functioning as the cooling apparatus  104  as well. 
     As a first state, a state where, in the first hydrogen release and storage unit  100 A, the first heating apparatus  103 A is driven and the first cooling apparatus  104 A and the first water supply apparatus  105 A are stopped and, in the second hydrogen release and storage unit  100 B, the second heating apparatus  103 B is stopped and the second cooling apparatus  104 B and the second water supply apparatus  105 B are driven is defined. In addition, as a second state, a state where, in the first hydrogen release and storage unit  100 A, the first heating apparatus  103 A is stopped and the first cooling apparatus  104 A and the first water supply apparatus  105 A are driven and, in the second hydrogen release and storage unit  100 B, the second heating apparatus  103 B is driven and the second cooling apparatus  104 B and the second water supply apparatus  105 B are stopped is defined. At this time, the hydrogen release and storage system  100  may further include a switching apparatus (not shown) configured to switch between the first state and the second state. 
       FIG.  2    is a view schematically showing the configurations of the hydrogen compound member  101  in a hydrogen absorption state (left-hand side) where hydrogen elements bond to (are stored in) almost all bonding sites of an X element that configures a hydrogen compound and in the hydrogen release state (right-hand side) where no hydrogen elements bond to some of the bonding sites of the X element due to hydrogen release. 
     When the first hydrogen release and storage unit  100 A and the second hydrogen release and storage unit  100 B that configure the hydrogen release and storage system of the present embodiment are each used as a hydrogen supply source, it is possible to carry out a hydrogen release and storage method in the following procedure. 
     Hydrogen Release Step 
       FIG.  3    is a view schematically showing the configuration of a facility that is used in a hydrogen release step. The heating apparatus  103  is composed of means for supplying a heating medium (first heating apparatus)  103 A and means for adjusting the temperature of the heating medium (second heating apparatus)  103 B. The cooling apparatus  104  and the water supply apparatus  105  that are not used in this step are not shown. 
       FIG.  4    is a graph showing the relationship between the temperature of the hydrogen compound member  101  and the amount of hydrogen that is generated from the hydrogen compound member  101  (the amount of hydrogen generated). As shown in this graph, the hydrogen compound member  101  is made to generate hydrogen at a temperature of 150° C. or higher. Therefore, first, the hydrogen compound member  101  in the hydrogen storage state shown in the left-hand side of  FIG.  2    is disposed in the container  102 , subsequently, the inside of the container  102  is heated using the heating apparatus  103  so as to reach 150° C. or higher (preferably 150° C. or higher and 300° C. or lower), and the hydrogen compound member  101  is made to release hydrogen. The inside of the container  102  is heated by supplying the heating medium into the container  102 . At the same time, the temperature of the heating medium is adjusted using the second heating apparatus  103 B in order to prevent the temperature from excessively rising. This makes the hydrogen compound member  101  lose some hydrogen and fall into the hydrogen release state shown in the right-hand side of  FIG.  2   . 
       FIG.  5    shows the flow of a more detailed process that is included in an actual hydrogen release step. First, the supply of the heating medium is begun, and the temperature T 1  of the inside of the container  102  on a side where the heating medium is disposed is controlled so as to become a temperature of 300° C. or lower. If the temperature exceeds 300° C., the temperature T 1  is controlled so as to become 300° C. or lower by changing the flow rate of water Q 1 . 
     Next, the temperature T 2  of the container  102  on a side where the heating medium is not disposed is controlled so as to become a temperature of 250° C. or lower. If the temperature exceeds 250° C., the temperature T 2  is controlled so as to become 250° C. or lower by changing the heating medium flow rate Q 2 . 
     Next, the pressure P 1  in the container  102  is measured, and whether or not hydrogen is generated depending on an increase in pressure is confirmed. Whether or not the pressure P 2  of hydrogen H 2  that is released from the container  102  is a predetermined pressure or higher is determined. In a case where the pressure P 2  is lower than the predetermined pressure, the pressure P 2  is controlled so as to reach the predetermined pressure by operating a valve V 2 . 
     Next, whether or not the pressure P 1  in the container  102  is a predetermined pressure or higher is determined. In a case where the pressure P 1  is lower than the predetermined pressure, the pressure P 1  is controlled so as to reach the predetermined pressure by changing the flow rate of water Q 1 . Subsequently, again, whether or not the pressure P 1  in the container  102  is the predetermined pressure or higher is determined. In a case where the pressure P 1  is lower than the predetermined pressure, the same determination is repeated by continuing the operation. 
     Next, whether or not Q 2 , T 1  and T 2  are the predetermined values or higher and P 1  is the predetermined pressure or lower, that is, a state where the release of H 2  is stopped has been formed in spite of the supply of heat is determined. In a case where these fail to satisfy the predetermined values, Q 2 , T 1  and T 2  are adjusted so as to reach the predetermined values or higher by changing the water flow rate Q 1 . In a case where these satisfy the predetermined values, the release of hydrogen is ended. 
     Hydrogen Storage Step 
       FIG.  6    is a view schematically showing the configuration of a facility that is used in a hydrogen storage step. The cooling apparatus  104  is composed of means for supplying a cooling water (first cooling apparatus)  104 A and means for adjusting the temperature of the cooling water (second cooling apparatus)  104 B. In addition, the water supply apparatus  105  is composed of means for supplying a raw material water (first water supply apparatus)  105 A and means for adjusting the flow rate of the raw material water to be supplied (second water supply apparatus)  105 B. The heating apparatus  103  that is not used in this step is not shown. 
     Next, water is supplied into the container  102  while cooling the inside of the container  102  so as to reach lower than 150° C. (preferably 80° C. or higher and 150° C. or lower) using the cooling apparatus  104 , and hydrogen is absorbed into the hydrogen compound member  101 . Hydrogen thermally decomposed from the water due to the temperature in the container  102  bond to a non-bonding site of the hydrogen compound member  101 , whereby the hydrogen compound member  101  returns to the hydrogen storage state shown on the left-hand side of  FIG.  2   . 
     When the hydrogen release step and the hydrogen absorption step are carried out alternately, it is possible to continuously supply hydrogen to predetermined facilities. 
       FIG.  7    shows the flow of a more detailed process that is included in an actual hydrogen storage step. First, the supply of the cooling water is begun, and the temperature T 3  of the inside of the container  102  on a side where the cooling water is disposed is controlled so as to become a temperature of 80° C. or lower. if the temperature exceeds 80° C., the temperature T 1  is controlled so as to become 80° C. or lower by changing the water flow rate Q 3 . 
     Next, the temperature T 4  of the container  102  on a side where the cooling water is not disposed is controlled so as to become a temperature of 75° C. or lower. If the temperature exceeds 75° C., the temperature T 1  is controlled so as to become 75° C. or lower by changing the amount of the cooling water Q 4 . 
     Next, hydrogen in the container  102  is removed by initiating VP. The operation of VP is continued until the pressure P 1  reaches a predetermined pressure or lower, thereby further removing hydrogen in the container  102 . 
     Next, the operation of VP is stopped, and the supply of the raw material water is begun by opening V 6 . Next, the temperature of the raw material water is adjusted so as to be in a predetermined temperature range by changing the water flow rate Q 5 . 
     Next, whether or not the pressure P 1  in the container is the predetermined pressure or higher is determined, and, in a case where the pressure P 1  is lower than the predetermined pressure, the operation is continued until the pressure P 1  reaches the predetermined pressure or higher. When the pressure P 1  is the predetermined pressure or higher, the production of hydrogen is ended. 
     A hydrogen release and storage method of the present embodiment alternately has a first step that is a combination of the hydrogen release step with the first hydrogen release and storage unit  100 A and the hydrogen storage step with the second hydrogen release and storage unit  100 B and a second step that is a combination of the hydrogen storage step with the first hydrogen release and storage unit  100 A and the hydrogen release step with the second hydrogen release and storage unit  100 B. 
     More specifically, the first step is a step of heating the inside of the first container  102 A so as to reach 150° C. or higher, releasing hydrogen from the first hydrogen compound member  101 A, supplying water to the inside of the second container  102 B while cooling the inside of the second container  102 B so as to reach lower than 150° C. and absorbing the hydrogen into the second hydrogen compound member  101 B. 
     More specifically, the second step is a step of supplying water to the inside of the first container  102 A while cooling the inside of the first container  102 A so as to reach lower than 150° C., absorbing the hydrogen into the first hydrogen compound member  101 A, heating the inside of the second container  102 B so as to reach 150° C. or higher and releasing hydrogen from the second hydrogen compound member  101 B. 
     As described above, the hydrogen release and storage system  100  of the present embodiment can be used as a hydrogen supply source in a variety of apparatuses in which hydrogen is used as a raw material. Furthermore, since hydrogen can be generated without newly adding energy by using exhaust heat that is generated in the apparatuses to heat the hydrogen compound member  101  to generate hydrogen, it is possible to reduce the amount of natural gas used in association with the addition of energy. 
     In addition, the hydrogen release and storage system  100  of the present embodiment is composed of two hydrogen release and storage units  100 A and  100 B that function as hydrogen supply sources, and it is possible to independently control timings of hydrogen generation and hydrogen storage in each of the hydrogen release and storage units. Therefore, while the generation of hydrogen is stopped and hydrogen is stored in one unit, it is possible to generate hydrogen in the other unit. This makes it possible to generate hydrogen in any one of the hydrogen release and storage units at all times and makes it possible to relentlessly supply hydrogen to target apparatuses. 
     Hereinafter, application examples of the hydrogen release and storage system  100  of the present embodiment will be listed. 
     APPLICATION EXAMPLE 1 
       FIG.  8    is a view schematically showing the configuration of an ammonia production apparatus  110  to which the hydrogen release and storage system  100  is applied. The ammonia production apparatus  110  is mainly composed of a raw material preparation portion  111 , an ammonia synthesis portion  112  and an ammonia collection portion  113 . The heating apparatus and the cooling apparatus that configure the hydrogen release and storage system  100  can be made to function as a temperature adjustment apparatus  114  that adjusts the temperature of generated ammonia. 
     The first heating apparatus  103 A and the first cooling apparatus  104 A may be a first temperature adjustment apparatus  114 A that adjusts the temperature of one part of the generated ammonia, and the second heating apparatus  103 B and the second cooling apparatus  104 B may be a second temperature adjustment apparatus  114 B that adjusts the temperature of the other part of the generated ammonia. 
     The use of exhaust heat having a medium temperature of approximately 400° C. that is generated in association with ammonia synthesis makes it possible to heat the hydrogen compound member  101  with no additional energy and to generate hydrogen. When the generated hydrogen is supplied at a predetermined timing of raw material preparation, it becomes possible to synthesize additional ammonia using this hydrogen as a raw material. This makes it possible to reduce the amount of a methane raw material that is injected as a raw material for ammonia synthesis. 
     APPLICATION EXAMPLE 2 
       FIG.  9    is a view schematically showing the configuration of a gas turbine  120  to which the hydrogen release and storage system  100  is applied. The use of exhaust heat of approximately 300° C. that is generated in the gas turbine  120  makes it possible to heat the hydrogen compound member  101  with no additional energy and to generate hydrogen. When the generated hydrogen is supplied to a combustor  120 A that configures the gas turbine  120 , additional gas turbine combustion becomes possible using this hydrogen as a fuel. This makes it possible to reduce the amount of natural gas that is injected as a fuel for gas turbine combustion. 
     APPLICATION EXAMPLE 3 
       FIG.  10    is a view schematically showing the configuration of a solid oxide fuel cell (SOFC)  130  to which the hydrogen release and storage system  100  is applied. The use of exhaust heat of approximately 600° C. to 1200° C. that is generated in the production process of the fuel cell  130  makes it possible to heat the hydrogen compound member  101  with no additional energy and to generate hydrogen. When the generated hydrogen is supplied to the fuel cell  130 , the hydrogen can be used as a fuel of the fuel cell. This makes it possible to reduce the amount of natural gas that is injected as a fuel of the fuel cell. 
     APPLICATION EXAMPLE 4 
       FIG.  11    is a view schematically showing the configuration of a steel mill  140  to which the hydrogen release and storage system  100  is applied. The use of exhaust heat that is generated in an iron-making step makes it possible to heat the hydrogen compound member  101  with no additional energy and to generate hydrogen. The generated hydrogen can be used as a raw material for iron reduction for iron making (Fe 2 O 3 +3H 2 →2Fe+3H 2 O). This makes it possible to reduce the amount of natural gas that is injected as a raw material for iron reduction. 
     REFERENCE SIGNS LIST 
       100  Hydrogen release and storage system 
       100 A First hydrogen release and storage unit 
       100 B Second hydrogen release and storage unit 
       101  Hydrogen compound member 
       101 A First hydrogen compound member 
       101 B Second hydrogen compound member 
       102  Container 
       102 A First container 
       102 B Second container 
       103  Heating apparatus 
       103 A First heating apparatus 
       103 B Second heating apparatus 
       103 C Heating medium supply means 
       103 D Temperature adjustment means 
       104  Cooling apparatus 
       104 A First cooling apparatus 
       104 B Second cooling apparatus 
       104 C Cooling water supply means 
       104 D Temperature adjustment means 
       105  Water supply apparatus 
       105 A First water supply apparatus 
       105 B Second water supply apparatus 
       105 C Raw material water supply means 
       105 D Flow rate adjustment means 
       106  Hydrogen release portion 
       107  Oxygen release portion 
       110  Ammonia production apparatus 
       111  Raw material preparation portion 
       112  Ammonia synthesis portion 
       113  Ammonia collection portion 
       114  Temperature adjustment apparatus 
       120  Gas turbine 
       120 A Combustor 
       130  Fuel cell 
       140  Steel mill