Patent Publication Number: US-2023141693-A1

Title: Hydrogen release and storage system, hydrogen release and storage method, ammonia production apparatus, 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 a steel mill. 
     Priority is claimed on Japanese Patent Application No. 2020-071758, 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 hydrogen energy. 
     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 cost as much 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 hydrogen compound member, a container that accommodates the hydrogen compound member, a heating apparatus configured to heat an inside of the container, a cooling apparatus configured to cool the inside of the container and a water supply apparatus configured to supply water to the inside of the container. 
     (2) In the hydrogen release and storage system according to (1), a stoichiometric ratio between an element other than a hydrogen element that configures the hydrogen compound member and the hydrogen element is preferably 1:1 to 3:4. 
     (3) In the hydrogen release and storage system according to (2), an element other than hydrogen may be boron. 
     (4) The hydrogen release and storage system according to any one of (1) to (3) may further include a switching apparatus that switches between a first state and a second state, the first state is a state where the heating apparatus is driven and the cooling apparatus and the water supply apparatus are stopped and a second state is a state where the heating apparatus is stopped and the cooling apparatus and the water supply apparatus are driven. 
     (5) 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 (4) is used as a hydrogen supply source and alternately has a hydrogen release step of heating the inside of the container so as to reach 150° C. or higher and releasing hydrogen from the hydrogen compound member and a hydrogen absorption step of supplying water to the inside of the container while cooling the inside of the container so as to reach lower than 150° C. and absorbing the hydrogen into the hydrogen compound member. 
     (6) 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 (4) as a hydrogen supply source. 
     (7) 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 (4) as a hydrogen supply source. 
     (8) 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 (4) as a hydrogen supply source. 
     (9) 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 (4) 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. 
    
    
     
       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 to be exemplified in the following description are simply 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 hydrogen compound member  101 , a container (reaction container)  102  that accommodates the hydrogen compound member  101 , a heating apparatus  103  configured to heat the inside of the container  102 , a cooling apparatus  104  configured to cool the inside of the container  102  and a water supply apparatus  105  configured to supply water to the container  102 . 
     The stoichiometric ratio between an element X other than a hydrogen element that configures the hydrogen compound member  101  and the 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 an element other than hydrogen include boron B. 
     In the side wall portion of the container  102 , a hydrogen release portion  106  that releases hydrogen generated from the hydrogen compound member  101  to the outside of the container  102  and an oxygen release portion  107  that releases oxygen that is generated from supplied water to the outside are provided apart from each other. 
     The heating apparatus  103  may be in direct contact with or may not be in contact with the hydrogen compound member  101  to be heated. Here, a heating apparatus that is attached to the outside of the container  102  is exemplified. As the heating apparatus  103 , a combustor, an electric heater, a steam heating apparatus and the like are exemplary examples. 
     The cooling apparatus  104  may be attached to the outside of the container  102  or accommodated in the container  102  as long as the hydrogen compound member  101  in the container  102  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  supplies a fluid containing liquid or gaseous water as a main component to the inside of the container  102 . 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. 
     The hydrogen release and storage system  100  may further include a switching apparatus (not shown) that switches between a first state where the heating apparatus  103  is driven and the cooling apparatus  104  and the water supply apparatus  105  are stopped (hydrogen release state) and a second state where the heating apparatus  103  is stopped and the cooling apparatus  104  and the water supply apparatus  105  are driven (hydrogen storage 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 almost all bonding sites of an X element that configures a hydrogen compound and in the hydrogen release state where no hydrogen elements bond to some of the bonding sites of the X element due to hydrogen release. 
     When the hydrogen release and storage system of the present embodiment is 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 (heating medium supply means)  103 A and means for adjusting the temperature of the heating medium (temperature adjustment means)  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 temperature adjustment means  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 amount of 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, 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 (cooling water supply means)  104 A and means for adjusting the temperature of the cooling water (temperature adjustment means)  104 B. In addition, the water supply apparatus  105  is composed of means for supplying a raw material water (raw material water supply means)  105 A and means for adjusting the flow rate of the raw material water to be supplied (flow rate adjustment means)  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 water flow rate 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 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. 
     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. 
     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 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 
               101  Hydrogen compound member 
               102  Container 
               103  Heating apparatus 
               103 A Heating medium supply means 
               103 B Temperature adjustment means 
               104  Cooling apparatus 
               104 A Cooling water supply means 
               104 B Temperature adjustment means 
               105  Water supply apparatus 
               105 A Raw material water supply means 
               105 B 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