Patent Publication Number: US-2021188630-A1

Title: Hydrogen purification/storage apparatus and method using liquid organic hydrogen carrier

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims, under 35 U.S.C. § 119(a), the benefit of priority to Korean Patent Application No. 10-2019-0170353 filed on Dec. 19, 2019, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     (a) Technical Field 
     The present disclosure relates to a hydrogen purification/storage apparatus and method using a liquid organic hydrogen carrier (LOHC). 
     (b) Background Art 
     Demand for new renewable energy is high due to depletion of fossil fuels and environmental pollution; however, new renewable energy has problems of imbalance between supply and demand, a long distance between a production place and a demand place, etc., and therefore an efficient energy storage method is required. For this reason, hydrogen, which has a high ratio of energy density to weight and is capable of stably storing a large amount of energy for a long time, has attracted attention as a new renewable energy carrier. In particular, a fuel cell and a hydrogen combustion apparatus use hydrogen as a reaction gas. In order to use the fuel cell and the hydrogen combustion apparatus in vehicles or various kinds of electronic products, for example, technology capable of stably and continuously supply high-purity hydrogen is required. 
     In an apparatus using hydrogen, a method of receiving hydrogen from a separately installed hydrogen purification/storage apparatus (hydrogen supply apparatus) whenever hydrogen is necessary may be used in order to supply hydrogen. Representative examples thereof include a compressed hydrogen storage method and a liquefied hydrogen storage method. These methods may have issues related to price and safety in transporting hydrogen from a hydrogen production place to a hydrogen demand place. 
     In addition, a method of loading a material capable of storing and generating hydrogen in an apparatus using hydrogen, generating hydrogen through reaction of the material, and supplying the same may be used. A method of using a metal hydride, a method of using absorbents/carbon, and a chemical hydrogen storage method have been proposed as examples of this method, and research on hydrogen storage technology using various chemical hydrides, such as ammonia borane, a silane compound, and formic acid, has been conducted. 
     Research on a material capable of storing hydrogen has been actively conducted; however, research on an overall process or system capable of selectively storing hydrogen from a mixed gas using the same to simultaneously perform hydrogen purification and storage is insufficient. 
     PRIOR ART DOCUMENT 
     [Patent Document] 
     (Patent Document 1) Korean Registered Patent No. 10-1845515 
     The above information disclosed in this Background section is provided only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY OF THE DISCLOSURE 
     The present invention has been made in an effort to solve the above-described problems associated with the prior art. 
     It is an object of the present invention to provide a hydrogen purification/storage apparatus and method capable of economically storing a large amount of hydrogen. 
     It is another object of the present invention to provide a hydrogen purification/storage apparatus and method capable of using hydrogen that is supplied irrespective of the state thereof. 
     The objects of the present invention are not limited to those described above. The objects of the present invention will be clearly understood from the following description and could be implemented by means defined in the claims and a combination thereof. 
     In one aspect, the present invention provides a hydrogen purification/storage apparatus including a hydrogen supply unit, a reaction unit connected to the hydrogen supply unit via a hydrogen supply line, the reaction unit including a hydrogen storage material and a catalyst configured to accelerate hydrogenation of the hydrogen storage material, and a compressor installed in the hydrogen supply line, the compressor being configured to compress hydrogen supplied from the hydrogen supply unit, wherein the hydrogen storage material includes a liquid organic hydrogen carrier (LOHC). 
     The hydrogen supply unit may supply pure hydrogen or a mixed gas including hydrogen and an impurity selected from the group consisting of nitrogen (N 2 ), carbon oxide, hydrocarbon, oxygen (O 2 ), and a combination thereof. 
     The hydrogen purification/storage apparatus may further include no hydrogen purification unit. 
     The hydrogen supply line may include a first hydrogen supply line configured to interconnect the hydrogen supply unit and the compressor, a second hydrogen supply line configured to interconnect the compressor and the reaction unit, and a third hydrogen supply line configured to interconnect the compressor and the reaction unit along a path different from the path of the second hydrogen supply line, the third hydrogen supply line having a buffer tank. 
     The hydrogen supply line may further include a bypass line configured to interconnect the first hydrogen supply line and the second hydrogen supply line, the bypass line being configured to bypass the compressor. 
     When the pressure of hydrogen supplied from the hydrogen supply unit is equal to or higher than a predetermined pressure value, a valve installed in each of the first hydrogen supply line and the second hydrogen supply line may be opened such that the hydrogen is supplied to the first hydrogen supply line and the second hydrogen supply line. 
     When the pressure of hydrogen supplied from the hydrogen supply unit is lower than the predetermined pressure value, the compressor may compress the hydrogen and supply the compressed hydrogen, and a valve installed in each of the first hydrogen supply line and the third hydrogen supply line may be opened such that the compressed hydrogen is supplied to the first hydrogen supply line and the third hydrogen supply line. 
     The liquid organic hydrogen carrier (LOHC) may include any one selected from the group consisting of biphenyl dissolved in diphenylmethane, N-ethylcarbazole, dibenzyl toluene, toluene, and a combination thereof. 
     The catalyst may include a catalyst metal selected from the group consisting of ruthenium (Ru), nickel (Ni), palladium (Pd), platinum (Pt), and a combination thereof. 
     The reaction unit may be operated at a temperature of 20° C. to 150° C. and a pressure of 10 bar to 50 bar. 
     The reaction between the hydrogen storage material and the hydrogen in the reaction unit may be performed in a closed system. 
     The hydrogen purification/storage apparatus may further include a pressure measurement unit installed at the reaction unit, the pressure measurement unit being configured to measure the pressure of the reaction unit. 
     The hydrogen purification/storage apparatus may further include a storage unit connected to the reaction unit, the storage unit being configured to store a product in the reaction unit. 
     The hydrogen purification/storage apparatus may further include a hydrogen storage material supply unit connected to the reaction unit, the hydrogen storage material supply unit being configured to supply a hydrogen storage material to the reaction unit. 
     The hydrogen purification/storage apparatus may further include a purge gas supply unit communicating with the second hydrogen supply line, the purge gas supply unit being configured to supply a purge gas to the reaction unit, wherein residual gas in the reaction unit may be discharged outside via the third hydrogen supply line and a purge gas discharge line communicating therewith by the purge gas. 
     In another aspect, the present invention provides a hydrogen purification/storage method including reacting hydrogen supplied from the hydrogen supply unit to the reaction unit and a hydrogen storage material in the reaction unit with each other. 
     When the pressure of hydrogen supplied from the hydrogen supply unit is equal to or higher than a predetermined pressure value, the hydrogen may be supplied to a first hydrogen supply line configured to interconnect the hydrogen supply unit and the compressor and a second hydrogen supply line configured to interconnect the compressor and the reaction unit. 
     When the pressure of hydrogen supplied from the hydrogen supply unit is lower than the predetermined pressure value, the hydrogen may be compressed and supplied to the first hydrogen supply line and a third hydrogen supply line configured to interconnect the compressor and the reaction unit along a path different from the path of the second hydrogen supply line, the third hydrogen supply line having a buffer tank. 
     The hydrogen purification/storage method may further include injecting a purge gas into the reaction unit to discharge residual gas in the reaction unit to the outside before supplying hydrogen to the hydrogen supply unit. 
     The reaction between the hydrogen storage material and the hydrogen in the reaction unit may be performed in a closed system, and when the pressure in the reaction unit reaches a predetermined value, the reaction unit may be opened to move a product in the reaction unit to a storage unit connected to the reaction unit. 
     A new hydrogen storage material may be supplied to the reaction unit after the product in the reaction unit is moved to the storage unit. 
     Other aspects and preferred embodiments of the invention are discussed infra. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated in the accompanying drawings which are given hereinbelow by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a process view schematically showing a hydrogen purification/storage apparatus using a liquid organic hydrogen carrier (LOHC) according to the present invention; 
         FIG. 2  is a reference view illustrating an embodiment of a hydrogen purification/storage apparatus and method according to the present invention; 
         FIG. 3  is a reference view illustrating another embodiment of the hydrogen purification/storage apparatus and method according to the present invention; 
         FIG. 4  is a reference view illustrating a purge process in the hydrogen purification/storage apparatus and method according to the present invention; 
         FIG. 5  is a graph showing the profile of pressure in a reaction unit when hydrogen is stored using a process of  FIG. 2 ; and 
         FIG. 6  is a graph showing the profile of pressure in the reaction unit when hydrogen is stored using a process of  FIG. 3 . 
     
    
    
     It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment. 
     In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
     DETAILED DESCRIPTION 
     The objects described above, and other objects, features and advantages will be clearly understood from the following preferred embodiments with reference to the attached drawings. However, the present invention is not limited to the embodiments and will be embodied in different forms. The embodiments are suggested only to offer thorough and complete understanding of the disclosed contents and sufficiently inform those skilled in the art of the technical concept of the present invention. 
     Like reference numbers refer to like elements throughout the description of the figures. In the drawings, the sizes of structures are exaggerated for clarity. It will be understood that, although the terms “first”, “second”, etc. may be used herein to describe various elements, corresponding elements should not be understood to be limited by these terms, which are used only to distinguish one element from another. For example, within the scope defined by the present invention, a first element may be referred to as a second element and similarly, a second element may be referred to as a first element. Singular forms are intended to include plural forms as well, unless the context clearly indicates otherwise. 
     It will be further understood that the terms “comprises”, “has” and the like, when used in this specification, specify the presence of stated features, numbers, steps, operations, elements, components or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof. In addition, it will be understood that, when an element such as a layer, film, region or substrate is referred to as being “on” another element, it can be directly on the other element or an intervening element may also be present. It will also be understood that, when an element such as a layer, film, region or substrate is referred to as being “under” another element, it can be directly under the other element or an intervening element may also be present. 
     Unless the context clearly indicates otherwise, all numbers, figures and/or expressions that represent ingredients, reaction conditions, polymer compositions and amounts of mixtures used in the specification are approximations that reflect various uncertainties of measurement occurring inherently in obtaining these figures among other things. For this reason, it should be understood that, in all cases, the term “about” should modify all numbers, figures and/or expressions. In addition, when numeric ranges are disclosed in the description, these ranges are continuous and include all numbers from the minimum to the maximum including the maximum within the range unless otherwise defined. Furthermore, when the range refers to an integer, it includes all integers from the minimum to the maximum including the maximum within the range, unless otherwise defined. 
       FIG. 1  is a process view schematically showing a hydrogen purification/storage apparatus using a liquid organic hydrogen carrier (LOHC) according to the present invention. Referring to this figure, the hydrogen purification/storage apparatus includes a hydrogen supply unit  10 , a reaction unit  30  connected to the hydrogen supply unit  10  via a hydrogen supply line  20 , the reaction unit  30  including a hydrogen storage material and a catalyst configured to accelerate hydrogenation of the hydrogen storage material, and a compressor  40  installed in the hydrogen supply line  20 , the compressor  40  being configured to compress hydrogen supplied from the hydrogen supply unit  10 . 
     The hydrogen supply unit  10  may supply pure hydrogen. However, the present invention is not limited thereto. The hydrogen supply unit  10  may supply a mixture of hydrogen and an impurity selected from the group consisting of nitrogen (N 2 ), carbon oxide, hydrocarbon, oxygen (O 2 ), and a combination thereof. In the present invention, hydrogen is stored through hydrogenation of a liquid organic hydrogen carrier (LOHC). That is, even in the case in which the above mixed gas is supplied, only hydrogen selectively reacts with the liquid organic hydrogen carrier (LOHC), and therefore there is no limitation in supply gas. Hereinafter, in describing the present invention, “hydrogen” may mean a kind of feed supplied from the hydrogen supply unit  10  to the reaction unit  30 , and the feed may be interpreted as pure hydrogen or the above mixed gas. 
     Also, in the present invention, since the liquid organic hydrogen carrier (LOHC) selectively stores hydrogen, as described above, a separate purification unit configured to purify supply gas is not required. Conventionally, in the case in which a mixed gas including hydrogen and an impurity is used as the feed, the hydrogen is purified from the mixed gas through pressure swing adsorption using a purification unit, is compressed, and is stored. In the present invention, hydrogen is selectively stored through hydrogenation of the liquid organic hydrogen carrier (LOHC), and therefore it is not necessary to provide the above purification unit or to perform a purification process. In storing high-purity hydrogen, therefore, the process may be simplified. 
     The hydrogen supply line  20  includes a first hydrogen supply line  21  configured to interconnect the hydrogen supply unit  10  and the compressor  40 , a second hydrogen supply line  22  configured to interconnect the compressor  40  and the reaction unit  30 , and a third hydrogen supply line  23  configured to interconnect the compressor  40  and the reaction unit  30  along a path different from the path of the second hydrogen supply line  22 , the third hydrogen supply line  23  having a buffer tank  90 . 
     In the present invention, the reason that the second hydrogen supply line  22  and the third hydrogen supply line  23  are configured as different paths is that it is necessary to select one of the paths depending on the pressure of the feed supplied from the hydrogen supply unit  10 . Consequently, the hydrogen purification/storage apparatus according to the present invention is applicable irrespective of sources from which the feed is supplied. The detailed description thereof will be given below. 
     The hydrogen supply line  20  may further include a bypass line  24  configured to interconnect the first hydrogen supply line  21  and the second hydrogen supply line  22 , the bypass line  24  being configured to bypass the compressor  40 . This line is also provided to select a supply path of the feed depending on the pressure of the feed. 
     In the reaction unit  30 , hydrogenation of the hydrogen storage material is performed. 
     The hydrogen storage material may be a material capable of reacting with a material including hydrogen (H) atoms, storing the hydrogen atoms through chemical bonding, and reversibly discharging hydrogen (H 2 ) when predetermined energy is applied. 
     The present invention is characterized in that a liquid organic hydrogen carrier (LOHC) is used as the hydrogen storage material. Consequently, it is possible to exclude a purification process, which is required in conventional hydrogen production and hydrogen purification/storage methods, and to safely supply hydrogen in large quantities, since hydrogen is capable of being stored in a liquid state. 
     The liquid organic hydrogen carrier (LOHC) may include any one selected from the group consisting of biphenyl dissolved in diphenylmethane, N-ethylcarbazole, dibenzyl toluene, toluene, and a combination thereof. The reaction unit  30  may include a catalyst configured to accelerate hydrogenation of the hydrogen storage material. 
     The catalyst may include a catalyst metal selected from the group consisting of ruthenium (Ru), nickel (Ni), and a combination thereof. In the catalyst, the catalyst metal may be supported on a ceramic support, such as alumina (Al 2 O 3 ), zirconia (ZrO 2 ), or ceria (CeO 2 ), or a carbon support, such as carbon, carbon nanotube, or graphene. 
     In the reaction unit  30 , hydrogenation of the hydrogen storage material may be performed at a temperature of 80° C. to 150° C. and a pressure of 30 bar to 50 bar. If the temperature of the reaction unit  30  is lower than the above range, the speed of hydrogenation may be reduced. If the temperature of the reaction unit  30  is higher than the above range, a compound may be decomposed. Also, if the pressure of the reaction unit  30  is lower than the above range, the speed of hydrogenation may be reduced. If the pressure of the reaction unit  30  is higher than the above range, economic effectiveness may be lowered. 
     Hydrogenation of the hydrogen storage material in the reaction unit  30  may be performed in a closed system. Consequently, the reaction unit  30  may be a kind of batch reactor. 
     The reaction unit  30  may further include a pressure measurement unit  31  configured to measure the pressure thereof. Since the reaction unit  30  is a closed system, as described above, the pressure in the reaction unit  30  becomes uniform when the hydrogenation is in equilibrium. Consequently, it is possible to determine whether the hydrogenation is finished by measuring the pressure of the reaction unit  30  in real time or at regular intervals using the pressure measurement unit  31 . 
     The hydrogen purification/storage apparatus according to the present invention may further include a storage unit  50  connected to the reaction unit  30 , the storage unit  50  being configured to store a product in the reaction unit  30 . 
     When hydrogenation is finished, as described above, the reaction unit  30  may be opened, and a product in the reaction unit  30  may be moved to the storage unit  50  in order to store the product. 
     The storage unit  50  may be a storage tank or a transport means including a storage tank. However, the present invention is not limited thereto. Any storage unit  50  may be used as long as it is possible to provide sufficient space to store the product in the reaction unit  30 . 
     The hydrogen purification/storage apparatus according to the present invention may further include a hydrogen storage material supply unit  60  connected to the reaction unit  30 , the hydrogen storage material supply unit  60  being configured to supply a hydrogen storage material to the reaction unit  30 . 
     After the product in the reaction unit  30  is moved to the storage unit  50 , as described above, the hydrogen storage material supply unit  60  and the reaction unit  30  may communicate with each other to supply a new hydrogen storage material to the reaction unit  30 . 
     The hydrogen purification/storage apparatus according to the present invention may further include a construction configured to supply a purge gas used to remove gas remaining in the reaction unit  30 . When the hydrogen purification/storage apparatus is operated for the first time or before a new batch is commenced, it is necessary to remove gas remaining in the reaction unit  30 , thereby further improving hydrogen storage efficiency. 
     The hydrogen purification/storage apparatus may further include a purge gas supply unit  70  communicating with the second hydrogen supply line  22 , the purge gas supply unit  70  being configured to supply a purge gas to the reaction unit  30 . The purge gas may be hydrogen (H 2 ) and/or nitrogen (N 2 ) although not being particularly restricted. 
     The purge gas may be supplied to the reaction unit  30  via the second hydrogen supply line  22 , and the purge gas and residual gas in the reaction unit  30  are discharged to the outside via the third hydrogen supply line  23  and a purge gas discharge line  80  communicating therewith. 
     Hereinafter, a method of storing hydrogen using the hydrogen purification/storage apparatus will be described in detail. 
     A hydrogen purification/storage method using a liquid organic hydrogen carrier (LOHC) according to the present invention may include a step of reacting hydrogen supplied from the hydrogen supply unit  10  to the reaction unit  30  and a hydrogen storage material in the reaction unit  30  with each other. 
     At this time, the reaction between the hydrogen storage material and the hydrogen in the reaction unit  30  may be performed in a closed system. When the pressure in the reaction unit  30  reaches a predetermined value, the reaction unit  30  may be opened, and a product in the reaction unit  30  may be moved to the storage unit  50 . Here, the “predetermined value” means equilibrium pressure of the hydrogenation or pressure approximate thereto, and an appropriate value may be selected in consideration of the kind of a hydrogen storage material that is used and the pressure of hydrogen that is supplied to the reaction unit  30 . 
     The hydrogen purification/storage method may further include a step of allowing the hydrogen storage material supply unit  60  and the reaction unit  30  to communicate with each other to supply a new hydrogen storage material to the reaction unit  30  after moving the product in the reaction unit  30  to the storage unit  50 . 
     In the present invention, one of the hydrogen supply lines may be appropriately selected depending on the pressure of a feed supplied from the hydrogen supply unit  10 , and then the above process may be performed.  FIGS. 2 and 3  are reference views illustrating the same. 
       FIG. 2  is a reference view illustrating the hydrogen purification/storage apparatus and method in the case in which the pressure of a feed supplied from the hydrogen supply unit  10  is equal to or higher than a predetermined value. Here, the “predetermined value” is not particularly restricted, and an appropriate value may be selected in consideration of operation pressure of the reaction unit  30 . In addition, the pressure of the feed may be measured using a pressure measurement instrument installed at the hydrogen supply unit  10 . 
     First, a feed is supplied from the hydrogen supply unit  10  to the compressor  40  via the first hydrogen supply line  21  ( 101 ). 
     The compressor  40  supplies the feed to the second hydrogen supply line  22  without compressing the feed, or compresses the feed to the extent to which the pressure of the feed to be reduced during movement to the reaction unit  30  is offset and supplies the feed to the second hydrogen supply line  22  such that the feed is supplied to the reaction unit  30  ( 102 ). 
     In the case in which the pressure of the feed is sufficiently higher than the predetermined value, however, the feed may flow to the second hydrogen supply line  22  via the bypass line  24  ( 101 ′). 
     When the feed is supplied to the reaction unit  30 , hydrogenation in the reaction unit  30  is performed in a closed system, as previously described. At this time, the pressure in the reaction unit  30  is measured by the pressure measurement unit  31 . 
     When there is no change in the pressure in the reaction unit  30 , which means that the hydrogenation is in equilibrium, the reaction unit  30  is opened, and a product in the reaction unit  30  is discharged to the storage unit  50  ( 103 ). 
     Subsequently, the hydrogen storage material supply unit  60  and the reaction unit  30  communicate with each other, a new hydrogen storage material is supplied to the reaction unit  30  ( 104 ), and the above process is repeated. 
       FIG. 3  is a reference view illustrating the hydrogen purification/storage apparatus and method in the case in which the pressure of a feed supplied from the hydrogen supply unit  10  is lower than a predetermined value. 
     First, a feed is supplied from the hydrogen supply unit  10  to the compressor  40  via the first hydrogen supply line  21  ( 201 ). 
     The compressor  40  compresses the feed and supplies the feed to the third hydrogen supply line  23  ( 202 ). At this time, the extent to which the feed is compressed by the compressor  40  is not particularly restricted. The feed may be compressed to the extent to which the pressure of the reaction unit  30  satisfies the above pressure range when the feed is supplied to the reaction unit  30 . 
     The feed introduced into the third hydrogen supply line  23  is supplied to the reaction unit  30  via the buffer tank  90  ( 203 ). The buffer tank  90  is configured to offset excessive pressure of the feed. 
     When the feed is supplied to the reaction unit  30 , hydrogenation in the reaction unit  30  is performed in a closed system, as previously described. At this time, the pressure in the reaction unit  30  is measured by the pressure measurement unit  31 . 
     When there is no change in the pressure in the reaction unit  30 , which means that the hydrogenation is in equilibrium, the reaction unit  30  is opened, and a product in the reaction unit  30  is discharged to the storage unit  50  ( 204 ). 
     Subsequently, the hydrogen storage material supply unit  60  and the reaction unit  30  communicate with each other, a new hydrogen storage material is supplied to the reaction unit  30  ( 205 ), and the above process is repeated. 
       FIG. 4  is a reference view illustrating a purge process of removing gas remaining in the reaction unit  30  when the hydrogen purification/storage apparatus is operated for the first time or before a new batch is commenced. 
     A purge gas supplied from the purge gas supply unit  70  is introduced into the reaction unit  30  via the second hydrogen supply line  22  ( 301 ). 
     The purge gas and residual gas in the reaction unit  30  pushed thereby are discharged through the third hydrogen supply line  23  ( 302 ). The purge gas and the residual gas pass through the buffer tank  90 , by which the pressure of the purge gas and the residual gas is increased, and are discharged to the outside through the purge gas discharge line  80  communicating with the third hydrogen supply line  23  ( 303 ). 
     The processes described with reference to  FIGS. 2 to 4  may be realized by opening and closing a valve installed in each line. The valve may be automatically or manually opened and closed. 
     Hereinafter, the present invention will be described in more detail based on concrete examples. However, these examples are provided only for illustrating the present invention, and the scope of the present invention is not limited thereby. 
     A mixed gas including about 75 mol % of hydrogen (H 2 ) and about 25 mol % of nitrogen (N 2 ) was used as a feed, and hydrogen was stored through the processes shown in  FIGS. 2 and 3 . At this time, biphenyl dissolved in diphenylmethane was used as a hydrogen storage material, and Ru/Al 2 O 3  was used as a catalyst. In addition, the reaction unit  30  was operated at about 120° C. and about 30 bar. 
     The pressure in the reaction unit  30  was measured in real time, and ingredients of the gas remaining in the reaction unit  30  when there was no change in pressure as the result of hydrogenation being in equilibrium were measured by gas chromatography (GC). 
       FIG. 5  is a graph showing the profile of pressure in the reaction unit  30  when hydrogen is stored using the process of  FIG. 2 . Ingredients of the gas remaining in the reaction unit  30  when there was no change in internal pressure of the reaction unit  30  are shown in Table 1 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Classification 
                 Hydrogen [mol %] 
                 Nitrogen [mol %] 
               
               
                   
               
             
            
               
                 Feed 
                 75 
                 25 
               
               
                 Residual gas 
                 18 
                 82 
               
               
                   
               
            
           
         
       
     
       FIG. 6  is a graph showing the profile of pressure in the reaction unit  30  when hydrogen is stored using the process of  FIG. 3 . Ingredients of the gas remaining in the reaction unit  30  when there was no change in internal pressure of the reaction unit  30  are shown in Table 2 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Classification 
                 Hydrogen [mol %] 
                 Nitrogen [mol %] 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Feed 
                 75 
                 25 
               
               
                 Residual gas 
                 13.36 
                 86.64 
               
               
                   
               
            
           
         
       
     
     Referring to Table 1 and Table 2 above, it can be seen that mol % of the hydrogen included in the residual gas after hydrogenation is finished was remarkably reduced, whereby most of the hydrogen in the feed was stored in the hydrogen storage material. 
     As is apparent from the foregoing, the hydrogen purification/storage apparatus and method according to the present invention are capable of economically storing a large amount of hydrogen, whereby it is possible to secure price competitiveness of hydrogen provided to consumers. 
     The hydrogen purification/storage apparatus and method according to the present invention are capable of using by-product hydrogen including hydrocarbon without change in addition to pure hydrogen, whereby it is possible to further simplify the process. 
     The effects of the present invention are not limited to those mentioned above. It should be understood that the effects of the present invention include all effects that can be inferred from the foregoing description of the present invention. 
     The embodiments of the present invention have been described with reference to the accompanying drawings. However, it will be apparent to those skilled in the art that the present invention may be embodied in specific forms other than those set forth herein without departing from the spirit and essential characteristics of the present invention. Therefore, the above embodiments should be construed in all aspects as illustrative and not restrictive.