Method and Device for Generating and Storing Hydrogen

Abstract

A method and device for charging a metal hydride hydrogen store ( 13 ) is described. It comprises generating gaseous hydrogen in an electrolyser ( 1 ), transporting the gaseous hydrogen to the metal hydride store and feeding the metal hydride store with the hydrogen. For having the hydrogen free of water contamination, the gaseous hydrogen is first transported under a first pressure of at least 1 MPa which pressure is then reduced by a pressure adjusting means ( 11 ) to a second, designated pressure lower to the first pressure, the second pressure being the feeding pressure to the metal hydride store. FIG. 1.

1 - 11 . (canceled) 
     
     
         12 . A method for charging a metal hydride hydrogen store ( 13 ), the method comprising:
 generating gaseous hydrogen in an electrolyser ( 1 );   transporting the gaseous hydrogen to the metal hydride store at a first pressure of at least 1 MPa;   providing a pressure adjusting means ( 11 ) for reducing the first pressure;   reducing the first pressure to a second pressure lower than the first pressure by use of the pressure adjusting means; and   feeding the metal hydride store ( 13 ) with the gaseous hydrogen at the second pressure.   
     
     
         13 . The method of  claim 12  wherein the first pressure of the gaseous hydrogen is generated in the electrolyser ( 1 ). 
     
     
         14 . The method of  claim 12  further comprising prior to reducing:
 further providing dehydrating means ( 32 ,  33 ,  34 ) for dehydrating the gaseous hydrogen; and 
 dehydrating the gaseous hydrogen by conducting it through the dehydrating means. 
 
     
     
         15 . A device for generating and storing hydrogen gas comprising:
 an electrolyser ( 1 );   a metal hydride hydrogen store ( 13 );   a conduit ( 5 ,  12 ) connecting said electrolyser to said metal hydride hydrogen store; and   a pressure adjusting device ( 11 ) which is integrated into said conduit.   
     
     
         16 . The device of  claim 15  wherein the electrolyser ( 1 ) incorporates a polymer electrolyte membrane PEM ( 4 ). 
     
     
         17 . The device of  claim 15  wherein said pressure adjusting device ( 11 ) is a pressure retention valve having an input side ( 55 ) and an output side ( 56 ) which maintains the pressure at the input side ( 55 ) at a first pressure of at least 1 MPa regardless of the second pressure at the output side ( 56 ). 
     
     
         18 . The device of  claim 15  wherein said conduit is further comprised of a first conduit ( 5 ) and a second conduit ( 12 ). 
     
     
         19 . The device of  claim 18  further comprising liquid separator means connected to said first conduit for separating water from the hydrogen gas. 
     
     
         20 . The device of  claim 19  wherein said liquid separator means further comprises:
 a radiator ( 32 ) connected to said first conduit and 
 a water collecting tank ( 33 ) connected to said radiator. 
 
     
     
         21 . The device of  claim 20  further comprising:
 a liquid level sensor ( 34 ) connected to said water collecting tank; 
 a valve ( 35 ) connected to and controlled by said liquid level sensor; and 
 a pressure reducer ( 36 ) connected to said valve and to said water collecting tank and controlled by said liquid level sensor. 
 
     
     
         22 . The device of  claim 20  further comprising a water vapour separator which functions as a chemical absorber ( 44 ), said separator being connected to said water collecting tank. 
     
     
         23 . The device of  claim 22  further comprising a safety valve connected between said water collecting tank and said water vapour separator. 
     
     
         24 . The device of  claim 22  further comprising a pressure sensitive switch means ( 45 ) connected between said water vapour separator and said pressure adjusting device for determining whether the first pressure has fallen below a first threshold. 
     
     
         25 . The device of  claim 18  further comprising a pressure sensitive switch means ( 48 ) connected to said second conduit between said pressure adjusting device and said metal hydride store for determining whether the second pressure is above a second threshold. 
     
     
         26 . A device for generating and storing hydrogen gas comprising:
 an electronic control device ( 19 );   a supply unit ( 22 ) connected to said electronic control device;   a PEM electrolysis cell ( 1 ) having a cathode compartment ( 2 ) and an anode compartment ( 3 ), the cathode compartment of which is connected to said supply unit;   a water tank ( 17 ) having a water supply inlet ( 25 ), a water level sensor ( 26 ) connected by a control line ( 27 ) to said electronic control device, an oxygen outlet ( 28 ), a back water line ( 21 ) connected to the anode compartment of said cell and a recycling line ( 37 );   a pump ( 18 ) controlled by said electronic control device, said pump being connected to said water tank and to the anode compartment of said cell;   a first conduit ( 5 ) connected to the anode compartment of said cell;   a radiator having an input and an output, being connected at its input to said first conduit;   a water collecting tank ( 33 ) having an input and two outputs, said water collecting tank being connected at its input to the output of said radiator;   a pressure reducer ( 36 ) connected to the first output of said water tank;   a first valve ( 35 ) connected to said pressure reducer;   a recycling line connected on one end to said first valve and on the other end to said water tank;   a purging line connect to said recycling line and to said first valve;   a liquid level sensor ( 34 ) located inside said water collecting tank and electronically connected to said first valve;   a safety valve ( 43 ) connected to the second output of said water collecting tank;   a chemical absorber ( 44 ) having an input and an output, connected at its input to the second output of said water collecting tank and to said safety valve;   a first pressure sensitive switch ( 45 ) connected to the output of said chemical absorber and controlled by said electronic control device;   a pressure adjusting device ( 11 ) having an input and an output connected at its input to the output of said water collecting tank and to said pressure sensitive switch ( 45 );   a second conduit ( 12 ) connected to the output of said pressure adjusting device;   a second pressure sensitive switch ( 48 ) connected to said second conduit and controlled by said electronic control device;   a conduit flushing valve ( 49 ) having an input and an output connected at its input to said second conduit;   a mounting sensor ( 5 ) connected to the output of said conduit flushing valve and controlled by said electronic control device; and   a metal hydride store ( 13 ) connected to the output of said conduit flushing valve.