Apparatus for the electrical production of hydrogen

Abstract

An apparatus for the electrical production of hydrogen from water includes an electrolyzer ( 1 ) of the PEM type. The electrolyzer ( 1 ) has an inlet ( 2 ) for the introduction of water and a first outlet ( 3 ) for the hydrogen which is enriched with water and/or water vapor and is produced in the electrolyzer ( 1 ) and also a second outlet ( 4 ) for oxygen. A water separation device ( 7 ) which has at least a thermal separation stage ( 10 ) adjoins the electrolyzer ( 1 ).

1 . An apparatus for the electrical production of hydrogen from water, the apparatus comprising:
 an electrolyzer of the PEM type, which has an inlet for introducing water and a first outlet for the hydrogen enriched with water and/or water vapor and produced in the electrolyzer, as well as a second outlet for oxygen and water; and   a water separation device with an inlet connected to the first outlet of the electrolyzer by means of a line and with a gas-carrying outlet leading to a hydrogen removal port in or at the apparatus, wherein the water separation device comprises a thermal separation stage.   
     
     
         2 . An apparatus in accordance with  claim 1 , wherein the water separation stage further comprises a second separation stage wherein the thermal separation stage is followed by the second separation stage. 
     
     
         3 . An apparatus in accordance with  claim 2 , wherein the second separation stage is also a thermal separation stage such that there are first and second thermal separation stages. 
     
     
         4 . An apparatus in accordance with  claim 3 , further comprising a common cooling circuit wherein the first and second thermal separation stages are connected to the common cooling circuit. 
     
     
         5 . An apparatus in accordance with  claim 2 , wherein the second separation stage has a pressure swing adsorption apparatus. 
     
     
         6 . An apparatus in accordance with  claim 1 , further comprising a mechanical preseparator between the first outlet of the electrolyzer and the inlet of the thermal separation stage. 
     
     
         7 . An apparatus in accordance with  claim 6 , wherein the water separated in the separation stage is introduced into the preseparator via return lines. 
     
     
         8 . An apparatus in accordance with  claim 7 , wherein the return lines are provided with shut-off valves and a bypass line, which bypasses the preseparator and can be shut off by means of a valve, and wherein gas-carrying inlet and outlet lines of the preseparator can be shut off by means of valves. 
     
     
         9 . An apparatus in accordance with  claim 7 , wherein the preseparator is connected to the inlet for introducing water by means of a line in the form of a return line that can be shut off by means of a valve. 
     
     
         10 . An apparatus in accordance with  claim 1 , wherein the water separation device has a water-carrying outlet of at least the first separation stage, which said outlet is connected to the inlet of the electrolyzer for returning the water by means of a line at least from time to time. 
     
     
         11 . An apparatus in accordance with  claim 1 , wherein the thermal separation stage has an electrically operated cooling apparatus. 
     
     
         12 . An apparatus in accordance with  claim 11 , wherein the cooling apparatus comprises an absorber cooling apparatus, a compressor cooling apparatus or a cooling apparatus operated with Peltier elements. 
     
     
         13 . An apparatus in accordance with  claim 1 , wherein the separation stage is designed such that hydrogen arriving from the electrolyzer and enriched with water and/or hydrogen is cooled to a temperature below 5° C. and above the freezing point. 
     
     
         14 . An apparatus in accordance with  claim 2 , wherein the second separation stage is a thermal separation stage, which is designed such that the hydrogen discharged from the first separation stage and enriched with water and/or water vapor is cooled to below 0° C. 
     
     
         15 . An apparatus in accordance with  claim 2 , wherein the second separation stage is a thermal separation stage and is operated intermittently. 
     
     
         16 . An apparatus in accordance with  claim 1 , wherein hydrogen that is produced is maintained under a pressure of 20 bar or more. 
     
     
         17 . An electrical hydrogen from water production apparatus comprising:
 a polymer electrolyte membrane electrolyzer comprising an electrolyzer body with an electrolyzer inlet for introducing water, an electrolyzer first outlet for hydrogen enriched with water and/or water vapor and a second electrolyzer outlet for oxygen and water;   an electrolyzer outlet line; and   a water separator with a separator inlet connected to the electrolyzer first outlet via said electrolyzer outlet line and with a gas-carrying outlet leading to a hydrogen removal port, the water separator comprising a thermal separation stage.   
     
     
         18 . An apparatus in accordance with  claim 17 , wherein said water separator further comprises another separation stage wherein the thermal separation stage is followed by the another separation stage. 
     
     
         19 . An apparatus in accordance with  claim 18 , wherein the another separation stage is also a thermal separation stage such that there are first and second thermal separation stages. 
     
     
         20 . An apparatus in accordance with  claim 19 , further comprising a cooling apparatus cooling the first and second thermal separation stages.