Systems and methods for processing hydrogen

Abstract

The present disclosure provides a fuel cell comprising: an electrochemical circuit comprising an anode, a cathode, and an electrolyte between the anode and the cathode; a first channel comprising a first inlet and a first outlet, wherein the first channel is in fluid communication with the anode, wherein the first channel comprises one or more features, wherein the one or more features comprise (i) one or more cuts, (ii) one or more cutouts, (iii) one or more grooves, or (iv) any combination thereof; and a second channel comprising a second inlet and a second outlet, wherein the second channel is in fluid communication with the cathode.

1 . A method comprising:
 using an ammonia reformer to generate a first stream comprising hydrogen and nitrogen;   directing the first stream and a second stream comprising oxygen to a fuel cell,
 wherein the fuel cell is in fluid communication with the ammonia reformer, wherein the fuel cell comprises: 
 an electrochemical circuit comprising an anode, a cathode, and an electrolyte between the anode and the cathode; and 
 a channel in fluid communication with the anode, wherein the channel comprises an inlet configured to receive the first stream comprising nitrogen and hydrogen, 
 wherein the channel further comprises one or more features which are configured to purge nitrogen from the fuel cell while the fuel cell is generating electricity, 
 wherein a volume fraction of the hydrogen in the first stream comprises at most about 85%, wherein a volume fraction of the nitrogen in the first stream comprises at least about 15%; 
   directing the hydrogen through the channel to the anode to react with the oxygen, thereby generating electricity; and   purging nitrogen out of the fuel cell.   
     
     
         2 . The method of  claim 1 , wherein a hydrogen consumption rate of the fuel cell is at least about 20% of the hydrogen in the first stream. 
     
     
         3 . The method of  claim 1 , wherein a hydrogen consumption rate of the fuel cell is intermittently reduced to purge out at least one of hydrogen, nitrogen, or water. 
     
     
         4 . The method of  claim 1 , wherein the fuel cell comprises a plurality of channels in fluid communication with the anode, wherein the plurality of channels comprises the channel. 
     
     
         5 . The method of  claim 4 , wherein the plurality of channels comprises a stack of layers that are adjacent to one another. 
     
     
         6 . The method of  claim 1 , wherein the fuel cell further comprises a second channel in fluid communication with the anode, wherein the second channel comprises a second inlet configured to receive the first stream comprising nitrogen and hydrogen, wherein the second channel does not comprise or lacks the one or more features. 
     
     
         7 . The method of  claim 1 , wherein the fuel cell is configured to output unconverted hydrogen from the fuel cell. 
     
     
         8 . The method of  claim 7 , wherein the unconverted hydrogen is combusted to heat the ammonia reformer. 
     
     
         9 . The method of  claim 7 , wherein the unconverted hydrogen is flared. 
     
     
         10 . The method of  claim 1 , wherein the fuel cell comprises a plurality of fuel cells, wherein at least one fuel cell of the plurality of fuel cells is configured to reduce an electrical power output while others of the plurality of fuel cells maintain their respective power outputs. 
     
     
         11 . The method of  claim 1 , wherein at least part of the first stream is directed to a combustion heater to reduce a portion of the hydrogen in the first stream that is reacted in the fuel cell, thereby reducing a hydrogen consumption rate of the fuel cell, reducing the electricity generated by the fuel cell, and purging nitrogen out of the fuel cell,
 wherein the combustion heater is in thermal communication with the ammonia reformer,   wherein the at least part of the first stream is directed to the combustion heater based at least in part on a temperature of the ammonia reformer.   
     
     
         12 . The method of  claim 1 , wherein a hydrogen consumption rate of the fuel cell is intermittently reduced to purge out hydrogen, nitrogen, and water. 
     
     
         13 . The method of  claim 1 , wherein the one or more features are parallel to each other. 
     
     
         14 . The method of  claim 1 , wherein the one or more features are perpendicular to each other. 
     
     
         15 . The method of  claim 1 , wherein the one or more features are disposed at an angle relative to each other, wherein the angle ranges from about 0 degree to about 90 degrees. 
     
     
         16 . The method of  claim 1 , wherein the one or more features intersect with each other. 
     
     
         17 . The method of  claim 1 , wherein the one or more features do not intersect. 
     
     
         18 . The method of  claim 1 , wherein the one or more features have a depth ranging from about 0.01 millimeter (mm) to about 10 mm. 
     
     
         19 . The method of  claim 1 , wherein an ammonia concentration in the first stream is less than about 1 parts-per-million (ppm). 
     
     
         20 . A system comprising:
 (a) an ammonia reformer configured to convert ammonia into a first stream comprising nitrogen and hydrogen;   (b) a fuel cell in fluid communication with the ammonia reformer, wherein the fuel cell comprises:
 i. an electrochemical circuit comprising an anode, a cathode, and an electrolyte between the anode and the cathode; and 
 ii. a channel in fluid communication with the anode, wherein the channel comprises an inlet configured to receive the first stream comprising nitrogen and hydrogen, wherein the channel further comprises one or more features which are configured to purge nitrogen from the fuel cell while the fuel cell is generating electricity;
 wherein the fuel cell comprises a plurality of fuel cells, wherein at least one fuel cell of the plurality of fuel cells is configured to reduce an electrical power output while others of the plurality of fuel cells maintain their respective power outputs; and 
 
   (c) a controller comprising at least one processor configured to perform executable instructions, wherein the executable instructions are configured to:
 i. use the ammonia reformer to generate the first stream comprising hydrogen and nitrogen; 
 ii. direct a second stream comprising oxygen to the cathode; 
 iii. direct the first stream through the channel to the anode to react the hydrogen with the oxygen, thereby generating electricity; and 
 iv. direct at least part of the first stream to a combustion heater to reduce a portion of hydrogen in the first stream that is reacted in the at least one fuel cell, thereby reducing a hydrogen consumption rate of the at least one fuel cell, reducing the electrical power output of the at least one fuel cell, and purging nitrogen out of the at least one fuel cell, 
   wherein the combustion heater is in thermal communication with the ammonia reformer,   wherein the at least part of the first stream is directed to the combustion heater based at least in part on a temperature of the ammonia reformer.   
     
     
         21 . The system of  claim 20 , wherein a hydrogen consumption rate of the fuel cell is at least about 20% of the hydrogen in the first stream. 
     
     
         22 . The system of  claim 20 , wherein the executable instructions are further configured to intermittently reduce a hydrogen consumption rate of the fuel cell to purge out at least one of hydrogen, nitrogen, or water. 
     
     
         23 . The system of  claim 20 , wherein the executable instructions are further configured to intermittently reduce a hydrogen consumption rate of the fuel cell to purge out hydrogen, nitrogen, and water. 
     
     
         24 . The system of  claim 20 , wherein the fuel cell comprises a plurality of channels in fluid communication with the anode, wherein the plurality of channels comprises the channel. 
     
     
         25 . The system of  claim 24 , wherein the plurality of channels comprises a stack of layers that are adjacent to one another. 
     
     
         26 . The system of  claim 20 , wherein the fuel cell further comprises a second channel in fluid communication with the anode, wherein the second channel comprises a second inlet configured to receive the first stream comprising nitrogen and hydrogen, wherein the second channel does not comprise or lacks the one or more features. 
     
     
         27 . The system of  claim 20 , wherein the fuel cell is configured to output unconverted hydrogen from the fuel cell. 
     
     
         28 . The system of  claim 27 , wherein the unconverted hydrogen is combusted to heat the ammonia reformer. 
     
     
         29 . The system of  claim 27 , wherein the unconverted hydrogen is flared. 
     
     
         30 . The system of  claim 20 , wherein a volume fraction of the hydrogen in the first stream comprises at most about 85%, wherein a volume fraction of the nitrogen in the first stream comprises at least about 15%.