Energy recovery from electrolysis compression for use in water circulation

Abstract

The following disclosure relates to electrolysis systems having an electrolysis cell stack and a fluids processing system (e.g., an oxygen and water gas separator). In certain examples, a portion of the fluids processing system is configured to operate at a reduced (lower) pressure than the electrolysis cell stack within the electrochemical processing system through the use of a recovery turbine positioned between the electrolysis cell stack and the oxygen and water gas separator along a fluids transfer line, wherein the recovery turbine is configured to reduce a pressure within the fluids transfer line from an elevated pressure at the electrolysis cell stack to the lower pressure at the separator.

1 . An electrochemical system comprising:
 an electrochemical stack comprising a plurality of electrochemical cells, the electrochemical stack configured to receive water and generate oxygen gas and hydrogen gas through a water splitting reaction within the electrochemical stack;   an oxygen gas and water separator configured to receive unreacted water and the generated oxygen gas from the electrochemical stack and separate at least a portion of the generated oxygen gas from the unreacted water;   a recovery turbine positioned between the electrochemical stack and the oxygen gas and water separator;   a first fluids transfer line connecting the electrochemical stack and the recovery turbine; and   a second fluids transfer line connecting the recovery turbine and the oxygen gas and water separator,   wherein the electrochemical stack and first fluids transfer line are configured to operate at an elevated pressure greater than atmospheric pressure,   wherein the oxygen gas and water separator and second fluids transfer line are configured to operate at a lower pressure than the electrochemical stack, and   wherein the recovery turbine is configured to reduce the elevated pressure within the first fluids transfer line to the lower pressure within the second fluids transfer line.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The electrochemical system of  claim 1 , further comprising:
 a water pump positioned between the oxygen gas and water separator and the electrochemical stack;   a first water transfer line configured to supply water from the oxygen gas and water separator to the water pump; and   a second water transfer line configured to supply water from the water pump to the electrochemical stack,   wherein the water pump is configured to step up a pressure in the first water transfer line from the lower pressure to the elevated pressure in the second water transfer line.   
     
     
         5 . The electrochemical system of  claim 4 , wherein energy is generated at the recovery turbine through the reduction in pressure from the elevated pressure to the lower pressure, and
 wherein at least a portion of the generated energy is configured to be provided to the water pump to assist in operation of the water pump.   
     
     
         6 . The electrochemical system of  claim 5 , wherein the generated energy provides 100% of an energy required to operate the water pump during operation of the electrochemical system. 
     
     
         7 . The electrochemical system of  claim 5 , wherein at least a portion of the generated energy is configured to be provided to at least one additional component of the electrochemical system to assist in operation of the at least one additional component of the electrochemical system. 
     
     
         8 . The electrochemical system of  claim 7 , wherein the at least one additional component of the electrochemical system is the electrochemical stack. 
     
     
         9 . The electrochemical system of  claim 1 , further comprising:
 a back pressure device; and   a gas line connecting the back pressure device and the oxygen gas and water separator,   wherein the back pressure device is configured to release gas from the oxygen gas and water separator to atmosphere via the gas line, therein assisting in controlling an operating pressure at the oxygen gas and water separator.   
     
     
         10 . The electrochemical system of  claim 1 , further comprising:
 a controller in communication with the electrochemical stack, the recovery turbine, and/or the oxygen gas and water separator via a connected network.   
     
     
         11 . The electrochemical system of  claim 10 , wherein the controller is configured to provide instructions to adjust an operating pressure of the electrochemical stack or the oxygen gas and water separator. 
     
     
         12 . The electrochemical system of  claim 10 , wherein the controller is configured to provide instructions to adjust operation of the recovery turbine to increase or decrease a step down in pressure between the electrochemical stack and the oxygen gas and water separator. 
     
     
         13 . The electrochemical system of  claim 1 , wherein the elevated pressure is in a range of 8-40 atm, and
 wherein the lower pressure is greater than 0 atm and less than or equal to 10 atm.   
     
     
         14 . (canceled) 
     
     
         15 . A fluids processing system in communication with an electrochemical stack of an electrochemical system, the fluids processing system comprising:
 a recovery turbine configured to receive unreacted water and a generated oxygen gas from the electrochemical stack; and   an oxygen gas and water separator configured to separate at least a portion of the generated oxygen gas from the unreacted water; and   a fluids transfer line connecting the recovery turbine and the oxygen gas and water separator,   wherein the oxygen gas and water separator and fluids transfer line are configured to operate at a lower pressure than an elevated pressure of the electrochemical stack, and   wherein the recovery turbine is configured to reduce the elevated pressure of the electrochemical stack to the lower pressure within the fluids transfer line and oxygen gas and water separator.   
     
     
         16 - 17 . (canceled) 
     
     
         18 . The fluids processing system of  claim 15 , further comprising:
 a water pump positioned between the oxygen gas and water separator and the electrochemical stack; and   a water transfer line configured to supply water from the oxygen gas and water separator to the water pump,   wherein the water pump is configured to step up a pressure from the lower pressure to the elevated pressure of the electrochemical stack.   
     
     
         19 . The fluids processing system of  claim 18 , wherein energy is generated at the recovery turbine through the reduction in pressure from the elevated pressure to the lower pressure, and
 wherein at least a portion of the generated energy is configured to be provided to the water pump to assist in operation of the water pump.   
     
     
         20 . The fluids processing system of  claim 19 , wherein the generated energy provides 100% of an energy required to operate the water pump during operation of the electrochemical system. 
     
     
         21 . The fluids processing system of  claim 19 , wherein at least a portion of the generated energy is configured to be provided to at least one additional component of the electrochemical system to assist in operation of the at least one additional component of the electrochemical system. 
     
     
         22 . The fluids processing system of  claim 21 , wherein the at least one additional component of the electrochemical system is the electrochemical stack. 
     
     
         23 . The fluids processing system of  claim 15 , further comprising:
 a back pressure device; and   a gas line connecting the back pressure device and the oxygen gas and water separator,   wherein the back pressure device is configured to release gas from the oxygen gas and water separator to atmosphere via the gas line, therein assisting in controlling an operating pressure at the oxygen gas and water separator.   
     
     
         24 . The fluids processing system of  claim 15 , further comprising:
 a controller in communication with the recovery turbine and/or the oxygen gas and water separator via a connected network.   
     
     
         25 . The fluids processing system of  claim 24 , wherein the controller is configured to provide instructions to adjust an operating pressure of the oxygen gas and water separator, and/or
 wherein the controller is configured to provide instructions to adjust operation of the recovery turbine to increase or decrease a step down in pressure between the electrochemical stack and the oxygen gas and water separator.   
     
     
         26 . (canceled)