Membrane-enabled reverse lung

A method using an electrochemical process to remove gaseous carbon dioxide (CO2), water vapor, and heat from air and to generate a stream of oxygen (O2) gas and a stream of concentrated CO2 gas, comprising:

• blowing air through a first gas-liquid contactor configured to convert a first precursor solution into a first electrolyte solution,
• flowing the first electrolyte solution into a second channel of a four channel electrochemical cell,
• flowing a second electrolyte solution into a third channel of the four channel electrochemical cell;
• applying a voltage between a hydrogen producing cathode in a first channel of the four channel electrochemical cell and an oxygen producing anode in a fourth channel of the four channel electrochemical cell to cause water splitting, H2 gas production at the cathode for H2 gas flow from the first channel, oxygen gas production at the anode for oxygen gas flow from the fourth channel, and ion flow through a first anion-exchange membrane separating the first from the second channels, the first electrolyte solution, a second anion-exchange membrane separating the second from the third channels, the second electrolyte solution, and a cation-exchange membrane separating the third and fourth channels
• flowing a second precursor solution produced in the third channel through a second gas-liquid contactor configured to absorb the H2 gas flow from the first channel into the second precursor solution to emit H2 and CO2 gas and to convert the second precursor solution into the second electrolyte.

An apparatus, to remove gaseous carbon dioxide (CO2), water vapor, and heat from air and to generate a stream of oxygen (O2) gas and a stream of concentrated CO2 gas, comprising:

• a first gas-liquid contactor configured to:
• absorb CO2, water vapor, and heat from air into a hydroxide solution circulating through the first gas-liquid contactor, and
• convert the hydroxide solution into a first carbonate solution by reaction with the absorbed CO2;
• an electrochemical cell configured to:
• receive the first carbonate solution from the first gas-liquid contactor,
• convert the first carbonate solution back into the hydroxide solution,
• electrolyze the water vapor from the air into separate hydrogen (H2) and oxygen (O2) gas flows, and
• convert a second carbonate solution, different from the first carbonate solution, into a bicarbonate solution;
• a first pump configured to receive the hydroxide solution from the electrochemical cell and recirculate the hydroxide solution back through the first gas-liquid contactor;
• a second pump configured to receive the bicarbonate solution from the electrochemical cell;
• a second gas-liquid contactor configured to:
• receive the bicarbonate solution pumped from the second pump,
• desorb CO2 from the bicarbonate solution into the H2 gas flow from the electrochemical cell to produce concentrated CO2 gas, and
• convert the bicarbonate solution back into the second carbonate solution.