Aircraft cabin contaminant removal using liquid sorbent

1. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent; and

discharge the contaminant in a contaminant stream; and

a humidity management system configured to:

maintain a humidity of the clean air stream or a water concentration of the liquid sorbent using one or more water sources of the aircraft; and

remove water from the contaminant stream,

wherein the humidity management system comprises:

a condenser configured to condense water from the contaminant stream; and

a water separator configured to separate the condensed water from the condenser.

2. The aircraft contaminant removal system of claim 1 , wherein at least a portion of water from the one or more water sources is recycled to the liquid sorbent.

3. The aircraft contaminant removal system of claim 1 , wherein the stripper-separator is configured to desorb the contaminant using a ram air stream as a sweep gas stream.

4. The aircraft contaminant removal system of claim 1 , wherein the water sources comprise at least one of:

the cabin air stream;

a crown water collection system;

a potable water storage system; and

the liquid sorbent.

5. The aircraft contaminant removal system of claim 1 , further comprising a manifold configured to:

receive a cooled and pressurized conditioned air stream from an air conditioning system;

receive the clean air stream from the membrane scrubber-separator; and

control flow rates of the conditioned air stream and the clean air stream to achieve a target contaminant concentration, temperature, and pressure of the cabin.

6. An aircraft contaminant removal system comprising:

a membrane separator configured to:

in a scrubbing mode:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream; and

in a stripping mode:

receive an external air stream;

desorb the contaminant from the liquid sorbent using the external air stream; and

discharge the contaminant in a contaminant stream.

7. The aircraft contaminant removal system of claim 6 , further comprising:

an inlet configured to receive the cabin air stream from the cabin of the aircraft;

an outlet configured to discharge the clean air stream to the cabin;

an overboard inlet configured to receive the external air stream into the aircraft; and

an overboard outlet configured to discharge the contaminant stream from the aircraft.

8. The aircraft contaminant removal system of claim 6 , further comprising a dehumidifier fluidically coupled to the membrane separator and configured to:

in the scrubbing mode:

receive the cabin air stream as a feed gas; and

receive the clean air stream as a sweep gas; and

in the stripping mode:

receive the external air stream as a feed gas; and

receive the contaminant stream from the membrane separator as a sweep gas.

9. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent; and

discharge the contaminant in a contaminant stream; and

a thermal management system configured to maintain a temperature of the liquid sorbent using one or more heat exchangers fluidically coupled to an aircraft air stream.

10. The aircraft contaminant removal system of claim 9 , wherein the thermal management system further comprises a heater configured to heat the liquid sorbent using a bleed air stream from an aircraft propulsion system.

11. The aircraft contaminant removal system of claim 9 , wherein the thermal management system further comprises a cooler configured to cool the liquid sorbent using a ram air stream.

12. The aircraft contaminant removal system of claim 9 , wherein the aircraft air stream comprises at least one of a cabin discharge stream, a ram air stream, an exhaust air stream, or a bleed air stream.

13. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent; and

discharge the contaminant in a contaminant stream; and

a humidity management system configured to maintain a humidity of the clean air stream or a water concentration of the liquid sorbent using one or more water sources of the aircraft,

wherein at least a portion of water from the one or more water sources is recycled to the liquid sorbent.

14. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent; and

discharge the contaminant in a contaminant stream; and

a humidity management system configured to maintain a humidity of the clean air stream or a water concentration of the liquid sorbent using one or more water sources of the aircraft,

wherein the humidity management system further comprises a water vaporizer configured to add water from the one or more water sources to at least one of:

the clean air stream; or

a sweep gas stream of the stripper-separator.

15. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent; and

discharge the contaminant in a contaminant stream; and

a humidity management system configured to maintain a humidity of the clean air stream or a water concentration of the liquid sorbent using one or more water sources of the aircraft,

wherein the humidity management system comprises a dehumidifier configured to return humidity from the cabin air stream to the clean air stream using the clean air stream from the scrubber-separator as a sweep gas stream.

16. The aircraft contaminant removal system of claim 15 , wherein the dehumidifier is further configured to receive at least one of the cabin air stream or the contaminant stream as a feed gas stream.

17. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a contaminant membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent; and

discharge the contaminant in a contaminant stream; and

a humidity management system configured to maintain a humidity of the clean air stream or a water concentration of the liquid sorbent using one or more water sources of the aircraft,

wherein the humidity management system further comprises a water stripper-separator configured to:

receive liquid sorbent from the contaminant stripper-separator; and

receive the clean air stream as a sweep gas stream.

18. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent using a ram air stream as a sweep gas stream; and

discharge the contaminant in a contaminant stream; and

a humidity management system configured to maintain a humidity of the clean air stream or a water concentration of the liquid sorbent using one or more water sources of the aircraft.

19. The aircraft contaminant removal system of claim 18 , further comprising:

an inlet configured to receive the cabin air stream from the cabin of the aircraft;

an outlet configured to discharge the clean air stream to the cabin;

a sweep gas inlet configured to receive the ram air stream into the aircraft; and

an overboard outlet configured to discharge the contaminant stream from the aircraft.

20. An aircraft contaminant removal system comprising:

a membrane scrubber-separator configured to:

receive a cabin air stream from a cabin of an aircraft;

absorb a contaminant from the cabin air stream into a liquid sorbent; and

discharge a clean air stream;

a membrane stripper-separator configured to:

desorb the contaminant from the liquid sorbent; and

discharge the contaminant in a contaminant stream;

a humidity management system configured to maintain a humidity of the clean air stream or a water concentration of the liquid sorbent using one or more water sources of the aircraft; and

a manifold configured to:

receive a cooled and pressurized conditioned air stream from an air conditioning system;

receive the clean air stream from the membrane scrubber-separator; and

control flow rates of the conditioned air stream and the clean air stream to achieve a target contaminant concentration, temperature, and pressure of the cabin.