Ionic liquid CO2 scrubber for spacecraft
An environmental control system includes an air conditioning subsystem; a mix manifold downstream of the air conditioning subsystem and upstream of an environment to be conditioned; and a contaminant removal subsystem downstream of the environment to be conditioned. The contaminant removal subsystem includes a first gas-liquid contactor-separator. The first gas-liquid contactor-separator includes a first packed, stationary bed that provides a heat/mass transfer surface for contact between a contaminated air from the environment and a liquid absorbent.
1. A contaminant removal subsystem, comprising:
a scrubber that includes a housing and a packed bed that is non-rotating relative to the housing;
wherein the scrubber is configured to receive a contaminated air and a clean liquid absorbent, and discharge a cleaned air and a used liquid absorbent;
wherein the cleaned air contains a lower concentration of gas contaminant than the contaminated air;
wherein the used liquid absorbent includes gas contaminant absorbed into clean liquid absorbent;
a stripper downstream, with respect to used liquid absorbent, of the scrubber;
wherein the stripper is configured to desorb gas contaminant from the used liquid absorbent to produce a regenerated liquid absorbent;
a heat exchanger between the scrubber and the stripper; and
a heater directly downstream, with respect to used liquid absorbent, of the heat exchanger and directly upstream, with respect to used liquid absorbent, of the stripper, wherein the heater is configured to heat used liquid absorbent without employing another heater for heat exchange.
2. The subsystem of claim 1 , wherein the used liquid absorbent contains a higher concentration of gas contaminant than the cleaned air.
3. The subsystem of claim 1 , wherein the used liquid absorbent contains a higher concentration of gas contaminant than the regenerated liquid absorbent.
4. The subsystem of claim 1 , wherein the packed bed enables transfer of gas contaminant to clean liquid absorbent, coalescence of droplets of used liquid absorbent, and separation of used liquid absorbent from cleaned air.
5. The subsystem of claim 1 , further comprising a clean liquid absorbent storage between the scrubber and the stripper.
6. The subsystem of claim 1 , further comprising a centrifugal separator downstream of the packed bed.