Abstract: In some examples, a composition includes a hydrocarbon and ozone catalyst. The hydrocarbon and ozone catalyst includes one or more catalytic layers overlying a substrate. The one or more catalytic layers include a non-catalytic component, an ozone catalytic component, and a hydrocarbon catalytic component. The non-catalytic component includes titanium oxide. The ozone catalytic component includes cobalt oxide. The hydrocarbon catalytic component includes platinum. An outermost layer of the one or more catalytic layers includes the hydrocarbon catalytic component distributed in the non-catalytic component.

Abstract: A spacesuit contaminant removal system includes at least one membrane separator and a liquid sorbent circuit. The at least one membrane separator is configured to receive a spent air stream from a ventilation system of a spacesuit and absorb a contaminant from the spent air stream into a liquid sorbent. The at least one membrane separator is configured to discharge a clean air stream to the ventilation system and discharge the contaminant in a contaminant stream to a space environment using a vacuum of the space environment. The liquid sorbent circuit is configured to circulate the liquid sorbent through the at least one membrane separator.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: A contaminant removal system for removing a contaminant from an environment includes a gas separator, a scrubber-separator downstream of the gas separator, and a stripper-separator downstream of the scrubber-separator. The gas separator is configured to receive a cabin air stream from the environment and concentrate the contaminant from the cabin air stream to produce a concentrated cabin air stream. The cabin air stream includes the contaminant, and the concentrated cabin air stream has a higher concentration of the contaminant than the cabin air stream. The scrubber-separator is configured to absorb the contaminant from the concentrated cabin air stream into a liquid sorbent and discharge a clean air stream to the environment. The stripper-separator is configured to desorb the contaminant from the liquid sorbent into a contaminant stream.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: In some examples, a composition includes a hydrocarbon and ozone catalyst. The hydrocarbon and ozone catalyst includes one or more catalytic layers overlying a substrate. The one or more catalytic layers include a non-catalytic component, an ozone catalytic component, and a hydrocarbon catalytic component. The non-catalytic component includes titanium oxide. The ozone catalytic component includes cobalt oxide. The hydrocarbon catalytic component includes platinum. An outermost layer of the one or more catalytic layers includes the hydrocarbon catalytic component distributed in the non-catalytic component.

Abstract: An aircraft contaminant removal system includes one or more membrane separators configured to absorb a contaminant from a cabin air stream into a liquid sorbent, desorb the contaminant from the liquid sorbent, discharge the contaminant in a contaminant stream, and return clean air back to the cabin. In some examples, the contaminant removal system includes a membrane scrubber-separator and a membrane stripper-separator, while in other examples, the contaminant removal system may include a single membrane separator configured to operate in a scrubbing mode and a stripping mode. The contaminant removal system may include a humidity management system configured to maintain a humidity of the clean air stream or water concentration of the liquid sorbent using one or more water sources of the aircraft or 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.

Abstract: In some examples, a membrane module includes a fiber bundle. The fiber bundle includes a tubular first region and a tubular second region positioned around the tubular first region. One of the first or second regions includes hollow fibers oriented along an axis of the fiber bundle. Another of the first or second regions includes hollow fibers that are not colinear in a radial direction from the axis of the fiber bundle. A void fraction of the second region is different from a void fraction of the first region.

Abstract: In some examples, a membrane module includes a fiber bundle. The fiber bundle includes a tubular first region and a tubular second region positioned around the tubular first region. One of the first or second regions includes hollow fibers oriented along an axis of the fiber bundle. Another of the first or second regions includes hollow fibers that are not colinear in a radial direction from the axis of the fiber bundle. A void fraction of the second region is different from a void fraction of the first region.

Abstract: A spacesuit contaminant removal system includes at least one membrane separator and a liquid sorbent circuit. The at least one membrane separator is configured to receive a spent air stream from a ventilation system of a spacesuit and absorb a contaminant from the spent air stream into a liquid sorbent. The at least one membrane separator is configured to discharge a clean air stream to the ventilation system and discharge the contaminant in a contaminant stream to a space environment using a vacuum of the space environment. The liquid sorbent circuit is configured to circulate the liquid sorbent through the at least one membrane separator.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: A contaminant removal system for removing a contaminant from an environment includes a gas separator, a scrubber-separator downstream of the gas separator, and a stripper-separator downstream of the scrubber-separator. The gas separator is configured to receive a cabin air stream from the environment and concentrate the contaminant from the cabin air stream to produce a concentrated cabin air stream. The cabin air stream includes the contaminant, and the concentrated cabin air stream has a higher concentration of the contaminant than the cabin air stream. The scrubber-separator is configured to absorb the contaminant from the concentrated cabin air stream into a liquid sorbent and discharge a clean air stream to the environment. The stripper-separator is configured to desorb the contaminant from the liquid sorbent into a contaminant stream.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: An aircraft contaminant removal system includes one or more membrane separators configured to absorb a contaminant from a cabin air stream into a liquid sorbent, desorb the contaminant from the liquid sorbent, discharge the contaminant in a contaminant stream, and return clean air back to the cabin. In some examples, the contaminant removal system includes a membrane scrubber-separator and a membrane stripper-separator, while in other examples, the contaminant removal system may include a single membrane separator configured to operate in a scrubbing mode and a stripping mode. The contaminant removal system may include a humidity management system configured to maintain a humidity of the clean air stream or water concentration of the liquid sorbent using one or more water sources of the aircraft or 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.

Abstract: An environmental control system includes an air conditioning subsystem and a contaminant removal subsystem downstream of the environment to be conditioned. The contaminant removal subsystem includes a first gas-liquid contactor-separator, a second gas-liquid contactor-separator, and a third gas-liquid contactor-separator. One of the first, the second, and the third gas-liquid contactor-separators is configured to receive used absorbent liquid having at least a first contaminant and discharge at least a first contaminant for recovery and reuse. Another of the first, the second and the third gas-liquid contactor-separators is configured to receive used absorbent liquid having at least a second contaminant and discharge at least the second contaminant for recovery and reuse.

Abstract: A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

Abstract: An environmental control system includes an air conditioning subsystem and a contaminant removal subsystem downstream of the environment to be conditioned. The contaminant removal subsystem includes a first gas-liquid contactor-separator, a second gas-liquid contactor-separator, and a third gas-liquid contactor-separator. One of the first, the second, and the third gas-liquid contactor-separators is configured to receive used absorbent liquid having at least a first contaminant and discharge at least a first contaminant for recovery and reuse.