Abstract: Contaminants are removed from a raw natural gas stream and other types of mixed-gas streams by a separation system. The system is based on using a series of cryogenic cells, devices that can impose essentially any desired temperature and pressure conditions on a volume of incoming gas, down to cryogenic temperatures and up to multiple atmospheres of pressure. Used in succession at specific setpoints of temperature and pressure, the cryogenic cells cause gaseous contaminants in the raw gas stream to condense into liquid form, at which point, they can be separated from the stream. Flowmeters and component detectors, like mass spectrometers, are used to detect the state of the gas stream at various points in the system. The system may be divided into stages, each stage having cryogenic cells operating at different setpoints of temperature and pressure, in order to cause different contaminants to liquefy for separation.

Abstract: A liquid nitrogen-based cooling system features a cooling circuit and a liquid nitrogen-based heat sink. Heat absorbed by fluid flowing in the cooling circuit is subsequently absorbed by liquid nitrogen within the heat sink, which causes the liquid nitrogen to vaporize. The vaporized nitrogen is condensed back to liquid form, e.g., by means of a helium-based cryo-refrigeration system. The heat-sink includes at least a first vessel that contains the liquid nitrogen, with the cooling circuit including a series of coils passing around the first vessel in heat-exchanging contact with an exterior surface thereof so that heat can be transferred into the liquid nitrogen. The first vessel and coils may be contained within a second, outer vessel that minimizes heat transfer from the ambient environment to the fluid flowing in the cooling circuit and the liquid nitrogen within the first vessel.