Apparatus and process for the separation of gases using supersonic expansion and oblique wave compression

A method for the removal of a gaseous constituent from a gas stream comprised of a carrier gas and the gaseous constituent, where the gas stream is at an initial temperature and an initial pressure, and where the carrier gas and the gaseous constituent comprising the gas stream are in a gaseous state at the initial temperature and the initial pressure, and where the gaseous constituent alters phase by desublimation or condensation at a higher temperature than the carrier gas at a given pressure, comprising:

• accelerating the gas stream to a specified supersonic velocity, thereby establishing the gas stream at an acceleration temperature and an acceleration pressure, where the acceleration temperature is less than the initial temperature and where the acceleration pressure is less than the initial pressure;
• directing the gas stream at the specified supersonic velocity to a diffuser inlet of an oblique shock diffuser, where the oblique shock diffuser is comprised of a compression corner and a diffuser profile, where the diffuser profile is a converging diffuser profile;
• contacting the gas stream and the compression corner and allowing the compression corner and the diffuser profile to generate an oblique shock wave pattern in the oblique shock diffuser;
• decelerating the gas stream at the specified supersonic velocity to a subsonic flow at a subsonic velocity through a deceleration temperature-pressure profile by flowing the gas stream through the oblique shock wave pattern in the oblique shock diffuser and subjecting the gas stream to the converging diffuser profile of the oblique shock diffuser, where the deceleration temperature-pressure profile is a plurality of pressure and temperature conditions experienced by the gas stream during the decelerating, and where the deceleration temperature-pressure profile originates at the acceleration temperature and the acceleration pressure and terminates at a deceleration temperature and a deceleration pressure at a diffuser outlet of the oblique shock diffuser, where the deceleration temperature is greater than the acceleration temperature and the deceleration pressure is greater than the acceleration pressure, and where the gaseous constituent crosses a phase boundary of the gaseous constituent as the gas stream transitions from the initial temperature and the initial pressure to the deceleration temperature and the deceleration pressure such that the gaseous constituent forms a collectable constituent, where the collectible constituent is a non-gaseous phase at the deceleration temperature and the deceleration pressure, and where the carrier gas is maintained in the gaseous state at the deceleration temperature and the deceleration pressure, such that the collectible constituent and the carrier gas comprise the subsonic flow at the diffuser outlet of the oblique shock diffuser, and thereby increasing a pressure of the gas stream and thereby decreasing a velocity of the gas stream, and thereby subjecting the collectible constituent to at least some portion of the converging diffuser profile;
• and
• transferring the subsonic flow from the diffuser outlet to a separation means, and separating the collectible constituent and the carrier gas using the separation means, thereby removing the gaseous constituent from the gas stream.