Systems and methods for separating effluent from a propane dehydrogenation reactor to recover propylene are disclosed. The systems and methods involve using turbo-expanders in a cooling process that does not cool below 140 C. and may also use a de-ethanizer unit to remove ethane and components more volatile than ethane from propylene streams.

A hydrocyclone for separating a vapor from a carrier gas is disclosed. The hydrocyclone comprises one or more nozzles. A cryogenic liquid is injected to a tangential feed inlet at a velocity that induces a tangential flow and a cyclone vortex in the hydrocyclone. The carrier gas is injected into the cryogenic liquid, causing the vapor to dissolve, condense, desublimate, or a combination thereof, forming a vapor-depleted carrier gas and a vapor-enriched cryogenic liquid. The vapor-depleted carrier gas is drawn through a vortex finder and the vapor-enriched cryogenic liquid is drawn through an apex nozzle outlet. In this manner, the vapor is removed from the carrier gas.

A device for separating a gas mixture containing at least 35 mol % carbon dioxide and also at least one gas lighter than carbon dioxide, comprising a first phase separator configured to receive a first partially condensed flow from an exchange line; a first phase separator configured to separate the gas phase from the liquid phase; a cooling means configured to receive the gas phase from the first phase separator and cool said gas phase to form a second partially condensed flow. The resulting liquid phase is then sent to a first valve and is expanded to a lower pressure that is at most 300 mbar lower in order to form a first expanded liquid, which is then mixed with a second liquid originating from the second phase separator in a mixing means that is located upstream of a third valve.

A method for separating hydrogen and nitrogen from a gas mixture, including a) thereby partially condensing a hydrogen and nitrogen gas mixture and producing a two-phase stream, b) phase separating the two-phase stream, producing a nitrogen-enriched liquid fraction and a hydrogen-enriched gaseous fraction, c) expanding the nitrogen-enriched liquid fraction, producing a lower-pressure nitrogen-enriched liquid or two-phase stream, d) adding heat to the lower-pressure nitrogen-enriched liquid stream, producing a warm nitrogen enriched gaseous stream, and e) adding heat to the hydrogen-enriched gaseous fraction, producing a hydrogen-rich product stream. Wherein, at least a portion of the heat added in step d) is removed in step a), at least a portion of the heat added in step e) is removed in step a), or at least a portion of the heat added in step d) and at least a portion of the heat added in step e) is removed in step a).

A process to produce at least carbon dioxide and carbon monoxide from a feed gas containing carbon dioxide, hydrogen and carbon monoxide; comprises separating at least part of the carbon dioxide from the compressed feed gas by partial condensation and/or distillation producing a carbon dioxide product and a carbon dioxide depleted stream, treating the carbon dioxide depleted stream in a treatment unit to produce a feed stream containing carbon monoxide and hydrogen, less rich in carbon dioxide than the carbon dioxide depleted stream and feeding at least part of the feed stream containing carbon monoxide and hydrogen to a separation unit operating at cryogenic temperatures to produce a carbon monoxide product.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a single heat exchanger, multiple gas-liquid separators, multiple expander/compressor sets, and a rectifier attached to a liquid product drum.

A system for removing carbon dioxide from anode exhaust gas that has been compressed to form pressurized anode exhaust vapor includes a feed/effluent heat exchanger configured to cool the anode exhaust vapor to a first predetermined temperature and partially condense carbon dioxide in the anode exhaust vapor; a first vapor-liquid separator configured to receive an output of the feed/effluent heat exchanger and separate liquid carbon dioxide from uncondensed anode exhaust vapor; a feed/refrigerant heat exchanger configured to receive the uncondensed anode exhaust vapor from the first vapor-liquid separator, cool the uncondensed anode exhaust vapor to a second predetermined temperature, and condense carbon dioxide in the uncondensed anode exhaust vapor; a second vapor-liquid separator configured to receive an output of the feed/refrigerant heat exchanger and separate liquid carbon dioxide to form hydrogen rich, uncondensed anode exhaust vapor.

Methods and systems for the dehydrogenation of hydrocarbons include a direct contact condenser to remove compounds from an offgas process stream. The reduction of compounds can decrease duty on the offgas compressor by removing steam and aromatics from the offgas. The dehydrogenation reaction system can be applicable for reactions such as the dehydrogenation of ethylbenzene to produce styrene, the dehydrogenation of isoamiline to produce isoprene, or the dehydrogenation of n-pentene to produce piperylene.

In a process for separating a mixture containing hydrogen and carbon dioxide, the following steps are present: a) cooling of the mixture in a heat exchanger by sending the mixture to the heat exchanger, resulting in the partial condensation of the mixture into a liquid phase enriched in carbon dioxide and a gas phase depleted in carbon dioxide, a gaseous fluid which is heated in the heat exchanger by indirect heat exchange, b) separating the liquid phase from the gas phase in a separator vessel, c) heating of the gas phase originating from at least one of the separator vessels in the heat exchanger, d) sending of the at least one heated part from step c) to a membrane separation unit, generating a residue depleted in hydrogen and carbon dioxide and e) expansion of the at least one residue in a turbine producing an expanded fluid, f) the expanded fluid constituting the gaseous fluid of step a) which is heated in the heat exchanger by indirect heat exchange.

In a process for separating a mixture containing hydrogen and carbon dioxide, the mixture is compressed to form a compressed mixture, the compressed mixture is separated by partial condensation and/or distillation generating a first CO2-depleted stream, the first CO2-depleted stream is separated by permeation through a membrane system to form a residue of the membrane system which is depleted in hydrogen and carbon dioxide and a portion of the residue is recycled, after expansion, to the compressor to be compressed therein.