In a propane dehydrogenation (PDH) process, the purpose of the deethanizer and chilling train systems is to separate the cracked gas into a methane-rich tail gas product, a C2, and a C3 process stream. By the use of staged cooling, process-to-process inter-change against propane feed to the reactor and use of high efficiency heat exchangers and distributed distillation techniques, refrigeration power requirements are reduced and a simple and reliable design is provided by the process described herein.

The invention relates to a method for separating a synthesis gas comprising hydrogen and carbon monoxide by cryogenic distillation, according to which the synthesis gas (1, 5) is cleaned and cooled to a cryogenic temperature, the cooled synthesis gas is separated by a first means (15) in order to produce a hydrogen-depleted liquid (33), the hydrogen-depleted liquid is introduced into the upper part of a stripping column (25) and a hydrogen-enriched gas (27) is drawn off at the head of the stripping column, at least partially condensed and sent back to the upper part of the stripping column.

The present invention provides a method of liquefying a contaminated hydrocarbon-containing gas stream: (a) providing a CO2 contaminated hydrocarbon-containing gas stream (20); (b) cooling the contaminated hydrocarbon-containing gas stream to obtain a partially liquefied stream (70); (c) separating the partially liquefied stream obtaining a liquid stream (90); (d) cooling the liquid stream (90) in a direct contact heat exchanger (200) obtaining a multiphase stream (201) containing at least a liquid phase and a solid CO2 phase; (e) separating the multiphase stream in a solid-liquid separator (202) obtaining a CO2 depleted liquid stream (141); (f) passing the CO2 depleted liquid stream (141) to a further cooling, pressure reduction and separation stage to generate a further CO2 enriched slurry stream (206); (g) passing at least part of the further CO2 enriched slurry stream (206) to the direct contact heat exchanger (200) to provide cooling duty to and mix with the liquid stream (90).

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 and a process for processing a natural gas liquid feed is provided. In the system, a dense fluid expander is positioned downstream from a subcooler heat exchanger. The subcooler heat exchanger cools one or more reflux streams against an overhead vapor stream and a distillation column positioned downstream from the dense fluid expander. An increase in recovery of natural gas liquids is provided through the use of this system having at least one dense fluid expander.

A system includes a first separator that separates water from a fluid material. The water settles on the bottom of the water knock-out tank. The system includes multiple compressors to boost the pressure of the fluid material. The system includes a second separator that separates condensate from the fluid material. The system includes a mixing pipe that mixes glycol with the fluid material and a first heat exchanger that cools the mixed fluid material and glycol. The system includes a third separator that separates gaseous components and liquid components of the mixed fluid material and glycol and a fourth separator that separates the liquid components of the mixed fluid material and glycol. The system includes a fractional distillation column that heats a first liquid from the fourth separator, gasifying a first portion of the first liquid. A second portion of the first liquid remains liquid and is natural gas liquids.

A system for removing nitrogen from a natural gas fluid feed stream includes a main heat exchanger that receives the natural gas fluid feed stream. A distillation column receives a cooled fluid stream from the main heat exchanger and features a return vapor outlet and a side vapor outlet port, The return vapor outlet provides nitrogen vapor to the main heat exchanger which is warmed therein. The side vapor outlet port provides vapor to the main heat exchanger and a reflux compressor receives and compresses the resulting fluid from the main heat exchanger. A reflux aftercooler receives and cools fluid from the reflux compressor, directs cooled fluid to the main heat exchanger and the resulting fluid is directed to a reflux separation device. The reflux separation device has a vapor outlet and a liquid outlet. The vapor outlet of the reflux separation device directs fluid to the main heat exchanger so that fluid is directed to the first reflux inlet port of the distillation column. The liquid outlet of the reflux separation device directs fluid to a second reflux inlet port of the distillation column.

Plant and process for the production of liquid methane from a feed gas stream comprising at least methane and carbon dioxide. A feed gas stream is injected into a CO.sub.2 crystallizer in countercurrent fashion against a stream of predominantly liquid methane, thereby crystallizing amounts of carbon dioxide from the feed gas stream. Gaseous methane recovered from the CO.sub.2 crystallizer is liquefied at a liquefaction exchanger.

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 method comprising the cooling of the feed natural-gas (15) in a first heat exchanger (16) and the introduction of the cooled feed natural-gas (40) in separator flask (18). The method further comprising dynamic expansion of a turbine input flow (46) in a first expansion turbine (22) and the introduction of the expanded flow (102) into a splitter column (26). This method includes sampling at the head of the splitter column (26) a methane-rich head stream (82) and sampling in the compressed methane-rich head stream (86) a first recirculation stream (88). The method comprises the formation of at least one second recirculation stream (96) obtained from the methane-rich head stream (82) downstream from the splitter column (26) and the formation of a dynamic expansion stream (100) from the second recirculation stream (96).