A main heat exchanger receives and partially condenses an effluent fluid stream so that a mixed phase effluent stream is formed. A primary separation device receives and separates the mixed phase effluent stream into a primary vapor stream including hydrogen and a primary liquid stream including an olefinic hydrocarbon. The main heat exchanger receives and warms at least a portion of the primary vapor stream to provide refrigeration for partially condensing the effluent fluid stream. The main heat exchanger also receives, warms and partially vaporizes the primary liquid stream. A mixed refrigerant compression system also provides refrigeration in the main heat 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 integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.

Process for the synthesis of ammonia from a make-up gas containing hydrogen and nitrogen, said process comprising: generation of a synthesis gas (8) containing hydrogen and nitrogen in a molar ratio lower than 3, inside a front-end section (2); a first cryogenic purification, designed to remove nitrogen and raise said molar ratio; conversion of the synthesis gas into ammonia (13) inside a high-pressure synthesis loop (6), with extraction from said loop of a purge stream (14) containing hydrogen and inert gases; wherein at least a portion of said purge stream (14) undergoes a further purification in order to recover at least part of the hydrogen contained therein, obtaining at least one stream (15, 15a, 16, 18) containing recovered hydrogen which is recycled to the process.

Separating propane and heavier hydrocarbons from a feed stream by cooling the feed stream, introducing the chilled feed stream into a feed stream separation unit, pumping the separator bottom stream, introducing the pressurized separator bottom stream into a stripper column, reducing the pressure of the separator overhead stream, introducing the letdown separator overhead stream into an absorber column, collecting a stripper overhead stream from the stripper column, chilling the stripper overhead stream, reducing the pressure of the chilled stripper overhead stream, introducing the letdown stripper overhead stream into the absorber column, collecting an absorber bottom stream, pumping the absorber bottom stream, heating the absorber bottom stream, introducing the heated absorber bottom stream into the stripper column, and collecting the stripper bottom stream from the stripper column. The stripper column bottom stream includes the propane and heavier hydrocarbons and less than about 2.0% of ethane by volume.

In a method for producing a gaseous mixture of CO and H.sub.2, a first gas comprising at least 50% CO is compressed in a first compressor to form a first compressed gas cooled to a first temperature and mixes with a second gas comprising at least 50% hydrogen in order to form the gaseous mixture, at least one of the first and second gases originating from a cryogenic distillation separation unit in which a feed gas containing H.sub.2 and CO cools in a first heat exchanger and is separated in at least one distillation column and at least one part of the second gas heats in the separation unit to a third temperature lower than the first temperature and is then sent to mix with the first gas.

A process and plant are proposed for separating a feed mixture predominantly or exclusively containing carbon monoxide and hydrogen, in which the feed mixture is subjected to a cryogenic separation process in which a carbon monoxide-rich liquid and at least one residual gas mixture which is depleted in carbon monoxide and enriched in hydrogen, in comparison with the feed mixture, are formed. It is intended that the at least one residual gas mixture is subjected to a membrane separation process in which at least one hydrogen-rich permeate and at least one carbon monoxide-rich retentate are formed, wherein the or at least one of the carbon monoxide-rich retentates is recirculated to the cryogenic separation process.

Described herein are systems and processes to produce liquefied natural gas (LNG) using liquefied nitrogen (LIN) as the refrigerant. Greenhouse gas contaminants are removed from the LIN using a greenhouse gas removal unit. The LNG is compressed prior to being cooled by the LIN.

An ammonia plant is disclosed, where ammonia purge gas (20), is sent to a cryogenic recovery unit, said recovery unit comprising means of cooling (102, 202, 302, 402, 502) and a high-pressure phase separator (103, 203, 303, 403, 503) operating at loop pressure; inside said unit the purge gas (20) is cooled to a cryogenic temperature, and a partial liquefaction of methane and argon is achieved; the high-pressure phase separator separates the cooled stream into a gaseous stream and a bottom liquid; the gaseous stream is reheated in a passage of a heat exchanger; the unit is then capable to export a gaseous stream (123, 223, 323, 423, 523) containing nitrogen and hydrogen at loop pressure, that can be reintroduced at the suction side of the circulator (4) of the loop.

The invention relates to a of processing a liquid natural gas stream at a LNG import terminal. The method comprises operating a vaporization unit obtaining a pressurized vaporized natural gas stream and operating a slushification unit to obtain a slush of liquid and solids and a cooled vapour phase. The method further comprises withdrawing the cooled vapour phase from the slushifier providing a cooled vapour stream and passing the cooled vapour stream to the vaporization unit.

A method of cooling a process stream with an auxiliary stream is described, wherein the exchange of heat between the process stream and the auxiliary stream is effected in a first heat exchanger and a second heat exchanger connected downstream thereof.