Helium can be recovered from nitrogen-rich natural gas at high pressure with low helium loss by cryogenic distillation of the natural gas after pre-treatment of the gas to remove incompatible impurities and then recovery of natural gas liquid (NGL) from the pre-treated gas by distillation. Overall power consumption may be reduced, particularly if the feed to the helium recovery column system is at least substantially condensed by indirect heat exchange against a first portion of nitrogen-enriched bottoms liquid at first pressure, and a second portion of nitrogen-enriched bottoms liquid at a second pressure that is different from the first pressure.

Overall power consumption in a cryogenic distillation process for recovering helium from nitrogen-rich gases comprising helium may be reduced if the feed to the distillation column system is at least substantially condensed by indirect heat exchange against a first bottoms liquid at first pressure, and a second bottoms liquid at a second pressure that is different from the first pressure.

A process and an apparatus are disclosed for a compact processing assembly to improve the recovery of C.sub.2 (or C.sub.3) and heavier hydrocarbon components from a hydrocarbon gas stream. The preferred method of separating a hydrocarbon gas stream generally includes producing at least a substantially condensed first stream and a cooled second stream, expanding both streams to lower pressure, and supplying the streams to a fractionation tower. In the process and apparatus disclosed, the tower overhead vapor is directed to an absorbing means and a heat and mass transfer means inside a processing assembly. The outlet vapor from the processing assembly is compressed to higher pressure and cooled, then a portion is substantially condensed in a heat exchange means inside the processing assembly, expanded to lower pressure, and supplied to the heat and mass transfer means to provide cooling. Condensed liquid from the absorbing means is fed to the tower.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

The present invention relates to a method of liquefying a hydrocarbon stream such as a natural gas stream, the method at least comprising the steps of: supplying a partly condensed hydrocarbon feed stream (10) to a first gas/liquid separator (2); separating the feed stream (10) in the first gas/liquid separator (2) into a gaseous stream (20) and a liquid stream (30); expanding the gaseous stream (20) thereby obtaining an expanded stream (40) and feeding it (40) into a second gas/liquid separator (3); feeding the liquid stream (30) into the second gas/liquid separator (3); removing from the bottom of the second gas/liquid separator a liquid stream (60) and feeding it into a fractionation column (5); removing from the top of the second gas/liquid separator (3) a gaseous stream (50) and passing it to a compressor (6) thereby obtaining a compressed stream (70); cooling the compressed stream (70) thereby obtaining a cooled compressed stream (80); heat exchanging the cooled compressed stream (80) against a stream being downstream of the first gas/liquid separator (2) and upstream of the fractionation column (5).

A system and method for removing nitrogen from an intermediate stream in a gas subcooled process operation that processes natural gas into a sales gas stream and a natural gas liquids stream. The system and method of the invention are particularly suitable for use with gas subcooled process operations where the sales gas stream exceeds pipeline nitrogen specifications by up to about 3%, such as for reducing the nitrogen content of sales gas streams to levels permissible for pipeline transport.

The invention relates to a method for recovery of methane from hydrocarbon streams comprising the following steps: a. Introducing a feed fluid stream (F), which comprises methane fluid, at least one hydrocarbon free fluid, wherein in particular said at least one hydrocarbon free fluid is nitrogen, and at least one hydrocarbon fluid, into a demethanizer system (1); b. Separating said feed fluid stream (F) in the demethanizer system (1) into a carbon rich fraction (C), comprising hydrocarbons with a carbon content of C2 and higher, and a separation stream (S), comprising methane fluid and at least one hydrocarbon free fluid; c. Introducing said separation stream (S) into a hydrocarbon-free fluid separation system (2), in particular in a cryogenic hydrocarbon-free fluid separation system (2′), more particularly into a cryogenic nitrogen rejection system (2″); wherein said separation stream (S) is compressed by a compressor system (6) before said separation stream (S) is introduced in said hydrocarbon-free fluid separation system (2), wherein said separation stream is compressed to a pressure of 12 bar to 80 bar; d. Separating said separation stream (S) in said free fluid separation system (2) into a methane stream (M) and a hydrocarbon-free fluid stream (HF) and a respective system for recovery of methane from hydrocarbon streams.

An intelligent controls system for a field-deployable system for producing dry natural gas (NG) and natural gas liquids (NGLs) from a raw gas stream is disclosed. The control system is used to ensure correct specifications of both dry NG (above a desired minimum methane number) and NGLs (below a desired maximum vapor pressure) from any supplied raw natural gas source by controlling three system parameters: inlet gas flow rate, system operating pressure, and separator-reboiler temperature set point. The input parameters include: heat content of the input gas stream, volume of the input gas stream, desired methane number of the NG, and desired vapor pressure of the NGLs. The controls system allows any piece of remote field equipment for performing complex chemical processing to be monitored, controlled, and operated remotely. A large array of distributed field equipment situated around the world can all be controlled primarily through a single interface provided in a central control center.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

A method for producing hydrocarbons is proposed, in which a product stream containing hydrocarbons is produced from a methane-rich feed stream and from an oxygen-rich feed stream in a reaction unit which is configured for implementing a method for oxidative coupling of methane, the product stream or at least a stream formed therefrom being treated cryogenically in at least one separation unit using at least one liquid, methane-rich stream. It is provided that in the at least one separation unit (10) a recycle stream is formed from methane contained in product stream (c) and from methane contained in the at least one liquid, methane-rich stream (e, v), the recycle stream being fed to the reaction unit (1) as the methane-rich feed stream (a), and in that the liquid, methane-rich stream (e, v) is provided as makeup.