In a process of the separation of a mixture of carbon monoxide, hydrogen and methane, the mixture is sent to a scrubbing column, a bottom liquid withdrawn at the bottom of the scrubbing column is depleted in hydrogen with respect to the mixture and is sent to a stripping column, a bottom liquid from the stripping column is sent to a separation column and a liquid enriched in methane withdrawn from the bottom of the separation column is vaporized in order to form a final product.

A process for separating undesired, in particular acidic gas constituents from a raw gas, in particular raw synthesis gas, by absorption with cold methanol as physical detergent, wherein the methanol is cooled in a compression refrigeration machine by using a multi-component coolant. The use of the coolant according to the invention provides significant advantages with regard to the compressor capacity required in the compression refrigeration machine for the provision of a defined cooling capacity.

Gas processing plants and methods are contemplated in CO.sub.2 is effectively removed to very low levels from a feed gas to an NRU unit by adding a physical solvent unit that uses waste nitrogen produced by the NRU as stripping gas to produce an ultra-lean solvent, which is then used to treat the feed gas to the NRU unit. Most preferably, the physical solvent unit includes a flash unit and stripper column to produce the ultra-lean solvent.

A molten carbonate fuel cell-powered system for capturing carbon dioxide produced by a steam methane reformer system. Tail gas from a pressure swing adsorption system is mixed with exhaust gas from the fuel cell anode, then pressurized and cooled to extract liquefied carbon dioxide. The residual low-CO.sub.2 gas is directed to an anode gas oxidizer, to the anode, to the reformer to be burned for fuel, and/or to the pressure swing adsorption system. Low-CO.sub.2 flue gas from the reformer can be vented to the atmosphere or directed to the anode gas oxidizer. Reduction in the amount of CO.sub.2 reaching the fuel cell allows the fuel cell to be sized according to the power demands of the system and eliminates the need to export additional power output.

A LNG liquefaction plant includes a propane recovery unit including an inlet for a feed gas, a first outlet for a LPG, and a second outlet for an ethane-rich feed gas, an ethane recovery unit including an inlet coupled to the second outlet for the ethane-rich feed gas, a first outlet for an ethane liquid, and a second outlet for a methane-rich feed gas, and a LNG liquefaction unit including an inlet coupled to the second outlet for the methane-rich feed gas, a refrigerant to cool the methane-rich feed gas, and an outlet for a LNG. The LNG plant may also include a stripper, an absorber, and a separator configured to separate the feed gas into a stripper liquid and an absorber vapor. The stripper liquid can be converted to an overhead stream used as a reflux stream to the absorber.

A system (102; 302) for recovering natural gas liquid from a low pressure gas source (110; 310), comprising a gas/gas heat exchanger (104; 304), fluid from the gas source flowing therethrough; at least one separator (108; 308) for receiving the fluid from the gas/gas heat exchanger (104; 304) and separating liquid from the gas, the gas being directed via a connecting pipe (116; 316) to the gas/gas heat exchanger (104; 304) where it cools the fluid from the gas source; characterised in that the connecting pipe (116; 316) includes expansion means (106; 322) for cooling the gas therein and liquid injection means (120; 320) for saturating the gas with liquid.

Gas processing plants and methods are contemplated in CO.sub.2 is effectively removed to very low levels from a feed gas to an NRU unit by adding a physical solvent unit that uses waste nitrogen produced by the NRU as stripping gas to produce an ultra-lean solvent, which is then used to treat the feed gas to the NRU unit. Most preferably, the physical solvent unit includes a flash unit and stripper column to produce the ultra-lean solvent.

Enhanced low temperature separation (LTS) processes are provided for separating light hydrocarbon components from heavy hydrocarbon components. The enhanced LTS process utilizes an absorber and a de-ethanizer tower to achieve sufficiently pure natural gas liquid (NGL) products and residue gas products. A portion of the de-ethanizer tower overhead is condensed and recycled as reflux for the absorber. The enhanced LTS process requires less refrigeration of the feed gas stream yet still achieves increased recovery of the valuable heavier hydrocarbons from hydrocarbon gas streams. The enhanced LTS process also reduces compression requirements compared to conventional LTS processes.

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.

A LNG liquefaction plant includes a propane recovery unit including an inlet for a feed gas, a first outlet for a LPG, and a second outlet for an ethane-rich feed gas, an ethane recovery unit including an inlet coupled to the second outlet for the ethane-rich feed gas, a first outlet for an ethane liquid, and a second outlet for a methane-rich feed gas, and a LNG liquefaction unit including an inlet coupled to the second outlet for the methane-rich feed gas, a refrigerant to cool the methane-rich feed gas, and an outlet for a LNG. The LNG plant may also include a stripper, an absorber, and a separator configured to separate the feed gas into a stripper liquid and an absorber vapor. The stripper liquid can be converted to an overhead stream used as a reflux stream to the absorber.