The invention relates to a process and device for the cryogenic separation of a methane-containing feed gas predominantly consisting of hydrogen and carbon monoxide, that is partially condensed in this case by cooling, in order to obtain a hydrogen-containing first liquid phase predominantly consisting of carbon monoxide and methane, from which first liquid phase, in an H.sub.2 separation column that is heated via a circulation heater, a second liquid phase is generated by separating off hydrogen, from which second liquid phase, in a CO/CH.sub.4 separation column, a carbon monoxide-rich gas phase is obtained having a purity that permits release thereof as carbon monoxide product. It is characteristic in this case that a low-methane material stream is withdrawn from the H.sub.2 separation column and is then applied to the CO/CH.sub.4 separation column as reflux.

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.

The invention provides a method for recovering 3-Helium (3He) from natural Helium (He), comprising the following steps: supplying the feed stream comprising natural liquid helium from an appropriate liquid helium source; introducing a feed stream into a rectification column system; condensing at least a first portion of a vapour stream comprising 3He enriched Helium in the intermediate section of the rectification system, condensing at least a second portion of a vapour stream comprising 3He enriched Helium in the upper section of the rectification system by heat exchange with colder liquid Helium; merging and compressing of the low-pressure vaporous streams; withdrawing an overhead stream comprising 3He enriched Helium from a top section of the rectification system as a product; withdrawing a bottom stream comprising 3He depleted Helium from a bottom section of the rectification system; withdrawing of a vaporous helium stream from the lower part of the rectification system.

A device for recovering carbon dioxide and nitrogen from flue gas includes a pretreatment system, a CO.sub.2and N.sub.2separation system, a N.sub.2purification and liquefaction system, and a CO.sub.2 purification and liquefaction system. The pretreatment system includes a high-temperature NG cooler, a gas-liquid separator, a booster fan, and a dryer; the CO.sub.2and N.sub.2 separation system includes a low-temperature LNG cooler and a cryogenic adsorption device; the N.sub.2 purification and liquefaction system includes a set of N.sub.2 distillation and liquefaction device consisting of a compressor, a cooler, a heat exchanger, a gas-liquid separator, and a distillation tower; and the CO.sub.2purification and liquefaction system includes a set of CO.sub.2 distillation and liquefaction device consisting of a compressor, a cooler, a condenser, an evaporator, a liquefier, and a purification tower, which are used for further purifying and liquefying desorbed gas obtained from the CO.sub.2and N.sub.2 separation system.

The present disclosure provides a distillation tower for separating a feed stream. The distillation tower includes a controlled freeze zone section having a controlled freeze zone upper section and a controlled freeze zone lower section below the controlled freeze zone upper section. The controlled freeze zone section includes: (a) a spray assembly in the controlled freeze zone upper section; (b) a melt tray assembly in the controlled freeze zone lower section; (c) a feed stream distribution mechanism between the spray assembly and the melt tray assembly. The feed stream distribution mechanism is constructed and arranged to uniformly distribute the feed stream in the controlled freeze zone section.

A gas plant using an Ortloff or similar process comprising the use of a second expander in place of a valve used in most demethanizer reflux systems, wherein a compressor wheel is used to increase the pressure of the partial stream of inlet gas that is used to provide heat to the demethanizer reboilers. This stream remains a separate stream and is used for the flow of gas that feeds the demethanizer reflux expander.

Systems and methods for recovering light hydrocarbons from refinery waste gas using a back-end turboexpander to generate a higher recovery of the light hydrocarbons for use as petrochemical feedstock and to remove the liquid light hydrocarbons before entering the turboexpander.

A system and method for removing nitrogen and producing a high pressure methane product stream and an NGL product stream from natural gas feed streams where at least 90%, and preferably at least 95%, of the ethane in the feed stream is recovered in the NGL product stream. The system and method of the invention are particularly suitable for use with feed streams in excess of 5 MMSCFD and up to 300 MMSCFD and containing around 5% to 80% nitrogen. The system and method preferably combine use of strategic heat exchange between various process streams with a high pressure rectifier tower and the ability to divert all or a portion of a nitrogen rejection unit feed stream to optionally bypass a nitrogen fractionation column to reduce capital costs and operating expenses.

An apparatus is disclosed for maintaining constant fluid pressure and equalized fluid flow among a plurality of downcomer lines through which liquid from a tower is directed. A substantially annular fluid distribution belt is disposed at the circumference of the tower. The fluid distribution belt collects liquid from the tower. At least two outlets direct liquid from the fluid distribution belt out of the tower and into a corresponding number of downcomer lines disposed external to the tower.

The present invention relates to a method of cooling and separating a hydrocarbon stream: (a) passing an hydrocarbon feed stream (7) through a first cooling and separation stage to provide a methane enriched vapour overhead stream (110) and a methane depleted liquid stream (10); (b) passing the methane depleted liquid stream (10) to a fractionation column (200) to obtain a bottom condensate stream (210), a top stream enriched in C1-C2 (220) and a midstream enriched in C3-C4 (230), (c) cooling the upper part of the fractionation column (201) by a condenser (206), (d) obtaining a split stream (112) from the methane enriched vapour overhead stream (110) and obtaining a cooled split stream (112) by expansion-cooling the split stream (112), (e) providing cooling duty to the top of the fractionation column (201) using the cooled split stream (112).