A process and facility for producing gaseous methane by purifying biogas from landfill can include a VOC purification unit, at least one membrane, a CO.sub.2 purification unit, a cryodistillation unit comprising a heat exchanger and a distillation column, a deoxo, and a dryer.

A method and apparatus for producing liquefied natural gas. A portion of a natural gas stream is cooled in a first heat exchanger and re-combined with the natural gas stream, and heavy hydrocarbons are removed therefrom to generate a separated natural gas stream and a separator bottom stream. Liquids are separated from the separator bottom stream to form an overhead stream, which is cooled and separated to form a recycle gas stream. The recycle gas stream is compressed. A first portion of the compressed recycle gas stream is directed through the first heat exchanger and directed to the separator as a column reflux stream. The separated to natural gas stream is used as a coolant in the first heat exchanger to thereby generate a pretreated natural gas stream, which is compressed and liquefied.

A method including entraining carbon dioxide (CO.sub.2) in a cement slurry composition and subjecting the cement slurry composition to conditions under which the CO.sub.2 achieves and maintains a supercritical state; and allowing the cement slurry composition to harden to form a hardened cement having CO.sub.2 sequestered therein.

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.

In a method for separating a synthesis gas containing carbon monoxide and hydrogen, a synthesis gas flow from a synthesis gas source is compressed in a compressor and separated into at least three gaseous products. If there is insufficient synthesis gas, at least three separation products are recycled in the compressor in order to separate said products.

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 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.

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.

The present invention provides strategies to integrate adsorption and liquefaction techniques to separate hydrocarbon feed mixtures into purified light and heavy components, respectively. Initially, the hydrocarbon stream is separated into a light and heavy stream. The light stream can be integrated into a natural gas product. The heavy stream is partially liquefied. A first gas liquid separation of the partially liquefied heavy stream at an elevated pressure separates the liquid heavy stream from a methane-containing gas. The rejected methane component, which generally will include some rejected C2 and C3+ material, can be recycled to be combined with the feed mixture for re-processing. A further aspect of the strategy is then to practice at least one additional gas-liquid separation of the separated liquid heavy stream at a lower pressure effective to help further resolve the liquid heavy stream from C2-containing gas. The rejected C2 component, which generally will include some rejected C1 and C3+ material, can then be recycled back into the feed mixture for reprocessing or used as all or a portion of a light hydrocarbon product.

A method for separating carbon dioxide from flue gas to generate a high purity CO2 stream.