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 and apparatus for producing liquefied natural gas. A portion of a natural gas stream is cooled in a heat exchanger and combined with the natural gas stream. Heavy hydrocarbons are removed from the combined natural gas stream, and the resulting separated natural gas stream is partially condensed in the first heat exchanger, with a liquid stream separated therefrom. The natural gas stream is warmed in the first heat exchanger and then is compressed and cooled. The resultant cooled compressed natural gas stream is expanded, thereby forming a chilled natural gas stream that is separated into a refrigerant stream and a non-refrigerant stream. The refrigerant stream recycled to the heat exchanger to be warmed through heat exchange with one or more process streams associated with pretreating the natural gas stream, thereby generating a warmed refrigerant stream. The warmed refrigerant stream and the non-refrigerant stream are liquefied.

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 process for recovering hydrogen from dehydrogenation reactor effluent is disclosed. A feed stream comprising hydrocarbons and hydrogen to a dehydrogenation reactor maintained at dehydrogenation conditions to provide a dehydrogenation reactor effluent. The dehydrogenation reactor effluent is passed to a cold box separation unit to provide a liquid hydrocarbon product stream and a recycle hydrogen stream. A return portion of the recycle hydrogen stream is passed to the reactor effluent compressor. The subject matter disclosed improved process and apparatus which enables the paraffin dehydrogenation reactor to run at reduced H.sub.2/HC ratio without requiring an investment in a resized compressor or resized turboexpanders or separators in the cold box.

Method and system for removing high freeze point components from natural gas. Feed gas is cooled in a heat exchanger and separated into a first vapor portion and a first liquid portion. The first liquid portion is reheated using the heat exchanger and separated into a high freeze point components stream and a non-freezing components stream. A portion of the non-freezing components stream may be at least partially liquefied and received by an absorber tower. The first vapor portion may be cooled and received by the absorber tower. An overhead vapor product which is substantially free of high freeze point freeze components and a bottoms product liquid stream including freeze components and non-freeze components are produced using the absorber 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.

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.

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.

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.

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.