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.

In a propane dehydrogenation (PDH) process, the purpose of the deethanizer and chilling train systems is to separate the cracked gas into a methane-rich tail gas product, a C2, and a C3 process stream. By the use of staged cooling, process-to-process inter-change against propane feed to the reactor and use of high efficiency heat exchangers and distributed distillation techniques, refrigeration power requirements are reduced and a simple and reliable design is provided by the process described herein.

Methods and systems for operating and NGL recovery process are provided. In an exemplary method, an absorber column upstream of a fractionator column is operated at a higher pressure than a pressure in the fractionator column. An NGL (C.sub.3 plus) stream is taken from the bottom of a fractionator column and then ethylene/ethane stream is taken from the top of the fractionator column. A differential pressure between the absorber column and the fraction are column is controlled based, at least in part, on a flow rate of the fractionator feed stream from the absorber column to the fractionator column.

A device for distributing a fluid to a processing component includes a vessel having an inlet port for receiving a stream of fluid. A vapor outlet line is in fluid communication with the fluid processing component and has a vapor outlet line inlet in fluid communication with the headspace of the vessel. A liquid outlet line has a liquid outlet line inlet in fluid communication with a liquid side of the vessel and the fluid processing component. A bypass line has a bypass line inlet in fluid communication with the liquid side of the vessel and a bypass line outlet in fluid communication with the vapor outlet line and is configured so that liquid travels through the bypass line and into the vapor outlet line when a liquid level within the vessel reaches a predetermined level so that a headspace is maintained above the liquid level as liquid enters the vessel through the inlet port, and liquid does not travel from the bypass line into the vapor outlet line when a liquid level within the vessel is below the predetermined level.

Implementations described and claimed herein provide systems and methods for processing liquefied natural gas (LNG). In one implementation, a feed gas is received and partially condensed into a two-phase stream by expanding the feed gas. A liquid containing fouling components is removed from the two-phase stream. A vapor generated from the two-phase stream is compressed into a compressed feed gas. The compressed feed gas is directed into a feed chiller heat exchanger. The compressed feed gas is free of the fouling components.

A method to recover hydrocarbonfractions from refineries gas streams involves a pre-cooled heat refinery fuel gas stream mixed with a pre-cooled and expanded supply of natural gas stream in an inline mixer to condense and recover at least C.sub.3.sup.+ fractions upstream of a fractionator. The temperature of the gas stream entering the fractionator may be monitored downstream of the in-line mixer. The pre-cooled stream of high pressure natural gas is sufficiently cooled by flowing through a gas expander that, when mixed with the pre-cooled refinery fuel gas, the resulting temperature causes condensation of heavier hydrocarbon fractions before entering the fractionator. A further cooled, pressure expanded natural gas reflux stream is temperature controlled to maintain fractionator overhead temperature. The fractionator bottoms temperature may be controlled by a circulating reboiler stream.

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.

Systems and processes are provided to prevent light ends such as methane, ethylene and ethane from building up in an olefin/paraffin separation system that uses a combination of a membrane and distillation column for this separation. In one embodiment a small stripper column is provided downstream from a selective hydrogenation reactor. In the other embodiment, a surge vessel with a receiver is added to the retentate stream of the membrane unit.

A method of recovering heat from a Natural Gas Liquid (NGL) fractionation plant for production of potable water. The method includes heating a buffer fluid via a heat exchanger in to transfer heat from the NGL fractionation plant to the buffer fluid. The method includes heating water with the buffer fluid discharged from the heat exchanger to produce potable water via train distillation effects.

A method for removing heavy hydrocarbons from a feed gas by: feeding, into an absorber, a top reflux stream and a second reflux stream below the top reflux stream, wherein the absorber produces an absorber bottom product stream and an absorber overhead product stream; depressurizing and feeding the absorber bottom product stream to a stripper to produce a stripper bottom product stream and a stripper overhead product stream; cooling and feeding a portion of the absorber overhead product stream back to the absorber as the top reflux stream; and pressurizing and feeding the stripper overhead product stream back to the absorber as the second reflux stream. Systems for carrying out the method are also provided.