A method comprising the cooling of the feed natural-gas (15) in a first heat exchanger (16) and the introduction of the cooled feed natural-gas (40) in separator flask (18). The method further comprising dynamic expansion of a turbine input flow (46) in a first expansion turbine (22) and the introduction of the expanded flow (102) into a splitter column (26). This method includes sampling at the head of the splitter column (26) a methane-rich head stream (82) and sampling in the compressed methane-rich head stream (86) a first recirculation stream (88). The method comprises the formation of at least one second recirculation stream (96) obtained from the methane-rich head stream (82) downstream from the splitter column (26) and the formation of a dynamic expansion stream (100) from the second recirculation stream (96).

Olefins may be recovered from a methanol to olefins reactor effluent by initially feeding the effluent to an absorber demethanizer to contact the effluent with an absorbent to recover an overheads including methane and ethylene and a bottoms including the absorbent, ethylene, and ethane. The bottoms are separated to recover an ethylene fraction and an ethane fraction. The overheads are cooled and partially condensed in a first heat exchanger to a temperature of 40 C. or greater. The resulting stream, or a portion thereof, may be further cooled and condensed via indirect heat exchange with a mixed refrigerant to a temperature of less than 40 C. The non-condensed vapors are separated from the condensed liquids to form a liquid fraction and a methane fraction. The liquid fraction is fed to the absorber demethanizer as reflux, and the methane and ethane fractions combined to form the mixed refrigerant.

A method comprising the cooling of the feed natural-gas (15) in a first heat exchanger (16) and the introduction of the cooled feed natural-gas (40) in separator flask (18). The method further comprising dynamic expansion of a turbine input flow (46) in a first expansion turbine (22) and the introduction of the expanded flow (102) into a splitter column (26). This method includes sampling at the head of the splitter column (26) a methane-rich head stream (82) and sampling in the compressed methane-rich head stream (86) a first recirculation stream (88). The method comprises the formation of at least one second recirculation stream (96) obtained from the methane-rich head stream (82) downstream from the splitter column (26) and the formation of a dynamic expansion stream (100) from the second recirculation stream (96).

Processes and systems for recovery of a dilute ethylene stream are illustrated and described. More specifically, embodiments disclosed herein relate to processes and systems for separation of a dilute ethylene stream from an offgas or other vapor streams, where the ultra-low temperature refrigeration for the desired separations is provided by the offgas itself, and only moderately-low temperature externally supplied propylene refrigerants (for example, at 40 C. to 15 C.) are necessary.

A process and an apparatus are disclosed for a compact processing assembly to improve the recovery of C.sub.2 (or C.sub.3) and heavier hydrocarbon components from a hydrocarbon gas stream. The preferred method of separating a hydrocarbon gas stream generally includes producing at least a substantially condensed first stream and a cooled second stream, expanding both streams to lower pressure, and supplying the streams to a fractionation tower. In the process and apparatus disclosed, the tower overhead vapor is directed to an absorbing means and a heat and mass transfer means inside a processing assembly. A portion of the outlet vapor from the processing assembly is compressed to higher pressure, cooled and substantially condensed in a heat exchange means inside the processing assembly, then expanded to lower pressure and supplied to the heat and mass transfer means to provide cooling. Condensed liquid from the absorbing means is fed to the tower.

A process and an apparatus are disclosed for a compact processing assembly to improve the recovery of C.sub.2 (or C.sub.3) and heavier hydrocarbon components from a hydrocarbon gas stream. The preferred method of separating a hydrocarbon gas stream generally includes producing at least a substantially condensed first stream and a cooled second stream, expanding both streams to lower pressure, and supplying the streams to a fractionation tower. In the process and apparatus disclosed, the tower overhead vapor is directed to an absorbing means and a heat and mass transfer means inside a processing assembly. A portion of the outlet vapor from the processing assembly is compressed to higher pressure, cooled and substantially condensed in a heat exchange means inside the processing assembly, then expanded to lower pressure and supplied to the heat and mass transfer means to provide cooling. Condensed liquid from the absorbing means is fed to the tower.

A process and an apparatus are disclosed for a compact processing assembly to improve the recovery of C.sub.2 (or C.sub.3) and heavier hydrocarbon components from a hydrocarbon gas stream. The preferred method of separating a hydrocarbon gas stream generally includes producing at least a substantially condensed first stream and a cooled second stream, expanding both streams to lower pressure, and supplying the streams to a fractionation tower. In the process and apparatus disclosed, the tower overhead vapor is directed to an absorbing means and a heat and mass transfer means inside a processing assembly. A portion of the outlet vapor from the processing assembly is compressed to higher pressure, cooled and substantially condensed in a heat exchange means inside the processing assembly, then expanded to lower pressure and supplied, to the heat and mass transfer means to provide cooling. Condensed liquid from the absorbing means is fed to the tower.

A feed gas including neon, nitrogen, and helium is cooled in a heat exchange system to a first temperature to produce a two-phase mixture that is introduced into a first phase separator and separated into a nitrogen-rich liquid and a first gaseous crude neon stream. The pressure is reduced in at least a portion of the nitrogen-rich liquid, which is vaporized in the heat exchange system to generate a portion of the refrigeration therein. The first gaseous crude neon stream is introduced into a first adsorber that removes impurities such as nitrogen. The gaseous crude neon stream is further cooled to a second temperature. A portion of the cooling duty may come from the heat exchange system and another portion may come from a cryocooler to produce a two-phase stream. The two-phase stream is separated in a second phase separator into a crude helium vapor stream and a crude neon liquid stream with the latter being introduced into a distillation column to produce a vent stream containing a helium impurity and a pure liquid neon product. The pure liquid neon product is vaporized in the heat exchange system to generate refrigeration and produce the pure gaseous neon product.

The present invention relates to a process for separating a hydrocarbon gas into a fraction containing a predominant portion of the methane or ethane and lighter components and a fraction containing a predominant portion of the C.sub.2 or C.sub.3 and heavier components in which process the feed gas is treated in one or more heat exchange, and expansion steps; partly condensed feed gas is directed into a separator wherein a first residue vapor is separated from a C.sub.2 or C.sub.3-containing liquid; and C.sub.2 or C.sub.3-containing liquids, at substantially the pressure of separation, are directed into a distillation column wherein said liquid is separated into a second residue is separated to recover a C.sub.2 or C.sub.3-containing product. The foregoing process is improved by cooling said second residue to partially condense it.

A transportable apparatus for production of liquefied natural gas (LNG) having include a housing, a natural gas feed inlet, a heat exchanger, a phase separator, a liquid outlet disposed on the cold end of the heat exchanger, an LNG product outlet disposed on the cold end of the heat exchanger, a first refrigeration supply, a second refrigeration supply, and wherein the heat exchanger, the phase separator, the first expansion valve, the first refrigeration supply, and the second refrigeration supply are all disposed within the housing. The first refrigeration supply includes expansion of a portion of the LNG product, and the second refrigeration supply can include expansion of another portion of the LNG product or expansion and heat exchange with a supply of liquid nitrogen. The production of LNG is achieved without the external supply of electricity.