A process for producing an olefin having N carbon atoms is proposed in which using a dehydrogenation a process gas is formed which contains at least the olefin having N carbon atoms, a paraffin having N carbon atoms and a hydrocarbon having N1 carbon atoms and in which using at least a portion of the process gas a separation input is formed which is subjected to a low temperature separation in which the separation input is cooled stepwise over a plurality of temperature levels and condensates are separated from the separation input, wherein the condensates are at least partly subjected to a first low temperature rectification to obtain a first gas fraction and a first liquid fraction, wherein the first gas fraction contains at least the olefin having N carbon atoms in a lower proportion than in the condensates and the hydrocarbon having N1 in a higher proportion than in the condensates. It is provided that the first gas fraction is at least partly subjected to a second low temperature rectification using a liquid reflux containing predominantly or exclusively the hydrocarbon having N1 carbon atoms in which the first gas fraction undergoes depletion in the olefin having N carbon atoms. A corresponding plant (100) likewise forms part of the subject matter of the invention.

Liquefaction of industrial gases or gas mixtures (hydrocarbon and/or non-hydrocarbon) uses a modified aqua-ammonia absorption refrigeration system (ARP) to chill the gas or gas mixture during the liquefaction process. The gas is compressed to above its critical point, and the heat of compression energy may be recovered to provide some or all of the thermal energy required to drive the ARP. A Joule Thomson (JT) adiabatic expansion process results in no requirement for specialty cryogenic rotating equipment. The aqua-ammonia absorption refrigeration system includes a vapour absorber tower (VAT) that permits the recovery of some or all of the heat of solution and heat of condensation energy in the system when anhydrous ammonia vapour is absorbed into a subcooled lean aqua-ammonia solution. The modified ARP with VAT may operate at pressures as low as 10 kPa, and the ammonia gas chiller may operate at temperatures as low as 71 C.

A method for separating nitrogen from an LNG stream with a nitrogen concentration of greater than 1 mol %. A pressurized LNG stream is produced at a liquefaction facility by liquefying natural gas, where the pressurized LNG stream has a nitrogen concentration of greater than 1 mol %. At least one liquid nitrogen (LIN) stream is received from storage tanks, the at least one LIN stream being produced at a different geographic location from the LNG facility. The pressurized LNG stream is separated in a separation vessel into a vapor stream and a liquid stream. The vapor stream has a nitrogen concentration greater than the nitrogen concentration of the pressurized LNG stream. The liquid stream has a nitrogen concentration less than the nitrogen concentration of the pressurized LNG stream. At least one of the one or more LIN streams is directed to the separation vessel.

Described herein are methods and systems for removing natural gas liquids from a natural gas feed stream and for liquefying the natural gas feed stream so as to produce a liquefied natural gas (LNG) stream and a natural gas liquids (NGL) stream

The present disclosure provides an integrated power generating system and method and liquefied natural gas (LNG) vaporization system and method. More particularly, heat from a CO.sub.2 containing stream from the power generating system and method can be used to heat the LNG for re-gasification as gaseous CO.sub.2 from CO.sub.2 containing stream is liquefied. The liquefied CO.sub.2 can be captured and/or recycled back to a combustor in the power generating system and method.

A method for liquefaction of industrial gases or gas mixtures (hydrocarbon and/or non-hydrocarbon) uses a modified aqua-ammonia absorption refrigeration system (ARP) that is used to chill the gas or gas mixture during the liquefaction process. The gas may be compressed to above its critical point, and the heat of compression energy may be recovered to provide some or all of the thermal energy required to drive the ARP. The method utilizes a Joule Thomson (JT) adiabatic expansion process which results in no requirement for specialty cryogenic rotating equipment. The aqua-ammonia absorption refrigeration system includes a vapor absorber tower (VAT) which permits the recovery of some or all of the heat of solution and heat of condensation energy in the system when anhydrous ammonia vapor is absorbed into a subcooled lean aqua-ammonia solution. The modified ARP with VAT may achieve operating pressures as low as 10 kPa which results in ammonia gas chiller operating temperatures as low as 71 C.

The present invention relates to a method for cooling down a liquefaction system for liquefying a hydrocarbon-containing gas stream. The method for cooling down the liquefaction system comprises: a) performing a pre-cool-down procedure to cool down the pre-cooling stage, b) performing a cryogenic cool-down procedure to cool down the main cooling stage. B) comprises forming a main cool-down stream (201) that meets a predetermined C.sub.n.sup.+specification. The main cool-down stream (201) is formed out of at least one auxiliary stream not being the pre-cooled hydrocarbon containing gas stream, and the cryogenic cool down procedure and the pre-cool down procedure are at least partially performed simultaneously.

A reliquefaction system and process for innovative reliquefaction of LNG boil-off gas (BOG), where the reliquefaction is propelled by LNG gas fuel. The reliquefaction system is preferably installed on shipboard including LNG carrier or harbor tug, where the LNG carrier and harbor tug use a gas fuel engine.

A floating liquefied natural gas (FLNG) commissioning system and method are described. A system for commissioning a FLNG vessel comprises a floating liquefaction vessel positioned offshore proximate a shipyard, the floating liquefaction vessel comprising a natural gas liquefaction module and a first LNG storage tank cryogenically coupled to the natural gas liquefaction module, a regasification vessel positioned alongside the floating liquefaction vessel, the regasification vessel comprising a second LNG storage tank fluidly coupled to a regasification facility onboard the regasification vessel, a high pressure natural gas conduit extending between an output of the regasification facility and an input of the liquefaction module, a cryogenic transfer member extending between the second LNG storage tank and the first LNG storage tank, and a gaseous natural gas coupling extending between the natural gas liquefaction module and one of the first LNG storage tank, the second LNG storage tank or a combination thereof.

A gas recovery system separates a mixed gas including a process gas and an inert gas. The gas recovery system includes a cooling section for cooling and liquefying the process gas contained in the mixed gas by cooling the mixed gas at a temperature higher than a condensation temperature of the inert gas and lower than a condensation temperature of the process gas, a separating section for separating the cooled mixed gas into the process gas in a liquid state and the inert gas in a gas state, and a process gas recovery line that is connected to the separating section which circulates and gasifies the liquid-state process gas and then supplies the process gas into the a compressor. The mixed gas is formed by mixing the process gas, which is compressed by the compressor, and the inert gas, which is supplied to a seal portion of the compressor.