A system for separating olefinic hydrocarbon and hydrogen in an effluent fluid stream from a dehydrogenation reactor includes a heat exchanger that receives and partially condenses the effluent fluid stream so that a mixed phase effluent stream is formed. A primary separation device receives and separates the mixed phase effluent stream into a primary vapor stream and a primary liquid product stream. A heat exchanger receives and partially condenses the primary vapor stream so that a mixed phase primary stream is formed. A secondary separation device receives and separates the mixed phase primary stream into a secondary vapor stream and a secondary liquid product stream. A heat exchanger receives and warms the secondary vapor stream to provide refrigeration for partially condensing the effluent fluid stream and a heat exchanger receives and warms the secondary vapor stream to provide refrigeration for partially condensing the primary vapor stream. A mixed refrigerant compression system provides refrigerant to a heat exchanger to provide refrigeration.

A method for operating a main cryogenic heat exchanger for use in a natural gas liquefaction process, involves monitoring or predicting variations in the flow rate of a feed gas stream provided to the main cryogenic heat exchanger. When a variation of the flow rate exceeding a predetermined threshold value is monitored or predicted, a control scheme is started to control one or more compressor recycle valves in response to the monitored or predicted variation of the flow rate to recycle part of a compressed mixed refrigerant stream in a refrigerant loop.

A liquefied natural gas (LNG) production complex includes a gravity-based structure (GBS), with liquid storage tanks inside and topside modules on the GBS top slab including interconnecting modules along the GBS top slab centerline, and equipment modules at least some of which are on each side. Equipment modules include: first row on one side: at least one module of reception installations, a condensate stabilization installation, and an acid gas removal installation, and at least one module of mixed refrigerant compressors, second row on the other side: modules of gas dehydration, mercury removal, wide fraction of light hydrocarbons extraction, fractionation and liquefaction installations, and at least one module of boil-off gas, fuel gas system and heating medium compressors; the equipment modules along the GBS short end include: one or more power plant modules, modules with the main technical room and emergency diesel generators, and auxiliary systems modules.

A natural gas liquefaction method and system having integrated nitrogen removal. Recycled LNG gas is cooled in a separate and parallel circuit from the natural gas stream in the main heat exchanger. Cooled recycled gas and natural gas streams are directed to a nitrogen rectifier column after the warm bundle. The recycle stream is introduced to the rectifier column above the natural gas stream and at least one separation stage is located in the rectifier column between the recycle stream inlet and the natural gas inlet. The bottom stream from the rectifier column is directed to a cold bundle of the main heat exchanger where it is subcooled.

In a gas liquefaction plant that produces a liquefied gas by liquefying a raw gas, a pipe rack portion in which an air-cooling heat exchanging system is disposed has a rectangular shape when viewed from above. A first compressor, a precooling heat exchanging portion, an auxiliary heat exchanging portion, and a fourth compressor are arranged in this order along one long side of the pipe rack portion. A second compressor, a primary heat exchanging portion, and a third compressor are arranged in this order along the other long side of the pipe rack portion. A pipe that carries the raw gas cooled at the precooling heat exchanging portion is connected to the primary heat exchanging portion across the pipe rack portion. A pipe that carries a primary refrigerant compressed at the second and third compressors is connected to the auxiliary heat exchanging portion across the pipe rack portion.

A natural gas liquefaction system and method for effectively and efficiently removing heavy hydrocarbons and converting natural gas into liquefied natural gas. Natural gas streams entering the system may consist of varied gas compositions, pressures, and temperatures. In embodiments the system may comprise a natural gas (NG)-to-liquefied natural gas (LNG) portion and a closed-loop refrigeration portion comprising a closed-loop single mixed refrigerant system. In other embodiments the system may comprise an NG-to-LNG portion and a closed-loop refrigeration portion comprising a closed-loop gaseous nitrogen expansion refrigeration system. All embodiments utilize an integrated heat exchanger with cold-end and warm-end sections and integrated multi-stage compressor and expander configurations (e.g. compander) in order to increase overall operation flexibility and efficiency. This optimized method and system is capable of more efficiently producing a liquefied natural gas product at a desired capacity using a minimum amount of equipment and a modularized design to reduce construction costs.

A system and method for cooling and liquefying a gas in a heat exchanger that includes compressing and cooling a mixed refrigerant using first and last compression and cooling cycles so that high pressure liquid and vapor streams are formed. The high pressure liquid and vapor streams are cooled in the heat exchanger and then expanded so that a primary refrigeration stream is provided in the heat exchanger. The mixed refrigerant is cooled and equilibrated between the first and last compression and cooling cycles so that a pre-cool liquid stream is formed and subcooled in the heat exchanger. The stream is then expanded and passed through the heat exchanger as a pre-cool refrigeration stream. A stream of gas is passed through the heat exchanger in countercurrent heat exchange with the primary refrigeration stream and the pre-cool refrigeration stream so that the gas is cooled. A resulting vapor stream from the primary refrigeration stream passage and a two-phase stream from the pre-cool refrigeration stream passage exit the warm end of the exchanger and are combined and undergo a simultaneous heat and mass transfer operation prior to the first compression and cooling cycle so that a reduced temperature vapor stream is provided to the first stage compressor so as to lower power consumption by the system. Additionally, the warm end of the cooling curve is nearly closed further reducing power consumption. Heavy components of the refrigerant are also kept out of the cold end of the process, reducing the possibility of refrigerant freezing, as well as facilitating a refrigerant management scheme.

A system and method for processing natural gas to produce liquefied natural gas is disclosed. The natural gas is cooled in one or more heat exchangers using a first refrigerant from a first refrigerant circuit in which the first refrigerant is compressed in a first compressor driven by a first gas turbine having a first inlet air stream. The natural gas is liquefied using a second refrigerant, the second refrigerant being compressed in a second compressor driven by a second gas turbine having a second inlet air stream. At least one of the inlet air streams is chilled from about the respective dry bulb temperature to a temperature below the respective wet bulb temperature. Water contained in at least one of the chilled first and second air streams is condensed and separated therefrom. At least a portion of the first refrigerant is condensed or sub-cooled using the separated water.

A refrigeration system for cooling a charge gas by a binary refrigerant. The refrigeration system comprises n heat exchangers, n compressor stages, at least one separator and a demethanizer. By flowing depressurized refrigerant through all the subsequent heat exchangers and installing interstage coolers, the overall energy for the refrigeration system is reduced.

Described herein are methods and systems for the liquefaction of a natural gas stream using a refrigerant comprising methane or a mixture of methane and nitrogen. The methods and systems use a refrigeration circuit and cycle that employs one or more turbo-expanders to expand one or more streams of gaseous refrigerant to provide one or more streams of at least predominantly gaseous refrigerant that are used to provide refrigeration for liquefying and/or precooling the natural gas, and a J-T valve to expand down to a lower pressure a stream of liquid or two-phase refrigerant to provide a vaporizing stream of refrigerant that provides refrigeration for sub-cooling.