A highly efficient refrigeration system and process for precooling/liquefaction of a hydrogen feed stream and method of turndown of such system is disclosed. The disclosed refrigeration system and associated methods employ a reverse Brayton refrigeration cycle using a nitrogen based refrigerant and a fully integrated three pinion bridge (BriM) machine operatively coupling at least two turbine/expanders and at least four nitrogen refrigerant compression stages. Turndown of the hydrogen precooling and liquefaction process requires removal of nitrogen refrigerant from the refrigeration recycle loop by retaining liquid nitrogen in the phase separator, which is sized to accommodate the bulk of the nitrogen refrigerant used in the refrigeration circuit.

A method and apparatus for liquefying a gaseous hydrocarbon stream such as natural gas. The method comprises at least the steps of providing a feed stream (10) and dividing the feed stream (10) to provide at least a first stream (20) and a second stream (30). The first stream (20) is liquefied using heat exchange against a liquid nitrogen stream (40) to provide a first liquefied hydrocarbon stream (60) and an at least partly evaporated nitrogen stream (70). The second stream (20) is cooled and liquefied by heat exchanging against the at least partly evaporated nitrogen stream (70) to provide a second cooled hydrocarbon stream (80).

Disclosed are processes in which the pressure of a dense phase fluid stream containing hydrocarbons is reduced to produce a two-phase fluid stream, and energy is recovered. The process includes passing the dense phase fluid stream at a pressure greater than the cricondenbar pressure of the dense phase fluid stream through an expander where the dense phase fluid stream is expanded isentropically such that a two phase fluid stream having a pressure lower than the pressure of the dense phase fluid stream leaves the expander. The expander is coupled to a rotating mechanical power user, such that the expander drives the rotating mechanical power user. The process further includes passing the two phase fluid stream leaving the expander to a separator such that the two phase fluid stream is separated into a vapor phase stream and a liquid phase stream. The composition or quantity of liquid formed can be adjusted to control the dew point of the gas produced from the dense-phase fluid.

A method for the production of liquefied natural gas (LNG) and nitrogen is provided. The method may include the steps of: a) providing a nitrogen production facility, wherein nitrogen production facility comprises: a main heat exchanger, an air separation unit, a nitrogen recycle compressor, a first nitrogen refrigeration supply configured to provide refrigeration to the main heat exchanger for cooling a main air feed, b) providing a secondary refrigeration supply; c) liquefying a natural gas stream using refrigeration from the secondary refrigeration supply to form an LNG product stream; wherein the secondary refrigeration supply is configured to compress and expand a refrigerant to produce refrigeration, wherein the refrigerant of the secondary refrigeration supply is shared with refrigerant of the first nitrogen refrigeration supply

By using the power generated by an expander by an expansion of material gas, the outlet pressure of a compressor is increased, and a requirement on the cooling capacity of a cooler is reduced. The liquefaction system (1) for natural gas comprises a first expander (3) for generating power by expanding natural gas under pressure as material gas; a first cooling unit (11, 12) for cooling the material gas depressurized by expansion in the first expander; a distillation unit (15) for reducing or eliminating a heavy component in the material gas by distilling the material gas cooled by the first cooling unit; a first compressor (4) for compressing the material gas from which the heavy component was reduced or eliminated by the distillation unit by using the power generated in the first expander; a second heat exchanger for exchanging heat between the material gas introduced into the first compressor and the material gas compressed by the first compressor; and a liquefaction unit (21) for liquefying the material gas compressed by the first compressor by exchanging heat with a refrigerant.

Described herein are systems and processes to produce liquefied natural gas (LNG) using liquefied nitrogen (LIN) as the refrigerant. Greenhouse gas contaminants are removed from the LIN using a greenhouse gas removal unit.

Described herein are systems and processes to produce liquefied natural gas (LNG) using liquefied nitrogen (LIN) as the refrigerant. Greenhouse gas contaminants are removed from the LIN using a greenhouse gas removal unit. The LNG is compressed prior to being cooled by the LIN.

A gas turbine engine includes a compressor section and a turbine section operably coupled to the compressor section. The gas turbine engine further includes a means for selectively releasing a cooling fluid flow produced at a cryogenic temperature and a plumbing system in fluid communication with the means for selectively releasing the cooling fluid flow. The plumbing system is configured to route the cooling fluid flow to one or more of the compressor section and the turbine section.

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.

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.