Processes and systems for producing liquefied natural gas (LNG) with a single mixed refrigerant, closed-loop refrigeration cycle are provided. Liquefied natural gas facilities configured according to embodiments of the present invention include refrigeration cycles optimized to provide increased efficiency and enhanced operability, with minimal additional equipment or expense.

A method includes receiving input corresponding to a proposed configuration of a liquefaction facility and identifying a plurality of components utilized to produce LNG and/or LIN at the facility. The method includes determining an alternative configuration that is different from the proposed configuration. Determining the alternative configuration may include identifying resources accessible to a proposed location for the liquefaction facility and whether at least one of the resources accessible to the proposed location corresponds to a resource generated by a component identified by the proposed configuration, and determining whether to omit at least one component of the plurality of components identified by the proposed configuration. The method includes omitting the at least one component from the alternative configuration, and generating a report based on the proposed configuration and the alternative configuration. The report includes information indicating a difference between the proposed configuration and the alternative configuration.

A method for the production of liquefied natural gas is provided. The method may include providing a high pressure natural gas stream, splitting the high pressure natural gas stream into a first portion and a second portion, and liquefying the first portion of the high pressure natural gas stream to produce an LNG stream. The refrigeration needed for cooling and liquefaction of the natural gas can be provided by a closed nitrogen refrigeration cycle and letdown of the second portion of the high pressure natural gas stream.

A method for the production of liquefied natural gas and liquid nitrogen is provided. The method may include providing a high pressure natural gas stream, splitting the high pressure natural gas stream into a first portion and a second portion, and liquefying the first portion of the high pressure natural gas stream to produce an LNG stream. The refrigeration needed for cooling and liquefaction of the natural gas and liquefaction of the nitrogen can be provided by a nitrogen refrigeration cycle and letdown of the second portion of the high pressure natural gas stream.

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

A method describing the integration of a nitrogen liquefier and letdown of natural gas for the production of liquid nitrogen and lower pressure natural gas is provided. The method may include: providing a nitrogen liquefier having a nitrogen refrigeration cycle, wherein the nitrogen liquefier comprises a nitrogen compressor, a nitrogen recycle compressor, a heat exchanger, and at least a first turbine booster and introducing a nitrogen gas stream to the nitrogen liquefier under conditions effective for liquefying the nitrogen to produce a liquid nitrogen product. The refrigeration needed to liquefy the nitrogen is provided for by the nitrogen refrigeration cycle and letdown of a high pressure natural gas stream.

A method for the integration of a nitrogen liquefier and liquefaction of natural gas for the production of liquefied natural gas and liquid nitrogen is provided. The method may include providing a nitrogen liquefaction unit and providing a natural gas liquefaction unit. Liquefaction of the nitrogen can be achieved via a nitrogen refrigeration cycle within the nitrogen liquefaction unit. Liquefaction of the natural gas can be achieved through the use of natural gas letdown and a second nitrogen refrigeration cycle. The two liquefaction units can be integrated via a common nitrogen recycle compressor, thereby providing significant capital savings.

The present invention relates to a single cycle mixed refrigerant process for industrial cooling applications, for example, the liquefaction of natural gas. The present invention also relates to a refrigeration assembly configured to implement the processes defined herein and a mixed refrigerant composition usable in such processes.

A process for liquefying natural gas by; a) causing it to flow through three series connected heat exchangers, where gas is cooled to T3; T3 is less/equal to the liquefaction temperature of natural gas at atmospheric pressure; and b) causing the closed circuit circulation of a first stream of refrigerant gas at a pressure P1 lower than P3 entering the third exchanger and leaving the first exchanger, the first stream obtained using a first expander to expand a first portion of a second stream at P3 higher than P2, the second stream flowing relative to the natural gas stream entering the first exchanger and leaving the second exchanger; and a third stream at a pressure P2 higher than P1 and lower than P3 flowing relative to the first stream, entering the second exchanger and leaving the first exchanger; c) the second stream at the pressure P3 obtained by compression.

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.