Described herein are systems related to at-shore liquefaction of natural gas. In some cases, the system for liquefaction of natural gas can include a land-based source of electricity; a land-based source of feed gas; an at-shore water-based apparatus moored to an at-shore location, and a transit bridge extending between the water-based apparatus and land upon which the land-based source of electricity and the land-based source of feed gas are located. The at-shore water-based apparatuses can include a hull, an air-cooled electrically-driven refrigeration system (AER System), and a plurality of liquefied natural gas (LNG) storage tanks that are on a lower deck of the hull. The transit bridge can support at least one of a first line for transmitting electricity from the land-based source of electricity to the water-based apparatus and a second line for carrying feed gas from the land-based source of feed gas to the water-based apparatus.

Described herein are methods of manufacturing an at-shore water-based apparatus for liquefaction of natural gas. In some cases, the methods can include determining a weight of an air-cooled electrically driven refrigeration system (AER System); locating a ballast medium in a hull where the ballast medium has a simulated weight approximate to the weight of the AER System; determining a deflection of the hull caused by the simulated weight; moving the ballast medium off the hull while attaching the AER System; assembling a plurality of liquefied natural gas (LNG) storage tanks in the hull; and coupling the AER System with the LNG storage tanks. The ballast medium can be moved off the hull such that the weight of the ballast medium supported by the hull is reduced in order to maintain the deflection of the hull while the AER System is attached.

This floating liquefied-gas production facility (1) is equipped with: a gas turbine unit (20); a liquefaction facility (90) that has a primary refrigeration compressor (40) driven by the gas turbine unit (20), and cools natural gas; a drum-circulation-type exhaust heat recovery boiler (30) that recovers the energy of exhaust heat from the gas turbine unit (20) as steam; a component separation system (85) that uses the steam generated by the drum-circulation-type exhaust heat recovery boiler (30) as a heat source to separate components in natural gas obtained from the ocean floor, and sends said components to the liquefaction facility (90); and a fuel gas supply device (100) that compresses end-flash gas and/or boil-off gas, and supplies said compressed gas to the gas turbine unit (20) as fuel.

Process for liquefying natural gas in a cryogenic heat exchanger by flowing in indirect contact with refrigerant fluid entering heat exchanger at a first inlet at temperature T0 and pressure P1, and flowing through the exchanger as co-current with the natural gas stream, leaving the heat exchanger in the liquid state, then being expanded at the cold end of the exchanger to return to gaseous state at a pressure P1 P1 and temperature T1 T0, before leaving the hot end of exchanger by outlet orifice in gaseous state T0. The fluid is then reliquefied to the inlet of the exchanger via compression followed by partial condensation and phase separation, a first liquid phase taken to the first inlet, a first gaseous portion compressed by a second compressor and cooled in desuperheater by contact with portion of the first liquid phase, prior to condensing in a second condenser.

Methods and systems for liquefying natural gas using environmentally-friendly low combustibility refrigerants are provided. Methods of liquefaction include cooling a fluid in an LNG facility via indirect heat exchange with an environmentally-friendly low combustibility refrigerants that are propane, ethane and methane mixed with small amounts of fluorinated olefin, but still within close proximity to the boiling points of the pure refrigerants such that the mixed refrigerants can still be used in an optimized cascade process.

Described herein are methods of manufacturing an at-shore water-based apparatus for liquefaction of natural gas. In some cases, the methods can include determining a weight of an air-cooled electrically driven refrigeration system (AER System); locating a ballast medium in a hull where the ballast medium has a simulated weight approximate to the weight of the AER System; determining a deflection of the hull caused by the simulated weight; moving the ballast medium off the hull while attaching the AER System; assembling a plurality of liquefied natural gas (LNG) storage tanks in the hull; and coupling the AER System with the LNG storage tanks. The ballast medium can be moved off the hull such that the weight of the ballast medium supported by the hull is reduced in order to maintain the deflection of the hull while the AER System is attached.

A liquefied natural gas production plant for producing a product stream of liquefied natural gas installed at a production location and a process for producing liquefied natural gas includes a plurality of modules and an air-cooled heat exchanger bank designed for the installed production train. The heat exchanger bank includes a first row of air-cooled heat exchanger bays, and an adjacent parallel second row of air-cooled heat exchanger bays.

A method of producing liquefied natural gas (LNG) is disclosed. A natural gas is compressed in at least two serially arranged compressors to a pressure of at least 2,000 psia and cooled to form a cooled compressed natural gas stream. The cooled compressed natural gas stream is additionally cooled to a temperature below an ambient temperature to form an additionally cooled compressed natural gas stream, which is expanded in at least one work producing natural gas expander to a pressure that is less than 3,000 psia and no greater than the pressure to which the at least two serially arranged compressors compress the natural gas stream, to thereby form a chilled natural gas stream. The chilled natural gas stream is liquefied by indirect heat exchange with a refrigerant to form liquefied natural gas and a warm refrigerant. The cooled compressed natural gas stream is additionally cooled using the warm refrigerant.

An LNG production plant and a method of constructing the LNG production plant is disclosed. The LNG production plant includes at least one plant module and a support structure to support the plant module. Each plant module is dry transported by a heavy lift vessel and subsequently transferred to the support structure without lifting the plant module from a deck of the vessel. The support structure includes a landing substructure onto which the plant module is transferred from the vessel. Landing substructure may be onshore or offshore. The support structure may also include one or more onshore support substructures and a transfer path enabling a plant module to be moved from the landing substructure to a corresponding onshore support substructure.

The process comprises the following steps: mixing a gaseous stream of flash gas and a gaseous stream of boil-off gas to form a mixed gaseous flow; compressing the mixed gaseous flow in at least one compression apparatus to form a flow of compressed combustible gas; withdrawing a bypass flow in the flow of compressed combustible gas; compressing the bypass flow in at least one downstream compressor; cooling and expanding the compressed bypass flow; reheating at least a first stream derived from the expanded bypass flow in at least one downstream heat exchanger, reintroducing the first reheated stream in the mixed gaseous flow upstream from the compression apparatus.