A system for cooling a gas with a mixed refrigerant includes a heat exchanger that receives and cools a feed of the gas so that a product is produced. The system includes a mixed refrigerant processing system having compression devices and aftercoolers as well as a low pressure accumulator and a high pressure accumulator. A cold vapor separator receives vapor from the high pressure accumulator and features a vapor outlet and a liquid outlet. Vapor from the cold vapor separator vapor outlet is cooled, expanded and directed to a primary refrigeration passage of the heat exchanger. Liquid from the liquid outlet of the cold vapor separator is subcooled, expanded and directed to the primary refrigeration passage. Liquid from the low pressure accumulator is subcooled, expanded and directed to the primary refrigeration passage. Liquid from the high pressure accumulator is subcooled, expanded and directed to the primary refrigeration passage.

Systems and methods are described for increasing capacity and efficiency of a nitrogen refrigerant boil-off gas recovery system for a natural gas storage tank. Boil-off gas is condensed against two-phase nitrogen in a condensing heat exchanger having an inner vessel through which the boil-off gas flows and an outer vessel through which the two phase nitrogen flows. Logic controls maintain storage tank pressure and power consumption within preferred levels by adjusting the pressure of the two-phase nitrogen in the heat exchanger. Additional logic controls maintain the temperature difference between the nitrogen streams entering into and returning from the cold end of a second heat exchanger by controlling the position of an expansion valve on the return circuit.

The present invention is directed to a method of separating carbon monoxide from syngas mixtures by cryogenic means where a partial condensation cycle is generally employed, and more specifically varying refrigeration generation based on income feed composition of the hydrocarbon feedstock being processed.

A method of constructing a coil wound heat exchange module and transporting and installing the coil wound heat exchange module at a plant site, such as an natural gas liquefaction plant. A module frame is constructed and attached to a heat exchanger shell prior to telescoping of a coil wound mandrel into the shell. The module frame includes a lug and two saddles that remain attached to the shell throughout the process and when the heat exchanger is operated. The lug and saddles are constructed and located to stabilize the shell during construction, telescoping and transport (when in a horizontal orientation), and when the shell is installed at the plant site (in a vertical orientation). The lugs and saddles are adapted to allow for thermal expansion and contraction of the shell when it is transitioned from ambient to operating temperature and vice versa.

Described herein are methods and systems for the liquefaction of natural gas to produce a LNG product. The methods and systems use an apparatus for separating a flash gas from a liquefied natural gas (LNG) stream to produce a LNG product and recovering refrigeration from the flash gas. The apparatus includes a shell casing enclosing a heat exchange zone comprising a coil wound heat exchanger, and a separation zone. The heat exchange zone is located above and in fluid communication with the separation zone. Flash gas is separated from the LNG product in the separation zone and flows upwards from the separation zone into the heat exchange zone where refrigeration is recovered from the separated flash gas.

Disclosed is a liquefied natural gas production train, comprising at least one integrated process unit having a structural frame forming multiple process equipment floors. The at least one integrated process unit extends in vertical direction, wherein a height of the at least one integrated process unit is substantially equal to or larger than a width and a length of the at least one integrated process unit. The disclosure also provides a method of producing liquefied natural gas, using the LNG production train.

A method of cooling a boil-off gas (BOG) stream from a liquefied gas tank comprising at least the step of heat exchanging the BOG stream with a first refrigerant in a heat exchanger, the heat exchanger having an entry port and a warmer exit port, and comprising at least the steps of: (a) passing the first refrigerant into the entry port of the heat exchanger and into a first zone of the heat exchanger to exchange heat with the BOG stream, to provide a first warmer refrigerant stream; (b) withdrawing the first warmer refrigerant stream from the heat exchanger at an intermediate exit port between the entry port and the warmer exit port; (c) admixing the first warmer refrigerant stream with an oil-containing refrigerant stream to provide a combined refrigerant stream; (d) passing the combined refrigerant stream into the heat exchanger through an entry port located in a second zone of the heat exchanger that is warmer than the first zone; (e) passing the combined refrigerant stream out of the heat exchanger through the warmer exit port. The present invention is a modification of a refrigerant cycle for BOG cooling, and LNG re-liquefaction in particular, that allows the use of a cost-efficient oil-injected screw compressor in the refrigerant system. The present invention is also able to accommodate the possibility of different flows or flow rates of the first refrigerant stream and the oil-containing refrigerant stream, such that there is reduced or no concern by the user of the process in relation to possible oil freezing and clogging of the heat exchanger caused by variation of the flow or flow rate of the oil-containing refrigerant stream.

An LNG production plant is constructed from a plurality of containerised LNG liquefaction units. Each containerised LNG liquefaction unit can produce a predetermined quantity of LNG. For example, up to 0.3 MPTA. A manifold system enables connection between the plurality of containerised LNG liquefaction units, and at least a feed stream of natural gas, a source of electrical power, and an LNG storage facility. The production capacity of the plant is incrementally changed by connecting or disconnecting containerised LNG liquefaction units to or from the plant via the manifold system. Each unit contains its own liquefaction plant having a closed loop SMR circuit. Refrigerant within the SMR circuit is circulated solely by pressure differential generated by refrigerant compressors in the liquefaction plant.

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.

An LNG production system including a boil off gas recondenser that can recondense boil off gas without using a BOG compressor and without depending on an LNG liquefaction process is provided.