A method for operating an air separation unit during an unexpected disturbance is provided. The method can include the steps of: determining that a process disturbance has occurred; starting-up a liquid back-up system that is configured to deliver a product gas at a desired product pressure; and introducing compressed air from an air accumulator into the air separation unit at a location that is downstream a main air compressor and upstream a cold box, wherein the compressed air is introduced in an amount that is effective for maintaining nominal operation of the air separation unit during the process disturbance and until the liquid back-up system is delivering the product gas at the desired product pressure.

A system and method is provided for efficiently managing the compression of gas depending on the operating conditions and operating mode of the compression system, wherein the system includes a booster compressor, a booster compressor bypass, a conduit connected to the booster compressor and the booster compressor bypass conduit, a means for selectively directing the flow of the gas based on current operating conditions, to the booster compressor bypass or the booster compressor and a baseline compressor connected to both the booster compressor and the booster compressor bypass conduit.

A method for increasing the reliability and availability of a cryogenic fluid reliquefaction system is provided. It may comprise at least N sub-coolers comprising a motor and a compressor and at least one variable speed. It may comprise N−1 variable speed systems to be shared between the motors and compressors if N equals 2, or N−2 variable speed systems to be shared between the motors and compressors if N is greater than 2. It may comprise two different liquid cryogenic fluid users are provided liquid cryogenic fluid, utilizing two different main cryogenic tanks, with a common sub-cooler and recirculation loop, wherein the pressure in the two different main cryogenic tanks are controlled with pressure controllers acting on two different subcooled liquid cryogenic fluid valves. And or, it may comprise at least one liquid cryogenic fluid user is provided refrigeration from two or more sub-cooling systems in a lead-lag arrangement.

A system and method is provided for efficiently managing the compression of gas depending on the operating conditions and operating mode of the compression system, wherein the system includes a booster compressor, a booster compressor bypass, a conduit connected to the booster compressor and the booster compressor bypass conduit, a means for selectively directing the flow of the gas based on current operating conditions, to the booster compressor bypass or the booster compressor and a baseline compressor connected to both the booster compressor and the booster compressor bypass conduit.

Natural gas liquefaction unit including at least one cryogenic cold box having at least one heat exchanger; a fixed assembly zone on its outer wall; at least one closed loop nitrogen refrigeration cycle; at least one device for equipment required for implementing the liquefaction of a natural gas stream from a hydrocarbon supply stream; at least one interconnection module comprising a pipe holder means and a set of pipes and valves, designed to connect said at least one cold box to at least one equipment device for the cycle for refrigerating and/or separating C6+ type hydrocarbon elements contained in the natural gas, wherein the interconnection module rests on a frame allowing it to be handled and is connected to the cold box and to the other method or equipment sub-assemblies located around said fixed assembly zone.

A liquefaction apparatus that automatically adjusts the load on the liquefaction apparatus correspondingly with an upper limit value of contracted power in different time slots, and which is capable of maximizing the amount of liquefied product produced and of achieving optimum operating efficiency is provided. In certain embodiments, the liquefaction apparatus can include: a production amount calculation unit 91 for obtaining an actual production amount of a liquefied product; a predicted power calculation unit 92 for obtaining a predicted power amount after a predetermined time has elapsed, on the basis of an integrated power value obtained by integrating a usage power; and a power demand control unit 93 for comparing the predicted power amount and a moving average of instantaneous power, and controlling a discharge flow rate of a compressor 3 in such a way as to come infinitely close to a target value, without exceeding the target value, and while using the larger value of the predicted power amount and the moving average of instantaneous power as a value being controlled.

A gas processing system according to an embodiment of the present invention controls inflow fuel pressure of a low pressure demand source according to an operation or a non-operation of a high pressure demand source and the low pressure demand source.

An air separation device can include: a first compressor and a second compressor for compressing feed air; a first refrigerator and a second refrigerator for cooling the feed air; a pre-purification unit for pre-purifying the feed air; a flow rate measuring unit for measuring the flow rate of the feed air; a main heat exchanger for subjecting the feed air to heat exchange; a purification portion into which the feed air led out from the main heat exchanger is fed, and which separates and purifies product nitrogen and/or product oxygen from the feed air; and a compressor control unit for controlling the feed quantity of the feed air in accordance with an increase or decrease in the production quantity of product nitrogen and/or product oxygen.

Provided are a method and apparatus for producing nitrogen and oxygen by means of cryogenic distillation of air. Nitrogen products are extracted only from the top of a tower. If a customer needs nitrogen with lower pressure, part of pure nitrogen that is partially located at a first nitrogen product pressure is reheated in a main heat exchanger, then decompressed to a second nitrogen product pressure by means of a nitrogen expander, further reheated by means of the main heat exchanger, and output as a low-pressure nitrogen product. The nitrogen expander can be braked by an expander booster for compressing air. By means of the method, nitrogen with different pressures can be suitably produced, and the energy consumption for producing the pressurized air can be reduced by utilizing the expansion work of nitrogen.

A method comprising the cooling of the feed natural-gas (15) in a first heat exchanger (16) and the introduction of the cooled feed natural-gas (40) in separator flask (18). The method further comprising dynamic expansion of a turbine input flow (46) in a first expansion turbine (22) and the introduction of the expanded flow (102) into a splitter column (26). This method includes sampling at the head of the splitter column (26) a methane-rich head stream (82) and sampling in the compressed methane-rich head stream (86) a first recirculation stream (88). The method comprises the formation of at least one second recirculation stream (96) obtained from the methane-rich head stream (82) downstream from the splitter column (26) and the formation of a dynamic expansion stream (100) from the second recirculation stream (96).