Method for the liquefaction of nitrogen using the recovery of cold energy deriving from the evaporation of liquefied natural gas comprising the steps of: sending a flow of nitrogen (100) to be liquefied to a precooler (101); sending a flow (107) of nitrogen gas exiting said precooler (101) to a heat exchanger (108) of the high pressure recirculation compressor; sending a flow (114) of nitrogen exiting said heat exchanger (108) to a high pressure recirculation compressor (115, 117); sending a flow (120) of nitrogen exiting said compressor (115, 117) to a liquefaction heat exchanger (121); sending to said liquefaction heat exchanger (121) a flow (123) of natural gas, countercurrent to the flow (120) exiting said compressor (115, 117); sending a flow (126, 150) of nitrogen exiting said liquefaction heat exchanger (121) to said heat exchanger (108) countercurrent to said flow (107) of nitrogen gas and to said flow (114) of nitrogen; sending a flow (151, 152) of nitrogen exiting said heat exchanger (108) to said precooler (101) countercurrent to said flow of nitrogen (100) to be liquefied; sending the flow (126, 130) of nitrogen exiting said liquefaction heat exchanger (121) to an expander (131); sending the flow of nitrogen exiting said expander (131) to a medium pressure separator (112) that delivers an exiting flow (132) of nitrogen.

A method for producing hydrocarbons is proposed, in which a product stream containing hydrocarbons is produced from a methane-rich feed stream and from an oxygen-rich feed stream in a reaction unit which is configured for implementing a method for oxidative coupling of methane, the product stream or at least a stream formed therefrom being treated cryogenically in at least one separation unit using at least one liquid, methane-rich stream. It is provided that in the at least one separation unit (10) a recycle stream is formed from methane contained in product stream (c) and from methane contained in the at least one liquid, methane-rich stream (e, v), the recycle stream being fed to the reaction unit (1) as the methane-rich feed stream (a), and in that the liquid, methane-rich stream (e, v) is provided as makeup.

Systems and methods for controlling a natural gas production system in an upset scenario, and/or during startup of turbo-expander system are disclosed. In one embodiment, a method of operating a Joule-Thomson valve of a natural gas production system includes determining an upset event within the natural gas production system, obtaining a flow rate through at least one expander prior to the upset event, and calculating, based on the flow rate, a percent opening of the Joule-Thomson valve. The method further includes opening the Joule-Thomson valve to the percent opening, controlling the Joule-Thomson valve by a PID controller in a set point tracking mode for a period of time, and controlling the Joule-Thomson valve by the PID controller in an automatic mode.

A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a single heat exchanger, multiple gas-liquid separators, multiple expander/compressor sets, and a rectifier attached to a liquid product drum.

The system for treating a gas deriving from the evaporation of a cryogenic liquid and supplying pressurized gas to a gas engine according to the invention comprises, on the one hand, from upstream to downstream, a reliquefaction unit (10) with compression means (11, 12, 13), a first heat exchanger (17) and expansion means (30), and, on the other hand, a pressurized gas supply line comprising, from upstream to downstream, a pump (48) for pressurizing the liquid and high-pressure vaporization means (61).

The pressurized gas supply line has, upstream of the vaporization means (61), a bypass (57) for supplying a second heat exchanger (60) between, on the one hand, pressurized liquid of the supply line (56) and, on the other hand, a line (22) of the reliquefaction unit (10) downstream of the first exchanger and upstream of the expansion means (30).

A system captures carbon dioxide from a flue gas of a power generation facility by using cold heat of liquefied natural gas and utilizes the captured carbon dioxide for mining natural gas, using heat of the flue gas to regasify the LNG. Solidified dry ice is captured from gaseous carbon dioxide contained in the flue gas, and the captured dry ice is used as filler when mining natural gas. The system includes a mining facility, a vehicle to transport LNG liquefied by the mining facility; and a facility for regasifying the transported LNG and capturing dry ice from the carbon dioxide. In the regasification and capture facility, the flue gas exchanges heat with the LNG, thereby regasifying the LNG at an increased temperature and capturing the dry ice from the carbon dioxide. The captured dry ice is transported to the mining facility, which uses it for mining the natural gas.

A method for liquid air and gas energy storage (LAGES) which integrates the processes of liquid air energy storage (LAES) and regasification of liquefied natural gas (LNG) at the import terminal through the exchange of thermal energy between the streams of air and natural gas (NG) in their gaseous and liquid states and includes harnessing the LNG as an intermediate heat carrier between the air streams being regasified and liquefied, recovering a compression heat from air liquefier for LNG regasification and utilizing a cold thermal energy of liquid air being regasified for reliquefaction of a part of send-out NG stream with its return to LNG terminal.

Systems, devices, and methods for recovering mixed refrigerant and/or nitrogen within liquefaction systems are provided. The systems, devices, and methods facilitate recovering mixed refrigerant (MR) and/or nitrogen vapor that can leak from a compressor, separating the MR from the nitrogen, and reusing the MR and/or the nitrogen within the liquefaction system. Recovering and reusing MR and/or nitrogen can minimize loss of MR and nitrogen which can lower the total operating cost of a liquefaction system. Additionally, recovering the MR, rather than burning it, can reduce environmental emissions by reducing the amount of MR that is burned.

A device for recovering carbon dioxide and nitrogen from flue gas includes a pretreatment system, a CO.sub.2and N.sub.2separation system, a N.sub.2purification and liquefaction system, and a CO.sub.2 purification and liquefaction system. The pretreatment system includes a high-temperature NG cooler, a gas-liquid separator, a booster fan, and a dryer; the CO.sub.2and N.sub.2 separation system includes a low-temperature LNG cooler and a cryogenic adsorption device; the N.sub.2 purification and liquefaction system includes a set of N.sub.2 distillation and liquefaction device consisting of a compressor, a cooler, a heat exchanger, a gas-liquid separator, and a distillation tower; and the CO.sub.2purification and liquefaction system includes a set of CO.sub.2 distillation and liquefaction device consisting of a compressor, a cooler, a condenser, an evaporator, a liquefier, and a purification tower, which are used for further purifying and liquefying desorbed gas obtained from the CO.sub.2and N.sub.2 separation system.