A method for recovering associated gaseous hydrocarbons from a well for producing liquid hydrocarbons, the method comprising (i) providing gaseous hydrocarbons from a hydrocarbon well; (ii) providing a cryogenic liquid from an air separation unit or an associated nitrogen liquefaction facility within proximity of the hydrocarbon well; (iii) liquefying the gaseous hydrocarbons at a hydrocarbon liquefaction facility within proximity to the hydrocarbon well to thereby produce a liquefied hydrocarbon gas, where heat associated with the gaseous hydrocarbons is transferred to the cryogenic liquid; and (iv) transferring the liquefied hydrocarbon gas to an air separation unit or nitrogen liquefaction facility.

The invention relates to a method and a device for generating electrical energy in a combined system consisting of a power plant and an air handling system. The power plant comprises a first gas expansion unit connected to a generator. The air handling system comprises an air compression unit, a heat exchange system, and a fluid tank. In a first operating mode, feed air is compressed in the air compression unit and cooled in the heat exchange system. A storage fluid is generated from the compressed and cooled feed air and is stored as cryogenic fluid in fluid tank. In a second operating mode, cryogenic fluid is removed from fluid tank and is vaporized, or pseudo-vaporized, at superatmospheric pressure. The gaseous high pressure storage fluid generated is expanded in the gas expansion unit. Gaseous natural gas is introduced into the heat exchange system (21) to be liquefied.

A fuel cell system using natural gas, which includes a fuel cell including a cathode and an anode and a cryogenic heat-exchanging apparatus configured to heat-exchange natural gas supplied from a natural gas station with introduced air or exhaust gas of the fuel cell. With the configuration, oxygen which is introduced into the fuel cell can be produced using cold energy of the natural gas, and energy consumed for the oxygen production can be reduced. Also, a discharge of seawater of low temperature can be minimized, thereby reducing negative effects caused by the discharge.