Hydrocarbon especially natural gas stream liquefaction

摘要

A process for liquefaction of a hydrocarbon-rich stream, especially of natural gas, involves (a) using an adsorber (A) to remove components (especially H2O and CO2) which deleteriously affect liquefaction; (b) cooling the purified stream (3) in an expansion turbine (X); (c) separating any higher hydrocarbons present; (d) liquefying the stream (5) in one or more Stirling cryogenerators (C1, C2); (e) passing the liquefied stream (7, 7') to a storage vessel (S); (f) withdrawing a sub-stream (11) from the storage vessel for thermal evaporation (E1) and supply as regenerator gas to the adsorber (A); and (g) supplying the loaded regeneration gas (15) as fuel to a motor (M) which drives the Stirling cryogenerator(s) (C1, C2) and/or one or more electric generators (G). Also claimed is a plant for liquefaction of a hydrocarbon-rich stream, especially of natural gas. Preferably, the energy recovered from the expansion step (X) is also used for driving the Stirling cryogenerator(s) (C1, C2) and/or one or more electric generators (G). The loaded regeneration gas (15) is preferably stored in a storage vessel (P) prior to supplying to the motor (M). Evaporation and heating of the sub-stream (11), withdrawn from the storage vessel (S), is preferably carried out by heat exchange (E1) with hot off-gases (21) from the cryogenerators (C1, C2) and/or with hot off-gases (19) from the motor (M).