Patent ID: 6334334
Filing Date: 2002-01-01
Classification: C09K,F25B,F25J

Abstract:
In a process for liquefying a hydrocarbon-rich stream by indirect heat exchange with the refrigerant mixtures of a refrigerant mixture cycle, wherein the refrigerant mixture is compressed in at least a penultimate pressure stage and a final pressure stage and the refrigerant mixture is fractionated into at least one lower-boiling refrigerant mixture fraction and into at least one higher-boiling refrigerant mixture fraction, the improvement comprising the following steps:a) at least partially condensing (E4) a compressed refrigerant mixture (23) downstream of the penultimate compressor stage, b) fractionating (D4) the resultant condensate from step (a) into a higher-boiling liquid fraction (26) and a lower-boiling gas fraction (24), c) compressing the lower-boiling gas fraction (24) in the final pressure stage, d) partially condensing (E5) the compressed lower-boiling gas fraction, e) fractionating (D5) the resultant partially condensed fluid from step (a) into a lower-boiling gas fraction (10) and a higher-boiling liquid fraction (27), f) adding the higher-boiling liquid fraction (27) to the partially condensed refrigerant mixture stream (23) prior to fractionation in step (b), and g) providing the gas fraction (10) as the lower-boiling refrigerant mixture fraction and the liquid fraction (26) as the higher-boiling refrigerant mixture fraction of the refrigerant mixture cycle.