| 摘要 |
A process for liquefying a flow of natural gas with simultaneous recovery of a C<SUB>3</SUB>/C<SUB>4</SUB>-rich fraction is described, whereby the liquefaction of the flow of natural gas is carried out in heat exchange for at least one refrigerant and/or mixed refrigerant flow, and the flow of natural gas that is to be liquefied, after precooling, is subjected to a rectifying column, in which higher hydrocarbons are separated from the flow of natural gas, and then is subjected to further cooling and liquefaction, whereby a C<SUB>2+</SUB>-rich fraction that is recovered in the subsequent cooling of the flow of natural gas is fed to the rectifying column as a reflux liquid. According to the invention, a C<SUB>4</SUB>/C<SUB>5</SUB>-rich fraction ( 20, 35 ) is fed directly and/or indirectly to rectifying column (T 1 ) as an additional reflux liquid, whereby the feed point of the C<SUB>4</SUB>/C<SUB>5</SUB>-rich [fraction ( 20, 35 ) is located at the top of rectifying column (T 1 ) or is identical to the feed point of the C<SUB>2+</SUB>-rich fraction ( 5 ).]
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