CPC C07C 7/005 (2013.01) [B01D 3/146 (2013.01); B01D 5/0036 (2013.01); B01D 5/0063 (2013.01); B01D 5/0075 (2013.01); B01D 5/009 (2013.01); B01D 53/002 (2013.01); C07C 7/09 (2013.01); C07C 7/11 (2013.01); C10G 70/043 (2013.01)] | 15 Claims |
1. Process for separating a component mixture (K) comprising hydrogen, methane, hydrocarbons having two carbon atoms and hydrocarbons having three or more carbon atoms, comprising a deethanization and a demethanization subsequent to the deethanization, wherein
in the deethanization at least a portion of the component mixture (K) is subjected to a first partial condensation by cooling from a first temperature level to a second temperature level at a first pressure level to obtain a first gas fraction (G1) and a first liquid fraction (C1),
in the deethanization at least a portion of the first gas fraction (G1) is subjected to a second partial condensation by cooling from the second temperature level to a third temperature level at the first pressure level to obtain a second gas fraction (G4) and a second liquid fraction (C2),
in the deethanization at least a portion of the first liquid fraction (C1) and at least a portion of the second liquid fraction (C2) is subjected to a rectification to obtain a third gas fraction (G3) and a third liquid fraction (C3+),
the second partial condensation is performed such that the second gas fraction (G4) contains more than 95% hydrogen, methane and hydrocarbons having two carbon atoms,
the first liquid fraction (C1) or its part subjected to the rectification and the second liquid fraction (C2) or its part subjected to the rectification are expanded from the first pressure level to a second pressure level before the rectification and the rectification is carried out at the second pressure level, the first pressure level being 25 to 35 bar and the second pressure level being 14 to 17 bar, and
an overhead gas formed in the rectification is cooled to −25 to −35° C. and thereby partially condensed, wherein a condensed portion of the overhead gas is used partially or completely as a reflux in the rectification and an uncondensed portion of the overhead gas is provided partially or completely as the third gas fraction (G3),
characterized in that
the rectification is carried out using a rectification column (T2), the condensed proportion of the overhead gas or its portion being fed back to the rectification column (T2) without using a reflux pump and/or a reflux vessel arranged outside the column.
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