Patent ID: 11965694
Assignee: L'AIR LIQUIDE, SOCIETE ANONYME POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE
Field: Chemical engineering (Chemistry)
Classification: CPC F | IPC F

Claim 0:
1. A process for separation of a mixture comprising carbon monoxide, hydrogen and methane, the process comprising the steps of:
i) sending the mixture or a fluid derived from the mixture, after cooling to a cryogenic temperature in a heat exchanger, to a scrubbing column fed at a top portion with a liquid containing at least 80 mol % carbon monoxide or to at least one phase separator;
ii) withdrawing a bottom liquid at a bottom portion of the scrubbing column or of the phase separator or of one of the phase separators that is depleted in hydrogen with respect to the mixture and then sending the bottom liquid to a stripping column;
iii) withdrawing a gas at a top portion of the stripping column;
iv) sending a bottom liquid from the stripping column to a separation column that is configured to separate the bottom liquid into a top gas enriched in carbon monoxide and a liquid enriched in methane; and
v) withdrawing the liquid enriched in methane from a bottom portion of the separation column and then vaporizing the liquid enriched in methane in the heat exchanger in order to form gaseous methane,
wherein the gaseous methane is compressed in a compressor and a first part of the gaseous methane following compression is returned at the bottom of the separation column for separation therein, and a second part of the gaseous methane following compression is collected as a compressed methane product stream,
wherein the separation column has a top condenser cooled by a closed nitrogen cycle comprising a gaseous nitrogen compressor or by a closed carbon monoxide cycle comprising a gaseous carbon monoxide compressor,
wherein the first part of the gaseous methane following compression that is returned to the bottom of the separation column has the same methane concentration as the liquid enriched in methane withdrawn the bottom portion of the separation column.