Process and plant for the combination production of a mixture of hydrogen and nitrogen and also of carbon monoxide by cryogenic distillation and cryogenic scrubbing
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
InventorBertrand Demolliens
Life of this patent
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Abstract
Process for the combined production of a mixture of hydrogen and nitrogen, and of carbon monoxide by cryogenic distillation and cryogenic scrubbing, wherein a methane-rich liquid is introduced at a first intermediate level of a scrubbing column as first scrubbing liquid and at least one nitrogen-rich liquid is introduced at a level higher than the first level of the scrubbing column as second scrubbing liquid and a mixture of hydrogen and nitrogen is drawn off as overhead gas from the scrubbing column.
Claims16
A process for the combined production of a mixture of hydrogen and nitrogen, of carbon monoxide by cryogenic distillation and cryogenic scrubbing, wherein the process comprises the steps of:
- i) cooling, in a heat exchanger, a gas mixture containing at least hydrogen, carbon monoxide and methane;
- ii) sending the cooled mixture to a scrubbing column;
- iii) introducing a methane-rich liquid at a first intermediate level of the scrubbing column as a first scrubbing liquid;
- iv) introducing at least one nitrogen-rich liquid at a level higher than the first level of the scrubbing column as a second scrubbing liquid,;
- v) withdrawing a mixture of hydrogen and nitrogen as an overhead gas from the scrubbing column;
- vi) withdrawing a first bottoms liquid from the scrubbing column and then sending said first bottoms liquid to a stripping column;
- vii) withdrawing a liquid that is level with an intermediate section of the scrubbing column and sending said liquid either to the heat exchanger, or to a stripping column overhead gas line, or to a second stripping column;
- viii) withdrawing a second bottoms liquid from the stripping column and then sending to a column configured to separate carbon monoxide and methane;
- and
- ix) withdrawing a fluid rich in carbon monoxide from the separating column;
- x) withdrawing a third bottoms liquid from the separating column, wherein at least one portion of the third bottoms liquid from the separating column constitutes the methane-rich liquid of step iii).
A plant for the combined production of a mixture of hydrogen and nitrogen, of carbon monoxide by cryogenic distillation comprising:
- a heat exchanger;
- a scrubbing column;
- a stripping column;
- a column configured to separate carbon monoxide and methane;
- a first line for sending a gas mixture containing at least hydrogen, carbon monoxide and methane to be cooled;
- a second line for sending the cooled mixture from the heat exchanger to the scrubbing column;
- a third line for introducing a methane-rich liquid at a first intermediate level of the scrubbing column to act as a first scrubbing liquid;
- a fourth line for introducing a nitrogen-rich liquid at a level higher than the first level of the scrubbing column to act as a second scrubbing liquid;
- a fifth line for drawing off a mixture of hydrogen and nitrogen as overhead gas from the scrubbing column;
- a sixth line for drawing off a bottoms liquid from the scrubbing column and for sending the bottoms liquid from the scrubbing column to the stripping column;
- a seventh line for drawing off a liquid level with an intermediate section of the scrubbing column and for sending the liquid either to the heat exchanger, or to a stripping column overhead gas line, or to a second stripping column;
- an eighth line for drawing off a bottoms liquid from the stripping column and sending the bottoms liquid from the stripping column to the column for separating carbon monoxide and methane, at least one portion of the bottoms liquid from the separating column constituting the methane-rich liquid;
- and
- a ninth line for drawing off a fluid rich in carbon monoxide from the separating column.
Dependencies are inferred from the claim text.