OPTIMIZATION OF A PROCESS FOR DENITROGENATION OF NATURAL GAS STREAM

摘要

Process for separating components of a gas mixture to be treated, comprising methane, nitrogen and at least one hydrocarbon having at least two carbon atoms, or a mixture of these hydrocarbons, comprising the following steps: a) introducing the gas mixture to be treated into a first distillation column in order to create, at the top of the column, a first methane-enriched gas stream and at a level lower than that of the top of said column, another gas stream; b) introducing said other gas stream derived from step a) into a second distillation column, at a level lower than that of the top of said second column, in order to create, at the top of this column, a second methane-enriched gas stream, characterized in that the nitrogen content of said second gas stream is at least 1.5 times lower than the nitrogen content of the first gas stream and in that from 5 mol% to 30 mol% of the methane initially present in the gas mixture to be treated is within the second gas stream (15').