Gas mixture separation method

Abstract

The present invention relates to the technology of processing byproduct gas or natural gas and in particular to a process for low-temperature separating gas components. The technical result targeted by the present invention resides in the improvement of the degree of purifying the outgoing gas. Said technical result is provided by the fact that in the process for separating a gas mixture comprising the steps of cooling the mixture, expanding the products obtained from the mixture, pumping at least a part of products via a fractionating column, expanding the mixture in a spun flow in a nozzle, the flow being separated into a flow enriched with components heavier than methane and a flow depleted of said components, heating the depleted flow at the expense of cooling the products obtained from the gas mixture, according to the present invention, the heated gas flow is compressed in a compressor, cooled in an air cooling apparatus, a part of gaseous product obtained is used as outgoing gas, the other part is additionally cooled, expanded, the expanded products are fed to a column and/or blended with the gaseous products incoming from the column to the nozzle. Besides, the enriched flow or a part of the same is used as a cooling agent to cool the mixture or the products obtained from the mixture, compressed, cooled with the air cooling apparatus and fed to the mixture.

1 . Process for separating a gas mixture comprising the steps of cooling the mixture, pumping a part of products obtained from the mixture via a fractionating column, expanding at least a part of products in a spun flow within a nozzle, the flow being separated into a flow enriched with components heavier than methane and a flow depleted of said components, heating the depleted flow at the expense of cooling the products obtained from the gas mixture, characterized in what that the heated depleted gas flow is compressed in a compressor, cooled in an air cooling apparatus, a part of gaseous product obtained is used as an outgoing product, the other part is additionally cooled, expanded, the expanded products are fed to a column and/or blended with the gaseous products incoming from the column to the nozzle. 
     
     
         2 . Process of  claim 1 , characterized in what that the enriched flow or a part of the same is used as a cooling agent to cool the mixture or a part of products obtained from the mixture, compressed, cooled with the air cooling apparatus and fed to the mixture. 
     
     
         3 . Process of  claim 1 , characterized in what that expanding the additionally cooled part of the gas is carried out in a centrifugal expander or in a throttle valve and/or in a nozzle. 
     
     
         4 . Process of  claim 1 , characterized in what that some mixture and/or products obtained from the mixture and having a temperature higher than the dew point of the enriched flow are added to the enriched flow. 
     
     
         5 . Process of  claim 1 , characterized in what that the additionally cooled part of the gas can be used in an ejector as ejecting or ejected gas after blending the same with products obtained from the gas mixture. 
     
     
         6 . Process of  claim 2 , characterized in what that expanding the additionally cooled part of the gas is carried out in a centrifugal expander or in a throttle valve and/or in a nozzle.