초록 ▼

The adsorption cycle comprises the following stages: (a) an isobaric adsorption stage at a high pressure of the cycle in which the mixture to be treated is admitted into the adsorber through a first end, termed inlet end, of the adsorber, circulates through the adsorber and is withdrawn therefrom by

The adsorption cycle comprises the following stages: (a) an isobaric adsorption stage at a high pressure of the cycle in which the mixture to be treated is admitted into the adsorber through a first end, termed inlet end, of the adsorber, circulates through the adsorber and is withdrawn therefrom by its other end, termed outlet end, the direction of circulation of the mixture being termed cocurrent; (b) a first stage for the cocurrent decompression of the adsorber to a medium pressure of the cycle; (c) a second stage for the countercurrent decompression of the adsorber to a low pressure of the cycle, the gas withdrawn in the course of this stage being the production gas, and (d) a stage for raising the pressure of the adsorber to the high pressure of the cycle. Application in the recovery of carbon dioxide from sources which contain only 10 to 30% thereof.

대표청구항 ▼

A process for recovering by adsorption at least one preferentially adsorbable constituent of a gaseous feed mixture, said process employing only two adsorbers and comprising the following cycle of operations for each adsorber: (a) an adsorption stage in which the feed mixture is admitted into a firs

A process for recovering by adsorption at least one preferentially adsorbable constituent of a gaseous feed mixture, said process employing only two adsorbers and comprising the following cycle of operations for each adsorber: (a) an adsorption stage in which the feed mixture is admitted into a first adsorber through an inlet end thereof and comprising an isobaric adsorption sub-stage at a high pressure of the cycle for adsorption of said preferentially adsorbable constituent, the mixture, at least during said isobaric sub-stage, circulating through the first adsorber and being withdrawn therefrom through an outlet end thereof, the direction of circulation of the mixture being termed cocurrent, said isobaric sub-stage being conducted until an adsorption front has reached said outlet end; (b) a first stage for cocurrent decompression of the first absorber to a medium pressure of the cycle; (c) a second stage for countercurrent decompression of the first adsorber to a low pressure of the cycle, the gas withdrawn in the course of this second stage being the production gas containing the desired content of said adsorbable constituent, at least a portion of the gaseous mixture extracted from the first absorber in the course of stage (b) being richer in said adsorbable constituent than said gaseous feed mixture and being recycled to the inlet end of the second adsorber and admixed with said feed mixture during at least a portion of stage (a) of said second adsorber; and (d) a recompression stage to raise the pressure in said first adsorber from said low pressure to an initial pressure of said stage (a) by introduction of gas cocurrently withdrawn from the second adsorber.