US 2005/0268780 A1Published application

Method of separating target gas

AssigneeSumitomo Seika Chemicals Co., Ltd.

InventorsToshihiko Sumida, Hiroaki Sasano, Masanori Miyake

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Abstract

The present invention is a gas separation method using a plurality of adsorption columns packed with an adsorbent. A cycle including a series of steps (adsorption, first pressure reduction, second pressure reduction, desorption, scrubbing, and repressurization) is repeated in each adsorption column. In the adsorption step, a gas mixture (G1) is introduced into a column (A) so as to cause the adsorbent to adsorb unnecessary components, and a product gas (G2) is led outside of the column (FIG. 3A). In the first pressure reduction step, the internal pressure of the column (A) is reduced by lead-out of a gas (G3) (FIG. 4A). In the second pressure reduction step, the internal pressure of the column (A) is further reduced by lead-out of the gas (FIG. 4B). In the desorption step, the unnecessary components are desorbed from the adsorbent and purged from the column (A) (FIG. 4C). In the scrubbing step, introduction of the gas (G3) and purging of the gas (G4) are performed simultaneously (FIG. 5A). In the repressurizing step, the internal pressure of the column (A) is raised by introducing the gas (G3) (FIG. 5B). The gas (G3) that is led out from the column (A) during the first pressure reduction step is introduced into the column (C) during the scrubbing step (FIG. 4A), and the gas (G3) that is led out from the column (A) during the second pressure reduction step is introduced into the column (C) during the repressurizing step (FIG. 4B).

Claims6

Dependent claims

A method of separating a target gas from a gas mixture using a plurality of adsorption columns packed with an adsorbent, the method comprising repeating a cycle for each of the adsorption columns, the cycle comprising:

an adsorption step in which said gas mixture is introduced into one selected adsorption column, an unnecessary component contained in said gas mixture is adsorbed into said adsorbent, and a product gas enriched with said target gas is led out from said adsorption column;
a first pressure reduction step for lowering the internal pressure of said adsorption column to a first intermediate pressure by leading out a first led-out gas;
a second pressure reduction step for lowering the internal pressure of said adsorption column even further to a second intermediate pressure by leading out a second led-out gas;
a desorption step for desorbing at least a part of said unnecessary component from said adsorbent and purging said unnecessary component;
a scrubbing step for introducing a scrubbing gas into said adsorption column and purging a purge gas from said adsorption column;
and
a repressurizing step for raising the internal pressure of said adsorption column by introducing a repressurizing gas into said adsorption column;
wherein said first led-out gas led out from said adsorption column during said first pressure reduction step is introduced as said scrubbing gas into an adsorption column in which said scrubbing step is underway, and said second led-out gas led out from said adsorption column during said second pressure reduction step being introduced as said repressurizing gas into an adsorption column in which said repressurizing step is underway.

5 more elements

Dependencies are inferred from the claim text.