초록 ▼

Pressure swing adsorption with increased recovery of a highly adsorbable product gas component is carried out with a cycling in which, during the flushing phase, and at least over the latter portion thereof, the flushing gas has a concentration in the product gas component which is substantially equ

Pressure swing adsorption with increased recovery of a highly adsorbable product gas component is carried out with a cycling in which, during the flushing phase, and at least over the latter portion thereof, the flushing gas has a concentration in the product gas component which is substantially equal to that of the product gas. To further increase the yield and the concentration of the product gas component in the product gas, the pressure in the absorber is reduced over a time period between the termination of the adsorption phase and the beginning of the desorption phase, with the effluent gas during this reduction in pressure being reused in the pressure swing adsorption cycle.

대표청구항 ▼

In a method of recovering, in a pressure swing adsorption process, at least one relatively highly adsorbable product gas component for a raw gas containing said product gas component in admixture with at least one less adsorbable gas component in a cycle wherein: (a) in an adsorption phase in a pres

In a method of recovering, in a pressure swing adsorption process, at least one relatively highly adsorbable product gas component for a raw gas containing said product gas component in admixture with at least one less adsorbable gas component in a cycle wherein: (a) in an adsorption phase in a pressure swing adsorber, said raw gas is passed through an adsorber bed at an adsorption pressure in a first gas flow direction to adsorb said highly adsorbable product gas component on said bed and past a waste gas containing said less adsorbable component, the adsorption phase of step (a) being terminated before breakthrough of said highly adsorbable product gas component through said bed; (b) said bed is flushed in a flushing phase with a flushing gas such that at least toward the end of said flushing phase said flushing gas has a concentration of said highly adsorbable product gas component substantially equal to that in a product gas; (c) the pressure is thereafter reduced in said adsorber in a desorption gas to desorb said highly adsorbable product gas component from said adsorber to produce said product gas containing said highly adsorbable product gas component, said product gas being withdrawn from said adsorber, and a portion of said product gas is fed as a flushing gas for use in a subsequent practice of step (b); and (d) the pressure in the adsorber desorbed in step (c) is thereafter rebuilt to said adsorption pressure, the improvement which comprises: (e) intermittently between the end of said adsorption phase and before the commencement of said desorption phase in the cycle of said adsorber, drawing a partial gas flow from said adsorber in the same direction as the flow of gas therethrough during an immediately prior period of the cycle to reduce the pressure in said adsorber; and (f) reusing said partial gas flow in said pressure swing adsorption process.