Pressure swing adsorption recovery
First Claim
1. In a pressure swing adsorption process for the selective adsorption of at least one gas component from a feed gas mixture in an adsorption system having at least three adsorbent beds, each of which undergoes, on a cyclic basis, higher pressure adsorption, cocurrent depressurization to intermediate pressure with release of void space gas from the bed, countercurrent depressurization to a lower desorption pressure, and repressurization to said higher pressure, and in which the void space gas released from one bed is passed to the product end of another bed initially at a lower pressure to equalize the pressure therebetween, said other bed also being repressurized by a portion of the product eflluent withdrawn from a bed undergoing adsorption at said higher pressure, the improvement comprising:
- (a) introducing released void space gas to be used for said pressure equalization purposes directly into the bed undergoing repressurization to equalize the pressure between the beds at an intermediate pressure;
(b) simultaneously passing a portion of the product effluent withdrawn from a bed undergoing adsorption at said higher pressure to an external repressurization storage tank; and
(c) upon completion of said pressure equalization, passing said gas from said repressurization storage tank to said bed undergoing repressurization, together with an additional portion of product effluent withdrawn from a bed undergoing adsorption at said higher pressure, whereby product recovery is enhanced without discontinuity in the substantially uniform flow of product effluent from the adsorption system.
4 Assignments
0 Petitions
Accused Products
Abstract
Void space gas is released from an adsorbent bed at a higher adsorption pressure by cocurrent depressurization of the bed. The released gas is passed to another bed of a pressure swing adsorption system to equalize the pressure therebetween, the other bed being initially at a lower pressure. A portion of the product effluent withdrawn from yet another bed of the system is not passed to the bed undergoing repressurization, as in conventional practice, but is passed to an external repressurization storage tank during said pressure equalization step. Upon completion of this step, the product effluent is withdrawn from the repressurization tank and passed to said bed undergoing repressurization.
110 Citations
22 Claims
-
1. In a pressure swing adsorption process for the selective adsorption of at least one gas component from a feed gas mixture in an adsorption system having at least three adsorbent beds, each of which undergoes, on a cyclic basis, higher pressure adsorption, cocurrent depressurization to intermediate pressure with release of void space gas from the bed, countercurrent depressurization to a lower desorption pressure, and repressurization to said higher pressure, and in which the void space gas released from one bed is passed to the product end of another bed initially at a lower pressure to equalize the pressure therebetween, said other bed also being repressurized by a portion of the product eflluent withdrawn from a bed undergoing adsorption at said higher pressure, the improvement comprising:
-
(a) introducing released void space gas to be used for said pressure equalization purposes directly into the bed undergoing repressurization to equalize the pressure between the beds at an intermediate pressure; (b) simultaneously passing a portion of the product effluent withdrawn from a bed undergoing adsorption at said higher pressure to an external repressurization storage tank; and (c) upon completion of said pressure equalization, passing said gas from said repressurization storage tank to said bed undergoing repressurization, together with an additional portion of product effluent withdrawn from a bed undergoing adsorption at said higher pressure, whereby product recovery is enhanced without discontinuity in the substantially uniform flow of product effluent from the adsorption system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. In a pressure swing adsorption system of at least three adsorbent beds for the selective adsorption of at least one gas component from a feed gas mixture, said system having conduit means for withdrawing product effluent from each bed at a higher adsorption pressure, on a cyclic basis, and for withdrawing a portion of said product effluent for delivery to an other bed undergoing repressurization from a lower pressure to said higher adsorption pressure, and conduit means for passing void space gas released from each bed, on a cyclic basis, to an other bed undergoing said repressurization for pressure equalization to an intermediate pressure, the improvement comprising:
-
(a) an external repressurization storage tank; (b) means for passing said withdrawn portion of the product effluent to the repressurization tank for delivery to a bed undergoing repressurization; and (c) means for passing product effluent from the repressurization tank to an other bed undergoing repressurization, on a cyclic basis, said means providing for the passage of said product effluent to said other bed subsequent to the repressurization of said bed from a lower pressure to an intermediate pressure by pressure equalization with a bed undergoing depressurization, whereby product recovery is enhanced without discontinuity in the substantially uniform flow of product effluent from the adsorption system. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
-
Specification