Patent ID: 8778051
Filing Date: 2014-07-15
Classification: B01D,Y02C

Abstract:
1. A process for separating a primary gas component from a feed gas mixture comprising the primary gas component and secondary gas components in a plurality of at least four adsorption beds, each adsorption bed containing an adsorbent selective for the secondary components, the process comprising subjecting each of the plurality of at least four adsorption beds to a repetitive cycle, the repetitive cycle comprising, in sequence, a feed step, a first pressure decreasing equalization step, a provide purge step, a blowdown step, a purge step, a first pressure increasing equalization step, and a repressurization step, wherein: the feed step comprises introducing the feed gas mixture at a feed gas pressure ranging from 1.0 MPa to 7.0 MPa into an adsorption bed undergoing the feed step and adsorbing the secondary gas components on the adsorbent in the adsorption bed undergoing the feed step while simultaneously withdrawing a product gas comprising the primary gas component from the adsorption bed undergoing the feed step; the first pressure decreasing equalization step comprises co-currently withdrawing a pressure equalization gas from an adsorption bed undergoing the first pressure decreasing equalization step, and passing the pressure equalization gas to an adsorption bed undergoing the first pressure increasing equalization step thereby equalizing the pressure between the adsorption bed undergoing the first pressure decreasing equalization step and the adsorption bed undergoing the first pressure increasing equalization step; the provide purge step comprises co-currently withdrawing a purge gas from an adsorption bed undergoing the provide purge step, and passing the purge gas from the adsorption bed undergoing the provide purge step to an adsorption bed undergoing the purge step; the blowdown step comprises counter-currently withdrawing a blowdown gas from an adsorption bed undergoing the blowdown step, the blowdown gas having a concentration of the secondary gas components that is higher than the concentration of the secondary gas components in the feed gas mixture; the purge step comprises counter-currently introducing the purge gas from the adsorption bed undergoing the provide purge step, into an adsorption bed undergoing the purge step and counter-currently withdrawing a purge gas effluent from the adsorption bed undergoing the purge step, the purge gas effluent having a concentration of the secondary gas components that is higher than the concentration of the secondary gas components in the feed gas mixture; the first pressure increasing equalization step comprises counter-currently introducing the pressure equalization gas from the adsorption bed undergoing the first pressure decreasing equalization step into the adsorption bed undergoing the first pressure increasing equalization step; and the repressurization step comprises increasing the pressure in an adsorption bed undergoing the repressurization step until the adsorption bed undergoing the repressurization step is substantially at the feed gas pressure, by at least one of co-currently introducing the feed gas mixture into the adsorption bed undergoing the repressurization step, and counter-currently introducing a portion of the product gas from the adsorption bed undergoing the feed step into the adsorption bed undergoing the repressurization step; wherein at least one of (i) the first pressure decreasing equalization step further comprises co-currently introducing a rinse gas simultaneously with the withdrawing of the pressure equalization gas, and (ii) the provide purge step further comprises co-currently introducing a rinse gas simultaneously with the withdrawing of the purge gas; wherein the rinse gas is formed by compressing at least a portion of at least one of the blowdown gas from the adsorption bed undergoing the blowdown step and the purge gas effluent from the adsorption bed undergoing the purge step; and wherein the first pressure increasing equalization step further comprises at least one of (i) co-currently introducing the feed gas mixture into the adsorption bed undergoing the first pressure increasing equalization step simultaneous with the counter-current introduction of the pressure equalization gas from the adsorption bed undergoing the first pressure decreasing equalization bed, and (ii) counter-currently introducing product gas from at least one of the adsorption beds undergoing the feed step into the adsorption bed undergoing the first pressure increasing equalization step simultaneous with the counter-current introduction of the pressure equalization gas from the adsorption bed undergoing the first pressure decreasing equalization step.