초록 ▼

The inclusion of one or more tanks in a two-bed pressure swing adsorption system provides for a further reduction in the pressure from which each bed is vented. According to the invention, following a bed pressure equalization step, the bed which is to undergo regeneration is equalized with at least

The inclusion of one or more tanks in a two-bed pressure swing adsorption system provides for a further reduction in the pressure from which each bed is vented. According to the invention, following a bed pressure equalization step, the bed which is to undergo regeneration is equalized with at least one tank, which is at a lower pressure, in order to transfer part of the gas located in the bed void volume. After the bed is regenerated, it is again equalized with the same tank, now at a higher pressure than the bed, in order to return the conserved gas. This process increases yield by decreasing the loss of gas attributable to bed void volume. The combination of the two-bed process with one or more pressure equalization tanks for conserving void gas for subsequent bed repressurization rather than use as purge gas is unique to the present invention. It is best applied to multicomponent gas mixtures, in which a moderately adsorbed component is distributed between a higher pressure primary product stream containing a mildly adsorbed component and a lower pressure secondary product or vent stream containing a strongly adsorbed component. The present process has been applied to increase the yield of argon which is separated from a mixture consisting of hydrogen, argon, nitrogen and methane.

대표청구항 ▼

A cyclical process for the separation of a multicomponent gaseous mixture at a high pressure, said multicomponent gaseous mixture comprising at least three components, said cyclical process utilizing a pressure swing adsorption system comprising two beds and at least one tank, wherein said two beds

A cyclical process for the separation of a multicomponent gaseous mixture at a high pressure, said multicomponent gaseous mixture comprising at least three components, said cyclical process utilizing a pressure swing adsorption system comprising two beds and at least one tank, wherein said two beds contain an adsorbent material of different selectivity with respect to each of said three components, and said tank is adapted to communicate with both beds, said process comprising in sequence: (i) a first pressure equalization of a first adsorption bed with said tank through the product end following top to top and bottom to bottom pressure equalization of the two beds; (ii) regeneration of said first adsorption bed; (iii) a second pressure equalization of said first adsorption bed with said tank again through the product end, thereby returning conserved high pressure void gas to said first bed; (iv) a first pressure equalization of a second adsorption bed with said tank through the product end, following top to top and bottom to bottom equalization of the two beds; and (v) regeneration of said second adsorption bed, and second pressure equalization of said second adsorption bed with said tank again through the product end, thereby returning conserved high pressure void gas to said second bed; whereby while one bed is pressure equalizing or regenerating, the other bed is being pressurized with feed and producing primary product at high pressure, and whereby at least two streams are produced by each bed, a primary product stream at relatively high pressure, rich in at least one mildly adsorbed component which is a desired high valued final product and a secondary product stream at relatively low pressure, rich in one or more strongly adsorbed component that must not be present in more than trace levels in the primary product, and wherein a component of said multicomponent gaseous mixture, which component is moderately adsorbed and present in significant amounts in said multicomponent gaseous mixture, is permitted to distribute between said primary product stream and said secondary product stream; wherein, the process improvement realized is the high yield of the mildly absorbed component in the primary product with a concurrent increase in the amount of the moderately adsorbed component going with the primary product.