Method of chromatographic separation

Claim 2

In a chromatographic process of a type wherein a feedstock fluid, containing a plurality of components having different degrees of affinity for an adsorbent, is supplied into a chromatographic separa­tion system in which the upstream end of a bed packed with the adsorbent is connected to its downstream end by a fluid channel to enable the circulation of fluids, and the feedstock fluid is passed through the packed bed for its upstream end to its downstream end to form adsorption zones having the concentration distributions of the respective components, followed by subsequent separation into three or more fractions, the improve­ment wherein one of the feedstock fluid and a desorbent fluid is supplied into the packed bed at the upstream end so that zones enriched in the respective components are withdrawn as separate fractions, with at least part of the zones in which the respective components are present in admixture being retained within the bed as a non-withdrawal zone, the improvement further comprising the step of circulating the fluids in the packed bed without supplying any fluid into the bed or withdrawing any fluid therefrom, so that said non-withdrawal zone is situated adjacent to the zone in which the fluid feedstock is supplied, thereby replacing the latter zone with a zone to be withdrawn at the time when said feedstock fluid is supplied to the bed.

Claim 3

A chromatographic process of a type wherein a feedstock fluid, containing a plurality of components having different degrees of affinity for an adsorbent, is supplied into a chromatographic separation system in which the upstream end of a bed packed with the adsor­bent is connected to its downstream end by a fluid channel to enable the circulation of fluids, and the feedstock fluid is passed through the packed bed from its upstream end to its downstream end to form adsorption zones having the concentration distributions of the respective components followed by subsequent separation into three or more fraction said process including the following steps in sequence: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a first component of the feedstock fluid is withdrawn from the downstream end of said bed; (ii) supplying the desorbent fluid into the packed bed at its upstream end to withdraw a fraction enriched in a second component of the feedstock fluid from the downstream end of the bed; and (iii) circulating the fluids in the packed bed without supplying any fluid into or withdrawing any fluid from the packed bed, thereby allowing a zone containing the component withdrawn in said step (i) and another component in admixture to be moved to the upstream end of the packed bed, said steps (i) to (iii) being performed cyclically.

Claim 4

A chromatographic process of a type wherein a feedstock fluid, containing a plurality of components having different degrees of affinity for an adsorbent, is supplied into a chromatographic separation system in which the upstream end of a bed packed with the adsor­bent is connected to its downstream end by a fluid channel to enable the circulation of fluids, and the feedstock fluid is passed through the packed bed from its upstream end to its downstream end to form adsorption zones having the concentration distributions of the respective components followed by subsequent separation into three or more fraction said process including the following steps in sequence: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a first component of the feedstock fluid is withdrawn from the downstream end of said bed; (ii) supplying the desorbent fluid into the packed bed at its upstream end to withdraw a fraction enriched in a second component of the feedstock fluid from the downstream end of the bed; and (iii) circulating the fluids in the packed bed without supplying any fluid into or withdrawing any fluid from the packed bed, thereby allowing a zone containing the component withdrawn in said step (i) and another component in admixture to be moved to the upstream end of the packed bed, said steps (i) to (iii) being performed cyclically.

Claim 5

A chromatographic process according to Claim 2 wherein a mixture is separated into three fractions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity in admixture with a component having a second, higher affinity for the adsorbent to be moved to the upstream end of the packed bed; (iii) supplying a desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having said second affinity; (iv) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component having a third affinity, lower than said first affinity, for the adsorbent; and (v) circulating the fluids in the packed bed without supplying any fluid into the bed or withdrawing any fluid from the bed, thereby allowing a zone con­taining the component having said first affinity in admixture with the component having said third affinity to be moved to the upstream end of the bed.

Claim 6

A chromatographic process according to Claim 2 wherein a mixture is separated into three fractions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) supplying a desorbent fluid into the packed bed at its middle portion to withdraw from the downstream end of said bed an additional fraction enriched in the component having said first affinity; (iii) circulating the fluids in the packed bed without supplying any fluid into the bed or with­ drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity in admixture with a component having a second, higher affinity for the adsorbent to be moved to the upstream end of the packed bed; (iv) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having said second affinity; (v) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component a third affinity, lower than said first affinity, for the adsorbent; and (vi) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed thereby allowing a zone containing the component having said first affinity in admixture with the component having said third affinity to be moved to the upstream end of the bed.

Claim 7

A chromatographic process according to Claim 2 wherein a mixture is separated into three reactions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) supplying an additional amount of the feedstock fluid into the packed bed at its upstream end while a fraction enriched in a component having a second, lower affinity for the adsorbent is withdrawn from the middle portion of the bed; (iii) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity in admixture with a component having a third affinity, higher than said first affinity, for the adsorbent to be moved to the upstream end of the bed; (iv) supplying a desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having said third affinity; (v) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having said second affinity; and (vi) circulating the fluids in the packed bed without supplying any fluid into the bed or withdrawing any fluid from the bed, thereby allowing a zone con­taining the component having said first affinity in admixture with the component having said second affi­nity to be moved to the upstream end of the packed bed.

Claim 8

A chromatographic process according to Claim 2 wherein a mixture is separated into four fractions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) supplying a desorbent fluid into the packed bed at its middle portion to withdraw from the downstream end of said bed an additional fraction enriched in the component having said first affinity for the adsorbent; (iii) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity for the adsorbent in admixture with a component having a second, higher affinity for the adsorbent to be moved to the upstream end of the packed bed; (iv) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having said second affinity for the adsorbent; (v) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component having a third affinity, lower than said first affinity, for the adsorbent; (vi) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component having a fourth affinity, between said first and third affinities, for the adsorbent; and (vii) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity for the adsorbent in admixture with the component having said fourth affinity for the adsorbent to be moved to the upstream end of the packed bed.

Claim 9

A chromatographic process according to Claim 2 wherein a mixture is separated into three fractions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity in admixture with a component having a second, higher affinity for the adsorbent to be moved to the upstream end of the packed bed; (iii) supplying a desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having said second affinity; (iv) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component having a third affinity, lower than said first affinity, for the adsorbent.

Claim 10

A chromatographic process according to Claim 2 wherein a mixture is separated into three fractions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity in admixture with a component having a second, higher affinity for the adsorbent to be moved to the upstream end of the packed bed; (iii) supplying a desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having said second affinity; (iv) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component having a third affinity, lower than said first affinity, for the adsorbent; and (v) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component having said first affinity.

Claim 11

A chromatographic process according to Claim 2 wherein a mixture is separated into three fractions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) supplying a desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having a second affinity, higher than said first affinity for the adsorbent; (iii) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component having a third affinity, lower than said first affinity, for the adsorbent; and (iv) circulating the fluids in the packed bed without supplying any fluid into the bed or withdrawing any fluid from the bed, thereby allowing a zone con­taining the component having said first affinity in admixture with the component having said third affinity to be moved to the upstream end of the bed.

Claim 12

A chromatographic process according to Claim 2 wherein a mixture is separated into three fractions by cyclically repeating the following steps: (i) supplying the feedstock fluid into the packed bed at its upstream end while a fraction en­riched in a component having a first affinity for the adsorbent is withdrawn from the downstream end of said bed; (ii) supplying a desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of said bed an additional fraction enriched in the component having said first affinity; (iii) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in the component having a second affinity, higher than said first affinity for the adsorbent; (iv) supplying the desorbent fluid into the packed bed at its upstream end to withdraw from the downstream end of the bed a fraction enriched in a component a third affinity, lower than said first affinity, for the adsorbent; and (v) circulating the fluids in the packed bed without supplying any fluid into the bed or with­drawing any fluid from the bed, thereby allowing a zone containing the component having said first affinity in admixture with the component having said third affinity to be moved to the upstream end of the bed.