First, at step 1 of the cycle, the circulation flow is stopped (shut-off
valve closed), feed mixture is fed in, and, in a similar way to the fixed-bed
mode, the component having an intermediate affinily to the adsorbent between
component A and B is withdrawn.
Next, the feeding in of the feed mixture is stopped and the shut-off
valve is opened. From step 2 on, this method proceeds in the same way as
does the simulated moving-bed mode, i.e. the desorbent feeding and component
drawing points, D, A, and C are periodically moved as components A and C
are continuously with draun.
The point of special interest here is that starting from step 2, the
feeding of the feed mixture is stopped. During this time, the migration
rate at each of the desorbent feeding and component withdrawal points becomes
approximately equal to the migration rate of component B (Ub).
Through such an operation, components A and C move towards the front
and rear of the in intermediate affinity component B, and gradually a zone
with only component B is formed.
When the fluid openings D, A, C have been moved periodically around until
they are back to the same way as in step 1, the circular flow is once again
cut (shut-off valve closed), the feed mixture is fed, and component B is
withdrawn.
Through the repetition of this operation, components A and C move in
opposite directions away from the position of component B, enabling us to
continuously extract components A and C from their respective openings.
The withdrawnal of component B can be done while the mixture is being fed.
In this way, under the New JO Chromatographic Separation System, the
separation of components A, B, and C can be done as a continuous operation. |
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