Abstract: A chromatographic process of a type wherein a feedstock fluid containing a plurality of components is supplied into a circulative chromatographic separation system, the process comprising the steps of (i) supplying the feedstock fluid and withdrawing a fraction enriched in a component, (ii) supplying a desorbent fluid and withdrawing a fraction enriched in another component, and (iii) circulating the fluid through the bed without supplying or withdrawing any fluid thereby making a mixed zone comprising a plurality of components move, a cycle including steps (i), (ii) and (iii) being repeated while controlling the discharged pressure of a pump delivering the feedstock fluid, the desorbent fluid, and the circulating fluid constant.

Abstract: A chromatographic process of a type wherein a feedstock fluid containing a plurality of components is supplied into a circulative chromatographic separation system, the process comprising the steps of (i) supplying the feedstock fluid and withdrawing a fraction enriched in a component, (ii) supplying a desorbent fluid and withdrawing a fraction enriched in another component, and (iii) circulating the fluid through the bed without supplying or withdrawing any fluid thereby making a mixed zone comprising a plurality of components move, a cycle including steps (i), (ii) and (iii) being repeated while controlling the discharged pressure of a pump delivering the feedstock fluid, the desorbent fluid, and the circulating fluid constant.

Abstract: A process for producing purified L-ascorbic acid, which comprises subjecting an aqueous solution of crude L-ascorbic acid to column chromatography using a strongly acidic cation exchange resin; and a method of purifying L-ascorbic acid, which comprises subjecting an aqueous solution of crude L-ascorbic acid to column chromatography using a strongly acidic cation exchange resin.

Abstract: The method of chromatographic separation comprises: a feed-withdrawal step in which, with liquid flow being permitted from the first to the third unit beds in the simulated moving bed, an eluant is fed into the first unit bed and the feed stock is fed into the third unit bed while, at the same time, part of the effluent from the first unit bed is withdrawn from the system as a fraction rich in component B and the effluent from the third unit bed is withdrawn from the system as a fraction rich in component C; a circulation stage in which, with liquid circulation being permitted through the simulated moving bed, the liquid in the simulated moving bed is moved downstream without liquid feed to or withdrawal from the simulated moving bed; and a withdrawal stage in which, with liquid flow being permitted from the second to the first unit beds, the eluant is fed to the second unit bed and the effluent from the first unit bed is withdrawn from the system as a fraction rich in component A; wherein, after the above th

Abstract: In a method using a chromatographic separation apparatus consisting of plurality of unit packed beds each having a supply inlet/extraction outlet, wherein the apparatus is effectively divided into four zones; an adsorption zone, a refining zone, a desorption zone, and a concentration zone. A supply and extraction step is performed in which all of the fluid flowing out of the adsorption zone is extracted through the nonadsorbate fluid extraction outlet, and then a recycle step, in which no fluid is supplied to or extracted from the bed, is performed to move the concentration distributions in the bed to a desired position. As a result, the method requires fewer unit beds, and enables extraction of components of higher purity.

Abstract: A chromatographic separation process employing fewer beds packed with an adsorbent, while enabling separation of feedstock fluid, containing a plurality of components which have different degrees of affinity for the adsorbent, into constituent fractions which are withdrawn separately. According to at least one preferred embodiment, a step of supplying feedstock fluid to the simplified separation apparatus is preceded and followed by a step of circulating the fluid through the apparatus, a cycle of supply-desorbing-circulation being carried out repeatedly.

Abstract: A method is disclosed for controlling a simulated moving bed system of a type including at least four series-arranged beds each packed with a solid adsorbent, with the downstream end of each bed and the upstream end of the next succeeding bed being connected by conduits to form an endless loop, and in which a fluid is caused to circulate through the beds in one direction, a feed stock and a desorbent are introduced into the system while a raffinate and a sorbate are withdrawn from the system, and the positions of introduction and withdrawal of the four kinds of fluid are periodically shifted in the direction of the circulating fluid flow. In accordance with the invention, two or more circulating pumps, provided with variable speed controllers and pressure detectors for detecting the suction pressure of each of the circulating pumps, are disposed between two beds.