MOVING BED CHROMATOGRAPHY

Abstract

Moving bed chromatography, and simulated moving bed chromatography has been known for over 50 years, but has recently become important in the isolation of pure substances where the components are very similar, as in the case of enantiomers and in the isolation of substances which would be difficult or impossible by other means. The first example of moving bed chromatography was in the separation of pure acetylene from methane oxidation products, reported in 1956. Subsequently, in 1958, the separation of pure benzene from coal gas was described using gas liquid chromatography and a moving bed system.

The movement of solely the chromatographic packing proved difficult to control and an alternative method using circular columns with moving ports to simulate the moving bed proved to be partially successful. Eventually, the circular columns were replaced by a group of static packed columns connected in series by a rotary valve that simulated a moving bed. This device proved very successful and was developed further, the disc valve eventually being replaced by low dead volume unit valves under computer control. Today, effective simulated moving bed chromatographic systems are becoming available, but it is still left to the operator to determine the optimum operating conditions, and that can often be difficult and tedious.

Acknowledgments