Development of Large Scale Commercial Systems

It is worth mentioning the work of Khosah [25] at the laboratory scale on elution with a supercritical fluid of compounds adsorbed on a porous material. Khosah discussed the technical and economic feasibility of the process at the pilot plant scale. 

Alkio et al. [26] published some results obtained with a preparative SFC unit built by conversion of a supercritical fluid extractor. Columns of 0.3 to 2L could be mounted in this unit and be swept at flow-rates of up to 8 kg of liquid carbon dioxide. However, both these devices suffer from a lack of automation and operating experience. Industrial development of these systems in the near future is unlikely. 

In order to widen the field of preparative SFC to more polar molecules an investigation of the addition of modifier solvents was carried out [31]. 

Several industrial scale separations were conducted by Berger and Perrut which demonstrated that preparative SFC could be a serious competitor to HPLC in the future for certain t5q es of separation [32]. 

We anticipate that the use of process scale SFC for the production of multi-kilogram quantities of product will be restricted primarily to high value products such as highly potent (low dose) pharmaceuticals whose annual production would be measured in kilograms rather than in tonnes. 

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