Application of Supercritical Fluids in the Fine Chemical Industry

Application of Supercritical Fluids in the Fine Chemical Industry 

Supercritical fluids, for example scCOa, could be an alternative for use as a process solvent because supercritical fluids have advantages, for example in terms of environmental benefits (SCCO2) 

From the viewpoint of chemical processes, the main advantages of supercritical fluids are 

The application of supercritical fluids, for example SCCO2, as an environmentally acceptable replacement for conventional solvents, is well documented in the industry. Based on the work of Zosel, the decaffeination of coffee and tea using SCCO2 was the first industrial use of this technology [1]. The advantages of supercritical fluids are not only useful in separation techniques, for example supercritical fluid extraction (SFE) or supercritical chromatography (SFC), their application as process solvents is well recognized [2, 3]. 

For new industrial processes, economic and ecological aspects arc closely related production of waste is per se not an economic achievement. Therefore environmentally friendly or so-called green chemistry is gaining increasing recognition. 

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I 7 3 Application of Supercritical Fluids in the Fine Chemical Industry... 

Bonrath, W. Karge, R. Application of Supercritical Fluids in the Fine Chemical Industry. In High Pressure Chemistry. Synthetic, Met nistic and Supercritical Applications-, van Eldik, R., Klarner, F.-G., Eds. Wiley-VCH Weinheim, 2002 Chapter 13. 

Bonrath, W. and Karge, R. (2002) Application of supercritical fluids in the fine chemical industry, in High Pressure Chemistry (eds R. van Eldick and F.G. Klarner), Wiley-VCH Verlag GmbH, Weinheim, pp. 398 21. 

In the following sections some aspects of (potential) applications of sc-fluids in the fine chemical industry with respect to product separation/purification and catalytic reactions are discussed. Earlier industrial applications of supercritical fluid reactions, for example the Haber-Bosch process for the synthesis of ammonia, synthesis of methanol from hydrogen and carbon monoxide, or the polymerization of ethene will not be discussed. An extensive overview on the use of sc-fluids in the synthesis of bulk chemicals is given in the book edited by fessop and Leitner [12],... 

As mentioned earlier, supercritical fluids have a broad potential for application in new processes. In recent years a number of publications reviewed the role of supercritical fluids in technical applications [9-16], and more industrial applications of sc-fluids were established in the synthesis of fine chemicals. In a variety of reactions such as hydrogenations, hydroformylations and Friedel-Crafts reactions, the advantageous use of sc-fluids as solvents has been demonstrated with respect to yield, selectivities, and no work-up procedure [17]. 

Examples of industrial applications of supercritical fluids can be found in pharmaceutical chemistry or in the synthesis of fine chemicals. 

The further optimization and development concerning stability and selectivity of the organometallic catalyst in these kinds of media and the application of isolation methodologies similar to CESS (catalysis and extraction using supercritical solutions [43]) together with the physical and chemical advantages of supercritical fluids can lead to high potential catalyst matrices that fulfil the requirements of industrial processes both for bulk and fine chemicals. 

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