Zosel, Kurt

Jens Zosel Kurt-Schwabe-Institut fiir Mess- und Sensortechnik e.V. Meinsberg, Waldheim, Germany... 

The solubility of a solute in scC02 is extremely dependent on its structure, with three features of paramount importance. As expected, compounds of low polarity are more soluble than very polar compounds or salts. However, solubility also increases greatly with increasing vapour pressure of a substrate. To account for the contribution of volatility and solvation to the solubility process, Kurt Zosel coined the term Destraktion (from Latin destillare and extrahere) in his pioneering work on natural product extraction with SCFs [5], Finally, some specific functional groups like perfluoroalkyl and polysiloxane substituents, or polyether/polycarbonate copolymers... 

Supercritical fluids (SCFs) have fascinated researchers ever since the existence of a critical temperature was first noted more than 175 years ago [1]. Although initial studies focussed mainly on the physical properties of supercritical phases, their chemical reactivity was of interest from the beginning, too [2]. In fact, several well established industrial processes for the production of bulk chemicals occur under temperatures and pressures beyond the critical data of the reaction mixture, the Haber-Bosch process and the high pressure polymerization of ethylene being just the most outstanding examples. Based on the pioneering work of Kurt Zosel at the Max-Planck-Institut fiir Kohlenfor-... 

Figure 1.1-12 Kurt Zosel (1913-1989) (photograph used with permission from the Photoarchiv MPI fiir Kohlen-forschung, Miilheim/Ruhr).

One of the best known and most influential developments in the use of SCCO2 was based on the work of Kurt Zosel in the early 1960s, where SCCO2 played a key role in the extraction of caffeine from coffee, which has obvious benefits to the consumer over alternative, solvent-based processes." This is now carried out industrially on a huge scale, producing many thousands of tons of decaffeinated coffee per year. Liquid and supercritical CO2 are routinely used for the extraction of natural products, particularly hops and essential oils, and this is now considered to be a relatively mature area of CO2 technology. 

The process of destraction dates back to a discovery by Kurt Zosel (1913-1989) at the Max-Planck-Institut fur Kohlenforschung in Miilheim, who was engaged in normal-pressure polymerisation of ethylene. He had incidentally noticed, that residues from the distillation of oU, but also waste oil, vegetable fats and oils from natural products, could be extracted very well with supercritical gases. [514] This methodology offered correspondingly a number of other applications, as to extract hop aroma from hops, unsaturated fatty acids from fish oUs, vitamin E from vegetable oils, and paraffins or phenols from bituminous tar. 

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