Multiple liquid-liquid partition: I. Theory of countercurrent distribution (CCD)

✍ Scribed by Paavo H. Hynninen

• Book ID: 102983831
• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 832 KB
• Volume: 74
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(76)90219-0

✦ Synopsis

The theory of countercurrent distribution (CCD) was reviewed and extended. The separation function for the fundamental distribution of CCD was presented intheform n = t2(akl + e)*/&(fl-l)* h w ere n is the number of transfers, t the abscissa of the standard normal distribution, o = u,/v, the phase ratio, p = kl/k2 s 1 the separation factor, and kl the partition coefficient of the more rapidly moving component; n was found to be minimal on the condition akl = fi The separation function for the single withdrawal of CCD was obtained in the form N = u + 1 = t2{(akl + 1)'" + [P(akl + P)]ln}*/(P -l)* + 1, where N is the number of partition units. From this equation it appears that N is minimal when akl = 0. Compared with the former separation functions presented in the literature, these separation functions have the advantage of giving directly the relationships among the phase ratio, the absolute partition coefficient, the separation factor, the resolution degree, and the number of transfers or partition units required. In addition, the dependencies of the elution volumes and the widths of the elution curves on (Y, p, and the partition coefficients were considered mathematically by means of differential calculus. The elution volumes were found to have minima at certain akl values. The standard deviations, on the contrary, did not have minima in respect to akl. The theory presented can be used for selecting proper operating conditions while separating chemical compounds.

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