“…Up to now almost all countercurrent supercritical fluid extraction studies have been carried out in spray, sieve tray, or packed columns (Peter and Brunner, 1978;Rathkamp et al, 1987;Lahiere and Fair, 1987;Seibert et al, 1988;Czech and Peter, 1990;de Haan and de Graauw, 1991;Brunner et al, 1991;Bernad et al, 1993;Meyer and Brunner, 1994;Lim et al, 1995;Simo ˜es et al, 1995;Sato et al, 1997;Nagase et al, 1997). In these studies countercurrent supercritical extraction columns, particularly packed columns, have been shown to be very efficient compared to conventional liquid-liquid extraction columns.…”