TURKISH JOURNAL OF CHEMISTRY, cilt.25, ss.477-484, 2001 (SCI İndekslerine Giren Dergi)
Reactive extraction of citric acid was investigated at atmospheric and supercritical. conditions. The most suitable diluent and amine from among the tertiary amines and eight different diluents were determined at atmospheric conditions. The distribution coefficient values obtained with Hostarex A 327 were higher than those of Alamine 336. The selected amine (Hostarex A327) and the diluent (Oleyl alcohol) were used for reactive extraction of citric acid at supercritical conditions. Separation yields of citric acid were obtained in the temperature ranges of 308 to 328 K and in the pressure ranges of 80 to 180 bars in a supercritical. extraction system which is continuous in terms of CO2. It was found that separation yield decreased with increasing extraction pressure at all investigated temperatures. The highest separation yield (28%) was obtained at near the critical pressure. It was observed that the separation yield did not change with increasing temperature in the pressure range of 80 to 180 bars.