VERFAHREN ZUR ABTRENNUNG VON KOFFEIN AUS MIT KOFFEIN BELADENER AKTIVKOHLE.

摘要

Sepn. of caffeine (I) from (I)-laden active carbon is effected by circulating an inert gas stream at right angles through the active carbon stream at 350-450 deg.C.. The desorbed (I) is recovered in the form of solid particles by cooling the gas stream. Pref. the active carbon moves under gravity through a crossflow oven (1) into which the inert gas is injected at a velocity of 1-10 (esp. 5-7) cm/sec so as to traverse a 20-60 (esp. 25-50) mm deep bed of the activated carbon. The gas temp. is 410-420 deg.C and the contact time is 10-60 (esp. 20-30) min.. The inert gas is CO2, N2 or their mixts. (e.g. flue gas), or is air which has been pre-contacted with unladen active carbon to reduce its O2 content to less than 100 ppm.. The (I)-laden active carbon has an initial moisture content of less than 15 (less than 1)% and may contain up to 10 (2-3) wt.% of adsorbed materials other than (I), e.g. paraffin oil or coffee oil. The gas stream is cooled in two stages in water, scrubbers.