Preferential removal of caffeine from aq. coffee extracts - using resins in countercurrent systems

摘要

Countercurrent adsorption process for separating a preferentially adsorbed component (I) from an aq. multicomponent soln. which contains other cpds. which are also adsorbed comprises (a) multi-component soln. is passed to the most spent section of a countercurrent multi-section adsorption system, and a soln. is withdrawn from the least spent section until the required amt. of (I) is adsorbed on the most loaded adsorbent; An aq. soln. of solids (higher concn. of (I) but lower total solids concn than in the multi-component soln. in step (a); solids desorbed during prior adsorbent regeneration steps) is (b) passed through the most loaded adsorbent to give an effluent. Fresh adsorbent is (c) added to the least spent section of the system; (d) effluent from (b) is passed to the most spent sections of the system together with a portion of the multi-component soln. (amt. of effluent sufficient to give reflux ratios for (I) of 0.01-5:1); (e) desorbent is passed through the step (b) adsorbent to remove adsorbed solids which contain a relatively high concn. of (I). Process is partic. suitable for decaffeinating aq. extracts of green or roasted coffee, while minimising the loss of non-caffeine solids.