| 摘要 |
<p>SLURRY DECAFFEINATION The object of the invention is to provide an improved method for removing caffeine from aqueous solutions such as coffee and tea extracts. Decaffeination with water-immiscible fatty materials is impractical because the ratio of fatty material to aqueous caffeine solution will typically be about 20:1. Non-solvent systems employing solid adsorbents have not been commercially practical because they are either too non-selective or too expensive. The process disclosed herein decaffeinates an aqueous caffeine solution by contacting it with a slurry comprising a solid caffeine adsorbent and a water-immiscible, caffeine-specific solvent. The caffeine is selectively extracted from the aqueous solution, leaving the solubles necessary for a good tasting beverage, and then removed from solution by the solid adsorbent. Because the solvent is selective, the adsorbent does not have to be. And, because the adsorbent continuously maintains a low concentration of caffeine in the solvent, much lower solvent to aqueous solution ratios can be employed, preferably less than 5:1.</p> |
