Decaffeination of tea leaves - uses pressure and temp to separate caffeine from carbon dioxide solvent

摘要

Caffeine is extracted from damp tea leaves using moist carbon dioxide as a solvent at a pressure of 150-400 bar and a temp. of 50-80[deg]C. This is followed by selective separation of the caffeine from the carbon dioxide, before the carbon dioxide still carrying the aromatic and flavour matter is returned to the tea leaves by pressure reduction. For the caffeine separation, the pressure and temp. are set at over-critical values.