METHOD FOR DECAFFEINIZING ORIGINAL COFFEE

摘要

PURPOSE: To decaffeinate source coffee beans at a high decaffeinating rate by the extraction of caffeine under a high pressure by a liquid solvent saturated with carbon dioxide, instantaneous expansion and the washing of the source coffee beans by the liquid solvent under a low pressure. CONSTITUTION: For the source coffee beans put in pressure tanks 1-6, the liquid solvent saturated with the carbon dioxide is introduced to the pressure tanks from the lower part of a separation column 7 and the extraction is performed for one to several hours at 20-110 deg.C under the pressure of 30-300 bars. After expanding pressure atmosphere to 1-10 bars, washing by the liquid solvent is performed. A circuit from the separation column 7 to the pressure tanks 1-6 and the circuit of the separation column 8, conversion infiltration devices 28-30 and pure water 33 are connected through an over-critical CO2 phase between the separation column 7 and the separation column 8.