Countercurrent packed column supercritical CO_2 extraction of olive oil.Mass transfer evaluation

摘要

Experiments to determine the number of transfer units (NTU)and height of a transfer unit (HTU)of different random packings such as Rasching rings,Dixon rings,Fenske rings and glass beads in a countercurrent (CC)supercritical fluid extraction (SFE)column of 17.6 mm I.D.and 1.8-m length at 20 MPa and 313 K,with olive oil and CO_2,were performed.The extracts were collected by means of two separators,the first one operated at 10 MP)a and 313 K and the second at 3 MPa and 273 K.The performance of SFE was studied by analyzing the content of vitamin E and sterols in teh raffinate and in teh collected extracts by HPLC equipped with a photodiode array detector.The value of HTU and the NTU were evaluated for each random packing at solvent to feed ratios from 23.14 to 41.65 kg CO_2/kg oil.Fenske rings showed the best results in terms of efficiency and performance of the CC system for the SFE of olive oil.