Open AccessComparative analyses of diffusion coefficients for different extraction processes from thyme
Author(s) -
Slobodan S. Petrović,
Jasna Ivanović,
Stoja Milovanović,
Irena Žižović
Publication year - 2012
Publication title -
journal of the serbian chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.227
H-Index - 45
eISSN - 1820-7421
pISSN - 0352-5139
DOI - 10.2298/jsc110616009p
Subject(s) - extraction (chemistry) , mass transfer , supercritical carbon dioxide , diffusion , supercritical fluid extraction , chromatography , supercritical fluid , mass transfer coefficient , chemistry , analytical chemistry (journal) , thermodynamics , organic chemistry , physics
This work was aimed to analyze kinetics and mass transfer phenomena for different extraction processes from thyme (Thymus vulgaris L.) leaves. Different extraction processes with ethanol were studied: Soxhlet extraction and ultrasound-assisted batch extraction on the laboratory scale as well as pilot plant batch extraction with mixing. The extraction processes with ethanol were compared to the process of supercritical carbon dioxide extraction performed at 10 MPa and 40°C. Experimental data were analyzed by mathematical model derived from the Fick’s second law to determine and compare diffusion coefficients in the periods of constant and decreasing extraction rate. In the fast extraction period, values of diffusion coefficients were one to three orders of magnitude higher compared to those determined for the period of slow extraction. The highest diffusion coefficient was reported for the fast extraction period of supercritical fluid extraction. In the case of extraction processes with ethanol, ultrasound, stirring and extraction temperature increase enhanced mass transfer rate in the washing phase. On the other hand, ultrasound contributed the most to the increase of mass transfer rate in the period of slow extraction