Kinetic Parameters of the Extraction of Tannis from Three Nicotiana Species

The extraction process of tannins from three tobacco species (Nicotiana alata Link&Otto, N. rustica L., N. tabacum L) was investigated. The extraction was carried out with ethanol solvent in concentration 70%, at a temperature 20-60°C and duration 1, 3, 5 and 7 hours. Rate of extraction of tannins, activation energy and the extraction coefficient were calculated. The molecular diffusion coefficient and the effective diffusion coefficient were calculated according to the equations of Wilke-Chang, Stokes-Einstein and Beloborodov for the three tobacco species.