Extraction for Different Geometries. Constant Diffusivity

The effect of rapeseed microstructure on the mechanism of solution and diffusion extraction

“…After the conversion time from minutes to seconds, the calculated diffusion coefficients differed from 8 × 10 −8 cm 2 s −1 (smaller particles) to 1 × 10 −8 cm 2 s −1 (for the large particles) in both cases (rapeseeds and soybeans). Obtained results were in agreement with literature data [38,39].…”

“…Genesis of ground tissues disruptions allowed intracellular miscella to diffuse in order to form external miscella transportable via capillaries [18][19][20][21]. "Diffusion extraction" process was slow and could explain the flat part of extraction curve [38,39]. The solution of diffusion equation and Fourier heat equation was analogous.…”

“…The migration of matter or energy down the concentration or temperature gradient was homothetic. The theoretical extraction rate was reduced to the first term in the series (n = 0) for the small values of time t [38,39]. After logarithmization by means of quotient log law, the solution of diffusion equation could be written as follows:…”

“…Important assumption was constant concentration at the particle surface during percolation extraction [38,39].…”

Ethanolic extraction of Rosa rubiginosa soluble substances: Oil solubility equilibria and kinetic studies

“…The diffusivity values obtained by us were similar to those obtained in literature for oil diffusivity in different solvents, considering no external resistance to mass transfer and similar sizes. We can find diffusivity values in literature around 2 · 10 À10 for 0.32-0.95 cm soybean pellets in trichloroethylene (Chorny & Krasuk, 1966), between 3.2 · 10 À9 and 8 · 10 À9 for 0.2-0.4 mm peanut slices in hexane (Fan, Morris, & Wakeham, 1948).…”