A mathematical model with two different methods to represent the mass transfer in the biomass matrix, (series and parallel) is proposed to simulate a supercritical extraction unit. The model is solved using the method of lines and finite differences with flow correction. Using experimental extraction curves, both models were fitted fairly well, with equivalent accuracy. Two operating regimes were detected in the selected experimental conditions: equilibrium and mass transfer controlled. The last one is more difficult to simulate, requiring specific mass transfer parameters for series and parallel alternatives, for its accurate representation.
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