D_B

e

H_B

Diameter of cell, m

Yield = 100 × mass of oil extracted/mass of solid phase (dimensionless)

Height of cell, m

N

Mass of the solute, kg

T_CER

Constant extraction period time, s

$k_f{a}_0$

Volumetric mass transfer coefficient in the fluid phase, 1/s

$k_s{a}_0$

Volumetric mass transfer coefficient in the solid phase, 1/s

$\dot{q}$

Mass flowrate of solvent per unit mass of solid phase, 1/s

q

specific amount of solvent = Q/N (dimensionless)

q_m

q_vol

Specific amount of solvent at the start of the extraction that occurs inside the trichomes

Volumetric flowrate of CO₂, m³/s

Q

V

Amount of solvent used, kg

Volume of cell, m³

W

Parameter of slow-extraction period (dimensionless)

x_k

Easily accessible concentration of a solute in solid substrate, kg/kg

x₀

Global yield, kg/kg

y_r

Solubility, kg/kg

Z

Parameter of the Sovová’s model for the CER period

Greek letters

$\epsilon$

Void fraction

$\rho$

Density of the solvent, kg/m³

${\rho }_s$

Density of the solid phase, kg/m³