Symbol	Unit	Description
$A_M$	${\mathrm{m}}^2$	Membrane area
b	$\mathrm{Barrer}$	Power-law set-point
B	$\mathrm{Barrer}$	Membrane gas permeability
C	$\mathrm{J}·{\mathrm{K}}^{-1}$	Heat capacity
$C_P$	$\mathrm{J}·{\mathrm{K}}^{-1}$	Heat capacity, isobaric
$C_V$	$\mathrm{J}·{\mathrm{K}}^{-1}$	Heat capacity, isochoric
D	${\mathrm{m}}^2·{\mathrm{s}}^{-1}$	Diffusion coefficient
${\mathit{e}}_0$	${\mathrm{m}}^2·{\mathrm{s}}^{-2}$	Specific energy
k	${\mathrm{m}}^2$	Darcy’s permeability
m	$\mathrm{kg}$	Mass
M	$\mathrm{kg}·{\mathrm{mol}}^{-1}$	Molar mass
n	$\mathrm{mol}$	Molar amount
p	$\mathrm{Pa}$	Pressure
$\overrightarrow{q}$	${\mathrm{m}}^3·{\mathrm{s}}^{-1}$	Volume flux
Q	$\mathrm{J}$	Heat
R	$\mathrm{J}·{\mathrm{K}}^{-1}·{\mathrm{mol}}^{-1}$	Universal gas constant
T	$\mathrm{K}$	Temperature
U	$\mathrm{J}$	Internal energy
$\overrightarrow{v}$	$\mathrm{m}·{\mathrm{s}}^{-1}$	Velocity vector field
W	$\mathrm{J}$	Work
$\alpha$	–	Selectivity
$\gamma$	–	Polytropic exponent/index
$\epsilon$	–	Porosity
$\mu$	$\mathrm{Pa}·\mathrm{s}$	Dynamic viscosity
$\rho$	$\mathrm{kg}·{\mathrm{m}}^{-3}$	Density