C	concentration in the stream (mol/m3)
Da	ordinary diffusion coefficient of CO2 in N2 (m2/s)
Db	ordinary diffusion coefficient of CO2 in MEA (m2/s)
Deq,b	the equivalent diameter of channel b (m)
dmn	coefficients in the eigenfunction $F_{a,m}$
E	the accuracy of the experimental results
emn	coefficient in the eigenfunction $F_{b,m}$
Fm	eigenfunction associated with eigenvalue ${\lambda }_m$
Gm	function defined during the use of orthogonal expansion method
Gza	Graetz number of gas feed stream
Gzb	absorbent Graetz number
H	Henry’s law constant
IM	absorption efficiency
$k_{b\xi }$	local mass transfer coefficient for liquid phase (m/s)
L	channel length (m)
N	the number of fiber cells
Nexp	the number of experimental measurements
Q	volumetric flow rate (m3/s)
r	transversal coordinate (m)
rf	free surface radius (m)
ri	fiber inside radius (m)
ro	fiber outside radius (m)
rs	shell outside radius (m)
Sm	expansion coefficient associated with eigenvalue ${\lambda }_m$
$S{h}_{b\xi }$	local Sherwood number
$\overline{S{h}_b}$	averaged Sherwood number
$v$	velocity distribution of fluid (m/s)
$\overline{v}$	averaged velocity of fluid (m/s)
z	longitudinal coordinate (m)
Greek letters
$\delta$	thickness of the porous membrane (m)
$\epsilon$	membrane porosity
$\phi$	packing density
$\eta$	dimensionless transversal coordinate, r/rf
${\lambda }_m$	eigenvalue
$\xi$	dimensionless longitudinal coordinate, $z/L$
$\psi$	dimensionless concentration
$\overline{\psi }$	averaged dimensionless concentration
$J$	absorption flux (mol/m2 s)
$J_j$	experimental data of $J$ (mol/m2 s)
${\widehat{J}}_j$	theoretical prediction of $J$ (mol/m2 s)
Superscripts and Subscripts
a	in the gas feed flow channel
b	in the liquid absorbent flow channel
i	at the inlet
e	at the outlet