Table 4.

The obtained quadratic equations for the prediction of molar fluxes of CO₂ and SO₂ in the nanofluids.

Gas type	Nanofluid type	Obtained equation based on BBD method
CO2	Al2O3-W NF	$N_{C{O}_2}=-0.001058+0.004208\ast d_o+0.000404\ast \omega -4.03699e-07\ast \tau +0.002346\ast d_o\ast \omega -4.3526e-06\ast d_o\ast \tau -5.64122e-06\ast \omega \ast \tau -0.002059\ast d_o^2+0.00369\ast {\omega }^2+3.71877e-09\ast {\tau }^2$
	SiO2-W NF	$N_{C{O}_2}=-0.002002+0.008836\ast d_o+0.003092\ast \omega -2.95113e-06\ast \tau -0.005848\ast d_o\ast \omega -1.75455e-06\ast d_o\ast \tau -5.55556e-07\ast \omega \ast \tau -0.006596\ast d_o^2+0.004687\ast {\omega }^2+5.09296e-09\ast {\tau }^2$
	ZnO-W NF	$N_{C{O}_2}=-0.001418+0.00615\ast d_o+0.000348\ast \omega -1.35e-06\ast \tau +0.001286\ast d_o\ast \omega -5.44636e-06\ast d_o\ast \tau -4.53015e-06\ast \omega \ast \tau -0.003306\ast d_o^2+0.005934\ast {\omega }^2+5.6326e-09\ast {\tau }^2$
SO2	Al2O3-W NF	$N_{S{O}_2}=+0.000617-0.00225\ast d_o+0.0002\ast \omega -1.41394e-07\ast \tau +0.001452\ast d_o\ast \omega -2.71407e-06\ast d_o\ast \tau -1.86292e-06\ast \omega \ast \tau +0.003002\ast d_o^2-0.000105\ast {\omega }^2+2.32481e-09\ast {\tau }^2$
	SiO2-W NF	$N_{S{O}_2}=0.000095-0.000649\ast d_o+0.001685\ast \omega +8.98625e-08\ast \tau -0.001237\ast d_o\ast \omega -2.16577e-06\ast d_o\ast \tau -2.4839e-06\ast \omega \ast \tau +0.001558\ast d_o^2-0.000025\ast {\omega }^2+1.599e-09\ast {\tau }^2$
	ZnO-W NF	$N_{S{O}_2}=-0.001653+0.007255\ast d_o+0.005006\ast \omega -2.07147e-06\ast \tau -0.003691\ast d_o\ast \omega -2.80421e-06\ast d_o\ast \tau -4.02089e-06\ast \omega \ast \tau -0.005015\ast d_o^2-0.016324\ast {\omega }^2+4.61985e-09\ast {\tau }^2$