The hydrogen sulfide is a basic contaminant which is exited to atmosphere from chemical factories. The study focuses on initialization of Stefan-Maxwell equations to calculate the hydrogen sulfide removal molar flux by nanofluid in an absorption process. The sweetening process is done in a packed bed tower, isothermally. The aluminum oxide nanofluid as solvent in the role of the liquid phase is considered as a non-ideal solution. The activity coefficient for the vapor-liquid equilibrium calculation is based on molar transfer equations is proposed. No ideality within vapor phase is considered based on the modified state equation of Virial. The hydrogen sulfide removal molar flux is based on two cases of film theorem and K(G)a calculation are investigated in this paper. Results show increasing percentage of mass transfer coefficient for increasing of solvent flow rate from 2 m(3)/h to 3 m(3)/h is 71.2%. The theoretical values of hydrogen sulfide molar flux which is based on film theorem using Fick's diffusion factor shows much deviation with experimental hydrogen sulfide molar flux. Also, H2S removal molar flux based on K(G)a is calculated in this research. Finally, the performance of absorber is modelled by ANN. The value of RMSE and R in this theoretical model is 0.2979 and 0.9537, respectively.