Optimization of hydrogen sulfide separation from oil-well-produced water in fiber membrane reactors with amine solvents

The presence of acidic gases in produced water, a byproduct of oil and gas extraction, is problematic in terms ofthe corrosion of equipment and pollution of the environment. In this study, after examiningthe relevant literature, the process of treatment of produced water in fiber membrane reactors was modeled, and after validation with the existing experimental data, the model was used for prediction and process optimization purposes. The solvents considered for the process were amine as the chemical solvent and nitrogen gas as the physical solvent. After examining the variety of membranes and their performance, the best type for use in the membrane reactor was chosen. The finite element software COMSOL was used for modeling and to achieve convergence in the results. For modeling, the module’s geometry was divided into three sections: membrane, inner chamber (feed flow path), and inter-membrane space, the conservation equations for mass transfer and momentum transfer were written for each section, Navier-Stokes velocity distribution was used to insert the velocity term in the momentum equation, and the resulting equations were solved simultaneously according to the boundary conditions. In this process, the walls were given the no-slip condition, and the fluidflow was assumed to remain laminar. The potential reactions between amine and hydrogen sulfide were determined from different sources, and the reaction constants, even for the reaction of hydrogen sulfide ions, were carefully considered. After choosingsuitable solvents, computational fluid dynamics modeling was conducted.