In this work, a universal rate-based model is presented that enables the rigorous Simulation of absorption and stripping units, as well as their combination as all absorption-stripping loop. The latter is realized by simultaneous treatment of the two units and their environment. The model is applied to the removal of acid gases by aqueous amine Solutions. It is capable of describing the complex interplay of chemical reactions and heat and multicomponent mass transfer, as well as accounting for thermodynamic nonidealities including the specific behavior of electrolyte Solutions. Furthermore, the influence of column internals and hydraulics is considered through relevant correlations. To simulate the total absorption-stripping loop, the model is supplemented by additional submodels for the column periphery (e.g., heat exchangers). All models are implemented in the simulation environment Aspen Custom Modeler and validated by comparison with experimental data of an industrial-scale acid gas removal process. In addition, the effects of model parameters oil the behavior of both the absorption and Stripping Columns and the impact of model simplifications are investigated.