Recently, we have investigated the use of engineered foam adsorbents for the treatment of dissolved and emulsified oily wastewater. The morphological structure of the foam absorbent highly influences the treatment efficacy and energy requirements when implemented as filtration media for continuous separation. Herein, it is hypothesized that the adsorption capacity increases with the surface area-to-volume ratio of the foam. To evaluate this hypothesis, the influence of free volume (porosity of 70%, 80%, and 90%) on pressure drop and droplet adsorption was estimated using multiphysics numerical modeling in the software COMSOL. The pressure drop across the foam was determined based on continuity, Navier-Stokes, and Brinkman equations. Simultaneously, the oil mass transport was described using mass convection coupled with fluid flow, diffusion, and adsorption models. Simulation results indicated that with increasing free volume, pressure drop across the foam would decrease. Similarly, with increasing free volume, the oil mass uptake was found to increase. The lower pressure drop at higher porosity is attributed to the low mass transfer resistance. The oil mass uptake increases due to larger available free volume of the foam. Furthermore, larger pores also allow higher adsorption mass uptake due to multiple layers of oil deposition. These results agree with our hypothesis. In future work, additional morphological properties will be studied and experimental data will be used to validate results.