Pore-scale simulations are used in the present work by building the actual porous geometry in order to minimize the uncertainties related to the porous transport models. The porous structures are built using Triply-Periodic-Minimal-Surfaces (TPMS) based Schoen I-WP lattice. A square mini-channel is considered for the numerical investigation, for the hydrodynamically developed and thermally developing flow domain. The rib's porosity is changed from 0% to 80% while the flow rate is kept at a low Reynolds number regime (Re = 1). In order to assess hydrodynamic performance, the three¬dimensional steady-state Navier-Stokes equations are solved, while, the steady-state energy equation is calculated, in both fluid and solid zones, in order to assess heat transfer performance. For a variety of rib porosities and fixed flow rate, parametric analyses for overall pressure drop and heat transfer coefficient are conducted. It has been demonstrated that as porosity increases, the flow resistance provided by porous ribs constantly decreases, resulting in a lower pressure drop across the channel. Additionally, it is found that the value of the effective heat transfer coefficient reduces as the rib porosity increases. Since the Thermal Performance Factor (TPF) is obtained in the range of 1.5 to 2.2, the channel with ribs is observed to be improving the overall thermo-hydraulic performance as compared to the empty channel. Placing the porous rib in the channel may therefore have the desired effects of improving the thermo-hydraulic performance, lowering the maximum temperature of the heated region, and assisting in the even distribution of temperature.