Two examples of gradient magnetic fields applied to porous media flows will be examined both experimentally and theoretically. The first example concerns a theoretical analysis of magnetoviscosity in flow of nanoparticle magnetic suspensions through anomalous porous media under low gradient magnetic fields. The second, mostly experimental in nature, focuses on the influence of strong inhomogeneous magnetic fields on the flow of gas-liquid non-magnetic fluids in cocurrent downflow trickle bed and cocurrent upflow packed bubble column reactors. In the latter case, specifically, the behavior of liquid-limited catalytic reactions will be investigated under macro and microgravity conditions down to 10-4 g along with the reactor hydrodynamic behavior (wetting efficiency, liquid holdup, pressure drop, flow regime). For the first case, we analyzed the phenomenon of ferrofluid magnetoviscosity in high-permeability wall-region non-magnetic porous media of the Müller kind. After upscaling the pore-level ferrohydrodynamic model, we obtained a simplified volume-average zero-order axisymmetric model for non-Darcy non-turbulent flow of steady-state isothermal incompressible Newtonian ferrofluids through a porous medium experiencing external constant bulk-flow oriented gradient magnetic field, ferrofluid self-consistent demagnetizing field and induced magnetic field in the solid. The model was explored in contexts plagued by wall flow maldistribution due to low column-to-particle diameter ratios. For the second case, a powerful superconducting magnet is used for generating an artificial gravity environment in earthbound lab experimentations. Here also, application of microgravity or macrogravity conditions could potentially open up attractive chemical engineering applications. For example, in multiphase catalytic systems, a number of factors must be optimized for improving process efficiency. Preliminary experimentations and model calculations reveal that inhomogeneous and strong magnetic fields, applied to such systems as mini trickle-bed reactors, are capable of affecting reactor catalytic performances and hydrodynamics which can be taken advantage of for improving process performance. Conversion of -methylstyrene, pressure drops, liquid holdups and wetting efficiency experimental data have been obtained for two-phase downward gas-liquid trickle beds and upward packed bubble columns in the presence of inhomogeneous magnetic fields. Magnetic field effects have been rationalized in terms of equivalent gravitational amplification factor which commutes the Kelvin body force density into an artificial gravitational body force.