NMR is employed to study liquid and gas flow in a tube and in the channels of shaped catalysts, mass transport during drying of water saturated porous monoliths, and gas adsorption by porous alumina pellets. NMR flow imaging and pulsed field gradient NMR are shown to yield the same average propagators for liquid and gas flow in a straight circular tube. The complicated patterns of gas or liquid flow in shaped reactors are characterized successfully by NMR flow imaging through the detection of all three flow velocity components.