Polymeric hollow fiber membranes represent a high degree of process intensification closer to scaling up. Metal organic framework ZIF-7 and ZIF-8 continuous membranes were synthesized on the inner surface of a 520 mu m outer diameter polysulfone hollow fiber using microlluidics. This provided a constant reactant concentration along the membrane for growing homogeneous, continuous and thin layers of ZIF-7 (2.4 mu m) and ZIF-8 (3.6 mu m) with good adherence. The high quality of the membranes and the zeolite-like sodalite porous structure of both MOFs with pore apertures of 0.30-0.34 nm allowed operation at high temperature (150 degrees C) and pressure (4 bar). High separation factors in CO2 and H-2 containing mixtures were achieved. (C) 2014 Elsevier B.V. All rights reserved.