High throughput, asymmetric carbon membranes derived from the pyrolysis of polyfurfuryl alcohol (PFA) have been fabricated on a novel support composed of porous stainless steel filled with nanoparticles. Variation of PFA molecular weight was found to have a significant impact on the single gas permeances of resultant carbon membranes. High molecular weight precursor materials yielded the best results; oxygen permeance values for membranes synthesized from high molecular weight resins were on the order of ∼1×10-8 mol m-2s-1Pa-1 with oxygen over nitrogen ideal selectivities of greater than 7. Binary separations of hydrogen from nitrogen and hydrogen from carbon monoxide were carried out using a nanoporous carbon (NPC) membrane synthesized from high molecular weight precursor material. For both separations, hydrogen purities of better than 99% by volume were obtained in the permeate stream.