Abstract
The flow of He, CO 2, CH 4, C 2H 6, C 3H 8, n-C 4H 10 and neo-C 5H 12 has been investigated using microporous carbon membranes. Physical constraint of the compacted carbon with steel plungers in a steel membrane holder substantially altered sorption equilibria and hysteresis loops in the multilayer and capillary condensation region as compared with unconstrained powder, but made little difference in the region below monolayer coverage. Capillary pressure differences between constrained compact and unconstrained powder showed maxima in the vicinity of monolayer coverage and near coverages where differential diffusion coefficients also went through maxima. This supports a hydrodynamic mechanism for sorbed fluids as monolayer coverage was approached and exceeded. For these larger uptakes flow rates were dominated by contributions arising from the presence of sorbed films with concentration gradients. Permeabilities did not show maxima found with differential diffusion coefficients. Blockage by sorbed films of the gas phase transport of helium was investigated for hydrocarbons using helium as internal indicator. Blockage became nearly complete as sorption approached monolayer coverage.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call