Water diffusion in zeolite 4Abeds measured by broad-line magnetic resonance imaging

Abstract
Broad-line magnetic resonance imaging has been used to monitor water transport in beds of industrial grade zeolite 4A. Diffusion profiles as a function of time have been obtained for a series of temperatures in the range 20–70 °C. The dynamics is observed to be strongly non-Fickian. A model based on coupled diffusion equations for the vapor in the interparticle space and water within the particles has been developed and shown to be in good agreement with experiment. Values for the intraparticle water diffusion coefficient and the interparticle vapor diffusion coefficient, which can be obtained from the model, and their respective temperature dependencies are in good agreement with other published results.