Membrane technology has been widely adopted for water purification and gas separation. Industrial membranes are often thin film composites comprised of a thin, dense skin layer (100 nm or below) performing molecular separation and a microporous support providing mechanical strength. However, the surface porosity and pore size of the microporous support can restrict the concentration profile of the permeant in the selective layer and thus reduce permeance.1-3 A high flux gutter layer is often employed between the selective layer and support layer to mitigate the geometric restriction from the support morphology. However, there lacks a precise quantitative understanding of the effect of gutter layer on the membrane permeance. This paper presents a thorough analysis of the membrane nanoscale structure parameters (such as support porosity, support pore size, the thickness of the selective layer and gutter layer) using computational fluid dynamics simulations. A three-dimensional (3D) computational model is developed using COMSOL to systematically study the effects of membrane configurations at nanoscale on membrane permeances. The results are expected to provide a clear and practical guideline to designing high flux ultrathin composite membranes for molecular separations.
Journal: TechConnect Briefs
Volume: 2, Materials for Energy, Efficiency and Sustainability: TechConnect Briefs 2015
Published: June 14, 2015
Pages: 263 - 266
Industry sector: Energy & Sustainability
Topic: Water Technologies