A flow distribution study of laboratory scale membrane gas separation cells

Abstract

Gas flows in laboratory membrane test cells are often assumed to be uniform due to the relatively small feed volumes and ideal mixing of gas mixtures such as air. Scientific literature on characterization of gas flow distribution in the feed volume above the membrane in laboratory cells is limited. (1) (2008) 58]. In this work, the conventional cell used in laboratories was first examined to determine the uniformity in flow distribution and its effects on membrane performance. Using a combination of experimental and numerical methods, the feed flow distribution in the conventional cell was found to be skewed towards the far (retentate) side of the feed volume and also resulted in short-circuiting of the gas mixture to the retentate outlet. A new design for laboratory cell was proposed and experimentally validated. This modified cell was found to have a more uniform flow distribution than the conventional cell, consequently leading to improved separation performance.Crown

Separation performance of asymmetric membranes based on PEGDa/PEI semi-interpenetrating polymer network in pure and binary gas mixtures of CO2, N2 and CH4

“…A cross-flow test cell having a permeation surface area of 9.6 cm 2 was used [28]. A feed pressure of 1.35 MPa and temperature of 22 • C was used for both single and mixed gas permeation studies.…”

A mass transport and hydrodynamic evaluation of membrane separation cell

“…Accordingly, the conventional test cell that has been reported in our earlier work [1] was considered for further evaluation. The generic separation cell as shown in Fig.…”

“…In present work, the numerical and mass transport studies for gas separation process were based on experimental results reported in our previous work [1] on flow distribution of gas feed mixture at constant pressure and concentration. The membrane, used in this work for gas permeation experiments, was comprised of highly microporous polysulfone support coated with a 0.2 m thick poly(dimethylsiloxane) (PDMS) layer.…”

“…The experimental conditions were maintained at steady state with laminar flow (125 < R e < 1500) at feed-inlet, and ambient temperature (22 • C). Also, based on the empirical data for gas [1] and liquid separation, it was determined that the plasticization and fouling effects can be neglected and the partitioning of selective species (O 2 or H 2 O) from the bulk feed to the membrane cannot be considered as mass transfer limiting.…”

“…A detailed investigation of fluid flow pattern in a test cell provides fundamental information for membrane based separations. In our earlier study [1] based on hydrodynamics of membrane separation cell, it was found that the geometry of a test cell played an important role in terms of membrane performance for binary feed gas mixture of oxygen and nitrogen (O 2 /N 2 ). However, in the study, average permeance across the membrane area and velocity profiles were considered for the ଝ NRCC No.…”