(557b) Experimental and Theoretical Evaluation of Feed-Flow Collar Design for 3D Printed Shell-Fed Flow Hollow Fiber Membrane Modules

Membrane separation processes are a promising technology for carbon capture from concentrated point sources. Optimal process performance requires membrane module designs which provide counter-current contacting between the feed and permeate streams and allow for use of a permeate sweep. Large hollow fiber modules require the introduction and removal of one stream in the shell space outside the fiber bundle. To achieve near counter-current contacting, module features such as flow distribution collars have been proposed in the literature. However, studies of these features are lacking in the literature.

An experimental and theoretical study of module collar design is presented here. Hollow fiber membranes are prepared by dip coating a poly(vinylidene) (PVDF) support with a polydimethylsiloxane (PDMS) gutter layer and a Pebax 2533 selective layer. Fiber bundles with a well-defined fiber packing are prepared using a 3D printed module. A parallel fiber bundle consisting of 4-9 uniformly spaced fibers is created with printed tabs that align the fibers and create a tubesheet. The tabs are sealed within a printed case that possesses a series of external ports for gas introduction and removal. Uniquely, both port location and the use of a collar to assist fluid distribution in the shell can be varied for the same fiber bundle. Experimental measurements are compared to computational fluid dynamics (CFD) simulations. The experimental module design allows high-fidelity representation of the fiber bundle and module case in the simulations.

Comparisons between experiment and simulation are in good agreement over a broad range of experimental conditions. The detrimental effect of having ports located too close, leading to stagnation regions, is captured as well as the beneficial effects of using a collar for shell-side fluid distribution around the fiber bundle. Such results help validate the use of CFD to develop high-performance module designs.