Performance Assessment of SWRO Spiral-Wound Membrane Modules with Different Feed Spacer Dimensions

Abstract

Reverse osmosis is the leading process in seawater desalination. However, it is still an energy intensive technology. Feed spacer geometry design is a key factor in reverse osmosis spiral wound membrane module performance. Correlations obtained from experimental work and computational fluid dynamics modeling were used in a computational tool to simulate the impact of different feed spacer geometries in seawater reverse osmosis spiral wound membrane modules with different permeability coefficients in pressure vessels with 6, 7 and 8 elements. The aim of this work was to carry out a comparative analysis of the effect of different feed spacer geometries in combination with the water and solute permeability coefficients on seawater reverse osmosis spiral wound membrane modules performance. The results showed a higher impact of feed spacer geometries in the membrane with the highest production (highest water permeability coefficient). It was also found that the impact of feed spacer geometry increased with the number of spiral wound membrane modules in series in the pressure vessel. Installation of different feed spacer geometries in reverse osmosis membranes depending on the operating conditions could improve the performance of seawater reverse osmosis systems in terms of energy consumption and permeate quality.

A Review of CFD Modelling and Performance Metrics for Osmotic Membrane Processes

“…Nonetheless, RO is an energy-intensive process and reduction of energy consumption remains one of the main research priorities to date [ 22 , 23 , 24 , 25 ]. Numerous studies have been conducted to attempt to reduce the energy consumption of RO processes, and they can be classified into: (1) developing ultra-high permeance membrane using advanced materials, e.g., graphene oxide (GO) membranes [ 26 , 27 ]; (2) using highly efficient energy recovery devices [ 28 ]; (3) using optimisation-based control systems [ 29 , 30 , 31 ]; and (4) optimising design of RO systems [ 32 , 33 ]. Despite these efforts, advances in reduction of energy consumption have almost plateaued.…”

“…CFD is a powerful tool for visualising hydrodynamics, mass transfer and fouling phenomena inside spacer-filled membrane channels, such as those encountered in SWM modules. Although the length scales usually considered in CFD models are of the order of millimetres, these small-scale results can be extrapolated to make full large-scale predictions of module-scale performance [ 33 , 46 ].…”

Theoretical Analysis of a Mathematical Relation between Driving Pressures in Membrane-Based Desalting Processes

“…Therefore, in actual RO processes, the presence of the other external factors should be considered as well to evaluate the loss of the hydraulic pressure. To deal with those malign factors, researchers have attempted a variety of optimization strategies such as applying optimal membrane spacers to RO processes [ 35 , 36 , 37 ]. However, the effects of the other harmful factors on the solute concentration are not taken into account in the current study because the objective of this paper is to establish a relation between the osmotic pressure and hydraulic pressure.…”

Comparative Analysis of Conventional and Emerging Technologies for Seawater Desalination: Northern Chile as A Case Study

“…Conceptual diagram of the conventional membrane technologies applied to desalination (Mentioned references[53][54][55][56][57][58][59][60][61][62][63]). …”

“…rocesses separate purified w ater due to th e in trin sic p rop erties of th e m em bran e. R O uses sem iperm eable polym er m em branes,d ense type (absence ofpores)and h yd rop h ilic p olym ers[53,54].  T h e an isotrop ic com p osite stru ctu re,allow s to h ave a th in layer (10-200 n m )term ed "active layer"[55,56]. T h is layer is in stalled on on e or m ore p olym eric m acrop orou s layers (50-100 ∝m ). T he selectivity and m echanical strength are given by an active layer and a m acrop orou s layer (p olyethersu lfon e), resp ectively.…”