On the reliability of lab-scale experiments for the determination of membrane specific flux measurements in organic solvent nanofiltration

Journal
Chemical engineering research and design  
Volume
148
Start Page
271
End Page
279
Citation
Chemical Engineering Research and Design (148): 271-279 (2019-08)
Publisher DOI
10.1016/j.cherd.2019.06.013
Scopus ID
2-s2.0-85067953502
While the scale-up from flat-sheet lab-scale experiments to larger modules for an industrial application requires consideration of the module geometry and according hydrodynamics, it is of high importance that the lab-scale experiments provide an accurate estimate of the membrane performance at ideal hydrodynamic conditions to make a proper selection and potentially allow for a model-based evaluation of the process performance. Due to inhomogeneity of the membrane material, it is however well known that the membrane flux determined by small samples in lab-scale experiments may vary in a considerable margin. The current study investigates these variations with an extensive experimental screening of lab-scale samples as well as a spiral-wound module for a commercially available polymeric membrane and pure solvent flux. This allows for an analysis of the comparability, as well as a best case estimate for the variance of the solvent flux, due to the industrially optimized membrane production process. The experimental results confirm considerable variations for single lab-scale samples, but also indicate good comparability on the basis of a statistical evaluation of the larger set of lab-scale samples. Based on the evaluation of the uncertainty of the solvent flux estimate, a minimum number of samples for an accurate estimate is determined and the recommendation is validated for additional membrane-solvent combinations. The importance of the derived uncertainty information for membrane selection and model-based conceptual process design is furthermore illustrated for a number of literature case studies.
Subjects
Lab-scale experiments
Organic solvent nanofiltration
Solvent resistant nanofiltration
Spiral-wound module
Statistical analysis
Uncertainty