Membrane Flash Index: Powerful and Perspicuous Help for Efficient Separation System Design

Andras Jozsef Toth; Botond Szilagyi; Daniel Fozer; Eniko Haaz; Asmaa Khaled Mohamed Selim; Milán Szőri; Bela Viskolcz; Peter Mizsey

doi:10.1021/acsomega.0c01063

Membrane Flash Index: Powerful and Perspicuous Help for Efficient Separation System Design

ACS Omega. 2020 Jun 17;5(25):15136-15145. doi: 10.1021/acsomega.0c01063. eCollection 2020 Jun 30.

Authors

Andras Jozsef Toth^{1

2}, Botond Szilagyi¹, Daniel Fozer¹, Eniko Haaz¹, Asmaa Khaled Mohamed Selim^{1

3}, Milán Szőri², Bela Viskolcz², Peter Mizsey^{1

2}

Affiliations

¹ Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, HU 1111 Budapest , Hungary.
² Institute of Chemistry, University of Miskolc, Egyetemváros C/1 108, HU 3515 Miskolc, Hungary.
³ Chemical Engineering Department, National Research Centre, El Buhouth Street 33, EG 12622 Cairo, Egypt.

Abstract

There are different factors and indices to characterize the performance of a pervaporation membrane, but none of them gives information about their capabilities in the area of liquid separation compared to the most convenient alternative, which is distillation. Membrane flash index (MFLI) can be considered the first and only one that shows if the membrane is more efficient or not than distillation and quantifies this feature too. Therefore, the MFLI helps select the best separation alternative in the case of process design. In this study, the evaluation and capabilities of membrane flash index are comprehensively investigated in the cases of six aqueous mixtures: methyl alcohol-water, ethyl alcohol-water, isobutyl alcohol-water, tetrahydrofuran-water, N-butyl alcohol-water, and isopropanol-water. It must be concluded that the separation capacity of organophilic type membranes is remarkably lower than hydrophilic membranes in all cases of separation. The study of the MFLI is extended with the consideration of other binary interaction parameters like separation factor, permeation flux, selectivity, and pervaporation separation index (PSI) in order to find a descriptive relationship between them. For the same membrane material type, descriptive function can be determined between feed concentration and MFLI and PSI and separation factor, which can be used to calculate each other's value. On the basis of the indices and especially the MFLI, a significant help can be given to the process design engineer to select the right liquid separation alternative and, in the case of pervaporation, find the most appropriate membrane.