Theoretical modeling and experimental validation of transport and separation properties of carbon nanotube electrospun membrane distillation

J.-G. Lee, E.-J. Lee, S. Jeong, J. Guo, A.K. An, H. Guo, J. Kim, T.O. Leiknes, N. Ghaffour
Journal of Membrane Science, Volume 526, pp. 395-408, (2017)

Theoretical modeling and experimental validation of transport and separation properties of carbon nanotube electrospun membrane distillation

Keywords

Carbon nanotubes, Desalination, Direct contact membrane distillation, Electrospun membrane, Heat and mass transfers

Abstract

Developing a high flux and selective membrane is required to make membrane distillation (MD) a more attractive desalination process. Amongst other characteristics membrane hydrophobicity is significantly important to get high vapor transport and low wettability. In this study, a laboratory fabricated carbon nanotubes (CNTs) composite electrospun (E-CNT) membrane was tested and has showed a higher permeate flux compared to poly(vinylidene fluoride-co-hexafluoropropylene) (PH) electrospun membrane (E-PH membrane) in a direct contact MD (DCMD) configuration. Only 1% and 2% of CNTs incorporation resulted in an enhanced permeate flux with lower sensitivity to feed salinity while treating a 35 and 70 g/L NaCl solutions. Experimental results and the mechanisms of E-CNT membrane were validated by a proposed new step-modeling approach. The increased vapor transport in E-CNT membranes could not be elucidated by an enhancement of mass transfer only at a given physico-chemical properties. However, the theoretical modeling approach considering the heat and mass transfers simultaneously enabled to explain successfully the enhanced flux in the DCMD process using E-CNT membranes. This indicates that both mass and heat transfers improved by CNTs are attributed to the enhanced vapor transport in the E-CNT membrane.​

Code

DOI: 10.1016/j.memsci.2016.12.045

Sources

Website PDF

See all publications 2017