Membrane distillation against a pressure difference

Journal article (2017)

Authors

T.J.H. Vlugt Engineering Thermodynamics - Mechanical, Maritime and Materials Engineering
S Kjelstrup Norwegian University of Science and Technology (NTNU)
Research Group
Engineering Thermodynamics (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2017 L. Keulen, LV van der Ham, N.J.M. Kuipers, J.H. Hanemaaijer, T.J.H. Vlugt, S Kjelstrup
DOI
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https://doi.org/10.1016/j.memsci.2016.10.054
Membrane distillation Water desalination Heat and mass transfer MemPower Irreversible thermodynamics
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Published Date

2017

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Process and Energy

Research Group

Engineering Thermodynamics

Abstract

Membrane distillation is an attractive technology for production of fresh water from seawater. The MemPower®MemPower® concept, studied in this work, uses available heat (86 °C) to produce pressurized water (2.2 bar and 46 °C) by membrane distillation, which again can be used to power a turbine for co-production of electricity. We develop a non-equilibrium thermodynamic model to accurately describe the transfer at the liquid-membrane interfaces, as well as through the hydrophobic membrane. The model can explain the observed mass flux, and shows that 85% of the energy is dissipated at the membrane-permeate interface. It appears that the system's performance will benefit from a lower interface resistance to heat transfer, in particular at the permeate side of the membrane. The nature of the membrane polymer and the pore diameter may play a role in this context.