Next Article in Journal
Quantifying Dynamical Complexity of Magnetic Storms and Solar Flares via Nonextensive Tsallis Entropy
Next Article in Special Issue
Effects of Radiation Heat Transfer on Entropy Generation at Thermosolutal Convection in a Square Cavity Subjected to a Magnetic Field
Previous Article in Journal
Tsallis Entropy for Geometry Simplification
Previous Article in Special Issue
Spectral Entropy in a Boundary-Layer Flow
Entropy 2011, 13(10), 1829-1864; doi:10.3390/e13101829
Article

Entropy Generation Analysis of Desalination Technologies

1
,
1
,
1
,
1
,
2
 and
V 1,*
Received: 5 September 2011 / Revised: 27 September 2011 / Accepted: 27 September 2011 / Published: 30 September 2011
(This article belongs to the Special Issue Entropy Generation Minimization)
Download PDF [297 KB, uploaded 24 February 2015]

Abstract

Increasing global demand for fresh water is driving the development and implementation of a wide variety of seawater desalination technologies. Entropy generation analysis, and specifically, Second Law efficiency, is an important tool for illustrating the influence of irreversibilities within a system on the required energy input. When defining Second Law efficiency, the useful exergy output of the system must be properly defined. For desalination systems, this is the minimum least work of separation required to extract a unit of water from a feed stream of a given salinity. In order to evaluate the Second Law efficiency, entropy generation mechanisms present in a wide range of desalination processes are analyzed. In particular, entropy generated in the run down to equilibrium of discharge streams must be considered. Physical models are applied to estimate the magnitude of entropy generation by component and individual processes. These formulations are applied to calculate the total entropy generation in several desalination systems including multiple effect distillation, multistage flash, membrane distillation, mechanical vapor compression, reverse osmosis, and humidification-dehumidification. Within each technology, the relative importance of each source of entropy generation is discussed in order to determine which should be the target of entropy generation minimization. As given here, the correct application of Second Law efficiency shows which systems operate closest to the reversible limit and helps to indicate which systems have the greatest potential for improvement.
Keywords: entropy generation; Second Law efficiency; desalination; energy efficiency; MED; MSF; MD; MVC; RO; HD entropy generation; Second Law efficiency; desalination; energy efficiency; MED; MSF; MD; MVC; RO; HD
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Share & Cite This Article

Further Mendeley | CiteULike
Export to BibTeX |
EndNote
MDPI and ACS Style

Mistry, K.H.; McGovern, R.K.; Thiel, G.P.; Summers, E.K.; Zubair, S.M.; Lienhard, J.H., V. Entropy Generation Analysis of Desalination Technologies. Entropy 2011, 13, 1829-1864.

View more citation formats

Article Metrics

Comments

Citing Articles

[Return to top]
Entropy EISSN 1099-4300 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert