A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption

The primary energy consumption of a spectrum of desalination systems is assessed using operating information for real plants configured for coproduction of electricity and water. The energy efficiency of desalination plants is often rated using metrics such as electrical energy consumption per unit...

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Main Authors: Lienhard, John, Bouma, Andrew Thomas
Format: Article
Published: 2022
Online Access:https://hdl.handle.net/1721.1/141350
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author Lienhard, John
Bouma, Andrew Thomas
author_facet Lienhard, John
Bouma, Andrew Thomas
author_sort Lienhard, John
collection MIT
description The primary energy consumption of a spectrum of desalination systems is assessed using operating information for real plants configured for coproduction of electricity and water. The energy efficiency of desalination plants is often rated using metrics such as electrical energy consumption per unit of water produced (SEC), water produced per unit of thermal energy consumed (GOR), or exergy use relative to the limit set by the second law of thermodynamics (ηII). Comparisons of desalination technologies using these metrics can be inaccurate if energy inputs to the desalination plant are not distinguished between electrical work input and heat input using exergetic methods. Further, the cost of electrical exergy and thermal exergy at a given temperature may be quite different. When both the heat and work inputs are drawn from a common primary energy source, as in electricity-water coproduction systems, work and heat can be compared and combined by tracing them to primary energy use. In the present study, we use an exergetic framework to compare 48 different configurations of electricity production and desalination, including cases with pretreatment and hybridized systems, based on performance figures from real and quoted desalination systems operating in the GCC region. The results show that, while reverse osmosis is the most energy efficient desalination technology, the gap between work and thermally driven desalination technologies is reduced when considered on the basis of primary energy. The results also show that pretreatment with nanofiltration can help to reduce energy requirements. Further, the differences are affected by the thermodynamic efficiency of the power plant itself. Conclusions with regard to hybrid systems are more ambiguous.
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spelling mit-1721.1/1413502022-03-24T03:10:59Z A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption Lienhard, John Bouma, Andrew Thomas The primary energy consumption of a spectrum of desalination systems is assessed using operating information for real plants configured for coproduction of electricity and water. The energy efficiency of desalination plants is often rated using metrics such as electrical energy consumption per unit of water produced (SEC), water produced per unit of thermal energy consumed (GOR), or exergy use relative to the limit set by the second law of thermodynamics (ηII). Comparisons of desalination technologies using these metrics can be inaccurate if energy inputs to the desalination plant are not distinguished between electrical work input and heat input using exergetic methods. Further, the cost of electrical exergy and thermal exergy at a given temperature may be quite different. When both the heat and work inputs are drawn from a common primary energy source, as in electricity-water coproduction systems, work and heat can be compared and combined by tracing them to primary energy use. In the present study, we use an exergetic framework to compare 48 different configurations of electricity production and desalination, including cases with pretreatment and hybridized systems, based on performance figures from real and quoted desalination systems operating in the GCC region. The results show that, while reverse osmosis is the most energy efficient desalination technology, the gap between work and thermally driven desalination technologies is reduced when considered on the basis of primary energy. The results also show that pretreatment with nanofiltration can help to reduce energy requirements. Further, the differences are affected by the thermodynamic efficiency of the power plant itself. Conclusions with regard to hybrid systems are more ambiguous. 2022-03-23T18:07:49Z 2022-03-23T18:07:49Z 2019 Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141350 T. Altmann, A.T. Bouma, J. Roberts, J. Swaminathan, J.H. Lienhard V, “A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption,” IDA World Congress on Desalination and Water Reuse, Dubai, UAE, 20–24 Oct. 2019. IDA Ref. No. IDAWC19-Altmann. The International Desalination Association World Congress on Desalination and Water Reuse 2019/Dubai, UAE Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Prof. Lienhard
spellingShingle Lienhard, John
Bouma, Andrew Thomas
A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption
title A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption
title_full A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption
title_fullStr A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption
title_full_unstemmed A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption
title_short A Comparison of Desalination Technologies on the Basis of Primary Energy Consumption
title_sort comparison of desalination technologies on the basis of primary energy consumption
url https://hdl.handle.net/1721.1/141350
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