Recent development in thermally activated desalination methods: achieving an energy efficiency less than 2.5 kWhelec/m3

Handle URI:
http://hdl.handle.net/10754/566156
Title:
Recent development in thermally activated desalination methods: achieving an energy efficiency less than 2.5 kWhelec/m3
Authors:
Shahzad, Muhammad Wakil; Thu, Kyaw; Ng, Kim Choon; WonGee, Chun
Abstract:
Water-Energy-Environment nexus is a crucial consideration when designing seawater desalination processes, particularly for the water-stressed countries where the annual water availability is less than 250 m3 per capita. Despite the thermodynamics limit for seawater desalination at normal conditions is about 0.78 to 1.09 kWhelec/m3, the specific energy consumption of desalination of real plants is found to operate at several folds higher. Today’s technological advancement in membranes, namely the reverse osmosis processes, has set an energy consumption of around 3.5–5 kWhelec/m3, while the conventional perception of thermally activated processes such as MSF and MED tends to be higher. Although the higher energetic specific consumption of MED or MSF processes appeared to be higher at 60–100 kWhthermal/m3, their true electricity equivalent has been converted, hitherto, using the energetic analyses where the work potential of working steam of the processes cannot be captured adequately. Thermally activated processes, such as MED and MSF, form the bottoming cycle of a cogeneration plant where both electricity and desalination processes operate in tandem in a cascaded manner. Only the bled-steam at lower exergy is extracted for the desalination processes. In this presentation, we demonstrate that in a cogen plant with 30% bled-steam for MED processes, the exergy destruction ratio is found to be less than 7% of the total available exergy that emanated from the boilers. By the exergetic approach, the equivalent electricity consumption of an average 75 kWhthermal/m3 would result in an electrical equivalent of less than 2.5 kWhelec/m3. Also in this presentation, the authors will elaborate the latest developments in the use of hybridization concept where the MED and the AD cycles are thermodynamically integrated and enhancing the overall efficiency of desalination. © 2015 Balaban Desalination Publications. All rights reserved.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC)
Publisher:
Informa UK Limited
Journal:
Desalination and Water Treatment
Issue Date:
19-May-2015
DOI:
10.1080/19443994.2015.1035499
Type:
Article
ISSN:
19443994
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorShahzad, Muhammad Wakilen
dc.contributor.authorThu, Kyawen
dc.contributor.authorNg, Kim Choonen
dc.contributor.authorWonGee, Chunen
dc.date.accessioned2015-08-12T09:30:25Zen
dc.date.available2015-08-12T09:30:25Zen
dc.date.issued2015-05-19en
dc.identifier.issn19443994en
dc.identifier.doi10.1080/19443994.2015.1035499en
dc.identifier.urihttp://hdl.handle.net/10754/566156en
dc.description.abstractWater-Energy-Environment nexus is a crucial consideration when designing seawater desalination processes, particularly for the water-stressed countries where the annual water availability is less than 250 m3 per capita. Despite the thermodynamics limit for seawater desalination at normal conditions is about 0.78 to 1.09 kWhelec/m3, the specific energy consumption of desalination of real plants is found to operate at several folds higher. Today’s technological advancement in membranes, namely the reverse osmosis processes, has set an energy consumption of around 3.5–5 kWhelec/m3, while the conventional perception of thermally activated processes such as MSF and MED tends to be higher. Although the higher energetic specific consumption of MED or MSF processes appeared to be higher at 60–100 kWhthermal/m3, their true electricity equivalent has been converted, hitherto, using the energetic analyses where the work potential of working steam of the processes cannot be captured adequately. Thermally activated processes, such as MED and MSF, form the bottoming cycle of a cogeneration plant where both electricity and desalination processes operate in tandem in a cascaded manner. Only the bled-steam at lower exergy is extracted for the desalination processes. In this presentation, we demonstrate that in a cogen plant with 30% bled-steam for MED processes, the exergy destruction ratio is found to be less than 7% of the total available exergy that emanated from the boilers. By the exergetic approach, the equivalent electricity consumption of an average 75 kWhthermal/m3 would result in an electrical equivalent of less than 2.5 kWhelec/m3. Also in this presentation, the authors will elaborate the latest developments in the use of hybridization concept where the MED and the AD cycles are thermodynamically integrated and enhancing the overall efficiency of desalination. © 2015 Balaban Desalination Publications. All rights reserved.en
dc.publisherInforma UK Limiteden
dc.subjectAdsorption desalination (AD)en
dc.subjectExergy analysisen
dc.subjectHybrid cyclesen
dc.subjectMulti-effect distillation (MED)en
dc.subjectThermal desalinationen
dc.titleRecent development in thermally activated desalination methods: achieving an energy efficiency less than 2.5 kWhelec/m3en
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalDesalination and Water Treatmenten
dc.contributor.institutionDepartment of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singaporeen
dc.contributor.institutionDepartment of Nuclear and Energy Engineering, Cheju National University, 66 Jejudaehakno, Jejusi, South Koreaen
kaust.authorShahzad, Muhammad Wakilen
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