Redox flow desalination based on the temperature difference as a driving force

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

3 Scopus Citations
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Author(s)

  • Jinhong Dai
  • Mingzhi Huang
  • Kwan San Hui
  • Dongliang Yan
  • Kwun Nam Hui
  • Swee Ching Tan
  • Liguo Zhang
  • Fuming Chen

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number127716
Journal / PublicationChemical Engineering Journal
Volume416
Online published16 Nov 2020
Publication statusPublished - 15 Jul 2021

Abstract

How to effectively reduce the consumption of electrical energy is a key topic in many studies of electrochemical desalination. In this work, we use the temperature difference to drive a continuous process of dialysis desalination. The system consists of a thermoelectric unit and a desalination unit connected in series. The thermoelectric unit includes a thermoelectric generator (TEG), a heater as heat source and an air-cooled heat sink to generate electricity and for the desalination unit. The desalination unit contains two platinum-coated hydrophobic carbon cloths as current collectors, a mixture of [Fe(CN)6]3-/4- as anolyte and catholyte, concentrated and diluted salt streams with two cationic and one anionic exchange membranes separated configuration (CEM|AEM|CEM). During the charging process driven by temperature difference, chloride and sodium ions in the diluted salt stream move to the concentrated salt stream and cathodic reservoir, respectively. The results show that the concentration of brine drops significantly from 5,000 ppm to 344.3 ppm as the current decreases to 0.06 mA from the initial 1.30 mA when the temperature difference is maintained at 65 K. Concurrently, the average salt removal rate is up to 8.8 μg cm−2 min−1 and average heat consumption is 284.3 MJ mole-1. Moreover, the influences from the temperature difference, salt feeds content and electrolyte concentration are also investigated in detail. This research has the potential application for the freshwater obtainment via the utilization of waste heat, and will be significant in places with the shortage of the electrical energy such as ships, islands and oceans with the temperature differences.

Research Area(s)

  • Electrochemical desalination, Energy consumption, Redox flow desalination, Thermo drive, Water treatment

Citation Format(s)

Redox flow desalination based on the temperature difference as a driving force. / Dai, Jinhong; Huang, Mingzhi; Hui, Kwan San; Yu, Denis Y.W.; Yan, Dongliang; Hui, Kwun Nam; Tan, Swee Ching; Zhang, Liguo; Chen, Fuming.

In: Chemical Engineering Journal, Vol. 416, 127716, 15.07.2021.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review