skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on September 1, 2020

Title: Molten chloride salts for next generation CSP plants: Electrolytical salt purification for reducing corrosive impurity level

Abstract

In this study, electrolysis with a Mg anode is presented to purify the molten chloride salt (MgCl 2/KCl/NaCl 60/20/20 mol.%) for reducing its corrosivity. Using a Mg anode, the production of toxic gases like Cl 2 on an inert anode (e.g., tungsten) can be avoided. Moreover, compared to an inert anode, a lower over-potential is required to remove the corrosive impurity MgOH + in the molten salt due to the high reactivity of Mg. In order to evaluate the effect of the salt purification, the cyclic voltammetry (CV) method developed in our previous work is used to in-situ measure the concentration of the corrosive MgOH + impurity in the molten salt. The CV measurements indicate that the corrosive impurity is efficiently removed by electrolysis. For decreasing the cathode inactivation due to produced MgO on the surface, a pulsed potential applied on the tungsten cathode during electrolysis shows to be promising. This electrochemical salt purification method has shown to be promising by efficiently controlling the corrosivity of the molten chloride salt. The potentiodynamic polarization (PDP) measurements on a commercial high-temperature alloy (Incoloy 800 H) immersed in the molten salt indicate that the corrosion rate of the alloy is significantly reduced duemore » to the salt purification. It could also lead to a reduction of the cost of the conventional salt purification step, structural container materials, and piping in next generation concentrated solar power (Gen3 CSP) plants.« less

Authors:
 [1];  [2];  [1];  [3]
  1. German Aerospace Center (DLR), Inst. of Engineering Thermodynamics, Stuttgart (Germany)
  2. National Renewable Energy Lab. (NREL), Golder, CO (United States). Building and Thermal Sciences Center
  3. German Aerospace Center (DLR), Cologne (Germany). Inst. of Engineering Thermodynamics
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1543119
Report Number(s):
[NREL/JA-5500-74320]
[Journal ID: ISSN 0927-0248]
Grant/Contract Number:  
[AC36-08GO28308]
Resource Type:
Accepted Manuscript
Journal Name:
Solar Energy Materials and Solar Cells
Additional Journal Information:
[ Journal Volume: 199; Journal Issue: C]; Journal ID: ISSN 0927-0248
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 47 OTHER INSTRUMENTATION; concentrated solar power (CSP); corrosion control; corrosive impurity; cyclic voltammetry (CV); electrolysis; potentiodynamic polarization (PDP)

Citation Formats

Ding, Wenjin, Gomez-Vidal, Judith, Bonk, Alexander, and Bauer, Thomas. Molten chloride salts for next generation CSP plants: Electrolytical salt purification for reducing corrosive impurity level. United States: N. p., 2019. Web. doi:10.1016/j.solmat.2019.04.021.
Ding, Wenjin, Gomez-Vidal, Judith, Bonk, Alexander, & Bauer, Thomas. Molten chloride salts for next generation CSP plants: Electrolytical salt purification for reducing corrosive impurity level. United States. doi:10.1016/j.solmat.2019.04.021.
Ding, Wenjin, Gomez-Vidal, Judith, Bonk, Alexander, and Bauer, Thomas. Sun . "Molten chloride salts for next generation CSP plants: Electrolytical salt purification for reducing corrosive impurity level". United States. doi:10.1016/j.solmat.2019.04.021.
@article{osti_1543119,
title = {Molten chloride salts for next generation CSP plants: Electrolytical salt purification for reducing corrosive impurity level},
author = {Ding, Wenjin and Gomez-Vidal, Judith and Bonk, Alexander and Bauer, Thomas},
abstractNote = {In this study, electrolysis with a Mg anode is presented to purify the molten chloride salt (MgCl2/KCl/NaCl 60/20/20 mol.%) for reducing its corrosivity. Using a Mg anode, the production of toxic gases like Cl2 on an inert anode (e.g., tungsten) can be avoided. Moreover, compared to an inert anode, a lower over-potential is required to remove the corrosive impurity MgOH+ in the molten salt due to the high reactivity of Mg. In order to evaluate the effect of the salt purification, the cyclic voltammetry (CV) method developed in our previous work is used to in-situ measure the concentration of the corrosive MgOH+ impurity in the molten salt. The CV measurements indicate that the corrosive impurity is efficiently removed by electrolysis. For decreasing the cathode inactivation due to produced MgO on the surface, a pulsed potential applied on the tungsten cathode during electrolysis shows to be promising. This electrochemical salt purification method has shown to be promising by efficiently controlling the corrosivity of the molten chloride salt. The potentiodynamic polarization (PDP) measurements on a commercial high-temperature alloy (Incoloy 800 H) immersed in the molten salt indicate that the corrosion rate of the alloy is significantly reduced due to the salt purification. It could also lead to a reduction of the cost of the conventional salt purification step, structural container materials, and piping in next generation concentrated solar power (Gen3 CSP) plants.},
doi = {10.1016/j.solmat.2019.04.021},
journal = {Solar Energy Materials and Solar Cells},
number = [C],
volume = [199],
place = {United States},
year = {2019},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on September 1, 2020
Publisher's Version of Record

Save / Share:

Works referencing / citing this record:

Review of supercritical CO 2 power cycles integrated with CSP
journal, December 2019

  • Yin, Jun‐Ming; Zheng, Qiu‐Yun; Peng, Zhao‐Rui
  • International Journal of Energy Research
  • DOI: 10.1002/er.4909