Red mud-molten salt composites for medium-high temperature thermal energy storage and waste heat recovery applications

Argyrios Anagnostopoulos; Maria Elena Navarro; Maria Stefanidou; Yulong Ding; Georgios Gaidajis

doi:10.1016/j.jhazmat.2021.125407

Red mud-molten salt composites for medium-high temperature thermal energy storage and waste heat recovery applications

Argyrios Anagnostopoulos^*, Maria Elena Navarro, Maria Stefanidou, Yulong Ding, Georgios Gaidajis

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Red mud (RM) is an industrial waste of the aluminum industry with presently estimated worldwide legacy-site stockpiles of 4 billion tones. RM is typically disposed in the sea, dams or dykes, posing a significant environmental hazard due to its high alkalinity and traces of heavy metals. Despite recent valorization efforts, only 15% of RM deposits are currently utilized. In this work, a novel use of RM to formulate composite phase change materials (CPCMs) is proposed. The CPCM is formulated by milling nitrate salts with RM, compressing and subsequent sintering of the two. Overall good performance over the temperature range of 25–400 ℃ is observed. Maximum latent heat of the CPCMs is 58 J/g, while average thermal conductivity and C_p are in the range of 0.77–0.83 W/mK and 1.03–1.31 J/g ℃, respectively. No variations in the melting point or latent heat are observed after 48 cycles. Energy storage density is calculated to be up to 1396 MJ/m³. The working temperature of this novel CPCM make it ideal for waste heat recovery of medium-high temperature waste heat streams providing a valorization pathway and valorization for RM as a by-product for energy-related applications.

Original language	English
Article number	125407
Number of pages	9
Journal	Journal of Hazardous Materials
Volume	413
Early online date	17 Feb 2021
DOIs	https://doi.org/10.1016/j.jhazmat.2021.125407
Publication status	Published - 5 Jul 2021

Bibliographical note

Funding Information:
The authors would like to acknowledge partial financial support from the UK Engineering and Physical Sciences Research Council ( EPSRC) under grants EP/V012053/1 , EP/S032622/1 , EP/P004709/1 and EP/T022981/1 .

Publisher Copyright:
© 2021 Elsevier B.V.

Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.

Keywords

Composite
Molten salt
Phase change
Red mud
Thermal energy storage
Waste heat recovery
Waste management
Waste valorization

ASJC Scopus subject areas

Environmental Engineering
Environmental Chemistry
Waste Management and Disposal
Pollution
Health, Toxicology and Mutagenesis

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Cite this

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title = "Red mud-molten salt composites for medium-high temperature thermal energy storage and waste heat recovery applications",

abstract = "Red mud (RM) is an industrial waste of the aluminum industry with presently estimated worldwide legacy-site stockpiles of 4 billion tones. RM is typically disposed in the sea, dams or dykes, posing a significant environmental hazard due to its high alkalinity and traces of heavy metals. Despite recent valorization efforts, only 15% of RM deposits are currently utilized. In this work, a novel use of RM to formulate composite phase change materials (CPCMs) is proposed. The CPCM is formulated by milling nitrate salts with RM, compressing and subsequent sintering of the two. Overall good performance over the temperature range of 25–400 ℃ is observed. Maximum latent heat of the CPCMs is 58 J/g, while average thermal conductivity and Cp are in the range of 0.77–0.83 W/mK and 1.03–1.31 J/g ℃, respectively. No variations in the melting point or latent heat are observed after 48 cycles. Energy storage density is calculated to be up to 1396 MJ/m3. The working temperature of this novel CPCM make it ideal for waste heat recovery of medium-high temperature waste heat streams providing a valorization pathway and valorization for RM as a by-product for energy-related applications.",

keywords = "Composite, Molten salt, Phase change, Red mud, Thermal energy storage, Waste heat recovery, Waste management, Waste valorization",

author = "Argyrios Anagnostopoulos and Navarro, {Maria Elena} and Maria Stefanidou and Yulong Ding and Georgios Gaidajis",

note = "Funding Information: The authors would like to acknowledge partial financial support from the UK Engineering and Physical Sciences Research Council ( EPSRC) under grants EP/V012053/1 , EP/S032622/1 , EP/P004709/1 and EP/T022981/1 . Publisher Copyright: {\textcopyright} 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",

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doi = "10.1016/j.jhazmat.2021.125407",

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AU - Anagnostopoulos, Argyrios

AU - Navarro, Maria Elena

AU - Stefanidou, Maria

AU - Ding, Yulong

AU - Gaidajis, Georgios

N1 - Funding Information: The authors would like to acknowledge partial financial support from the UK Engineering and Physical Sciences Research Council ( EPSRC) under grants EP/V012053/1 , EP/S032622/1 , EP/P004709/1 and EP/T022981/1 . Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/7/5

Y1 - 2021/7/5

N2 - Red mud (RM) is an industrial waste of the aluminum industry with presently estimated worldwide legacy-site stockpiles of 4 billion tones. RM is typically disposed in the sea, dams or dykes, posing a significant environmental hazard due to its high alkalinity and traces of heavy metals. Despite recent valorization efforts, only 15% of RM deposits are currently utilized. In this work, a novel use of RM to formulate composite phase change materials (CPCMs) is proposed. The CPCM is formulated by milling nitrate salts with RM, compressing and subsequent sintering of the two. Overall good performance over the temperature range of 25–400 ℃ is observed. Maximum latent heat of the CPCMs is 58 J/g, while average thermal conductivity and Cp are in the range of 0.77–0.83 W/mK and 1.03–1.31 J/g ℃, respectively. No variations in the melting point or latent heat are observed after 48 cycles. Energy storage density is calculated to be up to 1396 MJ/m3. The working temperature of this novel CPCM make it ideal for waste heat recovery of medium-high temperature waste heat streams providing a valorization pathway and valorization for RM as a by-product for energy-related applications.

AB - Red mud (RM) is an industrial waste of the aluminum industry with presently estimated worldwide legacy-site stockpiles of 4 billion tones. RM is typically disposed in the sea, dams or dykes, posing a significant environmental hazard due to its high alkalinity and traces of heavy metals. Despite recent valorization efforts, only 15% of RM deposits are currently utilized. In this work, a novel use of RM to formulate composite phase change materials (CPCMs) is proposed. The CPCM is formulated by milling nitrate salts with RM, compressing and subsequent sintering of the two. Overall good performance over the temperature range of 25–400 ℃ is observed. Maximum latent heat of the CPCMs is 58 J/g, while average thermal conductivity and Cp are in the range of 0.77–0.83 W/mK and 1.03–1.31 J/g ℃, respectively. No variations in the melting point or latent heat are observed after 48 cycles. Energy storage density is calculated to be up to 1396 MJ/m3. The working temperature of this novel CPCM make it ideal for waste heat recovery of medium-high temperature waste heat streams providing a valorization pathway and valorization for RM as a by-product for energy-related applications.

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Red mud-molten salt composites for medium-high temperature thermal energy storage and waste heat recovery applications

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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