A regenerable precipitant-solvent system for CO2 mitigation and metals recovery

Balucan, Reydick D. and Steel, Karen M. (2015) A regenerable precipitant-solvent system for CO2 mitigation and metals recovery. International Journal of Greenhouse Gas Control, 42 379-387. doi:10.1016/j.ijggc.2015.08.004


Author Balucan, Reydick D.
Steel, Karen M.
Title A regenerable precipitant-solvent system for CO2 mitigation and metals recovery
Journal name International Journal of Greenhouse Gas Control   Check publisher's open access policy
ISSN 1750-5836
1878-0148
Publication date 2015
Sub-type Article (original research)
DOI 10.1016/j.ijggc.2015.08.004
Open Access Status Not Open Access
Volume 42
Start page 379
End page 387
Total pages 9
Place of publication London, United Kingdom
Publisher Elsevier
Collection year 2016
Language eng
Formatted abstract
This work describes a new resource engineering process for greenhouse gas control and metals recovery, and reports initial progress in its development. Centralto this process is a regenerable solvent-precipitant system that enables pH-swing via a change in operational temperatures. In this particular contribution, various liquid-phase aliphatic tertiary amines and acids were examined to identify the suitable components that afford pH control between 10 and 2, deemed necessary for metal hydroxide precipitation and leaching metals from magnesium-bearing solids, respectively. Within the desired operational constraints (Tmax ≤ 110 ◦C, Pmax ≤ 1 bar, tmax ≤ 2 h), we found the triethylamine–sulphuric acid aqueous system (Et3N–H2SO4–H2O) has sufficiently covered the pH regimes of interest, affording a pH swing (at 25 ◦C) between 10.5 and 1.9. Triethylamine (Et3N) provided the highest acid neutralising capacity of 7 mol H+ L−1 Et3N, capable of aqueous alkalisation to pH > 10.5 (25 ◦C, 1 bar), and recoverable at ≤105 ◦C (1.0 bar) via fractional distillation. As for the acid component, H2SO4 allows for the formation of an acidic aqueous solution (pH 1.9, 25 ◦C, 1 bar) resulting from the partial liberation of Et3N from the acid-bound Et3N·H+ and HSO4 − counter anion dissociation.
Keyword pH swing
Mineralisation
CO2 sequestration
Metals recovery
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2016 Collection
 
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Created: Tue, 08 Sep 2015, 22:45:12 EST by Reydick Balucan on behalf of School of Chemical Engineering