Removal of Hg, As in FGD gypsum by different aqueous ammonia (amines) during CO2 sequestration
CO2 sequestration by flue gas desulfurization gypsum (FGDG) has become a promising FGDG disposal technology due to simultaneous CO2 emission reduction and FGDG conversion into calcium carbonate. In this paper, another merit of the novel technology, i.e., the removal of toxic elements (e.g., Hg and A...
| Veröffentlicht in: | Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA. - 1991. - 35(2017), 12 vom: 01. Dez., Seite 1296-1301 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2017
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| Zugriff auf das übergeordnete Werk: | Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA |
| Schlagworte: | Journal Article Flue gas desulfurization gypsum amine ammonia toxic element removal Amines Carbon Dioxide 142M471B3J Ammonia 7664-41-7 mehr... |
| Zusammenfassung: | CO2 sequestration by flue gas desulfurization gypsum (FGDG) has become a promising FGDG disposal technology due to simultaneous CO2 emission reduction and FGDG conversion into calcium carbonate. In this paper, another merit of the novel technology, i.e., the removal of toxic elements (e.g., Hg and As) in FGDG, will be addressed for the first time. In three different aqueous ammonia (or amines) media, removal efficiencies of Hg and As in FGDG samples were evaluated during CO2 sequestration. Higher than 90% and 20% removal efficiencies, respectively, for Hg and As are achieved at 40°C in aqueous ammonia media, but they decrease at elevated temperatures. Ammonia loss takes place at 80°C and pH varies greatly with temperatures in aqueous ammonia. This is disadvantageous for the formation of Hg-ammonia complexes and for the yield of carbonates, which are responsible for Hg or As re-adsorption. The sequential chemical extraction method suggests that the speciation changes of Hg are induced by FGDG carbonation, and that unstable Hg speciation in triethanolamine increases at elevated temperatures |
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| Beschreibung: | Date Completed 13.08.2018 Date Revised 02.12.2018 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1096-3669 |
| DOI: | 10.1177/0734242X17733540 |