Especially in proximity to metal smelters, heavy metal concentrations are high in the soil and the risk of heavy metal exposure is unneglectable. Therefore, an efficient removal of heavy metals from flue gases is essential. This thesis aim is to remove low concentrations of heavy metals from the flue gas. In order to achieve a high capture efficiency with a high flow rate of the flue gases, supported ionic liquid phases are used. For a pre-selection of suitable ionic liquids, the solubility of heavy metal oxides were screened in several ionic liquids. The best arsenic oxide solubility was observed in ionic liquids with Lewis basic anions. The solubility of arsenic(III) oxide and arsenic(V) oxide in ionic liquids with carboxylate anions decreases with increasing hydrophobicity. The arsenic(III) oxide solubility in phosphonium and ammonium chlorides increased with increasing hydrophobicity. In the solution arsenic(V) oxide, arsenic is present as arsenate anions. An equilibrium of arsenite and arsenate was found for arsenic (III) oxide in acetate containing ionic liquids and chloride - arsenic complexes are postulated in phosphonium chlorides. The highest lead(II) oxide solubility was observed in phosphonium chlorides, phosphonium bromides and imidazolium carboxylates. In the solution, lead is most likely present as anionic lead(ll) hydroxides. In the mixtures of selenium(IV) oxide and several ionic liquids, reduction of selenium(IV) to elemental selenium or H2Se occurs. In the solution, selenium might be present as selenite anions, or SeO2-ionic liquid cation or SeO2-ionic liquid anion complexes. The results of this thesis indicate, that it is possible to capture heavy metals from the gas phase more efficiency with SILP than uncoated activated carbon. [P6 6 6 14]CI coated on activated carbon was identified as the most efficient materials studied in this thesis to capture arsenic from a lead blast furnace flue gas stream (Umicore, Hoboken, Belgium).
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:711899 |
| Date | January 2016 |
| Creators | Schmidt, Anne |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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