Environmental remediation applications of ionic liquids

: developing ionic liquid technologies for aqueous and gaseous waste management

Abstract

This work focuses on the use of ionic liquids in two areas of industrial pollution management, aqueous sulfate removal and carbon dioxide capture from flue gas. Chapter two investigated the potential use of hydrophobic ionic liquid chlorides as liquid anion exchangers where sea water was used to model a competitive source of aqueous sulfate. Five ionic liquids (Cyphos® 101, Aliquat® 336, [HN888 ]Cl, [P1888 ]Cl and [N2OH888 ]Cl) that contain functional groups common to anion exchange resins where shown to form aqueous biphasic systems with water with varying levels of water saturation from 8 to 26.6 wt%.Chapter three aimed to build on the previous chapter whereby weakly binding bis or tris (thio)urea anion receptors were added to water saturated Cyphos® 101 and Aliquat® 336. The aim was to enhance the sulfate extraction via synergised anion recognition and ion-exchange. Chapter four moves away from aqueous sulfate removal and focuses on the development of a chemisorbant ionic liquid process for CO2 removal from flue gas. Initially, a small series of ionic liquids were tested for CO2 absorption under dry and humid conditions. [DBUH][Im] was shown as a potential candidate for a high-temperature absorption-desorption cycle under humid conditions with absorption and desorption temperatures of 95 and 160°C, respectively.

Date of Award	Dec 2024
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Chevron Energy Technology Company & Engineering and Physical Sciences Research Council
Supervisor	John Holbrey (Supervisor) & Gosia Swadzba-Kwasny (Supervisor)