Study on the absorbability, regeneration characteristics and thermal stability of ionic liquids for VOCs removal

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 328; pp. 353 - 359
• Main Authors: Wang, Wenlong, Ma, Xiaoling, Grimes, Sue, Cai, Hongfei, Zhang, Meng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-11-2017
• Subjects: Absorption; Ionic liquids; Regeneration; Thermal stability; Volatile organic compounds; Volatile organic compounds; Ionic liquids; Regeneration; Absorption; Thermal stability
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2017.06.178

•A novel IL-based technology is developed for removing VOCs from the atmosphere.•[Bmim][NTf2] is shown to be a promising absorbent for VOC pollutants.•Absorptivity of [Bmim][NTf2] for toluene is>94% over a wide range of conditions.•Toluene is easily removed from [Bmim][NTf2] permitting IL reuse in multiple cycles.
A novel method of removal of volatile organic compounds (VOCs) using the ionic liquid [Bmim][NTf2] as an absorbent is developed as a contribution to dealing with recent severe smog incidents in China. The effects of concentration, temperature and flow rates on the ability of [Bmim][NTf2] to absorb VOCs were studied using toluene as a model volatile organic pollutant. The potential of the use of [Bmim][NTf2] as an absorbent for VOCs is shown by the solubility of toluene in the ionic liquid; the absorptivity of the ionic liquid for toluene; and the fact that absorbed toluene can be removed easily from [Bmim][NTf2], permitting recycle of the ionic liquid in multiple reuse phases. The solubility of toluene in [Bmim][NTf2] is 61.5% at 20°C and atmospheric pressure; the highest absorptivity of [Bmim][NTf2] for toluene is 98.3%, achieved at a toluene concentration of 300ppm and a flow rate of 50mLmin−1 at 20°C; and the absorptivity of the ionic liquid is>94% over a wide range of conditions. The ionic liquid can be recovered and recycled in the absorption process at least five times, reducing the reagent cost in the VOC removal process.