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

Abstract

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 300 ppm and a flow rate of 50 mL min−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

Thermal Stability of Ionic Liquids: Current Status and Prospects for Future Development

“…Previous research has proved that ILs have many advantages, including non-volatility, non-flammability, high thermal and chemical stability, wide electrochemical window, tunable miscibility, and good extraction capability, which are not attained for the volatile organic solvents [6][7][8]. As a result of these features and advantages, ILs are used in a wide range of applications such as catalyst [9][10][11][12][13][14], pre-treatment of biomass [15][16][17], absorbent [18][19][20], gas sensors [21], electrolyte [22][23][24], and membrane separation [25][26][27]. Among all of the applications, high-temperature utilization accounts for the vast majority, including high-temperature lubricants [28][29][30], solvents for high-temperature organic reactions [31], heat-transfer fluids [32,33], and thermal energy storage [34,35].…”

Pore structure and VOCs adsorption characteristics of activated coke powders derived via one‐step rapid pyrolysis activation method

“…Due to the hypertoxicity of VOC pollutants, enormous efforts have been paid on various physical and chemical methods for controlling the emission of VOCs. Techniques that have been widely studied include adsorption, 2 absorption, 3 thermal oxidation, 4 catalytic oxidation, 5 photocatalytic oxidation, 6 and biological treatment 7 . Among these methods, adsorption is one of the most effective, simple, and low‐cost promising techniques for VOC abatement 8,9 …”

Characterization of Absorption Performance for Gaseous Acetone with Ionic Liquid Solutions

“…In recent years, ionic liquids (ILs) have received special attention as potential candidates of VOC solvents , owing to their unique characteristics such as extremely high thermal stability and designable structures . The organic fragments of ILs construct the affiliative relationship with VOCs.…”