Concentration control of volatile organic compounds by ionic liquid absorption and desorption

Abstract Volatile organic compounds (VOCs) are difficult to be eliminated safely and effectively because of their large concentration fluctuations. Thus, maintaining a stable concentration of VOCs is a significant study. In this research, H 2 O, Tween-80, [Emim]BF 4 , [Emim]PF 6 , and [Hnmp]HSO 4 were applied to absorb and desorb simulated VOCs. The ionic liquid [Emim]BF 4 demonstrated the best performance and was thus selected for further experiments. As the ionic liquid acted as a buffer, the toluene concentration with a fluctuation of 2000–20000 mg·m −3 was stabilized at 6000–12000 mg·m −3 . Heating distillation (90 °C) was highly efficient to recover [Emim]BF 4 from toluene. The regenerated [Emim]BF 4 could retain its initial absorption capacity even after multiple cycles. Moreover, [Emim]BF 4 had the same buffer function on various aromatic hydrocarbons.