Effectiveness of toluene separation from gas phase using supported ammonium ionic liquid membrane

Ammonium ionic liquids (ILs) are relatively cheap in synthesis and environmentally benign and despite that they have been very rarely used in gas separation. In this research we used several ammonium ILs as liquid membranes for removal of residual toluene from gas phase. Ionic liquids used in this study were composed of bis(trifluoromethylsulfonyl)imide anion [Tf2N] and trimethylbutylammonium [N-1114], trietylbutylammonium [N-2224], trietylhexylammonium [N-2226], trietyloctylammonium [N-2228] cations. Selected ILs formed stable membranes with limited swelling effect and good performance. The highest toluene permeability was recorded for [N-2228][Tf2N] of 2666 barrers and for triethyl based ILs it was decreasing with carbon atoms number. The selectivity of toluene/N-2 separation was in a range of 29-120. For better process illustration, the factors influencing the permeation process, namely viscosity and partition coefficients were examined. (C) 2020 Elsevier Ltd. All rights reserved.