Latest Development on Membrane Fabrication for Natural Gas Purification: A Review

Table 4

Effects of ionic liquid functionalization.

Functionalization	Effects
Nitrile and alkyne group	(i) Gas solubility and separation performance have been tailored.; (ii) Functionalized RTIL solvents displayed a decreasing in CO2, N2, and CH4 solubility, but, however, the selectivity of CO2/N2 and CO2/CH4 increased when compared to the nonfunctionalized RTIL [61].
Temperature	(i) As the temperature increases, the CO2 solubility is decreasing while the CH4 solubility remains unchanged.; (ii) The ideal solubility selectivity of mix gases for CO2/N2, CO2/CH4, and CO2/H2 increased as the temperature decreased [62].