(501g) Investigation On the Solubility of SO2 in Several Imidazolium Based Ionic Liquids Using NPT Monte Carlo Simulation
AIChE Annual Meeting
2010 Annual Meeting
Engineering Sciences and Fundamentals
Thermophysical Properties of Ionic Liquids
Wednesday, November 10, 2010 - 2:12pm to 2:29pm
Tthe solubility of sulfur dioxide (SO2) at P=1 bar and several temperatures in a series of Room Temperature Ionic Liquids (RTILs) has been calculated by Monte Carlo simulation at NPT ensemble. The 1-butyl-3-methylimidazolium ([bmim]+) cation in combination with tetrafluoroborate ([BF4]-), bromide ([Br]-), nitrate ([NO3]-) and bis-(trifluoromethyl) sulfonylimide ([Tf2N]-), plus 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) and 1,3-dimethylimidazolium bis-(trifluoromethyl) sulfonylimide ([dmim][Tf2N)]) are studied RTILs. The systems were chosen to study the influence of anion, alkyl chain length of cation and temperature on the solubility of SO2. Also, the micro-structure of pure RTILs and solutions has been studied via various center of mass and site-site Radial Distribution Functions (RDFs). For computing the potential energy and the solubility, the OPLS-AA force field and Widom Particle Insertion Method have been used, respectively. The long- range coulombic forces are taken into account using Wolf Method. The results show that for pure ionic liquids, there is a good agreement between experimental data and calculated liquid density, but the obtained solubility does not reproduce the experimental data with high accuracy which can be a result of incompatible force field and/or the method. The results demonstrate that the SO2 gas has the highest solubility in [bmim][NO3] and the lowest solubility in [dmim][Tf2N], where the solubility increases with alkyl chain length of cation and charge density on anions and it decreases with temperature.