Abstract
1-Butyl-3-methylimidazolium tetrafluoroborate ([BMINI][BF4]) ionic liquid (IL) is considered for CO2 capturing in a typical absorption/stripper process. The use of ionic liquids is considered to be cost-effective because it requires less energy for solvent recovery compared to other conventional processes. A mathematical model was developed for the process based on Peng-Robinson (PR) equation of state (EoS). The model was validated with experimental data for CO2 solubility in [BMEM][BF4]. The model is utilized to study the sorbent effect and energy demand for selected operating pressure at specific CO2 capturing rates. The energy demand is expressed by the vapor-liquid equilibrium temperature necessary to remove the captured CO2 from the spent solvent in the regeneration step. It is found that low recovery temperature can be achieved at specific pressure combination for the absorber/stripper units. In fact, the temperature requirement is less than that required by the typical monoethanolamine (MEA) solvent. The effect of the CO2 loading in the sorbent stream on the process performance is also examined.