Effect of environmental temperature on CO2 selective absorption characteristics by ionic liquid electrospray in flow system

Abstract

In this study, the effect of ambient temperature on ionic liquid electrospray is experimentally clarified for the selective absorption of CO2 in a flow system with 1-ethyl-3-methylimidazolium acetate. The physical properties of ionic liquids, such as viscosity and surface tension are dependent significantly on the liquid temperature. The spray mode transition voltage increases with temperature primarily because of the decrease in viscosity. Moreover, the ionic liquid feeding rate increases the threshold voltage for the spray mode transition when the liquid temperature is higher. The ionic liquid electrospray enhances selective CO2 absorption in the flow system, and the initial decay of CO2 concentration increases with applied voltage, indicating that widely spread ultrafine droplets of ionic liquid are continuously generated. Although the CO2 reaction rate increases with temperature, the CO2 absorption in the spraying chamber at the steady state is lower because of the lower solubility at higher temperatures.