Viscosity Data of Aqueous MDEA–[Bmim][BF4] Solutions Within Carbon Capture Operating Conditions

Abstract

Post–combustion capture with chemical absorption shows higher potential for commercial scale application compared with other technologies. To capture CO2 from the industrial and power plant's flue gases, aqueous alkanolamine solutions are widely used. However, several drawbacks from utilizing the aqueous alkanolamines such as MEA still need to be solved. For example, alkanolamine solutions require intensive energy for regeneration and cause severe corrosion to the equipment though they have high reactivity in capturing CO2. Ionic liquids have been of interest in the recent development of chemical absorption according to their unique characteristics including wide liquid range, negligible volatility and thermal stability. However, due to their high price, high viscosity and low absorption capacity compared to alkanolamines, ionic liquids are still non–desirable for industrial applications. One possible solution to improve the performance of ionic liquids is to use mixtures of ionic liquids and alkanolamines. For a better understanding of the absorption using the mixture of aqueous alkanolamines and ionic liquids, the knowledge of thermo–physical properties of the solutions, especially the viscosity and density are of importance. This paper reports the measured viscosity of MDEA–[Bmim][BF4] aqueous mixtures at various temperatures and concentrations. It was found that the viscosity increase with an increase in [Bmim][BF4] concentration, but decrease with an increase in temperature. Moreover, the impact of temperature on the viscosity is more significant at low temperature range.