Absorption of Carbon Dioxide with Ionic Liquid in a Rotating Packed Bed Contactor: Mass Transfer Study

Abstract

Using ionic liquids for CO2 capture is of great interest due to their unique characteristics. However, low gas–liquid mass transfer rates in conventional gas–liquid contactors due to the high viscosities of ionic liquids lead to the significant limitation for large-scale application of CO2 capture using ionic liquids. Therefore, there is an urgent demand to develop a novel gas–liquid contactor for the intensification of the mass transfer efficiency in such a system. In this article, CO2 absorption with an ionic liquid in a rotating packed bed (RPB) gas–liquid contactor is first reported. It was found that the RPB markedly enhanced the physical absorption of CO2 in the ionic liquid in a very short contact time, within seconds. Only one cycle gas–liquid contact in the RPB could make the saturation ratio of CO2 in the ionic liquid reach 60%. The effects of various operation conditions on the liquid side volumetric mass transfer coefficient (kLα) were elucidated. Increasing the rotating speed from 1100 to 310...