A Study on the CO2 Capture Performance using a Packing-free Absorber

Abstract

The packed tower that is commonly used for capturing CO2 from flue emissions has many disadvantages. This study analyzed the performance characteristics of the packing-free absorption tower and reviewed its type through experimental data and CFD simulation.CO2 capture using the vortex tube with strong swirl flow and the spray tower with weak swirl flow was examined in preliminary studies. From these results, the conclusion was drawn that it can be better, in terms of the actual capture of CO2, to capture CO2 effectively in the total gas rather than to increase the CO2 saturation degree of absorbents. Hence, the research involved a study on CO2 capture characteristics using aqueous ammonia with single nozzle spray towers, as a representative packing-free type absorber.Basic absorption performance characteristics of the spray tower type of CO2 capture devices were examined under various conditions, such as the flow rate and concentration of injected gas and injected absorbents

in addition, experiments and CFD simulation were conducted to deduce the optimum size of the absorption tower. From these results, universal parameters were selected that took into consideration all the influences of injection conditions, and their respective relationships were deduced. With these relationships, it was possible to predict the capture efficiency corresponding to each operating condition, even if an experiment with the conditions was not carried out. In addition, we defined a new performance indicator called ‘CO2 saturation degree’ to represent the performance of CO2 capture devices. We believe this can be utilized to suggest a direction of improvement in CO2 capture devices.