Experimental Study and Analysis of the Desublimation of CO2

The development of novel and economical methods to improve carbon capture from point sources is critical in alleviating global warming and climate change concerns. Cryogenic carbon capture (CCC) remains one of the prominent technologies, currently being studied as a viable replacement for other known conventional industrial technologies such as chemical sorption using amines. Though previous works began research on the main thermal properties of the deposited frost on a solid surface, the in-depth study of the CO2 frosting (desublimation) phenomena and the factors affecting the rate of frosting becomes a significant area of research that has not been fully understood. This study presents measurements of the desublimation rate on a coin under atmospheric conditions. These measurements aid to calculate the CO2 capture efficiency and enables the validation of the modelling efforts, which were relying on the thermophysical properties, heat, mass transport fluxes and their influences. The frost distribution and its characteristics are also discussed in this study. A fixed CO2 concentration of 16.2 % wt in the flue gas was used in all the experiments. Results show that the desublimation rate on the solid coin is faster in the first few minutes of the experiments. Precooling the inlet flue gas significantly influences the rate of frosting on the solid coin surface. Since temperature difference is the main driving force for CO2 frosting, the difference between the pre-cooling and coin temperatures determines the rate of desublimation, frost thickness, and distribution with time.