Solubility and diffusivity of CO2 in n-butanol+N235 system and absorption mechanism of CO2 in a coupled reaction-extraction process

The absorption of CO2 in insoluble organic amine is crucial for understanding the mechanism of coupled reaction-extraction-crystallization process between aqueous chloride and CO2. In this study, the solubility and diffusivity of CO2 in n-butanol + N235 system were measured and reported. The absorption of CO2 in the system is a physical absorption behavior and the solubility of CO2 decreases with the increase of the mass fraction of N235. The diffusivity of CO2 increases firstly and then decreases with the increase in the mass fraction of N235. Moreover, the absorption mechanism of CO2 in the coupled reaction-extraction-crystallization process was investigated and identified by experiments. The results indicated that in the coupled reaction-extraction-crystallization process, CO2 is absorbed by the aqueous phase rather than by the organic phase and further transferred into the aqueous phase.