An Acid Dissociation Constant (pK_a)-based Screening of Chemical Absorbents that Preferably Capture and Release Pressurized Carbon Dioxide for Greenhouse Gas Control

摘要

We describe an acid dissociation constant (pK_a)-based screening of chemical absorbents to treat a gas stream containing carbon dioxide (CO2) in a wide range of partial pressures (0.1-4MPa).The solubility differences of CO2 in aqueous amine solutions at 40 and 70 °C plotted against pK_a revealed volcano-shaped profiles.The availability of amines with pK_a values suitable for capture/release cycles of CO2 with targeted partial pressures shows that the pK_a-based screening method would be useful to develop advanced greenhouse gas control technologies.