Solubility and diffusivity of carbon dioxide in perfluoropolyethers

• We realized a setup for measuring gas solubility and diffusivity in liquids.
• We measured CO2 solubility, selectivity, and diffusivity in two perfluoropolyethers.
• Results confirm that perfluoropolyethers could be used for CO2 absorption processes.
• Solubility and selectivity could be enhanced by modifying the chemical structure.

The main objective of this work was to obtain new data for equilibrium and transport properties in the absorption of carbon dioxide into liquid solvents not yet investigated to this purpose. To this end, an experimental setup for measuring gas solubility and diffusivity in non-volatile solvents was designed, realized, and tested by comparison with literature data for the methane/n-dodecane pair.The solubility of carbon dioxide, nitrogen and oxygen in two different perfluoropolyethers, Fomblin® M03 and Fomblin® Y04, was measured at different temperature ranging from 10 °C to 100 °C and for pressures up to 7 bar. The diffusivity of carbon dioxide in the solvents was measured at 25 °C and 50 °C, through a pressure decay method.The results obtained in terms of carbon dioxide solubility and selectivity over other gases are encouraging for the possible use of Fomblin® perfluoropolyethers for the absorption of carbon dioxide from flue gases of industrial plants, also due to the complete immiscibility with water of this solvents. New compounds with similar chemical structure are being developed and tested in order to maximize the performances of the absorption process.