(602z) Surfactant Addition to Alkali Solutions for Increased Carbon Dioxide Absorption Rates

To meet the growing need for CO₂ capture and storage technology, Michigan Technological University is studying CO₂ capture.  Our current approach to CO₂ capture is to bubble CO₂ through alkali solutions.  The objective of the present study was to find a way to increase the absorption rate of CO₂ into the alkali solution without reducing the absorption capacity of the solution.  One approach to increasing absorption rate is to use a surfactant to chemically alter the gas bubble size.  The surfactant chosen for the study was a neutral charge surfactant called DOWFROTH 200 (DF200).  Experiments were conducted to study the absorption rate of CO₂ at varying surfactant concentrations of 0, 0.12, 0.24, 0.36, and 0.48 g/L. Results showed that as the concentration of DF200 increased in solution, the absorption rate also increased.  The CO­₂ absorption rate increased from 3.45*10^-3 mol/min CO₂ at 0g/L DF200 to 3.92*10^-3 mol/min CO₂ at 0.48 g/L DF200.  This amounted to a 14% increase in the CO₂ absorption rate with only a 3% loss in absorption capacity of the solution.