Enhanced Carbon Capture through Incorporation of Surfactant Additives

The CO₂ absorption properties of monoethanolamine (MEA) solutions containing varying amounts of surfactant were examined using different experimental apparatus: a packed column, a stirred reactor, a wetted wall column, and a bubble column. The carbon capture efficiency in the packed column was improved by the addition of surfactant. Surface tension measurements of the different solutions were taken over a range of CO₂ loadings, and the addition of surfactant was seen to lower the surface tension of the amine solvent. However, the improvement in carbon capture efficiency could not be fully correlated to the surface tension depression. The addition of surfactant improved CO₂ absorption in the packed and bubble columns, while the surfactant inhibited absorption in the stirred reactor and wetted wall column experiments. Visual inspection of solvent flowing down a packed column revealed the gas to be bubbling through the liquid, which increases the gas-liquid interfacial area and thus the overall level of mass transfer of carbon dioxide into solution.