The role of Tween 80 and SDS in the kinetics of semi-clathrate hydrates formation for carbon dioxide capture from flue gas

The present study focuses on integrated experimental evaluation of a concentration effect in nonionic and anionic surfactants on semi-clathrate hydrates formation during the capture low-pressure carbon dioxide from the flue gas (N-2 (83.13 mol.%)/CO2 (16.87 mol.%)). Semi-clathrate hydrates of tetra n-butylammonium bromide (TBAB) are favorable materials with phase changes due to their moderate hydrate formation conditions. The kinetics of CO2-N-2-TBAB semi-clathrate hydrate formation was studied in the presence and absence of Tween-80 as a nonionic surfactant and sodium dodecyl sulfate (SDS) as an anionic one. The experiments were performed in a stirred batch reactor at a constant temperature of 273.55 K and an initial pressure of 2.1 MPa. 5.0 wt.% TBAB's aqueous solutions were tested both in the absence of surfactants and in presence of Tween-80 and SDS at different concentrations (500, 1500, 3000 ppm). The separation factor and recovery for CO2 at low pressure were in situ controlled depending on the surfactant concentration. Adding 1500 ppm of Tween-80 provided optimal conditions for the CO2/N-2 separation process; the separation factor was 9.5, the CO2 recovery was 53.1%.