A laboratory study on foam-enhanced surfactant solution flooding in removing n-pentadecane from contaminated columns

The efficiency of a foam flooding process in removing n-pentadecane from a contaminated glass-bead column was evaluated by comparing with the results obtained by a surfactant-solution flooding process. Data on the foaming pro perties and solubilization efficiency of aqueous surfactant solutions were reported. Moreover, an experimental column containing n-pentadecane-contami nated glass beads was used to explore the effects of surfactant concentrati on and gas-liquid volumetric flow rate ratio on the recovery efficiency of n-pentadecane. It was found that the efficiency of a surfactant solution in recovering n-pentadecane increased with increasing surfactant concentratio n. The findings also suggest that in this study the surfactant-enhanced emu lsification of n-pentadecane played an important role in removing n-pentade cane from the contaminated column. Using foam flooding, the recovery of n-p entadecane was increased significantly compared with what obtained by surfa ctant-solution flushing, probably due to the reduced channeling flow effect . These data demonstrated that the dramatic improvement in residual n-penta decane recovery can be realized by the use of foam. In addition, at a const ant liquid flow rate, an increase in gas-liquid volumetric flow rate ratio may result in increased total n-pentadecane recovery. (C) 2000 Elsevier Sci ence B.V. All rights reserved.