Effect of Ionic Surfactants on Improving Deasphalting Selectivity in a Nonpolar System

• Published in: Energy & fuels 2016-03, Vol.30 (3), p.2076-2083
• Main Authors: Go, Kang Seok, Kwon, Eun Hee, Kim, Kwang Ho, Nho, Nam Sun, Lee, Ki Bong
• Format: Article
• Language: English
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.5b02860

To reduce the amount of solvent used in the solvent deasphalting process, this study investigated the possibility of improving deasphalting selectivity at a low solvent/oil ratio (SOR) by modifying the stability of the asphaltene colloidal dispersion with ionic surfactants. To do this, an experiment was conducted by changing the solvent types (n-pentane and n-heptane), temperature (35–90 °C), SOR (3–20, vol/vol), surfactants, and surfactant concentration (0.5–2.0 wt % of the feedstock). As a result, the ζ potential with sodium dodecyl sulfonate (SDS) was shown to decrease, while the ζ potential of pitch with cetylpyridinium chloride (CPCl) rose, as compared to those without surfactant. Also, the difference is bigger at a low SOR than at a high SOR. Finally, it was confirmed that, for SDS, the asphaltene content rose about 6% for the incremental 3% rise of pitch yield, while for CPCI, the asphaltene content rose 9–10% for the incremental 1.8% rise of the pitch yield, at the same time. The different movement of ζ potential and asphaltene content between SDS and CPCl can be explained by the adsorption mechanism.