April 4, 2024

Oxygenate Onboard Separation for Octane-on-Demand


This project further examines the use of Self-Assembled Monolayers on Mesoporous Supports® SAMMS®-based sorbent materials as a sorbent for alcohols from alcohol-gasoline blends in the context of an onboard separation approach for use in an octane-on-demand strategy. Several questions were posed by potential industry collaborators seeking to better understand how the SAMMS®-based materials would perform in a more realistic environment. Several conclusions can be made from the work conducted here, with the caveat that these experiments do not represent the results that would be obtained from continuous or long-term use of the sorbent, because of the short duration of the project. Vigorous extractions into warm gasoline did not reveal the presence of additional species in gas chromatographic analysis. Vibration testing for up to eight hours under aggressive conditions did not show particle attrition. Thermal desorption experiments showed that the SAMMS® have a higher capacity for methanol, approximately 50 weight-percent of the sorbent, than for ethanol, approximately 20 weight-percent of the sorbent, and that the methanol is easier to extract. Testing of the A20 fuel blends was insufficient and requires a slightly more sophisticated approach than was attempted here. Additionally, further work would be needed to assess the rate at which the alcohol is absorbed into the sorbent. The testing conducted here suggests that equilibrium is reached in well under an hour. While this study provides additional insights into the use of SAMMS®-based sorbent materials for onboard alcohol separation, there is room for further work employing a benchtop testing apparatus similar to that described herein.

Published: April 4, 2024


Bays J.T., T.J. Baker, D. Barpaga, K.B. Campbell, G.W. Coffey, M.A. Fuller, and J.C. Linehan, et al. 2023. Oxygenate Onboard Separation for Octane-on-Demand Richland, WA: Pacific Northwest National Laboratory.

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