Rapid adsorption of alcohol biofuels by high surface area mesoporous carbons

Surfactant templated mesoporous carbons were evaluated as biofuel adsorbents through characterization of equilibrium and kinetic behavior for both ethanol and n-butanol. Variations in synthetic conditions enabled facile tuning of specific surface area (500–1300 m2/g) and pore morphology (hexagonally packed cylindrical or BCC spherical pores). n-Butanol was more effectively adsorbed than ethanol for all mesoporous carbons, suggesting a mechanism of hydrophobic adsorption. The adsorbed alcohol capacity increased with elevated specific surface area of the adsorbents, irrespective of pore morphology. While adsorption capacity of these mesoporous carbons is comparable to commercially-available, hydrophobic polymer adsorbents of similar surface area, the pore morphology and structure of mesoporous carbons greatly influenced adsorption rates, enhancing them by up to 1–2 orders of magnitude over commercial polymer adsorbents. Multiple cycles of adsorbent regeneration did not impact the adsorption equilibrium or kinetics. The high chemical and thermal stability of mesoporous carbons provide potential significant advantages over other commonly examined biofuel adsorbents, such as polymers and zeolites.

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► Novel mesoporous carbons synthesized and evaluated as alcohol biofuel adsorbents.
► Well-defined pore sizes and geometries established according to tunable templating and synthetic processes.
► These adsorbents offer orders of magnitude enhancement over conventional adsorbents with respect to rates of adsorption.
► Promising for use with in situ product recovery applications.