Development of high-performance adsorbent via oxidation modification of activated carbon for adsorptive denitrogenation of liquid hydrocarbon streams

In order to increase the adsorption capacity of activated carbon (AC) for adsorptive denitrogenationen (ADN) of liquid hydrocarbon streams, oxidative modification of a commercial AC was conducted using (NH₄)₂S₂O₈ as an oxidant. The effects of (NH₄)₂S₂O₈ concentration, oxidation temperature, and oxidation time on the concentration of the oxygen-containing functional groups on the AC were examined. The oxygen-containing functional groups in the modified AC samples were identified and quantified by the temperature programmed desorption method (TPD-MS). The ADN performance of the modified adsorbent was evaluated. It was found that the oxidative modification increased the concentration of the oxygen-containing functional groups on AC from initial 6.2 mmol-O/g-A to 25.9 mmol-O/g-A. It resulted in a significant increase of the ADN capacity by a factor of 2.8, indicating that the oxidative modification with (NH₄)₂S₂O₈ as an oxidant is very effective in increasing the ADN capacity of AC.