Effective Adsorptive Denitrogenation from Model Fuels over CeY Zeolite

Abstract

Nitrogen-containing compounds (NCCs) in hightemperature coal tar have a negative impact on its utilization. This work aimed to prepare a series of Ce x Y adsorbents with superior capacity and selectivity by ion exchange, and further clarify the regeneration properties and adsorption mechanism. The adsorptive denitrogenation properties were evaluated at different temperatures using batch adsorption experiments in different model fuels. The implication of Ce loading on the adsorption properties has been studied. The results show that Ce 0.2 Y exhibits a remarkable performance in adsorption capacity. Ce 0.2 Y can reach 25.32 mg•N• g −1 absorption for quinoline and 23.78 mg•N•g −1 absorption for indole at 30 °C, which is much better than that of NaY. The effect of naphthalene on the adsorption of NCCs indicated that Ce 0.2 Y is much resistant to the influence of naphthalene. Furthermore, the regenerated adsorbents still retained better adsorption properties than NaY after five cycles. The adsorption mechanism for NCCs and naphthalene on Ce 0.2 Y was revealed by the IR spectra. By contrast, the interaction between Ce 0.2 Y and NCCs is stronger than the interaction between Ce 0.2 Y and naphthalene. The Ce 0.2 Y adsorbent preferentially adsorbed NCCs, which can be attributed to the introduction of Ce 4+ .

Advanced Technologies Conciliating Desulfurization and Denitrogenation to Prepare Clean Fuels

“…Zhang et al had previously reported that a Cuexchanged Y zeolite could adsorb ~50% more DBT than the pristine adsorbent, and the adsorption of SCCs using d-block metal exchanged Y zeolites mainly occurs through π complexation [81], which could explain the simultaneous deep ADN/S. Zhang et al studied the effect of ion-exchanged Y zeolite with cerium [82] on ADN, since it was previously reported that the incorporation of La 3+ species into aluminosilicate positively affected its sulfur adsorption capacity due to the introduction of the possibility for direct interactions between the lanthanum ions and the adsorbents [83,84]. The researchers found that increasing the amount of Ce in the adsorbent did not necessarily imply an increase in denitrogenation efficiency (Figure 5).…”