Adsorptive Denitrogenation of Coker Diesel over Carbon-Based Adsorbents for Producing Ultralow-Sulfur Diesel

• Published in: Industrial & engineering chemistry research Vol. 62; no. 50; pp. 21777 - 21786
• Main Authors: Ghaloum, Narjes, Safa, Muhieddine A., Alshemali, Mohammed S., Bouresli, Rashed, Albazzaz, Hamza, Ma, Xiaoliang
• Format: Journal Article
• Language: English
• Published: American Chemical Society 20.12.2023
• Subjects: Separations
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.3c03424

Removing nitrogen-containing compounds from middle distillates is crucial in deep hydrotreatment for producing ultralow-sulfur diesel (ULSD). Performances of three carbon-based adsorbents for adsorptive denitrogenation (ADN) of coker diesel were evaluated in detail in the batch and packed-bed adsorption models, and surface properties of the adsorbents were characterized by the low-temperature N2 adsorption–desorption and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). Among these adsorbents, the AC–CC adsorbent showed the best ADN performance due to its higher surface area, higher concentration of oxygen functional groups on the surface, and larger pore diameter, giving the breakthrough capacity of 3.9 mg-N/g-ads and the saturation capacity of 14.5 mg-N/g-ads. ADN selectivity and the relationship between the removal nitrogen ratio (NRR) and oil yield in the packed-bad adsorption process were also investigated. Further study in the regeneration of the spent AC–CC indicates that about 60% of the initial adsorption capacity can be recovered by the toluene elution and kept in the sequent adsorption–regeneration cycles. The results demonstrate that AC–CC is promising in the deep ADN of coker diesel for producing ULSD.