Adsorptive desulfurization of model diesel fuel over mono-functionalized nickel/γ-alumina and bi-functionalized nickel/cerium/γ-alumina adsorbents

Deep desulfurization of alkylated oil by alumina adsorbents: characteristics and mechanism study

Deep desulfurization of alkylated oil is the primary problem that has long plagued the petroleum refining industry. In this study, alkaline alumina adsorbent microspheres were synthesized by carbonization - hot oil column pelletization method. The adsorption desulfurization performance of as-synthesized adsorbent and three commercial alumina-based adsorbents were systematically evaluated and compared. The results showed that alkaline alumina adsorbent had the optimal adsorption performance with a saturated adsorption capacity of 8.604 mg·g^-1. Meanwhile, FTIR and sulfur speciation analysis indicated that the alkaline alumina adsorbent could deeply remove various sulfides (methyl mercaptan, dimethyl disulfide, hexacarbon sulfide, dibenzothiophene, <i>etc.</i>) from alkylated oil. Furthermore, the adsorption kinetics study manifested that the adsorption of sulfide was dominated by chemical adsorption, supplemented by physical adsorption, and accompanied by competitive adsorption among different sulfides. In addition, the regeneration experiment showed that nitrogen (90 °C) could realize the stable regeneration of the alkaline alumina adsorbent. To ensure stable regeneration performance in industry, it is recommended that the alkaline alumina adsorbent be regenerated once with nitrogen at 90 °C. This study will provide theoretical support for the process optimization of deep desulfurization of alkylated oil and contribute to the high-quality production of clean fuels worldwide.

Reduction of sulfur oxides emissions via adsorptive desulfurization of transportation fuels using novel silica-based adsorbent

Transportation fuels with high sulfur content are one of the primary contributors to air pollution because they emit massive quantities of sulfur oxides upon combustion. The emitted sulfur oxides undoubtedly contribute to global warming and climate change. Therefore, they should be minimized. The current study accurately describes a novel and direct synthetic pathway for the incorporation of sulfonic acid groups (-SO₃H) into mesoporous silica surface. The structure of the prepared materials was confirmed using FTIR, SEM, BET, SA-XRD, TEM, and TGA techniques. The batch adsorption technique was used to carefully evaluate the adsorption efficiency of the prepared adsorbent towards dibenzothiophene (DBT). At optimal adsorption conditions, a maximum adsorption capacity of 75-mg DBT/g adsorbent was achieved. The desulfurization process fitted well to Langmuir and pseudo-second-order models. In addition, the desulfurization process was found to be a spontaneous and exothermic process. As a final point, the practical applicability of the prepared adsorbent, as well as its reusability, was properly investigated, and the results were promising.