Hydrotreating of Light Cycle Oil over Supported on Porous Aromatic Framework Catalysts

Abstract

The hydroprocessing of substituted naphthalenes and light cycle oil (LCO) over bimetallic Ni-W-S and Ni-Mo-S catalysts that were obtained by decomposition of [N(n-Bu)4]2[Ni(MeS4)2] (Me = W, Mo) complexes in situ in the pores of mesoporous aromatic frameworks (PAFs) during the reaction, was studied. The promotion of acid-catalyzed processes by PAF-AlCl3, synthesized by impregnation of a PAF with AlCl3 from its toluene solution, was investigated. It has been found that Ni-W-S catalytic systems were more active in the hydrodearomatization reactions, while Ni-Mo-S catalytic systems were more active in hydrodesulfurization and hydrocracking reactions. The introduction of sulfur into the reaction medium enhanced the activity of the catalysts and the presence of PAF-AlCl3 led to an acceleration of the hydrocracking processes.

Metal-Free Oxidative Desulfurization Catalysts Based on Porous Aromatic Frameworks

“…25 Thus, after placing any of the sulfonated polymers in water, its color becomes light yellow; after drying the resulting "wet" material in a vacuum, it regains its dark blue color. We should note that such a change in the color of the material to dark blue is characteristic not only for sulfonated PAFs but also in Lewis acid/PAF composites, such as AlCl 3 /PAF-20 or FeCl 3 / PAF-20, 26,27 and even when PAFs are placed in a strong acid solution (HF, HCl, HBr, etc. ).…”

Production of cleaner waste tire pyrolysis oil by removal of polycyclic aromatic hydrocarbons via hydrogenation over Ni‐based catalysts

“…To compare the ability to eliminate dimethylnaphthalenes and trimethylnaphthalenes, it was observed that trimethylnaphthalenes could be more removed from WTPO than dimethylnaphthalene compounds. This was possible that the higher number of alkyl substituents in the naphthalene structure of trimethylnaphthalene could promote dealkylation and hydrocracking 17 . Sizova et al 63 also found the formation of a small amount of dimethyltetralins during hydrogenation of 2,3,6‐trimethylnaphthalene, which was the evidence for the cleavage of the methyl substituents.…”

“…This was possible that the higher number of alkyl substituents in the naphthalene structure of trimethylnaphthalene could promote dealkylation and hydrocracking. 17 Sizova et al 63 also found the formation of a small amount of dimethyltetralins during hydrogenation of 2,3,6-trimethylnaphthalene, which was the evidence for the cleavage of the methyl substituents. According to the steric hindrance generated from methyl substituents, the results in Figure 8 suggested that the elimination of dimethylnaphthalenes and trimethylnaphthalenes via hydrogenation required more severe reaction conditions; especially, high initial H 2 pressure and time to achieve the lower concentration in the obtained HWTPO from both catalytic systems.…”

“…Based on the results indicated in Table 5 and Figure 8 including the previous literatures, 17,63 the hydrogenation mechanism to reduce PAHs compounds found in the WTPO was proposed as shown in Figure 9. The PAHs compounds in the inherent WTPO were classified into 4 groups: (1) 1-methylnaphthalene, which could be isomerized as 2-methylnaphthalene, (2) dialkylnaphthalenes consisting of 1,5-dimethylnaphthalene, 2,6-dimethy lnaphthalene and 1-methyl-7-(1-methylethyl) naphthalene, (3) trialkylnaphthalenes such as 1,3,6-trimethy lnaphthalene and 2,3,6-trimethylnaphthalene, and (4) 1,2,3,4-tetramethylnaphthalene.…”

“…15 Hydrogenation is a recommended method since it has a high efficiency to convert PAHs into less toxic compounds, such as tetralin, which has a high LD 50 level with a faster biodegradable rate than naphthalene. 15 The hydrotreating process involving hydrogenation and elimination of some toxic compounds under a hydrogen atmosphere is normally applied to upgrade vacuum gas oil (VGO) 16 and light cycle oil (LCO) 17 containing high contents of sulfurous species and aromatic compounds including PAHs. Typically, Nibased catalysts are used for hydroconversion of PAHs due to their lower cost, which makes them more practical for mass-scale operation than the more expensive noble metal-based catalysts.…”