Molybdenum Carbide and Sulfide Nanoparticles as Selective Hydrotreating Catalysts for FCC Slurry Oil to Remove Olefins and Sulfur

Abstract

As the two types of major impurities in FCC slurry oil (SLO), olefins and sulfur seriously deteriorate the preparation and quality of mesophase pitch or needle coke. The development of a hydrotreatment for SLO to remove olefins and sulfur selectively becomes imperative. This work presents the potentiality of dispersed Mo2C and MoS2 nanoparticles as selective hydrotreating catalysts of SLO. Mo2C was synthesized by the carbonization of citric acid, ammonium molybdate and KCl mixtures while MoS2 was prepared from the decomposition of precursors. These catalysts were characterized by XRD, HRTEM, XPS, BJH, BET, and applied to the hydrotreating of an SLO surrogate with defined components and real SLO. The conversion of olefins, dibenzothiophene and anthracene in the surrogate was detected by GC-MS. Elemental analysis, bromine number, diene value, 1H-NMR and spot test were used to characterize the changes of the real SLO. The results show that hydrotreating the SLO surrogate with a very small amount of Mo-based nanoparticles could selectively remove olefins and sulfur without the overhydrogenation of polyaromatics. Mo2C exhibited much better activity than MoS2, with 95% of olefins and dibenzothiophene in the surrogate removed while only 15% anthracene was hydrogenated. The stability of the real SLO was significantly improved. Its structural parameters changed subtly, proving the aromatic macromolecules had been preserved.

Research progress in the preparation of mesophase pitch from fluid catalytic cracking slurry

“…The effect of FCC slurry on the synthesis of mesophase pitch is not only affected by the preparation process, but also by some basic factors on the formation of the products. The effects of raw materials, [94][95][96] temperature, [97][98][99] pressure, 100,101 reaction time, 80,102 system environment 103,104 and stirring rate [105][106][107] on the formation of mesophase pitch in the reaction system are reviewed below.…”

Evidence of water dissociation and hydrogenation on molybdenum carbide nanocatalyst for hydroprocessing reactions

“…Other reports also reported the stability of α-Mo 2 C in the presence of sulfur-containing compounds. 16,[24][25][26] A systematic approach is followed to probe the effect of steam partial pressure on the overall activity of the catalyst. In addition, experiments are carried out to thoroughly assess the effect of coexisting hydrogen on potential water dissociation that occurs on the catalyst.…”