Platinum Doped Hydrotreating Catalysts for Deep Hydrodesulfurization of Diesel Fuels

Abstract

International audienceTwo-stage processes are possible solutions for reaching 10 ppm sulfur in gas oil without severe running conditions. First, most of the sulfur is removed by using a CoMo conventional catalyst. Second, after H2S removal, the treated oil, with a remaining S content below 500 ppm, is again hydrotreated. In this latter case, the use of noble metal catalysts can be envisaged. In the present study dealing with this second stage reactor, we examined a catalytic system based on the addition of a low content of Pt to a commercial sulfide catalyst. An enhancement in catalytic activity can be obtained in the conversion of model molecules (tetralin and dibenzothiophene) as well as a hydrotreated straight run gas oil. The promotion effect strongly depends on the preparation procedure which requires the impregnation of Pt on a presulfided commercial HDT catalyst. Advanced EXAFS and HRTEM characterizations were used to characterize the active phases

Anthropogenic contributions to global carbonyl sulfide, carbon disulfide and organosulfides fluxes

“…Processes for removing H 2 S are not normally effective in removing OCS, and these may even produce OCS through a reaction of H 2 S with CO 2 (Pessayre et al, 2007;Rhodes et al, 2000).…”

Role of Pt–Pd/γ-Al2O3 on the HDS of 4,6-DMBT: Kinetic modeling & contribution analysis

“…1, the magnitude order of the relative estimated kinetic parameters can provide a preliminary idea of how HYD and DDS pathways occur during the HDS of 4,6-DMDBT. As expected steric effect related to the methyl groups of the 4,6-DMDBT leads mainly to the formation of 4,6-DM-th-DBT via HYD route than to 3,3′-DMBP via DDS route, [5,17,41,42], since the reaction rate coefficient k 2 is larger than k 1 . Besides, the catalyst activity to form MCHT (k 3 ) is the highest one since k 3 N k 2 N k 1 , indicating that once the 4,6-DM-th-DBT is formed its desulfurization to MCHT is kinetically favorable as corroborated on the contribution analysis further.…”

Single-atom Pt promotion of industrial Co-Mo-S catalysts for ultra-deep hydrodesulfurization

“…Thus, the Pt promotional effect of the industrial Co-Mo catalysts with Pt added prior to a sulfidation step may be associated with incorporation of Pt in the Co-Mo-S edge structures (referred to as the Pt-Co-Mo-S phase) rather than adsorption or a separate Pt (sulfide) phase, e.g. PtS which elsewhere have been observed as a stable phase at HDS reaction condition at higher temperatures (400 °C) [61], and also suggested in the case of platinum doping of a pre-sulfided NiW catalyst [62]. The Pt-Co-Mo-S phase, however, is consistent with a Pt(IV)-sulfide resembling structure with Pt-S bonds as revealed by XANES.…”