Hydrodesulfurization--3. Relation between pretreating conditions and hydrodesulfurization activity of Co-Mo/Al/sub 2/O/sub 3/ catalyst

Journal Article · Mon Sep 01 04:00:00 EDT 1980 · J. Catal.; (United States)

OSTI ID:6200683

Gissy, H; Bartsch, R; Tanielian, C

A Girdler G35 catalyst containing 3.1% CoO, 11.7% MoO/sub 3/, and 1.7% SiO/sub 2/ on alumina was pretreated in air for 3 hr at 350/sup 0/C, or prereduced in hydrogen for 1 or 10 hr at 250/sup 0/C or for 1 hr at 400/sup 0/C, or prereduced and sulfided with 6% H/sub 2/S in hydrogen at 250/sup 0/ or 350/sup 0/C. The initial activity of these catalysts for the hydrodesulfurization of 0.3% benzothiophene in n-dodecane was tested at 250/sup 0/ and 350/sup 0/C and 1 atm in a flow reactor as a function of time until steady state was reached. The activity of the reduced catalysts went through a maximum in the early reaction stages during sulfiding, and reached a steady-state activity that was lower than the steady-state activity of the oxidized or presulfided catalysts, as apparently the reduced sites were poisoned by adsorption and coke lay-down of n-dodecane. The sulfided species of the catalyst probably promoted the hydrogenation of coke precursors, as well as hydrogenolysis of sulfur compounds. As known from other studies, the steady-state activity was higher with catalysts incompletely sulfided at 250/sup 0/C than with catalysts sulfided at 350/sup 0/C, which suggested that hydrodesulfurization depends on an optimum ratio of reduced and sulfided surface sites.

• Research Organization: Univ. of Strasbourg
• OSTI ID: 6200683
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 65:1; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COBALT COMPOUNDS
COBALT OXIDES
COMPARATIVE EVALUATIONS
DATA
DESULFURIZATION
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HIGH TEMPERATURE
INFORMATION
KINETICS
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
REACTION KINETICS
REDUCTION
REFRACTORY METAL COMPOUNDS
SILICON COMPOUNDS
SILICON OXIDES
STEADY-STATE CONDITIONS
SULFIDATION
SYNTHESIS
THIOPHENE
TRANSITION ELEMENT COMPOUNDS