Hydrodesulfurization. IV. The effects of the feed components on Co-Mo-Al/sub 2/O/sub 3/ catalyst activation

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

OSTI ID:7048559

Gissy, H; Bartsch, R; Tanielian, C

Benzothiophene dissolved in n-dodecane was used to investigate the hydrodesulfurization (HDS) activation procedure of Co-Mo-Al/sub 2/O/sub 3/ catalyst. Prereduced samples were submitted to various treatments prior to contacting with standard feed, namely, (1) by varying the sulfur compounds (H/sub 2/S or thiophene) in the n-dodecane-H/sub 2/ mixture, (2) by changing the molecule type which contacts the freshly prereduced catalyst (n-dodecane, H/sub 2/S, or thiophene), and (3) by sulfiding with H/sub 2/S-H/sub 2/ before, during, or after n-dodecane treatment. It is shown that presulfiding with H/sub 2/S gives better HDS activity than presulfiding with thiophene, owing to the coke precursor which may be formed in the hydrogenolysis of thiophene. n-Dodecane leads to some catalyst coking especially when sulfided species are absent on the catalytic surface or when they are reduced by the H/sub 2/ flow. Although presulfiding with H/sub 2/S enhances hydrocracking activity, catalyst poisoning by n-dodecane is not a problem, providing that enough sulfur species are still held on the catalyst, allowing good hydrogenation activity toward coke precursors. It appears that both H/sub 2/S and benzothiophene play a protecting role against catalyst poisoning, the former by forming quickly sulfided sites and the latter by preventing too great a desulfurization of the catalytic surface as well as by competing favorably with n-dodecane adsorption. For optimal activation care has to be taken to secure good hydrogenation activity, notably during the initial stages of feed supply. This points to better HDS activity under higher sulfiding pressure, especially when sulfurized feedstock is used.

• Research Organization: Universite Louis Pasteur, Strasbourg, France
• OSTI ID: 7048559
• 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

02 PETROLEUM
020400* -- Petroleum-- Processing
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYSIS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COBALT
DESULFURIZATION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HETEROCYCLIC COMPOUNDS
HYDROGENATION
METALS
MOLYBDENUM
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM
PETROLEUM FRACTIONS
REFRACTORY METALS
THIONAPHTHENES
TRANSITION ELEMENTS