Hydrodemetalation of vanadium and nickel porphyrins over sulfided CoMo/Al/sub 2/O/sub 3/ catalyst

Journal Article · Thu Sep 01 00:00:00 EDT 1988 · Ind. Eng. Chem. Res.; (United States)

DOI:https://doi.org/10.1021/ie00081a012· OSTI ID:6240220

Chen, H J; Massoth, F E

Hydrodemetalation (HDM) of vanadium porphyrin (VP) and nickel porphyrin (NP) model compounds with a sulfided CoMo/Al/sub 2/O/sub 3/ catalyst was performed in a batch stirred autoclave at several temperatures, hydrogen pressures, and initial porphyrin concentrations. A hydrogenated intermediate leading to deposited metal was found for both reactants. The time course of the reaction followed pseudo first order in reactant concentrations above 350/sup 0/C, but followed lower order at lower temperatures. Runs at different initial concentrations showed that the reaction was inhibited by adsorption of reactant and products. HDM rates increased with temperature and hydrogen pressure and were very low without catalyst or hydrogen present. An apparent activation energy of 24 kcal/mol for the overall disappearance was obtained for both reactants. Kinetic analysis of the HDM of nickel porphyrin showed, in addition to a pathway through the hydrogenated intermediate, an apparent direct pathway to hydrocarbon products. The latter was interpreted in terms of a direct conversion of adsorbed NP to products in a single adsorption step, without desorption of hydrogenated intermediate. Evidence was obtained for a change in mechanism above 350/sup 0/C.

• Research Organization: Dept. of Fuels Engineering, Univ. of Utah, Salt Lake City, UT (US)
• OSTI ID: 6240220
• Journal Information: Ind. Eng. Chem. Res.; (United States), Vol. 27:9
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
NICKEL COMPOUNDS
SEPARATION PROCESSES
VANADIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYSTS
CHEMICAL REACTION KINETICS
COBALT
HYDROGEN
HYDROGENATION
MOLYBDENUM
PORPHYRINS
PRESSURE GRADIENTS
TEMPERATURE GRADIENTS
ALUMINIUM COMPOUNDS
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
KINETICS
METALS
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
320305* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Industrial Waste Management
400105 - Separation Procedures