Deactivation of HDT catalysts by formation of silica gels from silicone oil. Characterization of spent catalysts from HDT of coker naphtha using [sup 29]Si and [sup 13]C CP/MAS NMR

Journal Article · Wed Sep 01 00:00:00 EDT 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1252· OSTI ID:5772155

Kellberg, L; Jakobsen, H J ^[1]; Zeuthen, P ^[2]

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1. Univ. of Aarhus (Germany)
2. Haldor Topsoe Research Labs., Lyngby (Germany)

Catalysts used for hydrotreating of coker naphtha are found to deactivate very quickly because of deposition of Si-containing species on their surface. These species originate from the silicone oil (polydimethylsiloxane) added to the coker unit in order to suppress foaming during the coking process. Six samples of a spent catalyst from a HDT reactor have been analyzed by [sup 29]Si MAS, [sup 29]Si CP/MAS, and [sup 13]C CP/MAS NMR spectroscopy. From these studies it is concluded that the silicone oil in the naphtha feed is transformed (oxidized) to modified silica gels, i.e., silica with a partly methylated surface, under the operating conditions of the catalyst. Physi- or chemisorption of the silica gels on the catalyst explains the fast irreversible loss of activity during HDT of coker naphtha. 23 refs., 3 figs., 2 tabs.

• OSTI ID: 5772155
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 143:1; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400 -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON 13
CARBON ISOTOPES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTIONS
CHEMISORPTION
COBALT
COKE
DEACTIVATION
DISTILLATES
ELEMENTS
EVEN-ODD NUCLEI
HETEROGENEOUS CATALYSIS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
METALS
MOLYBDENUM
NAPHTHA
NICKEL
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
OXIDATION
POLYMERS
RESONANCE
SEPARATION PROCESSES
SILICON 29
SILICON ISOTOPES
SILICONES
SILOXANES
SORPTION
SORPTIVE PROPERTIES
STABLE ISOTOPES
SURFACE PROPERTIES
TRANSITION ELEMENTS