Characterisation of coke from FCC catalysts by solid state {sup 13}C NMR and mass spectrometry

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:215024

Andresen, J M; McGhee, B; Snape, C E ^[1]

---

1. Univ. of Strathclyde, Glasgow (United Kingdom); and others

Coke has been concentrated by demineralisation from deactivated FCC catalysts from both refinery operations with actual feeds and MAT tests using n-hexadecane to facilitate detailed characterisation by solid state {sup 13}C NMR and mass spectrometry. All the catalysts investigated contained about 1% w/w carbon. As for solid fuels, the use of a low-field spectrometer for solid state {sup 13}C NMR in conjunction with the single pulse excitation (SPE or Bloch decay) technique has enabled quantitative carbon skeletal parameters to be obtained for the cokes. Internal standard measurements demonstrated that most of the carbon was observed by SPE and, therefore, NMR-invisible graphitic layers are not thought to be major structural features of the cokes. Differences in feedstock composition were reflected in the structure of the refinery cokes with the aromatic nuclei from a residue feed (5% Conradson carbon) corresponding to 15-20 peri-condensed aromatic rings and being more highly condensed than those from a hydrotreated vacuum gas oil. Mass spectrometry (EI, CI and FIMS) has confirmed that the refinery cokes are highly condensed, but those obtained from n-hexadecane in the MAT tests displayed significant aliphatic character.

• OSTI ID: 215024
• Report Number(s): CONF-950801--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
36 MATERIALS SCIENCE
66 PHYSICS
CARBON 13
CATALYSTS
CATALYTIC EFFECTS
COKE
DEACTIVATION
MASS SPECTRA
MOLECULAR STRUCTURE
NMR SPECTRA
REFINING
ZEOLITES