Piperidine hydrogenolysis on a commercial hydrocracking catalyst: III. The effects of zeolite unit cell size, catalyst sulfur content, and coke deposition on catalyst activity and deactivation

Journal Article · Mon Jun 01 00:00:00 EDT 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90049-N· OSTI ID:7026689

Hadjiloizou, G C; Butt, J B; Dranoff, J S ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

A group of fresh, deactivated, and deactivated-regenerated commercial hydrocracking catalysts was characterized using piperdine hydrogenolysis as a probe reaction at 301 C, hydrogen partial pressures of about 16 atm, and initial concentrations of piperidine ranging from 4.14 [times] 10[sup [minus]3] to 11.86 [times] 10[sup [minus]3] g mol/liter. The first part of the study revealed that over the range of unit cell size examined, adsorption equilibrium constants associated with the acidic and metallic catalyst functions decreased while reaction rate constants increased with increasing unit cell size. An inverse relationship between catalyst deactivation and unit cell size was generally observed for both catalyst functions. The second part of the study showed that the regenerated catalysts with constant zeolite unit cell size and low levels of coke had similar acidic function activities. The activity correlation of the metallic function on these regenerated catalysts with low levels of sulfur also indicated the presence of two different types of metal sites. The activity of the metallic and acidic functions of the catalyst was also examined at high levels of sulfur and coke and constant unit cell size. The metallic function activity of these catalysts was found to decrease with the commercial time on stream. Between 2.2 and 2.6 wt% sulfur, the activity of the metallic function decreased linearly with the sulfur content on the catalyst. At higher levels of sulfur the deactivated catalysts had similar metallic function activities. Between 2 and 6 wt% carbon, the activity of the acidic function decreased linearly with the carbon content on the catalyst. At low levels of coke, the effect of the unit cell size on acidic activity prevailed.

• OSTI ID: 7026689
• Journal Information: Journal of Catalysis; (United States), Vol. 135:2; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
PIPERIDINES
HYDROGENATION
ZEOLITES
CATALYTIC EFFECTS
DEACTIVATION
MICROSTRUCTURE
SULFUR CONTENT
CATALYSIS
CATALYSTS
CHEMICAL REACTION KINETICS
COKE
DEPOSITION
PH VALUE
QUANTITY RATIO
REGENERATION
SURFACE PROPERTIES
AMINES
AZINES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
HETEROCYCLIC COMPOUNDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
KINETICS
MATERIALS
MINERALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIDINES
REACTION KINETICS
SILICATE MINERALS
020400* - Petroleum- Processing