A study on middle distillate hydrotreatment zeolite catalysts containing Pt/Pd and/or
Ni was performed. The effect of the addition of the corresponding CoMo, CoMoPd,
CoMoPtPd and CoMoNi in PdNiPt-zeolite, Pt-zeolite, Ni-zeolite, and PdPt-zeolite was
studied. The catalysts were characterized physically and chemically by methods and
techniques such as Brunauer-Emmett-Teller (BET), Barret-Joyner-Hallenda (BJH), and
neutron activation analysis. The structures of the Ni and Pt containing zeolite were
studied by X-ray Photoelectron Spectroscopy (XPS).
An experimental apparatus was constructed to investigate the activity of the
experimental catalysts. The catalysts activity measured in terms of conversion of
dibenzothiophene (DBT), substituted dibenzothiophenes (sDBT) and phenanthrene as
well as molar-averaged conversion was evaluated in a continuous flow Robinson
Mahoney reactor with stationary basket in the hydrodesulfurization and hydrogenation
of heavy gas oil which contains sulphur refractory compounds such as 4-
methyldibenzotiophene (4-MDBT) and 4,6- dimethyldibenzothiophene (4,6-DMDBT).
DBT, 4-MDBT, 3-MDBT, 1-EDBT, 3-EDBT, 4,6-DMDBT, 3,6-DMDBT, 2,8-
DMDBT and 4-methylnaphtho[2,1-b]thiophene were selected to calculate the molaraveraged
conversion.
The conversions of the sulfur containing compounds and phenanthrene were
determined as a function of the operating variables: space time (W/Fo
DBT), temperature,
H2/HC mol ratio and pressure. The Conversions of DBT and 4,6-DMDBT into their reaction products such as Biphenyl (BPH), Cyclohexylbenzene (CHB), Bicyclohexyl
(BCH) and 3,4-Dimethylbiyphenyl (3,4-DMBPH) were determined only as a function of
space time in the interval of 4000-6000 kgcath/kmol.
The results of this work showed that Pt-HY and PdPt-HY are good noble metals
catalysts for the hydrodesulfurization of heavy gas oil. Moreover, this study showed that
CoMoPd/Pt-HY and CoMoNi/PdPt-HY catalysts are good candidates for deep HDS and
hydrogenation of heavy gas oil. It was found that the conversions of sulfur compounds
were higher than the conversions provided by the conventional CoMo/Al2O3 catalyst.
Also higher hydrogenation of phenanthrene was observed. Deactivation of the catalysts
was not observed during the operation.
Finally, the study not only contributed to define the technical bases for the
preparation of the noble metal catalysts for hydrodesulfurization of heavy gas oil at pilot
scale, but also provided technical information for developing the kinetic modeling of the
hydrodesulfurization of heavy gas oil with the noble metal catalysts.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-1066 |
| Date | 15 May 2009 |
| Creators | Marin-Rosas, Celia |
| Contributors | Anthony, Rayford G., Froment, Gilbert F. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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