Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Metal – metal oxide or metal hydroxide
Reexamination Certificate
1997-08-22
2001-06-12
Griffin, Steven P. (Department: 1754)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Metal, metal oxide or metal hydroxide
C502S327000, C502S332000, C502S335000, C502S337000, C502S355000, C502S439000, C502S407000, C502S414000, C502S415000
Reexamination Certificate
active
06245709
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to nickel containing hydroconversion catalysts. More particularly, this invention relates to a bimetallic catalyst wherein the hydrogenolysis activity of a nickel containing catalyst is reduced. Still more particularly, this invention relates to a bimetallic, silica-alumina supported nickel containing catalyst useful in the hydroconversion of hydrocarbon containing feedstocks, particularly waxy products obtained from Fischer-Tropsch hydrocarbon synthesis processes.
BACKGROUND OF THE INVENTION
The use of supported Group VIII metals in hydroconversion processes is well known. Often, these metals are combined with Group VIA metals, e.g., cobalt and molybdenum, on suitable supports for use in hydroconversion processes. Group VIII noble metals, e.g., platinum and palladium, are efficient hydroconversion catalysts, but these metals are also relatively expensive. Consequently, there exists a desire to find non-noble metals or combination thereof that can provide activity, selectivity, and activity maintenance equivalent to that of noble metals, thereby reducing significantly catalyst costs.
SUMMARY OF THE INVENTION
In accordance with this invention, a new bi-functional catalyst for the hydro-conversion of hydrocarbons, particularly waxy hydrocarbons from Fischer-Tropsch hydrocarbon synthesis processes, is provided and comprises a supported non-noble Group VIII metal in conjunction with a Group IB metal, the support containing an acidic component, e.g., an amorphous silica-alumina, having an iso-electric point ≧6.5.
The iso-electric point depends on the relative concent species and the pK
a
and pK
b
of the surface species. A net charge occurs at the interface between a liquid which is hydrodynamically bound to the particle surface and the bulk fluid. The potential at this interface is the zeta potential. At the iso-electric point, the number of positively and negatively charged species on a surface of a colloidal particle are balanced, and the zeta potential is zero. Iso-electric points are typically measured using a Matec electrokinetic sonic amplitude (ESA) system. In the electrokinetic sonic amplitude effect, an electric field is applied to a colloidal suspension and the resulting sound wave is measured. The magnitude of the signal can be used to measure the charge on the particle surface. While the Matec system is capable of making the electroacoustic measurements, it is generally used in a scanning pH mode to determine the pH at which the iso-electric point occurs. Typically a sample is slurried with deionized water and the initial pH and zeta potential are measured. Then a titration is started, using acid or base, until the point of zero charge occurs. The resulting pH is then reported as the iso-electric point. See, for example, Packs, G. A., Chem Rev. (1965), 65, 177-198 and Hunter, R. J., Zeolite Potential in Colloid Science, Principles and Applications, New York, Academic Press, 1981, and Oja, T., Petersen, G. L., and Cannon, D. W., A Method for Measuring the Electrokinetic Properties of a Solution, U.S. Pat. No. 4,497,207; O'Brien, R. W., Journal of Fluid Mechanics, 190, 71 (1988); Babchin, A. J., Chow, R. S., and Sawatzky, R. P., Advances in Colloid and Interface Science, III, 30 (1989); James, Michael, Hunter, Robert J., and O'Brien, Richard W., Langmuir, 8, (1992).
The presence of the Group IB metal is believed to mitigate the excessive hydrogenolysis and cracking activity of Group VIII metals, e.g., nickel, which produce excessive amounts of undesirable naphtha and C
4
−
gases. Thus, the bifunctionality of hydrogenation and isomerization is maximized while hydrogenolysis and cracking activity is minimized. The preferred metals are nickel and copper.
The acidic support is preferably an amorphous silica-alumina and preferably contains a binder. The alumina content of the silica-alumina material is usually present in amounts of less than 30 wt %, preferably 5 to <30 wt %, more preferably 10-20 wt % of the silica-alumina component. Suitable binder materials include both amorphous and crystalline inorganic oxides, such as alumina, silica, clays, magnesia, titania, zirconia, and mixtures thereof. Preferred binders are silica and alumina, alumina being particularly preferred. Preferred alumina binders include reforming grade alumina such as a gamma alumina, having a relatively high surface area, e.g., ≧100 m
2
/gm. When an alumina binder is incorporated into the support, an amount ≧20% by weight of total support is preferred, more preferably ≧25 wt %, and still more preferably ≧28 wt %, and up to about 50 wt %.
Current speculation is that the binder assists in dispersing the nickel component of the catalyst, and that the binder increases the iso-electric point of the support as a whole.
In a particularly preferred embodiment the alumina concentration of the support, including binder, ranges from about 30-60 wt %, preferably 35-55 wt %, and more preferably 35 to 50 wt %.
REFERENCES:
patent: 4443329 (1984-04-01), Eberly, Jr. et al.
patent: 4513090 (1985-04-01), Eberly, Jr. et al.
patent: 4837193 (1989-06-01), Akizuki et al.
patent: 4939110 (1990-07-01), Sachtler et al.
patent: 5273949 (1993-12-01), Chopin et al.
patent: 5358917 (1994-10-01), Van Veen et al.
patent: 5660714 (1997-08-01), Wittenbrink et al.
patent: 5750819 (1998-05-01), Wittenbrink et al.
patent: 5756420 (1998-05-01), Wittenbrink et al.
patent: 197 04 875A1 (1997-08-01), None
patent: 0532117A1 (1993-03-01), None
patent: 0587246A1 (1994-03-01), None
patent: 0587245A1 (1994-03-01), None
patent: WO97/03750 (1997-02-01), None
Lanh et al, Conversion of Cyclohexane on Ni-(Sb, Pb, Cu)/Al2O3Bimetallic Catalysts, Journal of Catalysis 129, pp. 58-66 (1991).
Clark Janet R.
Davis Stephen M.
Riley Kenneth L.
Wittenbrink Robert J.
Exxon Research and Engineering Company
Griffin Steven P.
Nguyen Cam N.
Simon Jay
LandOfFree
Supported Ni-Cu hydroconversion catalyst does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Supported Ni-Cu hydroconversion catalyst, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Supported Ni-Cu hydroconversion catalyst will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2476028