Chemistry of inorganic compounds – Phosphorus or compound thereof – Oxygen containing
Reexamination Certificate
1999-12-21
2002-09-10
Griffin, Steven P. (Department: 1754)
Chemistry of inorganic compounds
Phosphorus or compound thereof
Oxygen containing
C423S306000, C423SDIG003, C502S209000, C502S213000, C502S063000
Reexamination Certificate
active
06447741
ABSTRACT:
BACKGROUND OF THE INVENTION
A. Field of the Invention
This invention relates to mesoporous aluminophosphate materials that are modified with at least one element selected from zirconium, cerium, lanthanum, manganese, cobalt, zinc, and vanadium. The materials have high surface area and excellent thermal and hydrothermal stability, with a relatively narrow pore size distribution in the mesoporous range.
Methods for producing the modified aluminophosphate materials also are disclosed. Advantageously, this material can be used as a support for a cracking catalyst, for example, in a fluid catalytic cracking process.
B. Description of the Prior Art
Amorphous metallophosphates are known and have been prepared by various techniques. One such material is described in U.S. Pat. No. 4,767,733. This patent describes rare earth aluminum phosphate materials, which, after calcination, have a relatively broad pore size distribution with a large percentage of pores greater than 150 Å. The typical pore size distribution is as follows:
Pore Size
Volume Percent
50 to 100 Å
5 to 20%
100 to 150 Å
10 to 35%
150 to 200 Å
15 to 50%
200 to 400 Å
10 to 50%
U.S. Pat. Nos. 4,743,572 and 4,834,869 describe magnesia-alumina-aluminum phosphate support materials prepared using organic cations (e.g., tertiary or tetraalkylammonium or phosphonium cations) to control the pore size distribution. When organic cations are used in the synthesis, the resulting materials have a narrow pore size distribution in the range from 30 to 100 Å. When they are not used, the pore size is predominantly greater than 200 Å. U.S. Pat. No. 4,179,358 also describes magnesium-alumina-aluminum phosphate materials, materials described as having excellent thermal stability.
The use of aluminophosphates in cracking catalysts is known. For example, U.S. Pat. No. 4,919,787 describes the use of porous, rare earth oxide, alumina, and aluminum phosphate precipitates for catalytic cracking. This material was used as part of a cracking catalyst, where it acted as a metal passivating agent. The use of a magnesia-alumina-aluminum phosphate supported catalyst for cracking gasoline feedstock is described in U.S. Pat. No.4,179,358. Additionally, a process for catalytic cracking high-metals-content-charge stocks using an alumina-aluminum phosphate-silica-zeolite catalyst is described in U.S. Pat. No. 4,158,621.
There remains a need in the art for highly stable aluminophosphate materials for use in catalytic cracking processes, as well as for simple, safe processes for producing these materials. The aluminophosphate materials preferably possess excellent hydrothermal and acid stability with uniform pore sizes in the mesoporous range, and provide increased gasoline yields with increased butylene selectivity in C
4
−
gas.
SUMMARY OF THE INVENTION
This invention relates, in a first aspect, to a mesoporous aluminophosphate material comprising a solid aluminophosphate composition modified with at least one element selected from zirconium, cerium, lanthanum, manganese, cobalt, zinc, and vanadium, wherein the mesoporous aluminophosphate material has a specific surface of at least 100 m
2
/g, an average pore diameter less than or equal to 100 Å, and a pore size distribution such that at least 50% of the pores have a pore diameter less than 100 Å.
Preferably, the mesoporous aluminophosphate material has an average pore diameter of 30 to 100 Å.
The invention also relates to a method of making the mesoporous aluminophosphate material described above, the method comprising the steps of:
(a) providing an aqueous solution containing a phosphorus component; an inorganic aluminum containing component; and an inorganic modifying component containing at least one element selected from zirconium, cerium, lanthanum, manganese, cobalt, zinc, and vanadium;
(b) adjusting the pH of said aqueous solution into the range of about 7 to about 12 so that a solid material is precipitated from said solution; and then
(c) recovering the solid material from said solution, wherein the solid material includes the mesoporous aluminophosphate material.
Preferably, the inorganic aluminum containing component includes sodium aluminate and the method includes the further step of lowering the sodium level of the solid material recovered in step (c). This may be achieved by ion exchange with an ammonium salt or an acid. Typically, the sodium level of the final aluminophospate material is less than 1.0 wt % Na.
Preferably, the method includes the further step of exposing the aqueous solution, after step (b) but before step (c), to hydrothermal or thermal treatment at about 100° C. to about 200° C. to facilitate uniform pore formation.
Advantageously, the solid materials according to the invention can be used as solid support materials for fluid catalytic cracking (“FCC”) catalysts.
REFERENCES:
patent: 4158621 (1979-06-01), Swift et al.
patent: 4179358 (1979-12-01), Swift et al.
patent: 4743572 (1988-05-01), Angevine et al.
patent: 4767733 (1988-08-01), Chester et al.
patent: 4834869 (1989-05-01), Angevine et al.
patent: 4845069 (1989-07-01), Fellmann et al.
patent: 4919787 (1990-04-01), Chester et al.
patent: 5264203 (1993-11-01), Beck et al.
Galanos et al., “Influence of vanadium and cerium additives in the development of porosity and surface acid catalytic properties of mesoporous aluminophosphates”, Stud. Surf. Sci. Cat., vol. 118 (Preparation of Catalysts VII), Elsevier Sci., 911-920, 1998.*
Luan, Z. et al., Tubular Aluminophosphate Mesoporous Materials Containing Framework Silicon, Vanadium and Manganese,Mesoporous Molecular Sieves, pp. 103-110 (1998).
Zhao, D. et al., Electron Spin Resonance and Electron Spin Echo Modulation Spectroscopy of Aluminophosphate—Based Mesoporous Manganese,J. Phys. Chem. B, vol. 101 Ch. 35, pp. 6943-6948 (1997).
Chester Arthur W.
Daugherty Frederick E.
Kresge Charles T.
Timken Hye-Kyung C.
Vartuli James C.
ExxonMobil Oil Corporation
Griffin Steven P.
Medina Sanabria Maribel
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