Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Metal – metal oxide or metal hydroxide
Reexamination Certificate
1998-06-08
2001-05-01
Griffin, Steven P. (Department: 1754)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Metal, metal oxide or metal hydroxide
C502S240000, C502S250000, C502S251000, C502S302000, C502S303000, C502S304000, C502S340000, C502S341000, C502S355000, C208S106000, C208S113000, C208S118000, C208S119000, C208S120010, C208S121000, C208S122000, C208S123000, C208S124000
Reexamination Certificate
active
06225255
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority of Japanese Patent Application No. HEI 09-165362 filed Jun. 6, 1997, which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to an additive catalyst for use with a cracking catalyst for cracking heavy oils, especially fluidized catalytic cracking (FCC) catalysts.
BACKGROUND OF THE INVENTION
The term “heavy oil” as used herein means a hydrocarbon oil containing heavy components having boiling points of about 650° F. (343° C.) and higher. Such heavy oils include various crude oils; non-distillates such as atmospheric distillation residues and vacuum distillation residues of such crude oils; solvent-deasphalted oil; solvent-deasphalted oil asphalt; shale oil; tar sand oil; liquefied coal oil; distillates such as HGO (topped heavy gas oil) and VGO (vacuum gas oil); and blends of these distillates and the above-described non- distillates.
A variety of methods are known for obtaining lighter products by cracking a heavier oil. One such method is fluidized catalytic cracking (FCC). A great deal of research has been conducted in FCC to achieve high yields and selectivity. One method for improving the yield of light oil is to use a mixture of an additive that acts to promote the cracking of heavy components in heavy oil, with a conventional cracking catalyst.
Typical FCC catalyst additives include alumina, clay and silica, particularly wherein the ratio of strong acidity to the total acidity is high. Consequently, such additives are accompanied by problems such as the cracking of heavy oil is not adequately promoted, or excessive coke is deposited on the catalyst. Further, additives composed of a composite oxide such as silica-alumina, clay and silica are also known to be effective for the promotion of cracking of heavy oil and for the suppression of deposition of coke. However, they do not make it possible to reduce the ratio of strong acidity to total acidity to or beyond a certain value, and therefore involve problems that a cracking reaction proceeds too much to increase the proportion of naphtha in the cracked product.
An object of the present invention is therefore to provide an additive catalyst for the cracking of heavy oil which: has high cracking activity for heavy components in the heavy oil; which features reduced coke deposition; and which brings about a high naphtha yield.
With a view to attaining the above-described object, the present inventors have proceeded with extensive research, leading to the completion of the present invention.
According to the present invention, there is thus provided an additive catalyst for the cracking of heavy oil (Catalyst I), characterized in that the additive catalyst comprises: (i) a mixed metal oxide composed of an acidic metal oxide and a basic metal oxide, in which the proportion of the basic metal oxide is from 5 to 50 mole %, (ii) clay, and (iii) silica.
The present invention also provides an additive catalyst for the cracking of heavy oil (Catalyst II), characterized in that the additive catalyst comprises: (i) an acidic metal oxide other than silica, or an acidic mixed metal oxide, (ii) clay, (iii) silica, and (iv) a basic metal oxide.
In addition, the present invention further provides an additive catalyst for the cracking of heavy oil (Catalyst III), characterized in that the additive catalyst comprises: (i) an acidic metal oxide other than silica, or an acidic mixed metal oxide, (ii) clay, (iii) silica, and (iv) basic metal cations.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided an additive catalyst for the cracking of heavy oil, characterized in that said additive catalyst comprises: (i) a mixed metal oxide composed of an acidic metal oxide and a basic metal oxide, in which the proportion of said basic metal oxide is from 5 to 50 mole %, (ii) clay, and (iii) silica.
In a preferred embodiment of the present invention the additive catalyst also includes a basic metal oxide.
In other preferred embodiments of the present invention the additive catalyst is comprised of: (i) an acidic metal oxide other than silica, or an acidic mixed metal oxide, (ii) clay, (iii) silica, and (iv) basic metal cations.
DETAILED DESCRIPTION OF THE INVENTION
The acidic metal oxide employed in the present invention has acidity at a surface thereof when wetted with water. Non-limiting examples include silica (SiO
2
), alumina (Al
2
O
3
), zirconia (ZrO
2
), titania (TiO
2
), and boria (B
2
O
3
). Specific examples of acidic mixed metal oxides which can be used in the practice of the present invention include silica-alumina, silica- zirconia, silica-boria, and alumina-boria.
The basic metal oxide employed in the present invention shows basicity at a surface thereof when wetted with water. Non-limiting examples of such include magnesia (MgO), calcia (CaO), and lanthana (La
2
O
3
).
The content of silica in the silica-containing mixed metal oxides range from about 5 to 30 wt. %, preferably about 10 to 20 wt. %. A silica content higher than this range results in a catalyst with reduced hydrothermal stability, whereas a silica content lower than the above range leads to a catalyst with lower cracking activity for heavy components. With regard to alumina-boria, the content of alumina ranges from about 5 to 95 wt. %, preferably about 10 to 90 wt. %.
It is preferred to use a silica-containing mixed metal oxide having a structure wherein a metal oxide other than silica is contained as a core where silica is adhered as a layer on a surface of said core. With regard to alumina-boria, it is preferred to use one having a structure wherein alumina is a core and boria is adhered as a layer on a surface of said core
Examples of clays which are suitable for use in the present invention include kaolin, bentonite and kibushi clay. Preferred is kaolin. In general, a clay containing one or more of the clay minerals: kaolinite, dickite, nacrite, halloysite and hydrated halloysite, as a primary component, is preferred.
A description will hereinafter be made in detail about the above described three types of catalysts additives (hereinafter may be referred to simply as “Catalsyt”) I to III according the present invention for the cracking of heavy oil.
Catalyst I
Catalyst I according to the present invention is characterized in that it contains, as a catalyst component, a mixed metal oxide composed of an acidic metal oxide and a basic metal oxide and the proportion of the basic metal oxide is from 5 to 50 mole %, preferably from 10 to 40 mole %.
Specific examples of the mixed metal oxide can include SiO
2
/MgO, SiO
2
/CaO, SiO
2
/La
2
O
3
, Al
2
O
3
/MgO, Al
2
O
3
/CaO, Al
2
O
3
/La
2
O
3
, B
2
O
3
/MgO, ZrO
2
/CaO, and TiO
2
/La
2
O
3
.
As the mixed metal oxide, it is preferred to use one having a structure wherein an acidic metal oxide is contained as a core and a basic metal oxide is adhered as a layer on a surface of said core.
One preferred method of producing Catalyst I is to add a gel of clay and the mixed metal oxide to a silica sol solution, then uniformly stirring the resulting mixture to prepare a dispersion. In this case, the average particle size of clay is from about 0.5 to 5 &mgr;m, preferably from about 2 to 3 &mgr;m. The average particle size of the mixed metal oxide is from about 0.1 to 10 &mgr;m, preferably from about 3 to 7 &mgr;m. Further, the total solid concentration of the dispersion can be from about 10 to 50 wt. %, preferably about 20 to 30 wt. %.
The dispersion prepared as described above is next spray dried at a temperature from about 180 to 300° C., preferably from about 200 to 270° C. By this spray drying, Catalyst I of the present invention is obtained in the form of a powder, the average particle size of which is about 50 to 80 &mgr;m, preferably about 55 to 70 &mgr;m. The dry product obtained as described above can be used after calcining it at a temperature from about 300 to 700° C., preferably 400 to 600° C., as needed. Moreover, this powdery additive can be formed, if needed, by extrusion or the lik
Nakamura Kaori
Ootake Nobuo
Shibasaki Masato
Cromwell Michael A.
Exxon Research and Engineering Company
Griffin Steven P.
Naylor Henry E.
Nguyen Cam N.
LandOfFree
Additive catalyst for the cracking of heavy oil does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Additive catalyst for the cracking of heavy oil, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Additive catalyst for the cracking of heavy oil will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2529968