Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Metal – metal oxide or metal hydroxide
Patent
1994-09-13
1996-05-21
Beck, Shrive
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Metal, metal oxide or metal hydroxide
502439, B01J 2102, B01J 2104
Patent
active
055189792
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to an abrasion-resistant catalyst carrier, carrier catalysts produced by means of these catalyst carriers and their use.
It is known that catalyst carriers may be produced from various materials. Very often, activated aluminum oxide is used as the carrier. Typically, it will then be present in the "gamma" modification. A disadvantage of previously known carriers made of aluminum oxide is their relatively low abrasion resistance.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a catalyst carrier with an improved abrasion resistance. This object is achieved by the abrasion-resistant catalyst carrier indicated in the claims.
The catalyst carrier according to the invention consists essentially of aluminum oxide (Al.sub.2 O.sub.3) and has the following characteristics: in which case the "delta" modification may possibly be contained as a contaminant present in an amount from 0 to maximum of 10 wt-%, or modifications, in which case the "alpha" modification may possibly be contained as a contaminant present in an amount from 0 to a maximum of 10 wt-%; distribution) or two maxima (bimodal pore distribution) in the range of between 100 and 1,500 .ANG.; method is between 33 and 63 m.sup.2 /g.
Catalyst carriers which have the above-mentioned characteristics are distinguished by a very high abrasion resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating the nitrate content of untreated and catalytically treated ground water.
FIGS. 2 through 9 are graphs illustrating the pore diameter distribution of the catalyst carriers of Examples 1 through 8, respectively.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to one variant, the carrier consists of the "gamma" and "kappa" modifications. Their weight ratio is preferably between 34:66 and 23:77.
According to the other, particularly preferred variant, the carrier consists of the "kappa" and "theta" modifications. Their weight ratio is preferably between 30:70 and 10:90.
The carrier may be present in conventional carrier forms, as a monolith or as a bulk material carrier of conventional shapes, for example, in the form of hollow spheres, cylinders, hemispheres, as powder, etc. Preferably, it is present in a spherical shape. The diameter of the spheres is expediently between 0.1 mm and 20 mm, preferably between 0.1 and 1.0 mm and particularly between 0.3 and 0.8 mm.
A particularly preferred catalyst carrier is characterized in that it is completely free of aluminum oxide of the "gamma" and "delta" modifications, that the "alpha" modification is possibly contained as a contaminant present in small amounts, that the distribution of the pore diameters has a maximum (monomodal pore distribution) in the range of from 700 to 1,500 .ANG. or two maxima (bimodal pore distribution) in the range of from 100 to 1,500 .ANG., that the median pore diameter amounts to from 300 to 500 .ANG. and the specific surface calculated according to the mercury method is between 41 and 50 m.sup.2 /g.
This catalyst carrier is very advantageous because it permits a good diffusion of the material to be treated catalytically into the interior areas.
In the following, the production of the catalyst carrier according to the invention will be described.
The process according to the invention for the production of the catalyst carrier according to the invention which consists essentially of aluminum oxide Al.sub.2 O.sub.3) and whose distribution of the pore diameters has a maximum (monomodal pore distribution) or 2 maxima (bimodal pore distribution) in the range of between 100 and 1,500 .ANG. and whose specific surface calculated according to the mercury method amounts to between 33 and 63 m.sup.2 /g, wherein amorphous aluminum oxide ("chi" modification) is mixed with aluminum oxide hydrate with the exception of .beta.-aluminum oxide monohydrate, preferably with the addition of water, is brought into the desired shape and calcined, wherein the "gamma" and "kappa" modifications, in which the "de
REFERENCES:
patent: 4102978 (1978-07-01), Kiovsky
patent: 4637908 (1987-01-01), Weingartner
patent: 4704378 (1987-11-01), Fleming et al.
patent: 4722920 (1988-02-01), Kimura et al.
patent: 4990266 (1991-02-01), Vorlop et al.
patent: 5122496 (1992-06-01), Vorlop et al.
Bonse Dirk
Bretz Karl-Heinz
Derleth Helmut
Sell Michael
Beck Shrive
Parker Fred J.
Solvay Umweltchemie GmbH
LandOfFree
Abrasion-resistant catalyst carrier formed of transition alumina does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Abrasion-resistant catalyst carrier formed of transition alumina, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Abrasion-resistant catalyst carrier formed of transition alumina will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2037952