DE1038540B - Process for the production of cobalt oxide-molybdenum oxide carrier catalysts - Google Patents

Description

Process for the production of cobalt oxide-molybdenum oxide supported catalysts The invention relates to a method for producing catalysts from the oxides of cobalt and molybdenum as such or from compounds of these oxides and a carrier.

Such catalysts are used to desulfurize hydrocarbons, especially petroleum hydrocarbons, used by catalytic hydrogenation.

Numerous attempts have been made to make it highly effective Prepare catalysts of the above type. So can a cobalt-molybdenum complex in solution be deposited on a carrier, the carrier can be deposited with separate solutions be soaked in cobalt and molybdenum salts, or the carrier can be with the oxides of cobalt and molybdenum are mixed. There are numerous variations of these Methods, and the large number of methods described so far is a sign for how difficult it is even for a professional to find the necessary effectiveness to find a possessing catalyst.

The process according to the invention for the production of cobalt oxide-molybdenum supported catalysts by mixing molybdenum oxide or molybdic acid in solid form, a solid cobalt compound and a carrier, in particular alumina, and heating the mixture is now through characterized in that the carrier is in the form of an aqueous slurry and as a cobalt compound a sparingly soluble cobalt salt of an aliphatic carboxylic acid is used, according to Mixing removes the excess water from the mixture and resists the mixture is dried before calcination.

The carrier is preferably made of alumina, but e.g. Belly Oxides of zirconium, titanium.

Silicon or thorium can be used. Can also be used as a carrier for the catalyst, mixtures of alumina with titanium, zirconium or silicon dioxide be used.

The organic cobalt salt should be as little water-soluble as possible and have a relatively high metal content, since salts with a relatively low metal content due to the high loss of volatile substances in the Calcination also results in a catalyst with too low a cobalt content. From these In certain cases, basic organic salts can be used instead of neutral ones Salts should be preferred. The preferred organic salt is cobalt formate used, but other organic salts, such as. B. cobalt oxalate used will.

The method according to the invention is preferably carried out in such a way that that cobalt formate, molybdic acid and an alumina hydrogel slurry in the appropriate Quantities are mixed well, remove the excess water by centrifugation or filtration removed and the mass is dried. The mass is then at a temperature calcined from 450 to 6500 C in order to remove the organic residue, whereby a granular catalyst is obtained. But the mass can also be ground up and in front of the Calcination to be compressed into pills.

The method according to the invention is much easier to carry out than the above-mentioned known methods in which the respective carrier with a corresponding catalyst solution impregnated or where the catalyst is on the carrier is precipitated. These processes each require numerous procedural steps and do not deliver homogeneous products.

There are also cobalt oxide-molybdenum oxide supported catalysts known, which, as already mentioned, by dry mixing of the individual Metal oxides are produced. However, with such dry blending it is also very difficult to obtain completely homogeneous products.

In addition, the grinding is known in this one procedure quite tedious and therefore expensive.

The inventive method in which the individual components only need to be stirred into the aqueous suspension of the carrier In contrast, it is much easier and always leads to homogeneous products.

It is also known for the production of catalysts for desulfurization of gases and vapors e.g. B. to use metal oxalates. In this procedure, at incidentally, the use of cobalt oxalate is not directly described Cobalt catalysts are only described as additional catalysts to the actual Catalyst should be upstream. The catalysts are manufactured at this known method in a completely different way. as claimed hereiii.

Example 111/4 kg cobalt formate and 423/4 kg niolybdic acid were mixed with 1710 kg of an alumina hydrogel which contained 100 / o Al 2 O 3. The excess of water was removed by filtering the suspension under reduced pressure and the paste obtained is dried at 60 to 700.degree. The material thus obtained was crushed, sifted to the desired size and then calcined activated at a temperature of 450 to 6500 C.

The catalysts prepared according to the invention are very effective for desulfurization of petroleum hydrocarbons by catalytic hydrogenation (e.g. according to the procedure of British patents 654152, 669536 and 669 553) and can also be used to remove nitrogen compounds from mineral oils used in refining.

P. & TENTANSPI: t'CII 1.

1. Process for the production of cobaltosd-molybdenum oxide supported catalysts by -N1 iscllen of molybdenum oxide or molybdic acid in solid form, a solid Cobalt compound and a carrier, in particular alumina, and heating the mixture, characterized. that the carrier is in the form of an aqueous slurry and as a cobalt compound, a sparingly soluble cobalt salt of an aliphatic carboxylic acid is used, the excess water is removed from the mixture after mixing and drying the mixture prior to calcination.

Claims (1)

2. The method according to claim 1, characterized in that the dried Mixture for the decomposition of the organic salt to a temperature of 450 to 6500 C is heated. 3. The method according to claim 2, characterized in that the dried Mixture is ground and made into pill form before calcination. 4. The method according to claim 1 to 3, characterized in that as organic salt cobalt formate or cobalt oxalate is used. 5. The method according to claim 4, characterized in that a basic Salt is used. Considered publications: German Patent Specifications No. 481 927, 807 419, 816115, 528915; British Patent Specification No. 654152. 669536, 669553; U.S. Patent Publication No. 2592016; Gmelin's Handbook of Inorganic Chemistry, 8th Edition, Syst. No. 53, Molybdenum (1935), p. 95. 106. 107, 256; Syst. No. 58A, Kobalt (1932), p. 77.