CS260553B1 - Process for preparing mixed oxide catalysts - Google Patents

Abstract

A method for preparing mixed oxide catalysts based on oxides of molybdenum, bismuth, cobalt, nickel, iron and optionally other transition metals and alkali metals for the oxidation of olefins from regenerated active components obtained by processing deactivated iron and optionally other metals on silica as a carrier in the form of a nitrate leachate, characterized in that the nitrate leachate is mixed with the missing salts dissolved in tartaric acid, after which the enriched leachate is mixed with ammoniacal molybdenum leachate, the pH is adjusted to a value of 7.5 to 8 with an aqueous solution of 26% ammonia, the mixture is dried, tableted and calcined.

Description

The invention relates to a process for preparing mixed oxide catalysts.

For the industrial production of unsaturated aldehydes or their mixtures with unsaturated carboxylic acids, Czechoslovakia has developed oxidation-free catalysts whose catalytically active component consists of a poly-component system of oxygen-containing metal compounds of the type:

Mo Bi. Co Ni.Fe X-Y O, a b c d efgz where X ......... is one or more other transition metals V. or VI. groups

Mendeleev's periodic system,

Y ......... is Na, K, or Li and the atomic values of the individual components are in the range of a = 6 to 16, b = 0.5 to 7, c = 2 to β, d = 0 to 4, e = 0.3 to 4, f = 0 to 1, g = 0.04 to 0.4, az = 10 to 60.

The preparation of these catalysts is based on aqueous solutions of salts of the individual active components which are mixed together and the resulting suspension or solution is dried, the salts contained are thermally decomposed and the mass thus obtained is tableted and calcined after addition of tableting ingredients to obtain the desired catalytic properties.

Due to the high content of deficit metals, the cost of these catalysts is quite high, and therefore it is desirable to reduce the foreign exchange requirements for the import of pure components from abroad. In search of economically advantageous utilization of discarded catalysts, mainly foreign companies, which represent industrial waste, it was found that the regeneration of the active ingredient obtained can be used for the preparation of MS. Carrier-free catalysts whose olefin oxidation properties are comparable to catalysts of the same composition but prepared from pure salts of the individual active components.

Process for preparing mixed oxide catalysts based on molybdenum oxides, bismuth, cobalt, nickel iron and optionally other transition metals and alkali metals for oxidizing olefins from regenerated active ingredients obtained by treating a deactivated supported catalyst based on molybdenum oxides, bismuth, cobalt, nickel, iron and optionally of other metals on the carrier oil in the form of a nitrate leach and an ammoniacal molybdenum leach by mixing the nitrate leach with the missing metal salts dissolved in tartaric acid, then adding the enriched leach with the ammoniacal molybdenum leach, adjusting the pH to 7.5 to 8% aqueous solution of 26% ammonia, the mixture is dried, ground and calcined.

The regeneration of active ingredients from a deactivated catalyst is the object of a separate invention AO 260 562: A method of regenerating active ingredients from a deactivated supported catalyst ...

When preparing the Czechoslovak. of the carrier-free catalyst from the regenerated components, the content of Bi is always taken. (i.e., bismuth nitrate) as the basis, i.e. 100% saturation of its consumption, Mo consumption from Mo-concentrate can be saturated in the range of 40 to 100%. Batches of other recovered metal components (Ni, Co, Fe) are tightly bound to the unitary amount of Bi presented in the nitrate extract already mentioned.

The example below illustrates an embodiment of the invention.

Example

Preparation about 5.1 kg of Czechoslovak. of a benzene catalyst

Solution A:

Boiler No. 1 is charged with approximately 28.3 L of nitrate extract from catalyst regeneration (see AO 260 562) with an amount of nitrate extract corresponding to a content of ca 1.376 kg of bismuth nitrate. In the present extract, 0.184 kg of nickel nitrate, 2.254 kg of cobalt nitrate, 1.259 kg of ferric nitrate are then dissolved successively at normal temperature and finally 2.47 kg of tartaric acid are added and the resulting solution is thoroughly mixed.

Solution B:

Boiler No. 2 is charged with about 58.7 L of ammoniacal Mo-leach, or an amount of Mo-leach that would add, after adding Mo from the nitrate leach, the total amount of heptamolybdate required, and then exactly 14.2 g of KOH are introduced and mix perfectly.

Casting of solutions and subsequent processing:

Solution A is transferred to solution B with stirring, and after stirring the pH is checked, which should be 7.5 to 8. If necessary, the pH is adjusted with an aqueous solution of 26% ammonia.

The resulting homogeneous solution is concentrated, dried, the contained salts are thermally decomposed, and the resulting mass is added after addition of 2 wt. % kaolin and 3 wt. the graphite is tabletted and the tablets are calcined at 350 ° C for 5 hours and at 420 ° C for 6 hours.

A catalyst with an atomic ratio of metals:

Mo ₁₂ Co ₅ 29 ^Ni 76 ^Fe l 76 ^Bi l 57 ^K 0 14 ^{8 5% by weight of} tablet additives.

Claims (1)

Process for preparing mixed oxide catalysts based on molybdenum oxides, bismuth, cobalt, nickel, iron and optionally other transition metals and alkali metals for the oxidation of olefins from regenerated active ingredients obtained by treating the deactivated molybdenum oxide, cobalt, cobalt, iron and optionally other supported cocatalyst of the metals on the silica carrier in the form of a nitrate leach and an ammoniacal molybdenum leach, characterized in that the nitrate leach is mixed with the missing metal salts dissolved in tartaric acid, then the enriched leach is mixed with an ammoniacal molybdenum leach, pH is adjusted to 7.5 to 8 aqueous solution of 26% ammonia, the mixture is dried, ground and calcined.