CS260554B1 - Process for preparing poly-component carrier-free catalysts - Google Patents

Abstract

The method of preparing polycomponent carrier-free catalysts based on oxides of molybdenum, bismuth, nickel, iron and optionally other transition metals and alkali metals for the oxidation of olefins in the gas phase from active components obtained from a deactivated Noel catalyst based on oxides of molybdenum, bismuth, cobalt, nickel, iron and optionally other metals on silica as a carrier for the first stage of propene oxidation, obtained in the form of a nitrate leachate, consists in mixing the nitrate leachate with 26% sodium hydroxide, dissolving the precipitated bismuth hydroxide paste in a calculated amount of nitric acid, dissolving the missing salts separately in tartaric acid, mixing both solutions and combining them with ammoniacal molybdenum leachate, and concentrating, tableting and calcining the homogeneous solution.

Description

The present invention relates to a process for the preparation of polycondientless catalysts.

For the industrial production of unsaturated aldehydes or their mixtures with unsaturated carboxylic acids, CSSR 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, and wherein 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 range from a = 6 to 16, b = 0.5 to 7, o = 2 to 8, d = 0 to 4, e = 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 the 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 ironed 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 the search for an economically advantageous use of discarded deactivated propene catalysts for the gas phase oxidation, which represents industrial waste, it has been found that the regeneration of the active ingredient obtained can be used for the preparation of No. 1. and catalysts of the same composition, but which were prepared from the pure salts of the individual active components. Process for the preparation of polycomponent non-carrier catalysts based on molybdenum oxides, bismuth, cobalt, nickel, iron and optionally other transition metals and alkali metals for the gas phase oxidation of olefins from active ingredients obtained from deactivated supported catalyst based on molybdenum oxides, bismuth, cobalt, nickel, iron and optionally other metals on silica as the carrier for the first stage of oxidation of the propene obtained in the form of a nitrate extract is characterized in that the nitrate extract is mixed with 26% sodium hydroxide, the precipitated bismuth hydroxide paste is dissolved in the calculated amount of nitric acid; It is dissolved by separation in tartaric acid, the two solutions are mixed and combined with an ammoniacal molybdenum extract and the homogeneous solution is concentrated, rendered and calcined.

Regeneration of active ingredients from deactivated catalyst is subject to separate MS. AO 260 562 A process for regenerating active ingredients from a deactivated carrier catalyst.

An advantage of the above process for the preparation of catalysts is a significant reduction in the ballast NH ₄ NO ₃ content, which has an adverse effect on the heat treatment process.

When preparing a carrier-free catalyst from the regenerated components, the Bi content (expressed as crystalline bismuth nitrate) in the BifOHi paste paste is always taken as the basis, ie 100% saturation of its consumption, Mo consumption from Mo-leach can be saturated in the range 40 to 100 %. Batches of other recovered metal components (Ni, Co, Fe) are firmly bound to the unitary amount of Bi presented in the Bi (0H) paste ₃ ·

The example below illustrates an embodiment of the invention.

t

Example

38.3 L of nitrate extract (obtained according to the process of AO No. 260 562) is introduced into the boiler and precipitated with 9.6 L of 26% NH 4 OH to a pH of about 6.5, whereby a BKOH precipitate precipitates). The temperature of the reaction mixture rises to 50 ° C during precipitation, and at the end it is heated to 70-75 ° C by external heating of the suspension and then allowed to coagulate for 30 to 40 minutes. After this time, the crude Bi (OH) 3 was filtered off and washed with 6.25 L of hot demineralized water (ca 90 ° C).

The violet ammoniacal extract containing residual Ni and Co is not processed at this stage (on an industrial scale it is assumed that NiCo concentrate is isolated by precipitation or separation of Ni and Co on the cation exchanger).

Pasta BKOH) ^ weighing 5.6 kg (dry basis at 110 ^P C ca 25%) is processed directly and without drying, the content of Bi is sufficient to prepare approx 4.94 kg of catalyst.

Catalyst preparation:

Solution A:

The Bi (OH) ₂ paste prepared as described above was introduced into the boiler and then 1.5 L of 65% nitric acid was added and the mixture stirred well at 40-50 ° C. During the stirring, the mixture is ocher yellow due to the falling fine suspension of molybdic acid, which in this case is not a problem, since Mo dissolves in the tartaric acid medium in the next step.

Solution B:

Solution B is prepared in a stirred vessel by introducing ca 14 L of demineralized water and 2.402 kg of tartaric acid, 2.455 kg of crystalline cobalt nitrate, 1.206 kg of ferric nitrate and 0.699 kg of nickel nitrate are gradually added under stirring. The solution does not heat during dissolution.

Solution C:

The evaporator was charged with 57.4 liters of Mo-leach (or, as determined by analysis, an amount such that ca 3.38 kg of ammonium heptamolybdate was in solution) and 0.014 kg of KOH was added with stirring.

Mixing of solutions and subsequent processing:

Solution A is transferred into solution B with stirring, and after stirring, the resulting solution is mixed with solution C. The resulting homogeneous solution is concentrated, dried, the salts contained are thermally decomposed, and the resulting mass is added with 2% strength by weight. kaloin and 3 wt. the graphite is tabletted and the tablets are calcined at 350 ° C for 3 h and at 20 ° C for 6 h.

This gives a catalyst with an atomic ratio of metals of Mo ₁₂ Co ₅ 29 ^Ni 1 76 ^Fe 1 76 ^Bi 1, 57 ^K 0 14 with 5% tabletting additives.

Claims (1)

OBJECT OF THE INVENTION A process for the preparation of polycomponent non-carrier catalysts based on molybdenum oxides, bismuth, cobalt, nickel, iron and optionally other transition metals and alkali metals for the gas phase oxidation of olefins from active ingredients obtained from a deactivated support catalyst for the first stage oxidation of molybdenum oxide propene. bismuth, cobalt, nickel, iron and possibly other metals, on a carrier oil, in the form of a nitrate extract, characterized in that the nitrate extract is mixed with 26% sodium hydroxide, the precipitated bismuth hydroxide paste is dissolved in the calculated amount of nitric acid, missing salts Dissolve separately in tartaric acid, mix the two solutions and combine with an ammoniacal molybdenum extract and concentrate the homogeneous solution. Stverography, n Price 2,40 Kčs