SU1598857A3 - Method of producing catalyst for oxidizing acrolein into acrylic acid - Google Patents

Abstract

PURPOSE:To enhance the selectivity of a desired compound at the time of gas- liquid contact oxidizing reaction, by uniting a composite oxide catalyst containing Sb, Mo, V and/or Nb with a supply source for supplying a specific required element and subsequently heat-treating the composite obtained to prepare a catalyst. CONSTITUTION:An Sb-Ni-X-O (X is Si or Al) composite oxide powder is subjected to the wet mixing with a poly-acid of Mo and V or Nb or a salt thereof, hydroxides of said metals or salts thereof and the resulting mixture is conc., dried and ground. The powder obtained is molded into a shape such as a small granular shape, a small columnar shape or a ring shape as it is or along with silica or graphite by tabletting or extrusion and the molded one is heated at about 300-500 deg.C for about 1-10hr to prepare a composite oxide catalyst. This composite oxide catalyst is extremely useful for ammoxidation and oxidative dehydrogenation reaction.

Description

The invention relates to methods for preparing catalysts for the oxidation of unsaturated aldehydes to unsaturated acids, in particular to a method for preparing an oxide catalyst for the oxidation of acrolein to acrylic acid.

The aim of the invention is to obtain a catalyst with increased selectivity.

The goal is achieved by using a nickel oxycarbonate as a suspension as a nickel compound, adding silicon dioxide or a-alumina, if necessary, and a certain ratio of components, providing the composition with the following empirical formula SbioNi4.3lo-8028.6-44.6. where I is silicon or aluminum,

Example 1. In 300 ml of pure water, 228 g of basic nickel carbonate (MUO2 2Ni (OH; 2 4H20)) are dispersed. To this mixture, 50 g of silica and 150 g of antimony trioxide are added and thoroughly mixed. The suspension is heated, concentrated and dried. thus, the solid product is calcined in a muffle furnace at 800 ° C for 3 hours. The calcined product Sbio-Ni4.3-Sis-0-i4.6 is crushed so that the particles pass through a 60 mesh sieve.

540 ml of pure water is heated to approximately 80 ° C and 8.1 g of antimony paratungstate, 63.9 g of ammonium paramolybdate, 8.4 g of ammonium metavanadate and 2.8 g of copper chloride are added and dissolved in sequence. The powder is then added.

ate you

00 00

ate

Xi

W

Sbio - Ni4.3 - Sis - 0 44.6 K to this solution and mix thoroughly.

The resulting suspension is heated to a temperature of 80-100 ° C, concentrated and dried. The dried product is pulverized so that the particles pass through a 24 mesh sieve, and 1.5 wt.% Of graphite is added and mixed. Then, the resulting mixture is loaded into a small-size tableting machine and tablets of 5 x 4 mm (height) are obtained. The resulting tablets are calcined in a muffle furnace at 400 ° C for 5 hours to form a catalyst.

The catalyst thus obtained has the composition represented by the following atomic ratios: Sb: Ni: Si: Mo: V: W: Cu: 0 100: 43: 80: 35: 7: 3: 3: 58

with a pore size of 9000 A.

50 ml of catalyst is loaded into a stainless steel reaction tube equipped with a jacket for nitrate heating medium and the catalytic oxidation of acrolein is carried out. Raw gas contains 4% acrolein, 46% steam and 50% air, it is passed through a tubular reactor with a bulk velocity of 870 h at 0 ° C. At a nitrate temperature of 250 ° C, the conversion of acrolein is 99.3%, the yield of acrylic acid is 97, b%, the selectivity of acrylic acid is 98.3%.

PRI me R. In 400 ml of pure water, 228 g of basic nickel carbonate is dispersed. To this mixture is added 150 gtrioxide of antimony and 11.1 hectares of alumina with stirring. The resulting suspension is heated, concentrated and dried. Then the obtained solid product is calcined in a muffle furnace at 800 ° C for 2 hours.

The calcined product Sbio-N14.3 - Al2 - Oz1. Is ground so that the particles pass through a 60 mesh sieve.

Pure water (540 ml) is heated to 80 ° C, 63.9 g of ammonium paramolybdate, 8.4 g of ammonium metavanadate, 4.6 g of niobium hydroxide and 21.2 g of copper sulfate are sequentially added and mixed. Then, the resulting Sbio-N14.3-Al2-Oz1 powder was slowly added to the resulting solution and mixed thoroughly. The catalyst was prepared as in example 1.

The catalyst thus obtained has the composition represented by the following atomic ratios: Sb: Ni: Al: Mo: V: Nb: Cu: 0 100: 43: 20: 35: 7: 3: 9: 445 with a pore size of 8000 A.

The same reaction as in Example 1 was carried out using this catalyst. In this case, the conversion of acrolein

99.7%, the yield of acrylic acid is 97%, the selectivity of acrylic acid is 97.3% at a reaction temperature of 250 ° C.

Froze In 300 ml of pure water, 228 g of basic nickel carbonate is dispersed. With stirring, 150 g of antimony trioxide is added to this mixture. Then the resulting suspension is heated, concentrated and dried. The obtained solid is calcined in a muffle furnace at 800 ° C for 3 hours.

Calcined. the Sbio-N14.3-028.6 product is ground to such an extent that the particles pass through a 60 mesh sieve.

By the method of Example 2, a catalyst of the following composition is obtained: Sb: NI: Mo: V: Nb: Cu: 0 100: 43: 35: 7: 3: 9: 415 with a pore size of 9000 A.

The reaction is carried out in the same manner as in Example 1 using this catalyst. The conversion of acrolein is 99.4%, the yield of acrylic acid is 97.4%, and the selectivity of acrylic acid is 98.0% at a reaction temperature of 250 ° C.

PRI me R 4. (comparative). A catalyst of this composition as in Example 1 is prepared analogously to Example 1, except that 136 g of nickel nitrate dissolved in 90 ml of warm water are used instead of nickel carbonate as a raw material when preparing Sbio - Ni4.3 - Sis - 044.6 in Example 1, and the reactivity was evaluated under the same conditions as before. The catalyst is obtained with a pore size of 2500 A.

Conversion of acrolein 98.4%, the yield of acrylic acid 94.7%. selectivity for acrylic acid 96.2% at a reaction temperature of 250 ° C.

PRI me R 5 (comparative). A catalyst of the composition as in example 3. is prepared analogously to example 3, except that 136 g of nickel nitrate dissolved in 90 ml of warm water are used instead of nickel carbonate as a raw material Ni when preparing Sbio - N14.3 - 028.6 in example 3, and the reactivity is evaluated under the same conditions as before, the catalyst is obtained with a pore size of 500 D.

Acrolein conversion 98.1%. the output of acrylic acid 94,8% at the reaction temperature of 250 ° C.

Thus, the proposed method allows to obtain a catalyst with selectivity for acrylic acid of 97.3-98.3% at 250 ° C, which exceeds the selectivity of the catalyst obtained by the known method, 94.8-96.2% at 250 ° C.

5 1598857b

Claims (1)

The invention claims tiri with the addition of graphite and procapad method for the preparation of catalyzing at 400 ° C, which is based on for the oxidation of acrolein to acrylic acid, for the purpose of obtaining a catalyst based on oxide compounds of antimony, by selectivity, as nickel, molybdenum, vanadium, copper, wolf-5, nickel is used as oxycarbonate frame or niobium, including the preparation of nickel in the form of a suspension, if necessary, a composition containing nickel and antimony, silicon dioxide or by mixing the nickel-a-alumina compound solution and components l with antimony trioxide, drying and calcination - in a ratio that ensures polishing at 800 ° C, adding to 10 the teaching of the composition of the following empiric the resulting composition of the solution, containing the clear formula SbioNl4,3lo-8028, e-44, e, molybdenum compound, vanadium, where I is silicon or aluminum, copper, tungsten or niobium, drying, table