RU2187364C2 - Catalyst for dehydrogenation of alkylaromatic hydrocarbons - Google Patents

Abstract

FIELD: hydrogenation- dehydrogenation catalysts. SUBSTANCE: catalyst is composed of, wt %: potassium compound 8-22, magnesium and/or calcium compound 0.5-10, molybdenum oxide 0.5-5, cerium oxide 1-8, Portland cement 5-10, strontium oxide and/or ferrite 0.5-10, lanthanum and/or neodymium oxide 0.01-1, iron oxide - the balance. Catalyst further contains 0.05-5.0% rubidium and/or cesium oxide and/or ferrite. Potassium and magnesium compounds can be oxides and/or ferrites. EFFECT: increased activity and selectivity. 4 cl, 1 tbl, 9 ex

Description

 The invention relates to the production of catalysts, and in particular to the production of catalysts for the processes of dehydrogenation of alkyl aromatic hydrocarbons.

A known catalyst for the dehydrogenation of alkylaromatic hydrocarbons containing, by weight. %: Fe ₂ O ₃ - 69-73; K ₂ CO ₃ - 19-20; Cr ₂ O ₃ - 7.5-8.5; K ₂ SiO ₃ - 2.0-2.6 (Kotelnikov G.R., Strunnikova L.V., Patanov V.A., Arapova I.P. Catalysts for the dehydrogenation of lower paraffins, olefin and alkylaromatic hydrocarbons, M., TsNIITEneftekhim 1978, p. 49).

Closest to the proposed is a catalyst for the dehydrogenation of ethylbenzene of the following composition, wt.%: Fe ₂ O ₃ - 45-90; K ₂ O - 5-40; MgO - 4-30; CeO ₂ 0-10; MoO ₃ 0-10; WO ₃ 0-10; CaO - 0-15, pore-forming, binding and forming agent (Application of Germany 3442636, CL 01 J 23/76, 1986).

 The disadvantages of these catalysts are their relatively low activity and selectivity.

 The aim of the invention is to increase the activity and selectivity of the catalyst.

 This is achieved by the fact that a catalyst for the dehydrogenation of alkylaromatic hydrocarbons is proposed, including iron oxide, potassium compounds, magnesium and / or calcium compounds, cerium oxide, molybdenum oxide, Portland cement, strontium oxide and / or ferrite, lanthanum oxide and / or neodymium oxide in the following the content of components, wt.%: potassium compounds 8-22; magnesium compounds and / or calcium compounds 0.5-10; cerium oxide 1.0-8.0; molybdenum oxide 0.5-5.0; Portland cement 5.0-10.0; strontium oxide and / or ferrite, 0.5-10.0; lanthanum oxide and / or neodymium oxide 0.01-1.0; iron oxide - the rest.

 Additionally, the catalyst may contain oxide and / or ferrite of rubidium and / or cesium in an amount of 0.05-5.0 wt.%.

 As potassium compounds, the catalyst may contain ferrite and / or potassium oxide.

 As magnesium compounds, the catalyst may contain ferrite and / or magnesium oxide.

 The difference between the proposed catalyst and the prototype is the additional content of oxide and / or ferrite of strontium, oxide of lanthanum and / or neodymium, as well as the possible content of oxide and / or ferrite of rubidium and / or cesium at the indicated content of components. The new composition of the catalyst can significantly increase its activity and selectivity.

 As raw materials for obtaining the inventive catalyst can be used oxides or decomposable to oxides of the compounds of these components, as well as ferrites.

 The proposed catalyst is prepared by mixing in a predetermined ratio of finely ground oxides or compounds of iron, oxide and / or ferrite of strontium decomposing to oxides, oxide or compounds of molybdenum, cerium, lanthanum and / or neodymium, compounds of magnesium and / or calcium, previously prepared, which are readily decomposed ferrite potassium, rubidium and / or cesium. The components are mixed and soaked in an aqueous solution of alkaline promoters, for example carbonates and / or potassium, rubidium and / or cesium hydroxides. Portland cement is introduced at the stage of mixing the dry catalyst components.

The catalyst mass is stirred for 0.5-2.5 hours to obtain a homogeneous mass, then molded by extrusion into bundles, dried at 100-170 ^o C and calcined at 550-750 ^o C.

The invention is illustrated by the following examples:
Example 1

Dry catalyst components, g: iron oxide - 117.98; molybdenum oxide - 2; cerium oxide - 8; Portland cement - 24; strontium oxide - 5; lanthanum oxide - 1, magnesium oxide - 10, mixed for 1 hour. Add 30 ml of an aqueous solution containing 47 g of potassium carbonate. The catalyst mass is stirred for 1.75 hours to obtain a homogeneous mass, then formed by extrusion into bundles with a diameter of 3.0 mm, dried at a temperature of 120 ^o C and calcined at 650 ^o C for 3 hours.

 Get the catalyst composition, wt. %: iron oxide - 58.99; potassium carbonate - 16 (counting on oxide); magnesium oxide - 5; molybdenum oxide - 1; cerium oxide - 4; Portland cement - 12; strontium oxide - 2.5; lanthanum oxide - 0.5.

Tests of the catalyst are carried out in the reaction of dehydrogenation of ethylbenzene in styrene at a temperature of 620 ± 20 ^o C, the feed rate of liquid ethylbenzene 0.5-1.5 l / l of catalyst per hour and mass dilution of the feedstock with water vapor 1: 2-3. The test data of the catalyst are shown in the table.

 Example 2

 The catalyst is prepared and tested analogously to Example 1, but magnesium carbonate is used instead of magnesium oxide, molybdenum acid is used instead of molybdenum oxide, rubidium nitrate is additionally added, and iron oxide hydrate is used instead of iron oxide. Data on the chemical composition (based on oxides) and catalyst testing are given in the table.

 Example 3

The catalyst is prepared and tested analogously to example 2, but instead of magnesium carbonate, calcium oxide is used, instead of potassium carbonate, potassium hydroxide is used, rubidium carbonate is introduced together with cesium carbonate, strontium ferrite is used as strontium compounds, and magnetite is used as iron oxide ( Fe ₃ O ₄ ). Data on the composition and testing of the catalyst are shown in the table.

 Example 4

 The catalyst is prepared and tested analogously to Example 3, but instead of cesium and rubidium carbonates, rubidium and cesium hydroxides are introduced, instead of calcium oxide, calcium carbonate is used, instead of cerium, lanthanum and neodymium oxides, cerium, lanthanum and neodymium carbonates are used, potassium ferrite is introduced as compounds, and as iron compounds, a mixture (50/50%) of iron oxide hydrate and magnetite is used. Data on the composition (based on oxides) and the catalyst test are given in the table.

 Example 5

The catalyst is prepared analogously to example 2, but calcium oxide is additionally introduced, magnesium ferrite is introduced instead of magnesium carbonate, strontium hydroxide is used instead of strontium oxide, cesium carbonate is introduced instead of rubidium nitrate and tested in the dehydrogenation reaction of isopropylbenzene in alpha-methylstyrene at a temperature of 560 ± 20 ^{° C.} the feed rate of liquid isopropylbenzene 0.5-1.5 l / l of catalyst per hour and mass dilution of the feed with water vapor 1: 3. The data on the composition and testing of the catalyst are shown in the table.

 Example 6

 The catalyst is prepared analogously to example 1, but ferrites of the corresponding compounds are used as strontium, potassium and magnesium compounds, calcium oxide is additionally added, and the catalyst is tested in the dehydrogenation reaction of isopropylbenzene to alpha-methyl styrene under the conditions described in example 5. Catalyst composition and test data are given in the table.

 Example 7

 The catalyst is prepared analogously to example 6, but as the compounds of potassium, magnesium and cesium, a mixture of carbonates and ferrites of the indicated elements is used in the ratio of carbonates (counting as oxides) / ferrites as 1 / 0.1 and they are tested in the dehydrogenation reaction of ethylbenzene under the conditions described in the example 1. Data on the composition and testing of the catalyst are shown in the table.

 Example 8

 The catalyst is prepared analogously to example 7, but instead of carbonate and cesium ferrite, carbonate and rubidium ferrite are used in a 1/3 ratio and a mixture of potassium and magnesium carbonates and ferrites in a ratio of 1/7. The catalyst is tested in the reaction of dehydrogenation of ethylbenzene under the conditions described in example 1. Data on the composition and testing of the catalyst are shown in the table.

 Example 9

 The catalyst is prepared analogously to example 7, but using a mixture of carbonates and ferrites of potassium, magnesium, rubidium and cesium in the ratio of carbonates / ferrites = 1/10. The catalyst is tested in the reaction of dehydrogenation of ethylbenzene, data on the composition and testing of the catalyst are shown in the table.

Claims (3)

1. A catalyst for the dehydrogenation of alkylaromatic hydrocarbons, including iron oxide, potassium compounds, magnesium compounds and / or calcium compounds, molybdenum oxide, cerium oxide and Portland cement, characterized in that it further comprises strontium oxide and / or ferrite, lanthanum oxide and / or neodymium oxide in the following ratio of components, wt.%:
Potassium Compounds - 8-22
Magnesium compounds and / or calcium compounds - 0.5-10
Molybdenum oxide - 0.5-5
Cerium oxide - 1-8
Portland cement - 2-12
Strontium oxide and / or ferrite - 0.5-10
Lanthanum oxide and / or neodymium oxide - 0.01-1
Iron Oxide - Else
2. The catalyst according to claim 1, characterized in that it further comprises an oxide and / or ferrite of rubidium and / or cesium in an amount of 0.05-5.0 wt.%.  3. The catalyst according to claim 1, characterized in that as potassium compounds it contains ferrite and / or potassium oxide.  4. The catalyst according to claim 1 or 2, characterized in that, as a magnesium compound, it contains ferrite and / or magnesium oxide, and as a calcium compound, it contains calcium oxide.

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