RU2370314C1 - Catalyst and method of producing propylene - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to petrochemistry, more specifically to production of catalysts for dimerisation and metathesis of olefins and a method of producing propylene from ethylene. Description is given of a catalyst for producing propylene from ethylene, containing rhenium oxide, tungsten oxide and palladium on an oxide carrier in form of aluminium oxide, in the following content of components, wt %: rhenium oxide 0.5-2.0; tungsten oxide 5.0-10.0; palladium 0.01-0.25; oxide carrier - the rest. Described also is a method of producing propylene from ethylene, which is carried out in the presence of the said catalyst in a flow reactor or autoclave at 40-100°C and pressure of ethylene of 0.5-5 MPa.

EFFECT: high selectivity of formation of propylene at low temperature.

4 cl, 2 tbl, 13 ex

Description

FIELD OF THE INVENTION

The invention relates to the field of petrochemistry and relates to the production of catalysts for the dimerization and metathesis of olefins and a method for the synthesis of propylene from ethylene.

State of the art

A known catalyst for the metathesis of unsaturated hydrocarbons containing rhenium heptoxide, tungsten trioxide and aluminum oxide (AS 978907, 1982). The disadvantage of this catalyst is the low activity in the dimerization of ethylene.

Closest to the proposed invention is a catalytic system containing a dimerizing component and a component that conducts metathesis (US 3689589, 1972). This system includes nickel oxide and other compounds, in particular tungsten, molybdenum or rhenium compounds, which are promoted with various carriers, for example, silica gel, thorium oxide, alumina or aluminosilicate. The disadvantages of this catalytic system are the low activity and low selectivity of the formation of propylene from ethylene, as well as the need for a reaction at high temperatures of 260-427 ° C.

A known method of dimerization of ethylene in butenes at temperatures of 25-100 ° C and pressure up to 0.3 MPa using a catalytic system comprising palladium oxide, molybdenum and / or tungsten oxides, the content of the latter oxides being 5-95 wt.%, And the carrier (US 3,728,415, 1973). The main reaction products are butenes, and a certain amount of propylene and pentenes are also formed. The disadvantage of this method is the low selectivity of the formation of propylene, which does not exceed 31%.

A known method for the synthesis of propylene by the metathesis reaction of ethylene and 2-butenes using a rhenium oxide catalyst, in which the concentration of rhenium is 0.01-20 wt.% Rhenium, and the carrier is gamma alumina or a mixture containing at least 20 wt.% aluminum oxide and other oxides (US 4795734, 1989). The disadvantage of this method for the synthesis of propylene is that in this way it is impossible to obtain propylene only from ethylene.

A known method of producing propylene of high purity, consisting of the following stages: the stage of dimerization of ethylene in 1-butene using a catalytic system comprising a complex of Nickel; hydroisomerization steps of a 1-catalyst system comprising a nickel complex; the hydroisomerization step of 1-butene to 2-butene in the presence of palladium on a support and the metathesis step of 2-butene with ethylene using a rhenium-containing catalyst (US 2006/0161033 Al). The disadvantage of this method of producing propylene is multi-stage.

Closest to the proposed invention is a method for producing 1-olefins of composition C ₃ -C ₆ by sequentially carrying out stages of oligomerization of ethylene and metathesis of the resulting mixture of olefins with ethylene (US 5723713, 1998). A catalytic system has been proposed for the ethylene oligomerization step, including compounds of the elements of the VIA, VIIA and VIIIA of the Periodic System groups (IUPAC). For the metathesis stage, a catalytic system is proposed containing one or more metal oxides selected from oxides of rhenium, tungsten, cobalt and molybdenum. The disadvantage of this method is the need to use two catalytic systems, necessarily located in a certain sequence along the reaction mixture (first a dimerization catalyst, and then a metathesis catalyst), and a low selectivity for the formation of propylene, since the resulting olefin fraction contains mainly butenes.

Disclosure of invention

The tasks to which the invention is directed are the development of a catalyst and a high-performance method for producing propylene from ethylene.

The technical result consists in the implementation of dimerization and metathesis of ethylene in one stage with high selectivity for the formation of propylene at low temperature.

The technical result is achieved in that the catalyst for producing propylene contains rhenium oxide, tungsten oxide and palladium on an oxide support, with the following components, wt.%:

rhenium oxide 0.5-2.0 tungsten oxide 5.0-10.0 palladium 0.01-0.25 oxide carrier rest

The claimed catalyst allows the dimerization and metathesis of ethylene in one stage with high selectivity for the formation of propylene

Alumina may be used as the oxide support.

Alumina can be further treated with inorganic acid solutions. This treatment allows you to further increase the selectivity of the formation of propylene.

The palladium content in the catalyst can be from 0.01 to 0.1 wt.%, Which can significantly reduce the cost of obtaining propylene.

The technical result is also achieved by the fact that the production of propylene from ethylene is carried out in the presence of a catalyst containing rhenium oxide, tungsten oxide and palladium on an oxide support, with the following components, wt.%:

rhenium oxide 0.5-2.0 tungsten oxide 5.0-10.0 palladium 0.01-0.25 oxide carrier rest

in a flow reactor or in an autoclave at 40-100 ° C, ethylene pressure of 0.5-5 MPa.

This method allows dimerization and metathesis of ethylene in one stage with high selectivity for the formation of propylene at low temperature.

The implementation of the invention

The preparation of the claimed catalyst is as follows. An oxide support, for example, aluminum oxide, is impregnated with an aqueous solution of ammonium metatungstate at 20-70 ° C, dried at 110 ° C and subjected to temperature treatment in an atmosphere of air at 550 ° C, after which it is impregnated with an aqueous solution of palladium chloride with the addition of dilute aqueous ammonia and an aqueous solution of ammonium perrenate at 20-70 ° C, dried at 110 ° C and conduct heat treatment in an atmosphere of air at 500-650 ° C, replace the air with an inert gas and blow off the catalyst.

The implementation of the method of producing propylene using a catalyst corresponding to the proposed invention is illustrated by Examples 1-13. The test results of the proposed catalyst in the reaction for the synthesis of propylene from ethylene (GOST 25070-87) in an autoclave are shown in Table 1, examples of the production of propylene from ethylene in a flow unit are shown in Table 2.

Table 1
Obtaining propylene from ethylene during an autoclave reaction Examples Working hours Conversion C ₂ H ₄ ,% Selectivity,% C ₃ H ₆ C ₄ H ₈ C ₅₊ Known Catalysts sample 1 7 77.7 <0.05 71.5 28.5 sample 2 7 2.2 9,4 71.6 19.0 one 7 60,2 62.0 29.9 8.1 2 8.5 31.1 67.0 26.5 6.5 3 8.5 59.3 67.4 24.9 7.7 four 8.5 22.2 72,2 12,4 15.4

Example 1

The catalyst is obtained by impregnation of alumina with a specific surface area of 210 m ² / g and a total pore volume of 0.52 cm ³ / g with an aqueous solution of ammonium metatungstate H ₂₆ N ₆ O ₄₁ W ₁₂ · 18H ₂ O at 20-70 ° C, dried at 110 ° C and carry out a temperature treatment in an atmosphere of air at 550 ° C for 5 hours, after which they are impregnated with an aqueous solution of palladium chloride PdCl ₂ with the addition of a dilute aqueous solution of ammonia and an aqueous solution of ammonium perrenate NH ₄ ReO ₄ at 20-70 ° C for 4-6 hours, dried at 110 ° C and conduct heat treatment in an atmosphere of air at 500 ° C in within 5 hours, replace the air with an inert gas, such as argon, and blow off the catalyst for 1 hour. The sample contains 2 wt.% Re ₂ O ₇ , 10 wt.% WO ₃ , 0.1 wt.% Pd and the rest is aluminum oxide.

In a 75 ml autoclave, 10 ml of decane (99.7%, Fluka) and a catalyst in the amount of 11 wt.% Of the decan charge were charged, the reaction was carried out at 60 ° C and 5 MPa (Table 1).

For comparison, prepared samples in a known manner (Patent US 3689589):

4% NiO, 10% WO ₃ and the rest Al ₂ O ₃ (sample 1) and 2% Re ₂ O ₇ , 4% NiO and the rest Al ₂ O ₃ (sample 2), the samples were tested in the ethylene conversion reaction (as in Example one).

Example 2

Obtaining a catalyst and testing it is carried out according to Example 1, except that the reaction is carried out at 40 ° C.

Example 3

The preparation of the catalyst is carried out according to Example 1, but the amount of PdCl ₂ is taken from the calculation of a sample containing 0.05 wt.% Pd. The sample was tested in the ethylene conversion reaction (as in Example 1).

Example 4

The preparation of the catalyst is carried out according to Example 1, but the amount of PdCl ₂ is taken from the calculation of a sample containing 0.01 wt.% Pd. The sample was tested in the ethylene conversion reaction (as in Example 1).

table 2
Production of propylene from ethylene in a flow unit. 3 hours Examples R, MPa Conversion C ₂ H ₄ ,% Selectivity,% Propylene removal, g / kg _cat. H 2-C ₄ H ₈ : 1-C ₄ H ₈ C ₃ H ₆ C ₄ H ₈ C ₅₊ Known Catalyst 2 0.6 5,6 90,4 4.0 0.8 0.3: 1 5 2 25,4 81.8 16.9 1.3 468 3.0: 1 6 0.5 11,4 84.8 14.6 0.6 223 1.4: 1 7 four 29.4 64.7 32,3 3.0 334 3.7: 1 8 2 18.9 60.1 35,4 4,5 251 3.8: 1 9 2 15,2 82.3 16.8 0.9 297 1.7: 1 10 2 10.3 86.6 12.8 0.6 203 0.7: 1 eleven 2 25.5 80,4 18.7 0.9 481 4.3: 1 12 2 16.3 72.8 25.0 2.2 277 3.6: 1 13 1.9 9.5 91.0 9.0 0 200 0.3: 1

Example 5

The preparation of the catalyst is carried out according to Example 1. The sample was tested in the reaction of ethylene conversion in a plant with a flow reactor at a temperature of 70 ° C, an ethylene pressure of 2 MPa and a weighted ethylene feed rate of 2.25 h ^-1 (Table 2).

For comparison, the conditions of Example 5 tested a known sample containing 2%

Re ₂ O ₇ , 4% NiO and the rest Al ₂ O ₃ (US Pat. No. 3,689,589).

Example 6

The preparation of the catalyst is carried out according to Example 1, the test is carried out as in Example 5 except that the pressure of ethylene in the reactor is 0.5 MPa.

Example 7

The preparation of the catalyst is carried out according to Example 1, the test is carried out as in Example 5 except that the temperature in the reactor is 100 ° C and the ethylene pressure is 4 MPa.

Example 8

The preparation of the catalyst is carried out according to Example 1 except that aluminum oxide with a specific surface of 178 m ² / g and a total pore volume of 0.65 cm ³ / g was used and the amount of PdCl _{2 was} taken from the calculation of obtaining a sample containing 0.25 wt.% Pd. The sample was tested in the ethylene conversion reaction (as in Example 5).

Example 9

The preparation of the catalyst is carried out according to Example 3 except that aluminum oxide with a specific surface area of 242 m ² / g and a total pore volume of 0.66 cm ³ / g was used. The sample was tested in the ethylene conversion reaction (as in Example 5).

Example 10

The preparation of the catalyst is carried out according to Example 1 except that the alumina of Example 9 was used, the amount of H ₂₆ N ₆ O ₄₁ W ₁₂ · 18H ₂ O was taken from the calculation of obtaining a sample with a content of 5 wt.% WO ₃ and the temperature treatment was carried out in air at 500 ° C for 3 hours and at 650 ° C for 0.5 hours. The sample was tested in the ethylene conversion reaction (as in Example 5).

Example 11

The preparation of the catalyst is carried out according to Example 10, except that the amount of NH ₄ ReO ₄ is taken from the calculation of obtaining a sample with a content of 1.0

wt.% Re ₂ O ₇ , the amount of H26N6O41W12 · 18H2O is taken from the calculation of obtaining a sample with a content of 8 wt.% WO ₃ . The catalyst was tested in an ethylene conversion reaction (as in Example 5).

Example 12

The preparation of the catalyst is carried out according to Example 11 except that the amount of NH ₄ ReO ₄ is taken from the calculation of obtaining a sample with a content of 0.5 wt.%

Re ₂ O ₇ . The sample was tested in the ethylene conversion reaction (as in Example 5).

Example 13

The preparation of the catalyst is carried out according to Example 3 except that the alumina of Example 8 was used, which was previously treated with a 0.1 M hydrochloric acid solution and then washed with distilled water. The sample was tested in the ethylene conversion reaction (as in Example 5).

Industrial applicability

The claimed catalyst can be used in the processing of lower olefins, because it allows with high yield and selectivity to obtain propylene from ethylene. Interest is determined by the thermal stability of the catalyst and the low content of metals in it, which reduces the cost of preparing the catalyst.

Claims (4)

1. The catalyst for the production of propylene from ethylene, characterized in that it contains rhenium oxide, tungsten oxide and palladium on an oxide support, which is used as alumina in the following components, wt.%:
rhenium oxide 0.5-2.0 tungsten oxide 5.0-10.0 palladium 0.01-0.25 oxide carrier rest 2. The catalyst according to claim 1, characterized in that the alumina is further treated with inorganic acid solutions. 3. The catalyst according to claim 1, characterized in that the palladium content is from 0.01 to 0.1 wt.%. 4. A method of producing propylene from ethylene, characterized in that the synthesis is carried out in the presence of a catalyst according to claim 1 in a flow reactor or in an autoclave at 40-100 ° C and an ethylene pressure of 0.5-5 MPa.