SU1286273A1 - Method of preparing catalyst for disproportioning olefins - Google Patents

Abstract

This invention relates to catalytic chemistry, in particular, to a method for preparing a catalyst (QD) for the disproportionation of olefins. The production of QDs with increased activity is achieved by additional processing of QDs under other conditions. CT is prepared by impregnation of silica gel with ammonium paramolybdate solution, dried, heated in a stream of air or oxygen. After reduction with hydrogen or carbon monoxide, QD is additionally treated with cyclopropane with its mass ratio to QD equal to (1, 1 SG): 1, and 300-400 ° C. Tests have shown that CT has a higher activity than the known one: the disproportionation rate of olefins and the conversion increases from 0.003-0.02 to 0.39-0.45 g / g CT min- and from 15-26 to 34-36% respectively, 3 tab. (L

Description

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The invention relates to the preparation of catalysts, in particular to methods for the preparation of catalysts on dcHose molybdenum for the disproportionation of olefins.

The purpose of the invention is to obtain a catalyst with increased activity due to the additional treatment of the catalyst with cycloropane with a mass ratio of cyclopropane to the catalyst (1, -1. 10): 1 at 300-400 C.

The invention is illustrated by the following examples.

Example l.lOr silica gel,. KSK grades with a specific surface area of 250 mm in diameter are impregnated with an aqueous solution of ammonium para-molybdate (0.172 g of salt per 30 IL of water) and dried in air at. The catalyst contains 1 wt.%

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molybdenum on the surface of silica gel A portion of a catalyst of 0.18 g is loaded into a flow-through reactor without a gradient circulating unit 5 with a volume of 580 cm and heated in a stream of dry air (1 atm) for 1 h at. After the air has been removed, the catalyst is heated in a stream of carbon monoxide for 1 hour. Cyclopropane in a quantity of 3.10 g / g (catalyzed) is injected into the catalyst thus treated at 350 ° C and then the products are desorbed with the same TehinepaType. Propylene disproportionation is carried out on the catalyst at a propylene pressure and 0.1. atm

2 The test results of the catalyst sample are shown in Table 2. one.

Table 1

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Of these data, the reaction rate is 0.41 g / g (Cat.) I min at a selectivity of 100% and a conversion degree of 36.0%,

Example 2 In order to determine the amount of cyclopropane required for the treatment of the catalyst.

the sample prepared and activated in example 1 is injected with cyclopropane in quantities. listed in table. 2. The reaction of the disproportionation of propylene on such catalysts is carried out under the conditions of Example 1. Tabl 2

Example 3. The catalyst prepared according to claim 1, containing 1 wt.% Molybdenum, after being loaded into the reactor, is heated in a stream of dry oxygen for 1 hour and then reduced in a stream of hydrogen (0.05, atm) at the same temperature for 1.5 hours. The catalyst is treated with 2.10 g / g (katal.) 1D1K Lopropana at temperatures,. listed in table. 3, On the prepared catalyst, the reaction is carried out: disproportionation of propylene under the conditions of example 1.

-Table 3

Example 4 According to the procedure of Example 1, a catalyst is prepared containing 0.5% by weight of molybdenum on KSK silica gel, for which 10 g of silica gel is impregnated with a solution of ammonium paramolybdate (0.086 g of salt per 30 ml of water), then dried on air at, a portion of the catalyst 0.27 g load in quartz

The reactor of the installation described in Example 1 is heated in a stream of dry oxygen at 600 ° C for 1.5 hours. The catalyst is photoreduced with carbon monoxide, i.e. irradiated with mercury UV light

20 DRSh-1000 lamps in a CO atmosphere

(0.07 atm) at room temperature for 1 hour. After removing carbon monoxide, the catalyst is treated at 350 ° C with cyclopropane in the amount of 1. 10: g / g (catalyzed).

Propylene disproportionation (1 atm) is carried out at room temperature. At a contact time of 0.25 min conversion of propylene

30 comprehends 36%, which corresponds to

reaction rate L, 35 g / g (CATAL), x with a selectivity of 100%.

At the second inlet, 0.4 atm of propylene conversion of 36% was reached at room temperature and a contact time of 0.5 min, which corresponds to the reaction rate. 1.64 g / g (Cat.) 1.

0 Example 5. According to the method of Example 1, a catalyst is prepared containing 0.1 wt.% Molybdenum on KSK silica gel, for which 10 g of ai-gel are impregnated with aqueous IBOp of ammonium paramolybdate (0.017 g of salt in 30 ml of water), then dried to air at 110 ° C. A catalyst sample of 0.22 g is loaded into a quartz, reactor of the installation described in Example 1 and subjected to heating in a current: dry oxygen and subsequent photoreduction, as described in Example 4.

At 350 ° C, such a catalyst is treated with cyclopropane in the amount of 1, 8, 10 t / g (Cat.). Propylene disproportionation (0.1 atm) is carried out at room temperature. The reaction rate is 0.38 g / g (catal) at a conversion degree of 35%.

Example 6 A catalyst prepared according to Example 1 and containing 1 mass molybdenum on the surface of silica gel is loaded into the quartz reactor of the installation described in Examples 1, and the catalyst is treated as in Example 4, i.e. heated in a stream of dry oxygen and photoreduced in CO at room temperature. Then the catalyst; a torus at 300 ° C is treated with cyclopropane in an amount of 5. 10. g / g (catal,), the catalyst is tested in the disproportionation reaction of hexene-1. The reaction rate is determined by the rate of ethylene recovery. At room temperature and initial pressure of hexene-1, equal to 0.05 atm, the reaction rate is 1.83 g / g (cate), min 1 at the contact time O, 2.min and the degree of conversion of hex-1, equal to 48.5%

Example 7 (comparative). The catalyst prepared according to example 1, containing 1 wt.% Molybdenum, activated according to example 4, not

subjected to pre-treatment with cyclopropane, and cyclopropane is added in the amount of 0.5 g / g (catal) directly to the propylene fed to the catalyst at room temperature. At this temperature and at a propylene pressure of 0.1 atm, disproportionation of propylene is carried out. The reaction rate is 2.5 Yu G / g (catal) min at a conversion of 26%, which is lower than in Example 4 ,

Example 8 (comparative). The catalyst prepared according to example 1, containing 1 wt.% Molybdenum, is placed in the reactor of the installation described in example 1, heated in a stream of dry oxygen at 350 ° C

for 2 hours and, min. the pre-reduction stage, is treated with cyclopropane in the amount of 0.5 g / g (cate) at room temperature.

On such a catalyst, disproportionation of propylene (0.1 atm) is carried out at room temperature.

no propylene is observed at this temperature, which indicates

Inactivity of such a catalyst.

Example 9 (comparative, known). The catalyst prepared according to example 1, containing

1Ms,% molybdenum on silica gel KSK, after treatment in a stream of dry air, 500-800 ° C is subjected to thermal reduction with hydrogen or carbon monoxide in a stream at 500-600 ° C for 0.5-1.5 h. On such catalysts, disproportionation reaction of propylene (0.05-0.2 atm) at room temperature

temperature without cyclopropane treatment. The reaction rate determined under these conditions is 2, 3, Yu — g / g (Cat.) Min at a conversion of 15–26%,

Claims (1)

Invention Formula . The method of preparation of the catalyst for the disproportionation of olefins, including silica gel impregnation with ammonium paramolybdate solution, drying, heating in air or oxygen flow, reduction with hydrogen or carbon monoxide, and so that, to obtain a catalyst with increased activity, after reduction, the catalyst is further treated with cyclopropane at a weight ratio of cyclopropane to catalyst equal to (1,. 10): I, at 300-400 ° C,