SU1423149A1 - Catalyst for pyrolysis of gaseous alkans - Google Patents

Abstract

The invention relates to catalytic chemistry, in particular to catalysts (QDs) for the pyrolysis of gas-phase alkanes. The goal is to increase the activity of CT. For this purpose, indium 3-5 oxide, magnesium oxide 0.5-1.5, and the rest of the ceramic carrier are introduced into the composition of QD (wt.%). The use of this CT allows to increase the ethylene yield by 1.8 wt.% With a selectivity of 81.5– 81, -7% and the yield of the amount of unsaturated hydrocarbons by 1.1 wt.% Higher than in the presence of a known CT. 2 tab. WITH

Description

eleven

The invention relates to catalysts for the pyrolysis of gaseous alkanes.

The aim of the invention is to increase the activity of the catalyst by additionally containing 1 modifying additive and a new carrier.

Example 1. 45 g of a ceramic carrier (particle size 3-5 mm) are placed in an aqueous solution of indium and magnesium nitrate salts, which is obtained by dissolving 2.8 g of In (NO.j), 4, and 1.6 g of Mg (NO ,) -. 6H20 200 m distilled. After 16 h

the solution is evaporated in a water bath while stirring to dryness. The granules are dried for 4 hours at 120 ° C and calcined at 800 ° C for 6 hours. The resulting catalyst has a composition, May. %:

Indium Oxide 2.0.

Magnesium oxide 0.5

Ceramic

carrierEverything

Examples 2-8. According to the procedure of Example 1, catalysts are obtained, containing various amounts of indium oxide and magnesium (table 1). The pyrolysis of ethane in the presence of catalysts prepared according to examples 1-8 was carried out in a flow-type laboratory installation. The ethane used had a purity of 99.9%. The temperature in the experiments -,. mass ratio nitrogen: H O: ethane 0.8: 0.5: 1 (molar ratio diluent:: ethane 1.7: 1), contact time - 0.4 s.

The test results are shown in Table. one.

From the data presented in table. it can be seen that catalyst samples containing 3-5% and 0.5-1.5% MgO (examples 2-4.6) exhibited activity higher than the limestone catalyst — 20% KVO / pumice. The ethylene yield is 62.1-62.5% by weight with a selectivity of 81.5-81.7%. Output these92

in the presence of a known catalyst - 60.8 wt.%, selectivity - 81, 5%. A decrease in the indium and magnesium oxides below the optimum (examples 1 and 8) leads to a decrease in the yield of ethylene. An increase in the content of indium oxide above the optimum (Example 5) does not lead to a further increase in the activity of the catalyst, and an increase in the content of magnesium oxide above the optimum reduces the yield of ethylene (Example 7).

During the pyrolysis of a mixture of gaseous alkanes containing (wt.%): Ethane - 10.7j propane - 69, Oj isobutane - 12.8; n-butane - 7.5 (liquefied gas) in the presence of a catalyst prepared according to example 2, at a temperature of 820 ° C, a mass ratio of nitrogen:: water vapor: raw materials 0.8: 0.5: 1 and contact time 0.4 With the yield of ethite lene it was 46.3 wt.% at a conversion of 90.3% (Table 2).

 .

As can be seen from table 2, the yield of ethylene in the presence of the proposed catalyst is 1.8 wt.%, And the yield of the amount is unsaturated by 1.1 wt.%, Than in the presence of a known catalyst.

F. formula

A catalyst for the pyrolysis of gaseous alkanes containing indium oxide on a large-porous silicon-containing carrier, characterized in that, in order to increase the activity, the catalyst additionally contains magnesium oxide and a ceramic carrier as a carrier in the following ratio of components, wt.%:

Indium Oxide 3-5

Magnesium oxide 0.5-1.5

Large pore

ceramic

carrier Else

table 2

46.3 10.8.

0.2

0.4 3.9

11.4

0.30.6 3.7

61.6 90.3

68.2

60.5 88.8

68.1

Claims (1)

A catalyst for pyrolysis of gaseous alkanes containing indium oxide on a large-pore silicon-containing support, characterized in that, in order to increase activity, the catalyst additionally contains magnesium oxide and, as a carrier, a ceramic carrier in the following ratio, wt.%: Indium oxide Magnesium oxide Large porous ceramic carrier