RU2103062C1 - Triethylenediamine production catalyst - Google Patents

Abstract

FIELD: catalysts for organic syntheses. SUBSTANCE: catalyst is composed of (in wt %): strontium phosphate, 12-30; barium phosphate, 23-65; titanium dioxide, 18-58; and binding agent, the balance. EFFECT: increased yield of desired product (to 76%). 2 tbl

Description

 The present invention relates to a catalyst for the production of triethylenediamine (DEDA), a substance that is widely used as a catalyst in the production of polyurethane foams.

 A known catalyst for the production of TEDA, which is strontium diorthophosphate on a carrier — silicon dioxide, aluminum oxide, or a mixture of silicon dioxide and aluminum oxide (US Pat. No. 4,405,724, class 544/352, 1983). The mentioned catalyst can be used when starting from the production of TEDA as piperazine derivatives (hydroxy- and N-aminoethylpiperazines) and ethanolamines. The disadvantage of this catalyst is that the ready-to-use catalyst is a non-standard extrudate, which does not ensure regular packaging when loading the catalyst into the tubes of the contact apparatus, and this, in turn, causes uneven gas flows.

 A catalyst for producing TEDA is also known, which is mono- and dihydrogen phosphates of strontium and barium on an aluminosilicate carrier (US Pat. No. 4,521,600, class 544/352, 1985). This catalyst is obtained by applying a powder of the active components to the carrier, and the finished catalyst contains 25% of the active components. This catalyst can be used to produce TEDA from hydroxyethylpiperazine, N-aminoethylpiperazine and ethanolamines. The disadvantage of this catalyst is that the active components are applied in powder form, which does not allow to obtain a catalyst with a sufficiently developed surface of the active components and to apply more than 25% of the active components to the carrier. The yield of TEDA when using diethanolamine on this catalyst as a feedstock was 52%.

 The objective of the invention was the creation of a more effective catalyst for the process of obtaining TEDA from ethanolamines.

 To solve this problem, a catalyst is proposed that includes strontium and barium phosphates, as well as additionally containing titanium dioxide and a binder in the following ratio of ingredients in the catalyst, wt.%: Strontium phosphate 12-30; barium phosphate 23-65; titanium dioxide 18-58; binding rest.

 When the amount of any of the ingredients of the catalyst is outside the specified limits, the yield of TEDA is significantly reduced. To obtain the proposed catalyst, a solution of strontium nitrate and barium nitrate and a solution of disubstituted ammonium phosphate in water are prepared and, with vigorous stirring, these solutions are added to an aqueous suspension of titanium dioxide. At the end of the introduction of the solutions, the mass is again mixed, the precipitate is filtered off, washed with water, dried and calcined. The resulting mass is molded with the addition of a binder, for example, graphite.

 Example 1. 132.5 g of strontium nitrate, 487.5 g of barium nitrate are dissolved by heating in 1250 ml of distilled water (solution 1).

 330 g of disubstituted ammonium phosphate are dissolved by heating in 1259 ml of distilled water (solution 2).

 125 g of titanium dioxide are suspended in 500 ml of distilled water and, with vigorous stirring, solution 1 and 2 are introduced into the suspension simultaneously in equal streams.

Upon completion of the solution, the suspension is stirred for another 15 minutes with heating. The precipitate is filtered off, washed with distilled water, dried at 100-110 ^o C and calcined at 340-400 ^o C.

 Get 625 g of the catalyst mass, which is formed into tablets with the addition of a binder - graphite.

 The resulting catalyst has the following composition, wt.%: Strontium phosphate 17; barium phosphate 63; titanium dioxide 18; graphite rest.

 Examples 2-6. The catalyst is prepared according to the method of example 1, but take other quantities of the starting components. The compositions of the catalysts in examples 2-6 are shown in table 1.

Example 7. 100 g of the catalyst of example 1 is loaded into the contact tube. The loaded catalyst is activated at 360-370 ^{° C.} and DEA and water are fed to the activated catalyst in a mass ratio of 60:40 at a rate of 5 ml per hour. The feed mixture is evaporated in a stream of ammonia. It is possible to use an inert gas or a mixture of ammonia with an inert gas. The process is carried out at a temperature of 370 ^o C. The reaction products are condensed in a receiver cooled by water and analyzed by GLC. The output at the stage of 76%. The resulting catalyzate is subjected to fractional distillation. TEDA from the commercial fraction is isolated by crystallization, followed by filtration and drying. The total yield of 64%.

Examples 8-12. The contacting process is carried out according to the method of example 7, but the catalysts used in examples 2-6 are used, as well as a mixture of DEA and triethanolamine (TEA) and the contact temperature are varied within the range of 343-363 ^o С. The process conditions and product yield are given in table 2.

 As can be seen from table 2, the proposed catalyst allows to increase the yield of TEDA when using ethanolamines as a feedstock up to 76%.

Claims (1)

 A catalyst for producing triethylenediamine from ethanolamines, including strontium and barium phosphates, characterized in that it additionally contains titanium dioxide and a binder in the following ingredients, wt. Strontium Phosphate 12 30
Barium Phosphate 23 65
Titanium dioxide 18 58
Binder Rest

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