SK286726B6 - Method of reusing fluoborate catalytic from production diphenylamine from aniline - Google Patents

Abstract

Substance of repeated use fluorborate catalyser from production diphenylamine from aniline rests in that, part of catalyser, which consists out of used catalyser of extract from reaction mixture and eventually of concentrated on volume of water 95 to 35% weight, is homogenize with fresh of catalyser at temperature 20 to 600 C in the rate of used catalyser: fresh catalyser 1: 0,001 to 100, whereby in case of need refilling water in value 95 to 35 % weight, and so arranged solution of used fluorborate catalyser is used to synthesis diphenylamine from aniline. Used catalyser may to homogenize directly with raw materials for production of fresh catalyser- hydrogenfluoride ammonium NH4HF2 and hypoboric acid H3BO3- and in case with water.

Description

The invention relates to a process for re-using fluoroboronium catalyst from the manufacture of diphenylamine from aniline as an intermediate for the production of antidegradants into rubber, plastics, fuels and lubricants.

BACKGROUND OF THE INVENTION

The production of diphenylamine (hereinafter DFA) from aniline can be divided into gas and liquid processes according to the reaction conditions. The liquid phase processes, in turn, depend on the catalyst system used. Still still industrially utilized liquid phase processes include production processes based on catalysis with fluoroboron compounds or mixtures thereof. So eg. in US Pat. 3,071,619 it was NH4BF4 or BF ₃ resp.NH ₃ BF ₃ According to DE Pat. 2 503 660 R ₂ O (BF ₃ ) 4, wherein R is ammonium or aniline. However, fluoroborates with a total F: B ratio of 2 to 4: 1 are also known (DE Pat. 2,521,293, but also catalytic mixtures with a higher F: B ratio than 4, e.g. CS AO 188809 and also catalysts with a lower F ratio : B as 2, eg CS AO192 322 (NH4) B ₃ O ₃ F ₄ OH The monograph Ryssa (Chimija ftora i jego neorganiceskich sojedinenij, Goschimizdat Moscow 1956) reveals the existence of almost innumerable chemical compounds containing boron and fluorine, BF ₃ -based molecular compounds are prepared mostly from BF ₃ gas and fluoroborates either directly from tetrafluoroboric acid or from NH ₄ HF ₂ and H ₃ BO ₃ , where the trifluoro- or tetrafluoroborate product is produced depending on the molar ratio of the reactants, but Trifluoroborate immediately converts to elevated temperature to tetrafluoroborate, but the pure ammonium trifluoro- and tetrafluorobontanes also have significant differences in physico-chemical properties. an ammonium salt has only about half the solubility in water compared to trifluoroborate prepared from NH ₄ HF ₂ and 3: 2 borohydride in a 3: 2 molar ratio. This significantly complicates the recycling of the catalyst used and significantly increases the energy consumption or production requirements space catalyst solution together with crystalline fraction.

SK PP 85-2004 describes a process for recycling fluoroboronium catalyst from diphenylamine production, but does not solve the problem of low solubility of the recycled catalyst in water, which increases the energy demand of diphenylamine production associated with evaporation of water from the reaction system.

It is an object of the present invention to overcome these as well as other disadvantages of the indicated fluorobontane catalyst recycling processes, whereby the use of the catalyst reuse method is not limited only to DFA aniline production technologies.

SUMMARY OF THE INVENTION

The above process complications are eliminated by the process of re-using the fluoroborous catalyst from the manufacture of diphenylamine from aniline according to the present invention, wherein the catalyst component consisting of the catalyst used is extracted from the reaction mixture and optionally concentrated to a water content of 95-35 wt. is homogenized with fresh catalyst at a temperature of 20 to 60 ° C in a ratio of used catalyst: fresh catalyst of 1: 0.01 to 100, adding, if necessary, water to a value of 95 to 35% by weight, and used for the synthesis of diphenylamine from aniline. It has been found that the catalyst used can also be homogenized directly with the basic raw materials for the production of a fresh catalyst - NH ₄ HF ₂ and boric acid H ₃ BO ₃ - and optionally water.

Since a certain amount of water is fed to produce a new batch of NH ₄ HF ₂ catalyst, the whole amount of the present catalyst used can be easily calculated according to its concentration, whether in diluted form starting directly from the extraction or concentrated form after distilling some water or aniline.

Where a new batch of fresh catalyst (for which a prescribed or reduced amount of water has been used) is produced, the used catalyst in the original or more concentrated form of the aqueous and / or aniline solution and / or the suspension obtained by concentration is added to that batch. aqueous phase from extraction of the reaction mixture with water. In both cases, the preparation of a catalyst with a high solids content, in the absence of solid particles, is provided at temperatures of 20 to 60 ° C.

Catalyst separation, concentration, and re-use in diphenylamine synthesis can be carried out batchwise, continuously, or semi-continuously.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

The reaction mixture from diphenylamine production was extracted with water and separated into two phases. The aqueous phase contained 4% NH4BF4. For the preparation of the new catalyst was weighed 4 g of the aqueous phase and 14 g of H3BO3, and 22.4 g NH ₄ HF _second As a result, a clear catalyst solution having a density of 1355.8 kg / m @ ^{3 was} designated Cat. Second

As no. 3, the catalyst was prepared by the same procedure, but the catalyst concentration in the dry phase was taken into account in the water phase used and was therefore weighed to prepare catalyst no. 3 4.4 g.

The prepared catalysts were then tested in the synthesis of diphenylamine from aniline, where they were compared to standard catalyst No. 1 prepared by an identical procedure but with the submission of 4 g of distilled water. The catalysts were tested in a Parr 4563 laboratory reactor in an amount of 1.26 g per 100 g of aniline. After four hours of reaction at 345 ° C and a turbine stirrer speed of 1500 min. ¹ , the following DFA concentrations in the reaction mixture were obtained: Cat. % 30.2 wt. Catalyst Converter DFA 2 31.0% h mot. Catalyst Converter DFA 3 31.4 wt. DFA

Example 2

The reaction mixture from diphenylamine production was extracted with water and separated into two phases. The aqueous phase, initially containing 4% NH ₄ BF ₄ , was concentrated to half volume by distillation to give a clear solution with a dry weight of 8.87%. For the preparation of the new catalyst, 4 g of this concentrated catalyst were weighed as water, 14 g of H ₃ BO ₃ and 22.4 g of NH ₄ HF ₂ . This resulted in a clear catalyst solution designated no. 4. As no. 5, the catalyst was prepared by the same procedure, but the catalyst concentration in the dry phase was taken into account in the water phase employed and was therefore weighed to prepare catalyst No. 5. 4.39 g.

The prepared catalysts were subsequently tested in the synthesis of diphenylamine from aniline, where they were compared with standard catalyst no. 1 of Example 1 by the procedure of this example.

Catalyst no. 4 31.6 wt. Catalyst Converter DFA % 31.8 wt. DFA

Example 3

From the aqueous phase from the extraction of the reaction mixture as in Example 1, 80% of the water was removed from the original volume of the aqueous phase by distillation. A concentrated catalyst solution in water containing 0.51 wt. aniline and 0.01% diphenylamine, but still free of solids after cooling to 20 ° C. 4 g of this solution were used again to prepare the catalyst according to the procedure of Example 1. A catalyst solution designated as catalyst 6 was thus prepared. After taking into account the dry weight of the concentrated catalyst used (18.61%), 4.91 g of concentrated catalyst was weighed of the catalyst used and the other reactants in an amount as in Example 1.

The catalysts were charged to the synthesis of diphenylamine in the same weight ratio to aniline as in Example 1. This resulted in reaction mixtures containing the following diphenylamine concentrations: Cat. % 32.2 wt. Catalyst Converter DFA 7 32.5 wt. DFA

Example 4

From the aqueous phase of the reaction mixture extraction as in Example 1, 90% of the water in the original volume of the aqueous phase was removed by distillation. A catalyst slurry in water containing 0.6 wt. aniline and 0.01% diphenylamine with a dry weight of 50.56%. The homogeneous suspension was mixed with an equal volume of catalyst prepared from NH ₄ HF ₂ and H ₃ BO ₃ as in Example 1, but prepared without the use of water. After mixing the two catalysts, the formation of a recycled catalyst slurry was not observed even after cooling to 15 ° C.

Catalyst No. 8, finally, in an amount of 1.26 g per 100g of aniline was charged to a Parr reactor and used to prepare diphenylamine. 33.1 wt.% Was measured in the reaction mixture after 4 hours of synthesis at 345 ° C. DFA.

Example 5

400 g of the concentrated catalyst slurry of Example 4 from which 90% by volume of water was removed was mixed with 1400 g of H ₃ BO ₃ and 2240 g of NH ₄ HF ₂ . A clear solution of a pale brown colored catalyst was formed. The solution was filtered, the brown filter residue was dissolved in toluene and proved to consist of DFA and aniline by GC-MS.

The catalyst solution was then charged at 4 ml. h ^{-1 was} injected into a laboratory continuous reactor at a temperature of 345 ° C. Aniline was metered at a rate of 400 ml.h ^-1 . After 20 hours of reactor run, the reaction mixture contained DFA at a concentration of 29.6% by weight. Using a standard catalyst prepared from the same procedure from 400 ml of water and the same amount of reactants as above, the average DFA concentration in the reaction mixture after stabilization was 28.6% by weight.

PATENT CLAIMS

Claims (2)

A process for the re-use of a fluoroborous catalyst from the production of diphenylamine from aniline, characterized in that a part of the catalyst consisting of the catalyst used, extracted from the reaction mixture and optionally concentrated to a water content of 95 to 35% by weight, is homogenized with fresh catalyst at a temperature 20 to 60 ° C in catalyst: fresh catalyst ratio of 1: 0.01 to 100, adding water to 95-35% by weight if necessary, and the treated fluoroboric catalyst solution thus used is used to synthesize diphenylamine from aniline . 2. The method according to claim 1, characterized in that the catalyst used was homogenized directly with the basic raw materials for the production of new catalyst - ammonium hydrogen fluoride NH4HF2 and boric acid H ₃ BO ₃ -, and optionally water.