DE2013299A1 - Circular process for the production of hydrogen peroxide - Google Patents

Description

Patent attorneys
Dr. Ing = A. van dar Werttl

Dr. F. 'Lederer. 'J9. March55

21 Harnburg SO
Wilstorfer Strasse 32

S-69/16

Solvay & Cie.

33 Rue du Prince Albert, B-IO5O Brussels 5 / Belgieh

Circular process for the production of hydrogen peroxide.

Priority: May 27, 1969, France, No. ₀ 6917283

The invention "relates to a circular method of manufacture of hydrogen peroxide, in which a 2-alkylanthraehinone is used as an intermediate.

It is known to produce hydrogen peroxide by a process which consists in producing a 2-alkyl anthraquinone to hydrogenate in solution in an organic and water-immiscible solvent in such a way that it is converted into 2-alkylanthrahydroquinone, then that Reaction environment by an oxygen-containing gas in such a way oxidize that the starting 2-alkylanthraquinone under Formation of hydrogen peroxide is regenerated, this latter is extracted by means of water and then the organic Solution of the 2-alkylanthraquinone back into the hydrogenation stage to redirect. ■

It is also known to act as intermediates in such a process the 2-methyl, 2-ethyl, 2-propyl, 2-tert-butyl and 2-Amylanth.rachinone to be used alone or as a mixture. In industrial practice, only that 2-ethyl, the 2-tert-butyl and also mixtures of 2-tert-amyl- and 2-sec-isoamylanthraquinones actually used, whereby the spontaneous generation of hydrogen peroxide in in the order 2-ethylanthraquinone, 2-tert.-butylanthraquinone, and mixture of isomeric 2-amylanthraquinones increase,

........ 009849/1664

The invention has for its object, hydrogen peroxide raifc improved yields using 2-tert-amylanthraehinone to produce, this being produced in a special process indicated below.

According to the invention, hydrogen peroxide is obtained through the cycle of autoxidation of 2-alkylanthraquinones, by using the 2-tert-amylanthraquinone as an intermediate, which is produced by that you can para-halo-tert-amylbenzene with magnesium with formation of the parahalide of tert-amylbenzene magnesium can be implemented, this last with phthalic anhydride condensed to the XKK ± 2- (4-tert-amylbenzQ7l) To obtain benzoic acid, which is then subjected to dehydration to give it to 2-tert-amylanthraquinone cyclize.

For the implementation of the circular process for extraction of hydrogen peroxide becomes the anthraquinone intermediate used in solution in an organic solvent immiscible with water, which preferably consists of a miscible mixture of a solvent from the quinone form and a solvent from the corresponding hydroquinone form consists. Aromatic hydrocarbons, in particular, are used as solvents of the quinone form the fractions of Cg - C ^, naphthalene, tetrahydronaphthalene the alkyl derivatives of naphthalene, anisole, the chlorinated ones Hydrocarbons, etc. For the dissolution of the hydroquinones, secondary aliphatic alcohols are used, especially the secondary alcohols with 7 to 11 carbon atoms, e.g. octanol-2 or diisobutylcarbinol, primary alcohols such as heptanol, methylcyclohexanol, ketones such as diisobutyl ketone, aliphatic or cycloaliphatic esters of carboxylic acids or phosphoric acids and the like.

In general, the solubility of a 2-alkyl anthrahydroohinone is in the solvents of the hydroquinone form significantly lower than the solubility deff corresponding 2-alkylanthraquinones in the solvents of the quinone

009849/1664

. ■ -5-

form. It may therefore seem logical at first glance to to use a mixture of solutions, which for one part the solvent of the quinone form contains at least two "to three parts of the solvent of the hydroquinone form, after these proportions are not necessarily satisfactory because of the increase in viscosity such a solution and because of the reduction in the partition coefficient of hydrogen peroxide between the Solution and the water, what difficulties in the extraction by means of water of the hydrogen peroxide with brings itself, which is generated during the cycle became. In practice, therefore, the 2-alkylantliachinoi is used dissolved in a mixed solvent, which has approximately equal amounts of solvent of the quinone form and solvent the hydroquinone form contains, and with such compositions of the solvent it is clear that the Yield of hydrogen peroxide always a puncture of the Solubility of the 2-alkylanthrahydroquinone in the consideration coming mixed solvent is "

Sun found in the case of 2-amylanthraquinones that the solubility of 2-amylanthrahydroquinones is regular as a function of the content of the isomeric tert-amyl constituent in the mixtures of 2-tert-aemylanthraquinone-2-seco-isoamylanthraquinone increases to reach its highest value when the 2-tert -.-amylanth.rachinone is present alone, regardless of which mixed solvent is used *

The Magramm available for three different temperatures, the solubility of the Anthrahydroehinonform (in mol / kg of solution as ordinate) in a mixture of equal parts by weight of di-isobutyl carbinol and a boiling between 140 and 19O ⁰ C petroleum fraction as a function of the content of 2-tert-Amylanthraehinon (in% as abscissa) in the mixtures of 2-tert. amylanthraquinone and 2-sec, isoamylanthraquinone on «,

9 / Ί664.

BATH ORIGINAL

This finding contradicts certain information in the technical literature, according to which the reduced form, ie the 2-amylanthrahydroquinone, has a maximum of solubility "if it corresponds to a mixture of 70o 2-terto-amylanthraquinone and 30 $ 2-sec-isoamylanthraquinone.

These results therefore justify the interest slightly above 2-tert.-amylanthraquinone, which is only slightly or does not contain any other isomer, for use in the process according to the invention.

However, the usual manufacturing processes for 2-alkylanthraquinones, which consists in condensing with phthalic anhydride in the presence of AlCl., to form 2- (4-alkylbenzoyl) benzoic acid to produce the latter then under the action of a fl'ehydrating agent, such as concentrated To cyclize sulfuric acid or oleum is not satisfactory here if the 2-terto-amylanthraquinone is used wishes to manufacture. In fact, it was found that the condensation of tertiary amylbenzene with phatalic anhydride in the presence of AlCl., always from partial isomerization the tert-amyl group to the dec-isoamyl group so that the end product after the cyclization is always a mixture of 2-terto-amylanthraquinone and 2-sec.-isoamylanthraquinone is. Modification of the working conditions of the condensation, in particular the type of solvent, Temperature and reaction time as well as type of catalyst, brought no improvement

On the other hand, assuming the procedure according to the invention, one obtains with good yields and without isomerization a 2-tert.-Amylanthraeh.inon, which directly as an intermediate can be used in the process according to the invention.

This procedure, which can be carried out continuously or discontinuously, comprises a sequence * of stages, which are based on reactions known per se, but their use for the production of amyl derivatives has never been realized so far became. It uses parahalogen-tert-amylbenzene,

009849/1664

which one goes through with good yields. Halogenation of tert-amylbenzene can be obtained. The halogenation is carried out by bromine or chlorine in the presence or absence of a catalyst, ZoB. Causes iron, perrichloride or iodine. You can work at temperatures between 10 and 100 ⁰ O with or without dilution of the tert-amylbenzene by a solvent. The diluting solvent used is carboxylic acids such as acetic acid, nitroalkanes such as uromethane and its homologues with Co-C., Chlorinated solvents such as dichloroethane, carbon tetrachloride, etc. In this way, increased yields of parahalogen derivatives are achieved with a minimum of dihalogen derivatives. This compound can also be obtained by alkylating halobenzene.

The halide of tert-amylbenzene magnesium is produced by reacting magnesium with the halogen-tert-amylbenzene. This reaction is carried out in customary solvents, for example _a aliphatic ethers such as Diäthylather, or dialkyl ethers of ethylene glycol, or cyclic Ä'theroxyden, in particular tetrahydrofuran. The reaction can be initiated by first adding ethyl bromide or ethyl iodine to the magnesium.

The condensation of organomagnesium with phthalic anhydride is carried out by gradually converting the solution of the organomagnesium into a solution of the phthalic anhydride in the same solvent as that used for the preparation of the organomagnesium. The anhydride / magnesium reactant molar ratio can be between 1 and -2 vary. The reaction temperature is generally determined by the boiling point of the solvent used. The 2- (4-tert-amylbenzoyl) benzoic acid is obtained in this way in good yield.

The cyclization of this acid to form tert-amylanthraquinone is carried out in concentrated sulfuric acid or oleum at a temperature of 50-125 ⁰ C for 1-5 hours. ■ -. ■ '■' - ■

0098Λ9 / 166Α .

The resulting quinone is a clear, k yellow solid having a melting point of 75 ⁰ C. shows the RMN spectrum, that it is the 2-ter.-amylanthraquinone is, containing no other isomer.

example 1

A- Production of Z-tert-amylanthraquinone.

1.Preparation of the parahalogen-tert-amylbenzene: a) by bromination

In a blackened glass reactor, which contains 298 g of tert- _o- amylbenzene and about 15 mg of reduced iron, 528 g of bromine are added with stirring over the course of 2 hours. The bromine can optionally be dissolved in a solvent such as carbon tetrachloride. The reactor is kept at 40 C for the entire duration of the bromination »

After a stay in a refrigerator kept at -20 C ^, the remaining gases emerging from the reactor are used to condense the unreacted bromine into a scrubber with water in order to obtain the hydrogen bromide formed "

When all the bromine has been added, the solution is still held at 40 ° C. for one hour under a stream of nitrogen.

During this reaction, $ 95-99 of the used tert-amylbenzene reacts and the resulting brominated Product contains approximately 96.5? 6 para-Broia-tert-ramylbenzene.

This latter is isolieift by distillation under vacuum but this operation is not strictly necessary (the boiling point at 20 mmrungefähr 121 ° C, refractive index at 20 ⁰ C: 1.5338).

b) by chlorination

Into a glass reactor, which is 296 g (2 moles) containing tert-amylbenzene and 296 g of nitromethane, one leaves slowly chlorine (10 normal liters / hour) for 2 hours Bubble through for 30 minutes.

009849/1664

During the duration of the introduction, the temperature of the reactor is kept between 30 and 35 ° C «,

The unreacted chlorine and; the evolved hydrogen chloride go through a water cooler and are absorbed in a scrubber, which is made up of a solution of 2N caustic soda is sprinkled. After interruption of the introduction of chlorine the reactor is gradually, but with sustaining a slight purging with nitrogen warmed up in such a way that to vent the dissolved chlorine and hydrogen chloride. To After degassing, the nitromethane is removed by distillation. The chlorinated product obtained is analyzed

Not taking into account the unconverted tertiary

\ 24W
Amylbenzene / one has

ino =

Number of moles of monochlorinated tert-amylbenzene Number of moles of chlorinated tert-amylbenzene. with a relationship

Parachloro-tert-amylbenzene ...

(ortho- + meta-) chloro-tert-amylbenzene ^ ^ι ^ ^{± άΙ11}

6/1, di. a yield parachloro tert. -Amylbenzene

^s ". chlorinated tert -amylbenzene

The mixture (0 + m + p _) _ chlorine-tert-amylbenzene (boiling temperature: 105 ° C. at 18 mm Hg) _{0 is obtained by vacuum distillation}

2.) Preparation of the halide of tert-amylbenzene magnesium; a) starting from bromide.

^from

In a reactor, which, previously flushed with nitrogen and provided with a water cooler and a stirrer 27.5 g (1.1 mol) of magnesium turnings are introduced. A solution of 226 g is then used within 2 hours (1.0 mol) parabromo-tert-amylbenzene in 500 em tetrahydrofuran to., which was previously dried over sodium ket. The reacti on is initiated by gently warming the reactor. I-ah complete addition and under! You keep the reflux ingang, bic angry almost complete disappearance of the magnesium (about 2 hours).

b) starting from chloride
In the same apparatus one puts 9.5 g of magnesium turnings, then

009849/166

BATH ORIGINAL

0.5 cm ⁵ bromoethyl and 10-15 cm ⁵ wine solution, prepared by "mixing 150 cm of tetrahydrofuran dried over sodium and 54.9 g (0.3 mol) of monochloro-tert-amylbenzene, obtained according to 1, b The mixture is brought to the boil and the remainder of the solution of monochloro-tert-amylbenzene in tetrahydrofuran is then introduced over the course of one hour, followed by stirring under reflux for a further 7 hours.

3.) condensation of the organomagnesium with phthalic anhydride

a) starting from the bromide of tert-amylbenzene magnesium.

With stirring and at 40 ⁰ C / is the solution according to 2.a) obtained organomagnesium slowly added over one hour to a solution containing 148 g (1 mole) of phthalic

■ 7.

anhydride in 500 cirr tetrahydrofuran, which previously dried over sodium. When the addition is complete, the solution is stirred for one hour at room temperature, and then during 2 hours and 30 minutes under reflux. The tetrahydrofuran is then completely driven off by evaporation. A solution of Add 6 N hydrochloric acid.

The organic phase is extracted by 3 portions of 300 cm ethyl ether. The three ether fractions are combined, washed with 500 cm of NaCl saturated water and then the 2- (4-tert-amylbenzoyl) -benzo. <? acid by means of five successive extractions with 50 cm of an aqueous solution of 5% Na ₂ CO. These proportions are combined and acidified with concentrated HCl to precipitate the 2- (4-tert-amylbenzoyl) benzoic acid, which is collected and purified by dissolving in 500 cm cold chloroform. After filtration, the chloroform is evaporated and 220 g of pure acid are obtained, which melt at 144 ° C.

The overall yield of measures 2. a) and 3. a) expressed by:

009849/16 6 4

Number of moles of benzoic acid obtained 1OO the number of moles of p.-bromo-terto-amyl- used. ^ T

benzene

b) starting from the chlorine of tert-amylbenzene magnesia

While stirring and at 40 ° C., the solution becomes organomagnesiun obtained according to 2. / b), slowly (1 hour) to a solution given, which by dissolving 44.4 g (0.3 mol) of phthalate

3
Acid anhydride was prepared in 180 cnr tetrahydrofuran, which was previously dried over sodium. After the addition is complete, the solution is brought to the boil and refluxed for a further 3 hours 30 minutes. Then the tetrahydrofuran is completely evaporated. The measures for obtaining and purifying the 2- (4-terto-amylbenzoyl) benzoic acid obtained are the same as under a). The overall yield of measures 2. b) and 3. b), expressed by:.

χ 100 reaches $ 82

Number of moles of benzoic acid obtained Number of moles of para used

ifchlor-tert. -Amylbenzene

i ») Cyclization of benzoic acid to 2-terto-amylanthraquinone

Into a reactor equipped with a cooler to run a 432 g H ₂ SO from 1009έ, the mixture is heated to 50 ⁰ C, then sets one unter'Rühren 54 g of 2- (4-tert-amylbenzoyl) -benzoic acid are added and brings diV solution at 85 ° C. at this temperature, stirring is continued ^weiterei: 4 hours. After the reaction, the warm mixture / 2.5 l of ice water is poured. The acidic solution will

washed twice with 400 cm benzene to remove the 2-tert-amylanthraquinone to extract. After decanting, the

Benzene phase once with 500 cm of water and "then twice" with ■ 2 3

300 cm 1 N NaOH solution, then twice more with 400 cm. Washed water, whereupon the benzene is evaporated.

Durchί are thus obtained 42 g of 2-tert-amylanthraquinone ₀ The yield, expressed

Number of moles of 2-tert.-amylanthraquinone

- - non '

Number of moles of benzoic acid used

00 9849/16 64

χ 100

achieved

$ 82

B - Production of hydrogen peroxide using the 2-tert-o-amylanthraquinone

Is given to using 1 kg of the organic solution obtained by dissolving 290 g of 2-tert-amylanthraquinone in a mixture consisting of 355 g of di-isobutyl carbinol and 355 g of a petroleum fraction containing mainly C _Q alkylbenzenes.

This solution is subjected to catalytic Hydrogenation in the presence of Raney Mckel in a vessel equipped with Rühywerk piston, and at a temperature of about 35 ⁰ C, interrupting the Hydrogenation, when the content of anthrahydroquinone is near saturation "The average Hydrogenationsgeschwindigkeit is for all of the organic solution used 30 1 hydrogen per hour "

The catalyst is then separated off and the hydrogenated organic solution is placed in another flask in which it is a Oxidation by oxygen is subjected to «after complete Oxidation, indicated by a change in the color of the solutions, extracts the hydrogen peroxide produced.

The amount obtained is 17.5 g, expressed as H ₂ O ₂ of 100 %. For comparison, two experiments to obtain water peroxide were carried out under the same working conditions as the above, but in a pail using a mixture consisting of 70 $ 2-tert-amylanthraquinone and 30 $ 2-sec-isoamylanthraquinone, and in the other case using a mixture of 40 $ 2-tert _e- amylanthraquinone and 60 $ 2-sec-isoamylanthraquinone. These two mixtures originated from the usual condensation of tert-amylbenzene with phthalic anhydride in the presence of AlCl ^ with subsequent cyclization and correspond to the extreme combinations that can be obtained if the working conditions of the condensation are varied.

The results follow in the table, in which also the results of Example 1 according to the invention on ge nomine ι are to better compare and value the inventive

Procedure to be able to show. -

009849/1664

In these comparative experiments one has the content of Anthraquinone in the dissolved mixture modified to account for the variation in solubility of the anthrahydroquinone form to wear. Which is a puncture of the content of the terto-amyl isomer in the 2-amylanthraquinone used

Table .

Used 2-amyl-2-tert-amyl mixture from mixture of anthraquinone obtained according to 2.-tert-amyl ~ 2-tert <, - ainyl-

Example 1 ($ 70) and (4OfO) and

2-sekoIso- 2-stko-Iso- -. amyl- ($ 30) amyl- ($ 60)

Composition of the organic solution in g / kg:

Anthraquinone

Diisobutyl carbinol

Petroleum fraction

Content of diisobutylcarbinol in the solution mixture in g io

290 250 355 . 363 355 387

48,, 5

200 500 300

62.5

Properties of the organic solution:

specific gravity at 35 ⁰ C in kg / dnP viscosity at 35 ° G in centipoise

Coefficient of division of H ₀ O ₀

0.902 0.892 0.872 2.3 2.0 2.3 58 60 44

generated hydrogen peroxide in g H ₉ O ₉ of 6 ^{ά ά}

17.5

15.1

12.1

The comparison of the generation of hydrogen peroxide clearly shows the superiority of the process according to the invention

Example 2 .

An organic solution is used in a pilot plant a content per kg of 290 g. 2-tert-amylanthraquinone according to the method of Example 1A, 355 g of diisobutylcarbinol and 355 g of a petroleum fraction, which essentially

^from S Ami

0098A9 / 166A

BATH ORIGINAL

This solution circulates in the plant, where it runs one after the other is subjected to the following treatments: hydrogenation in the presence of palladium on hydroxyapatite "to a degree vo: 50 ^, separating off the catalyst, oxidizing with air, extracting of the generated hydrogen peroxide by means of water, recycling of the organic solution in the hydrogenation stage, to start the cycle again, etc.

This plant has been operating continuously for 156 days worked. The production of organic solution is kept constant by a fraction of the solution continuously applied regeneration treatment and such additions of anthraquinone and solvents to the mechanical To compensate for losses and losses caused by chemical degradation, evaporation and entrainment in the aqueous Solution of hydrogen peroxide.

During this time, the plant has produced 3740 kg of hydrogen peroxide in the form of an aqueous solution of 31 wt. $. The total yield of hydrogen peroxide, based on the hydrogen consumed, was 92 ^,

After this operating time, the organic solution contained per kg 268 g of 2-tert-amylanthraquinone, 20 g of the corresponding derivative tetrahydrogenated on the core, 43 g of other degradation products, 2,338 g of diisobutylcarbinol and 331 g of petroleum solvent.

The viscosity of the solution, measured at 35 ° C, remained below 2.5 cP throughout the experiment.

Of the 43 g / kg of the breakdown products of 2-tert-aaylanthraquinone, 31 g / kg can be regenerated to 2-tert-amylanthraquinone by means of known methods. The same applies to the 20 g / kg of the derivative tetrahydrogenated at the core.

0 0 9 8 49/1664

Claims (1)

-13 claim Circular process for the production of hydrogen peroxide, in which an / alkylanthraquinone, dissolved in an organic, water-immiscible solvent, is hydrogenated to the corresponding 2-alkylanthrahydroquinone, which is then subjected to oxidation by means of an oxygen-containing gas to form hydrogen peroxide, and the second to regenerate -Alkylanthrachinon, whereupon the hydrogen peroxide extracted, and the 2-alkyl-anthraquinone is recycled to the hydrogen! erungsstufe, characterized in that äxh 2-alkylanthraquinone 2-tert-amylanthraquinone used as, which is prepared by reacting tert-ParaJTalogen .-ainyln can be reacted with magnesium to the parahalide of tert-2-amylbenzene magnesium to form, which is condensed with phthalic anhydride to form the 2- (4-amylbenzoyl) benzoic acid, which is then subjected to cyclization by dehydration « 009849/1664 Blank page