DE1945750C - Process for the production of hydrogen peroxide - Google Patents

Description

The present invention relates to! a process for the production of hydrogen peroxide according to the so-called Anlhraquinone process using a new type of solution for the Working solutions containing reaction liquids.

In the process mentioned, a quinone derivative, the reaction agent, is usually first dissolved in a solvent, and the resulting "working solution" is then hydrogenated in the presence of a catalyst in such a way that about 50% of the quinone is converted into the corresponding hydroquinone. In the oxidation stage, the hydroquinone solution is treated with a suucrstoffhalligcn gas, the quinone is formed and at the same time hydrogen peroxide is formed, which is washed out of the organic phase (working solution) with water. While the working solution is returned to the hydrogenation stage, with which the cycle is closed and can run again, the aqueous extraction product (referred to as crude Π, Ο, designated) grooves in a concentration of about 15 to 35 percent by weight and is in the processes that have become known with organic Parts mostly so heavily contaminated (C-Gclialtc from K) O to 8 (X) mg C / l) that it has to be aftertreated and possibly concentrated before it is suitable for further reactions or can be sold. Both the processing of the raw H ₂ O ₂ into a highly concentrated commercial product of good quality and the purity of the working solution, with which, as will be shown later, the quality of the RoIi H ₂ O _{2 is} closely linked, causes expenses in the cycle process, whose costs are included in the calculation of the ΙΙ, Ο, total price with a percentage greater than 25.

For this reason, many process proposals have been made to improve the quality, to avoid degradation of the working solution or to keep the working solution clean. The procedural requirements made for this purpose in the patent literature can be divided into three groups according to the intended objective.

The first group combines the methods that propose to bring the RoIi-IIjO ₂ obtained in the extraction stage to a high degree of purity and a commercially available concentration by a wide variety of measures. Examples of such measures are

H> O ₂ purified polyethylene

"(German patent I 047 755), ΙΙ, Ο, -cleaning with anion custodians

ÜÜ 24 625

H> O _r cleaning with activated charcoal
"(German Auslogeselirill I ()% SK2),

1 IjOj cleaning with waxes
(German Aiislegeschrifl I HIKI ¹ M),

Η, Ο, -Rciiiigung and Aufkoii / cnliiening by Distillation (many godparents).

Despite the many proposals, it has not yet been possible to achieve a dilute H, O, in high purity or an H ₃ O ₂ -DeSIiIIaI with a successful C content at an economically justifiable expense.

In the broad group, the processes are summarized which proposed to use such working solution components in the cycle, which not only remain stable under the reaction conditions of the working solution after years of exposure to the working solution, but also have such a low solubility in water or in hydrogen peroxide, that with them the production of a high-quality RoIi-II ₂ O _{2 is} ensured. The technical solutions used in production plants, a selection of which is compiled in Table I, meet the requirements placed on them either inadequately or not so completely that improvements in the sense of the above objective are not desired.

Table I. / US ₁ InInH-I ₁ SCUIIIi ! in I ΟΜίιιμ-, ιιιιΙΙι / Ι III)! Γ I Vcilnniprti / dil
('hjnnnliiscr Viilinnpiii / i-iil
I ΙμΙιικΙπμοιιΙο.ιί in?>"ι, ιμι · ιη
Cow 11, (), DiiImIk ", I 'c I Composition of work solutions 75 polyalkylbenzene 25 Trioelvlphosphai UH h / v, Auskgcitlirifl 50 t-hulyltoluene 50 diisohulvl- 171 I 2 () l K3K Ucikih.iiMr.i ^ cr carbinol I II2O5I Athy laiilhrachinou 50 Trimel hy! Benzene 50 Melhylc \ clo- ! ¹ pp Amvlantlirachinone hexanolacel.it 953 790 40 methylnaphthalene 60 Diisobul)! - 205 Ath) lanlhraquinone carbinol KKK K40 t-Hutylanlhraquinone

As can be seen from measurements, the results of which were also included in Table I, the fresh working solutions used in the cycle cause the so-called "basic carbon value", which is derived from the solubility of the individual components in the _{RoH-H 2} O _{2 produced after about 20 cycles} the RoH-H ₂ O ₂ explained. The level of the basic carbon value is, among other things, a measure of the usefulness of a working solution and already indicates the difficulties to be expected in the work-up of the H ₂ O ₂ crude product.

With the steady circulation of the working solution, the amount of carbon-containing contaminants in the RoIi-H ₂ O is steadily increasing. and one then arrives at what is known as the total carbon dioxide noise. whose value can be 4mnl as high as the basic carbon value over a long period of time. The phenomenon is based on the fact that from the

^fi 5 individual components of the working solution breakdown products are formed which have a high solubility in the Ro) I-II ₂ O. The dismantling takes place z. It. In the oxidation stage of the cycle process, where the

A rheilslosuiigskoniponenleu are exposed to constant fumigation with a sulphurous gas mixture at elevated temperature, this statement applies to quinonioses previously known, which are suitable for a technical Rinsnl / . In this way, the following oxidation products arise in the cycle of the C'hinone dissolvers mentioned in Table I

I-hatvlioluene

Melhylnitphtluilin

Alkylbenzenes

I-bulylhenzoic acid,

Naphthol,

Alkylated Benzoic Acid !!.

Hei the llydioquinone solvers, to which one in particular Calculating alcohols and esters, the result is a similar one if the workload is constantly circulated HiUI: Alcohols are broken down oxidatively, and listers are saponified and danacii are broken down further. Among the esters, the phosphorous and phosphonic acid esters make therefore an exception, because they are relatively well saponified.

However, the breakdown products of the working solution not only have a detrimental effect on the quality of the produced Hydrogen peroxide, but cause disturbances in almost all stages of the process or undesirable losses in yield by the fact that they /. H. the productivities of those used in the cycle Catalysts and regeneration media reduce or important properties of the working solution (Viscosity, surface tension, interfacial tension. Density, distribution coefficient, etc.) negatively affect.

With the results summarized in the third group Verfiihrensvorschliigen therefore, trying to keep the Arheitslösung in the original Rcinheitszusiaiul and the degradation products continuously by / .. It.

additional water washing of the working solution.
Alkali washes of the working solution,
Aular notification of the work solution or
the use of adsorbents

to remove. However, up to now all known processes of groups I to 3 have not yielded in all cases satisfactory results, especially in comparison with the high technical and economic effort in the processing of the ΙΙ, Ο, raw product into a highly concentrated commercial product.

It has now been found that one is a kohlensioffa lousy resting hydrogen peroxide based on the anthraquinone method can produce the low initial C-value with long circulation of the Retains working solution and easily converts to a highly concentrated hydrogen peroxide! Laiulelsprodukt can be processed further, if there. ·. Solution mixture for the reaction carrier z.u. 5 to XS volume percent consists of l-butylbenzene and preferably at least 20 percent by volume of 1-butylbenzene contains.

An advantageous combination of solvents results .sich if one uses t-bulylben / ol as a quinone solvent and as Ilydroquinone dissolving phosphorus or phosphoric acid ester is used. The solvents mentioned represent the the most favorable combination for the preparation of the working solution containing the reaction carrier, there will be but also in existing systems significant improvements are achieved if one t-Biilvlbcnzol or the solvent combination according to the invention admixes the previously known operating solutions.

A working solution that contains the solution to the invention makes it possible to realize the requirements described above, which otherwise can only be achieved very carefully and in an economically expensive standard through the procedural suggestions of (! Sips I to i .

With the combination as described above, it succeeds the production of a lljOj raw product in high Concentration and purity without the need for special cleaning measures such as those in the first Group are listed.

ίο The first solution millel combination according to the invention is largely stable under circulatory conditions, so that the Ahbaiproduklbildung to very small values sinks; this keeps the effectiveness of the catalysts and regeneration agents used in the circuit longer line than before and the physical data of the application change only insignificantly. After all, the quality of the hydrogen peroxide produced remains unchanged, so that an application of the groups 2

«» And i summarized known procedural measures can be completely or largely dispensed with. The t-butylncnzene used according to the invention as a quinone solvent is a technically easily accessible starting product and is not attacked in the circuit even under extreme reaction conditions. This statement was confirmed by the results of the tests compiled in Example I.

Also the phosphoric (I I and phosphoric acid esters (II) of the following constitution

OR, / OP OR,

OR, OR,

O --- ■ P - R, OR.,

(H)

have become technically easily accessible products today. Esters in which R ₁ , R ₂ and R ₃ denote I or aryl groups are suitable. Esters with aliphatic radicals in which the total carbon number in the chains (R, IR, IR,! For total ('values below 12,

so the water solubility of the compound / u resent, whereby the Veilungskocllizienl becomes worse. on the other hand, with Gesaint-C-Werlen above 27, the density and viscosity of the lister increases so sharply. that these are less suitable for use in the anlhraquinone process. Preference is given, in particular, to aliphatic radicals which are either straight-chain or contain 1-HuIy! Groups.

The mixture of t-l) utylbenzene phosphoric acid or Phosphonsäuieesler can be relatively wide

f '° limits fluctuate when the named components in the Aibeilslösung represent the sole solvents. Then the idnuhinone solver part should (Phosphorus or Phosphonsäurceslei I LS bis 40 percent by volume and the quinone remover (I-Bul \ l-

'' 5 benzene) 60 to SS volume percent in the solvent mixture be. The exact setting of the mixing ratio is primarily based according to the desired capacity of the application

ιιικΙ ik'i · desired Konxcnlnilion the I I ₁ O ₂ -Cool products *. Misungsnijltulgcinist-Iiu are preferred. in which the quinone fraction is 70 to 80 percent by volume and the hydroehinone fraction is 20 to 10 percent by volume.

With work instructions that adhere to the fiduciary geniiille I, osuiiysmiltclgL'inisch, don't just raise high letters! _{I produce 2} Oj concentrations in H ₂ O ₂ raw material, but I produce highly concentrated II ₂ O _{2 quality ingredients which are equivalent to the usual H 2} O ₂ deslil alcn, which is burdened with a high technical and economic effort for the work-up. The quality of the H ₂ O ₂ coarse product obtained in the process remains almost unchanged (inch with long circulation of the medicinal solution.

As a Keiiklioiisiräger for
Work solution see
become C'hinonderiviile.

the speedy walls nlle bishei hekaiinl-

_s H e ί s ρ ie II

In one with a hegasiingsfiitle and a liilcusivrüekfliiük bad misgerlislelen Uegiisiiiigsiippiiriilur wind each I I of the various Chiiionlöser Hl O / Stiinde at a Teniperalui from NOC

ίο hegiisl. During the experiment were slid Samples were taken and the oxidation resistance was measured, among other things, by measuring the l'eroxide content achieved checked. After research, the Elevation of the dichotomy brought about by the Oi grip

ij of the solvent is determined. The ei with share values are based on table 2.

Table 2
Resistant to oxidation of various chinoilosers

l'hiiioiiliiscr

Methylnaphlhiiline

No. 4 in Table I.
Polyalkylbenzene

No. I in Table I.
t-bulyltoluene

No. 2 in Table I.
Trimethylbenzene

No. 3 in Table I.
I-butylbenzene

1 * 1 However it) ⁰ O l-Biiljlbcn ^ Dcsiiurc.

Maximum achievable croxiilgchall

after 1.5 hours 0.9% na.cli 4 hours 7.5% (*) after 48 hours 1.5% after 9 hours 8.5%, after 48 hours (). ()% Dichli

0.992
0.885
0.860
0.876
0.867

ties ('hiintiilOM'rs l)' i

muli HlIi.iruiluriu

after 20 hours 0.996
after 4 hours 0.903
according to 48SlUiKiCM 0.871
according to 9SlUMdCIi 0.896
after 48 hours 0.867

Table 2 shows the superiority of the compound quinone solvent l-butylbenzene Compared to the technically common quinone solvents with regard to the oxidation resistance.

Example 2

A working solution was prepared in which the solvent consisted of 80 percent by volume of i-butylbutyl and 20 percent by volume of trilithylhexylphosphate. In one liter of this solvent, 50 g of 2-ethylanthraquinone and 50 g of 2-ethylietrahydroanthraquinone were dissolved in each case. When the working solution was circulated, a raw H ₂ O _{2 was} obtained in the extraction run of the process which had an average H ₂ O ₂ content of 42 percent by weight. In the first weeks of the experiment the carbon content in this raw material was 75 mg C / l, then gradually increased to a value of 90 mg C / l and maintained this value - even after months of circulating the working solution. The H ₂ O ₂ crude product was brought to a concentration of 60 percent by weight by water absorption, in which the C contents were around KX) mg C / l. With the constant circulation of this working solution, the service life of the Pd hydrogenation cone used improved by about 55V, while the consumption of the aluminum oxide used for regeneration purposes from 1 kg for 40 kg Fts HjOj (see Example 4) to 1 kg door 80 kg H ₂ O ₂ fell. As a reference for the stand / citcn and the Λί, Ο, -consumption, the best line of the chemical solutions mentioned in Table I (Chiiionlöser: polyalkylbenzene) was chosen.

B e i s ρ i e I 3

A working solution was prepared in which the solvent consisted of 85 percent by volume of 1-uulylbenzene and 15 percent by volume of tri-n-uni) phosphate. In each liter of this solvent, 27 g of 2-ΛI Ii y km II inch in on and 63 g of 2-ethyl-octrahydroanthraquinone were dissolved. When the working solution was circulated, a 27% RoIi-H ₂ O, with a C content of 52 mg I, was obtained in the I-cooling run of the process. After 3 months of circulation, the C - (! Ehall increased to 75 mg / l and then remained constant.

Example 4

A working solution according to Example 2 was used in the circuit, but instead of 80 percent by volume of 1-butylbenzene, it contained 80 percent by volume of polyalkylbenzene as a quinone solvent. The polyalkylbenzene (boiling point at normal pressure 184 to 207 C) is a technical one, according to the Pia! forming- ProzclJ produced flavoring th gasoline, which is a mixture of at least 20 components. 1-Utilylben / ol is not detectable among these components

In the first weeks of the experiment the green coal history was in the produced, about -42 "

ΙΙ, Ο, crude extraction product an average of 94 mg Cl and then rose to a value of about 160 mg C / 1. which could be maintained even after months of maintenance of the working solution, if _{1 kg of AI 2} O was consumed _{to produce about 40 kg of H 2} Oj (calculated as 100% goods).

Example 5

Working solutions according to Example 2 were used in the circuit, which are common as quinone solvents Contained l-butylbenzene and polyalkylbeiizole. It was observed that

ti) the carbon content in the RoIi-Ii ₂ O _{2 produced increased} almost linearly to the extent that the poly-

alkylbenzene content increased, and
b) the Al ₂ O, -Crbrueh also increased almost linearly as the polyalkylbenzene content in the quinone solvent mixture increased.

Claims (5)

Patent claims: 1. Process for the production of hydrogen peroxide by the anthraquinone process which a quinone derivative hydrogenates alternately as a reaction carrier in a solution medium and is oxidized, characterized in that this solvent amounts to 5 to K5 consists of t-butylbenzene by volume. 2. The method according to claim I, characterized in that the solvent mixture at least Contains 20 percent by volume of t-butylbenzene. 3. The method according to claim 1 and 2. thereby characterized that the solvent mixture in addition to t-bulylbenzene phosphoric acid ester 1 and / or phosphoric acid ester H of the following constitution: O-R ₁
/
O = POR ₂ O - R ₃
0 - R ₁
O = PR ₂ O-R ₃ (Π) where R denotes aryl or alkyl groups and for the latter the carbon number from the sum R, + R ₂ + R _{3 is} between 12 and 27. 4. The method according to claim 1 to 3, characterized in that in the solvent mixture t-butylbenzene to 60 to 85 percent by volume - in particular 70 to 80 percent by volume - and Phosphoric acid esters to I 5 to 40 percent by volume, in particular to 20 to 30 percent by volume, contain is. 5. The method according to claim 1 to 4, characterized in that the phosphoric acid ester from Tri-n-amyl phosphate, tri-n-hydroxyl phosphate, tri-n-heptyl phosphate or consists of mixtures of the compounds mentioned. 109635/30!