DE1140908B - Process for cleaning aqueous hydrogen peroxide solutions - Google Patents

Description

The invention relates to the purification of aqueous hydrogen peroxide solutions which ionized contain inorganic and / or organic impurities.

It is known per se to purify hydrogen peroxide solutions by treatment with ion-exchanging substances. In the Austrian patent specification 167 414, for example, a method for cleaning hydrogen peroxide solutions is described, according to which these are treated ^{one after the other with cations and anions exchanging substances at temperatures preferably below 0 ° C.} The practically salt-free and acid-free hydrogen peroxide is obtained according to the following scheme:

(1) H ₂ SO ₄ + OH-- exchange material
= SO ₄ - exchange material + H ₂ O

(2) NaOH + H ⁺ exchange material
= Na - exchange material + H ₂ O

(3) NaCl + H ⁺ exchange material
= Na - exchange material + HCl

(4) HCl + OH- exchange material
= Cl - exchange material + H ₂ O

It is also known from British patent specification 695 325, heavy metal impurities from hydrogen peroxide solutions by treatment with an aromatic hydrocarbon cation exchange resin sulfonated in the core to remove at a pH of 0 to 3.6, the resin previously with a aqueous solution of a strong mineral acid has been washed.

According to a proposal not previously published, the treatment of the H ₂ O ₂ solution to be purified can also take place in a mixed bed which contains both anions and cation exchange resins. To achieve a favorable effect, however, it is necessary to work at relatively low temperatures of about 0 ° C., and in addition the amount of cation exchange resin used should preferably be five times as large as the equivalent amount of cationic impurities in the solution to be treated. The mixed bed must also be filled with pure, pre-cooled water until it is completely covered, and the exchangers activated. This process also has disadvantages insofar as the used exchange resins have to be regenerated in a special way, the anion exchanger possibly having to be additionally treated to prevent fatigue.

Method of cleaning
of aqueous hydrogen peroxide solutions

Applicant:

Laporte Chemicals Limited,
Luton, Bedfordshire (UK)

Representative: Dr. K. Schwarzhans, patent attorney,
Munich 19, Romanplatz 9

Claimed priority:

Great Britain dated September 19, 1956 and February 6, 1957 (No. 28 669 and No. 4101)

Reginald Henry Banfield

and Peter Norman Geoffrye Rayner,

Luton, Bedfordshire (UK),

have been named as inventors

According to the invention, aqueous hydrogen peroxide solutions can now be used without disruptive signs of decomposition and without special pretreatment measures even clean at room temperature if you use a mixed bed where the Ratio of the anion-exchanging sites to the cation-exchanging sites between 1.5: 1 and 1:10 and in which the anion exchange resin is in the hydroxyl or carbonate form. The cation-exchanging resin component, on the other hand, is in the hydrogen form.

In the exchange resins, the ratio of the number of cation-exchanging sites to the number of anion-exchanging sites is advantageously about 1: 1.
If the hydrogen peroxide is to be brought into continuous contact with this material, the exchange resin is preferably stacked in a column through which the hydrogen peroxide is passed at a flow rate which is high enough to avoid local decomposition of the hydrogen peroxide.

If the hydrogen peroxide is brought into contact with the exchange resin in batches, it is

209 747/304

It is advisable to use suitable means, such as constant stirring, to ensure constant movement.

The cation exchange resins remove positively charged ions, while anion exchange resins remove the negatively charged ions. With the mixed bed provided according to the invention, both cations and anions can thus be removed in one operation. Anion-exchanging resins normally lead to the decomposition of aqueous hydrogen peroxide solutions. But if the ratio of anion-exchanging constituents to cation-exchanging constituents is not greater than 1.5: 1, this disturbance is largely prevented. The new mode of operation according to the invention therefore offers significant procedural advantages. The process can also be carried out at temperatures above ⁰ ° C., and in practice the working temperature is room temperature.

The method of the invention can be used to purify hydrogen peroxide of any concentration be used.

When the process is carried out in practice, the mixture of exchange resins, which may optionally be used has been cleaned beforehand, simply stirred with the hydrogen peroxide solution, or after In another embodiment, a column can be filled with the exchange resins and the hydrogen peroxide are passed through the column, at one end of which the purified Product is withdrawn.

The hydrogen peroxide solution with a mixture of anion-exchanging and Cation-exchanging resins stirred, a separation of the resins from the hydrogen peroxide only occurs when the anion-exchanging resin is practically completely exhausted.

By the method according to the invention it is possible to work at normal temperatures without a There is a fear of decomposition of the hydrogen peroxide or damage to the ion exchange material must because there is always a large amount of hydrogen peroxide compared to the amount of resin and the temperature increase does not exceed 1 ° C.

In the case of the batch process in particular, it is expedient to leave the solution to be purified in contact with the mixture of exchange resins until the anion exchanger is practically exhausted. In this state, the exchange points are occupied by inert ions and no longer by hydroxyl ions. There is then no risk of the H ₂ O ₂ decomposing by the resin. The invention is explained in more detail below by means of examples:

Time in minutes Specific
conductivity
OhHr ¹ cm- ¹ Weight percent
H ₂ O ₂ 0
20th
35 5.1 · 10- *
8.5 × 10 ⁶
6.4 × 10 ⁶ 38.3
38.1

The agitator was then turned off, the resin allowed to settle, and 6.8 liters of solution were added upper drain discharged. There were again 6.821 fresh hydrogen peroxide solution (35.3 percent by weight) added and the stirrer turned on again. The results of the second step > 5 goods;

Time in minutes Specific
conductivity
OhHi ^-1 cm " ¹ Weight percent
H ₂ O ₂ 0
40 2.6 · 10- *
6.4 × 10 ⁶ 36.5
36.5

6.821 solution was again drawn off and 6.821 fresh solution (35 percent by weight) added. The results of the third step were:

Time in minutes Specific conductivity
OtInT ¹ Cm- ¹ 0
60 2.6 · 10- *
9.9 × 10 ⁶

The specific conductivity fell very slowly at the end of the third operation; it was therefore the entire batch is filtered off and the resin is washed with water. The resins were then separated separated and regenerated.

A specific conductivity of 6.4 × 10 ^-6 for 35gewichtsprozentiges hydrogen peroxide is a very high degree of purity.

Stability was measured by the rate of oxygen evolution in cubic centimeters per minute from a sample of 25 ecm, which was kept at 100 ° C. The improvement was quite considerable.

example 1

11,371 commercial, unstabilized hydrogen peroxide solution (38.3 percent by weight) was added to the reaction vessel, then stirring was started and a thermometer was started as well a conductivity cell is used. There were 92 g of a strongly acidic cation exchanger and 184 g a strongly basic anion exchanger, both in pearl form and made of a polystyrene resin, added. The ratio of anion exchange sites to cation exchange sites was 0.8: 1. The specific conductivity, which was determined in time intervals, showed when the Cleaning was finished.

Specific
conductivity Speed of oxygen
development; ccm / muute;
25 cc sample at 100 ° C 2.6 · 10- *
6.4 × 10 ⁶ 2.0
0.06

55

Example 2

Hydrogen peroxide (about 30 percent by weight), which was heavily contaminated with seawater and a Had a chloride content of 400 mg / 1, was purified by a similar treatment as in Example 1: 9.091 solution with 90 g of cation exchange resin and 180 g of anion exchange resin were mixed. The ratio of anion exchange sites to cation exchange sites was 0.8: 1.

Time
in Specific
conductivity temperature Remarks Minutes OhITT ¹ CnT ^{1 0} C 0 1.1 · ΙΟ- ³ 19th Cl: 400 mg / l 5 0.5 × 10 ^-3 19.5 15th 0.2 ΙΟ- ³ 20th ■ 25 0.09 · ΙΟ- ³ 20th 30th 0.67 10- * 20th 40 0.4 · 10- * 20th Cl: traces 53 2.7 × 10 ^-5 20th Cl: low traces

4.55 l of solution were drained off and a further 4.75 l of untreated solution were added. The specific conductivity rose again to a value of 0.4 • ΙΟ " ³ and remained at this level. The resin was separated off, regenerated and replaced when the operation was continued.

Example 4

A column of 7 cm in diameter and 10 cm in length was with 250 g of a cation and Anion exchange resins existing, commercially available mixture filled. The ratio of Anion exchange sites to the cation exchange sites was 0.66: 1.

11 a strong hydrogen peroxide solution with ίο a lot of impurities, their original concentration 74 percent by weight hydrogen peroxide was diluted with distilled water to about 40 percent by weight Hydrogen peroxide and diluted from above through said column at one rate of 15 cc / minute passed through. No decomposition whatsoever was observed in the column and the eluate was - disregarded of the fractions which contained the volume of water taken up - improved as follows been:

Time
in
Minutes Specific
conductivity
OhIiT ¹ CnT ¹ temperature
⁰ C Remarks to> -
O O Ui O 0.4 x ³ ΙΟ-
0.3 x ³ ΙΟ-
1.0 · 10 ~ *
2.0 x 10- ⁵ 25th
25th
25th
25th free of Cl

4.551 of the H ₂ O ₂ solution were drawn off and another 5.551 of the fresh solution was added.

35

Time
in Specific
conductivity temperature Remarks Minutes OhIrT ¹ CnT ^{1 0} C 0 0.4 · ΙΟ " ³ 24 Cl: 200 mg / l 11 1.0 · 10- * 24 14th 0.65 10- * 24 18th 0.5 ■ 10- * 24 28 0.36 10- * 24 66 2.3 · ΙΟ- ⁵ 24 97 2.2 ΙΟ- ⁵ 24 free of Cl

Before the
treatment After
treatment Ammonia, in the form of
NH ₄ ⁺ , weight percent 0.1483 2.8 ■ 10- * Sulphate in the form of SO ₄ ,
Weight percent 0.4832 2.9 10- * Phosphate calculated as
P ₂ O ₅ , weight percent 0.1163 56.0 10- * H ₂ O ₂ concentration, Ge
weight percent 43.12 42.97 PH of the solution 3.2 2.6

Example 5

The resin was now apparently exhausted and it was separated and successfully regenerated. at these treatments should not achieve a high degree of purity, but freedom from chloride, what was achieved at a slightly higher conductivity value, possibly a certain Selectivity of the resin is attributable.

Example 3

11 of 83 weight percent hydrogen peroxide was treated in a manner similar to that in Example 1 with 1 g of cation exchange resin and 2 g of anion exchange resin. The ratio of the anion-exchange sites on the cation-exchange sites was 0.8: 1. The specific Leitfähigleit was of 1 × 10 ^-5 reduced to 2.3 x 10- ^{6 1} OhHi- CIN ^1, which corresponds to a very high degree of purity . The anionic resin was practically exhausted thereafter, but the separation could be carried out without difficulty. The time required to carry out this final cleaning was about 1 hour, and the otherwise very troublesome distillation was saved.

179 g of a cation exchange resin in its hydrogen form and 358 g of an anion exchange resin in its hydroxyl form were mixed together to form a column 6 cm in diameter and 24 cm in length. The ratio of anion-exchanging sites to cation-exchanging sites Digits was 0.8: 1.

9.09 135 weight percent technical hydrogen peroxide were passed through this column at a rate of 4.55 l / hour. At the beginning of the treatment, a water jet vacuum pump was attached to the lower end of the column connected to facilitate the flow of the hydrogen peroxide solution. In time intervals the specific conductivity was measured; this gives an exact measure of the purity.

55

-5 60 Before treatment

After the treatment <.

Specific conductivity OhIiT ¹ CIrT ¹

7.3

5.06
6.4
6.8
8.5

10- * 10- ⁶

ίο- ⁶

10- ⁶ 10- ⁶

Time

in

Minutes

30th

60

90

120

There was no change in the concentration of the hydrogen peroxide solution during the treatment on. The small increase in specific conductivity

however, after one hour of treatment, it shows that the column packing is gradually being exhausted.

Example 6

A column 3 cm in diameter and 20 cm in length was filled with 140 g of a mixed exchange resin filled, which was prepared according to the information in Example 5. The ratio of anions exchanging Cation-exchanging sites was 0.8: 1. To an 80 percent by weight hydrogen peroxide solution, which have been diluted with distilled water to 50 percent by weight hydrogen peroxide 1 g of sodium chloride per liter was added. 250 ecm of this solution were given by the said Column from top to bottom at a speed of 50 ccm / min. passed through. On the ground a water jet pump was connected to the column for this purpose. After the silver nitrate test all chloride present was removed.

The above procedure was repeated using 61 of a 35- bis 40 weight percent hydrogen peroxide solution, which in turn contained 1 g / l sodium chloride. The hydrogen peroxide was going through a top down at a rate of 11 per 10 minutes Column 6 cm in diameter and 30 cm in length passed through, which contained 567 g of the mixed exchange resin, which had been prepared according to Example 5 contained. Here too, the silver nitrate sample was used found that all of the chloride present had been removed.

Example 7

271 g of an exchange resin mixture which contained 1 part by weight of a cation exchanger in its hydrogen form and 2 parts by weight of an anion exchanger in its hydroxyl form were added to 11.37 l of 35% by weight hydrogen peroxide in the course of treating a single batch. The ratio of anion exchange sites to cation exchange sites was 0.8: 1. The specific conductivity was measured; it following values were obtained: batch treatment at 21 a 85% ^en hydrogen peroxide, which was diluted to about 45%, is added. The ratio of anion exchange sites to cation exchange sites was 0.32: 1. The entire mixture was ^{stirred at 23 °} C. for 1 hour. The values for the specific conductivity were as follows:

Specific conductivity
OhHT ¹ cm "" ¹ Time in minutes 183.0 · ΙΟ- ⁶
7.33 · 10- ⁶
6.93 · 10- ⁶ 0
30th
60

This example shows that the carbonate form is useful in removing contaminants from hydrogen peroxide is as effective as the hydroxyl form.

Example 9

A bed of mixed resin containing 40 grams of the cation exchanger in its hydrogen form and 40 grams of the Aninonexauschers contained in its hydroxyl form, was in a batch treatment of 21 of an 85 weight percent hydrogen peroxide is used, which is diluted to about 43 weight percent and to which about 5 ecm of glacial acetic acid had been added. The ratio of anions exchanging Cation exchange sites was 0.4: 1. The total mixture was Stirred at 23.5 ° C. for 1 hour. The values for the specific conductivity were as follows:

Specific conductivity
ObWT ¹ CTiF ¹ Time in minutes 158 · 10- ⁶
10.36 ΙΟ- ⁶ 0
60

Specific conductivity
OhIrT ¹ cm- ¹ Time in minutes 6.4 · IO- ⁴
6.4 × 10 ⁶ 0
30th

45

Then 4.55 l of the solution were separated off and 4.551 of an untreated hydrogen peroxide solution newly added. The values for the specific conductivity then achieved were:

Example 10

A resin mixture containing 40 g of the cation exchanger in its hydrogen form and 40 g of the Containing anion exchanger in its hydroxyl form, was in a batch treatment of 21 of an 85 weight percent hydrogen peroxide diluted to about 43 weight percent and to which about 12 ecm of pyridine had been added. The whole mixture was at one Stirred temperature of 23.5 ° C for 1 hour. The values for the conductivity are given below:

Specific conductivity
OhIiT ¹ CnT ¹ Time in minutes 2.56 · IO- ⁵
6.9 -ΙΟ- ⁶ 0
75

55

60

Specific conductivity
0ImT ¹ CnT ¹ Time in minutes 9.26 · IO- ⁴
10.91 · ΙΟ " ⁶
8.14 · ΙΟ- ⁶ 0
30th
60

A motor and a glass stirrer were used to stir continuously.

Example 8

80 g of an anion exchange resin in the carbonate form and 100 g of a cation exchange resin in its hydrogen form were The next table shows the results of experiments which have been carried out to show the decomposition of hydrogen peroxide when it using resin beds with different proportions between the anion exchangers and cation exchangers is cleaned. A single-functional one was used as the cation exchanger sulfonated polystyrene resin in pearl form and as

Anion exchanger, a monofunctional resin with amino groups, also in bead form, was used. The ratio of the number of exchanging sites in 1 part by weight of the cation exchanger to the number of exchanging sites in the same weight of the anion exchanger is 5: 2. the The way of working in the experiment was that

10

g of the mixed resin were added to 21 of an 85% by weight hydrogen peroxide, which had been diluted to about 46% by weight, and that the entire mixture was ^{stirred for 1 hour at 23 °} C., samples of the solution being taken at the beginning of the experiment and after 1 hour were examined for their concentration.

Ratio of anions
exchanging positions to the 1 Weight percent Weight percent Weight loss percent ⁰ I ₀ anion resin Cation exchanging 1 H ₂ O ₂ H ₂ O ₂ H ₂ O ₂ Place 1 at the beginning after 1 hour after 1 hour 0.00 1 46.21 45.95 0.26. 20.00 0.1 1 46.53 46.28 0.25 33.33 0.2 1 46.34 46.20 0.14 42.86 0.3 1 46.32 46.35 0.00 63.64 0.7 47.00 46.32 0.68 77.78 1.4 47.45 46.50 0.95 81.82 1.8 48.05 45.95 2.10 87.50 2.8 47.95 46.00 1.95 100.00 55.3 50.00 5.30

Claims (5)

PATENT CLAIMS: 1. A method for cleaning aqueous, ionized inorganic and / or organic impurities containing hydrogen peroxide solution with anion and cation exchange resins in the embedding system, characterized in that the ratio of the anions exchanging to the cation exchanging sites is between 1.5: 1 and 1:10 and that the anion exchange resin is in the hydroxyl or carbonate form. 2. The method according to claim 1, characterized in that the ratio of the anions exchanging to the cation-exchanging sites is 1: 1. 3. The method according to claim 1 and 2, characterized in that the cleaning process is continuous is carried out, the flow rate of the hydrogen peroxide solution being sufficient is high in order to avoid local decomposition. 4. The method according to claim 1 and 2, characterized in that the method under constant Stirring is carried out intermittently and that the exchange resins only after practically complete Exhaustion of the anion exchanger can be separated from the hydrogen peroxide solution. 5. The method according to claim 1 to 4, characterized in that it is carried out at room temperature will. Legacy Patents Considered:
German Patent No. 1 006 402. © 209 747/304 12.62