JP2000239006A - Activated alumina compact for production of hydrogen peroxide, its production, and purification of operating liquid for production of hydrogen peroxide by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an activated alumina compact for production of hydrogen peroxide having the same or more initial removing ability for removing an epoxide from an operating liquid, and a longer life for sufficient removal compared to the conventional one, and further to provide a production method thereof, and a method for purifying the operating liquid for the production of the hydrogen peroxide by using the same. SOLUTION: This activated alumina compact for production of hydrogen peroxide has >=0.5 mm and <2.0 mm average particle diameter, >=250 m2/g BET specific surface area, and 0.01-15 wt.% SiO2 concentration. The alumina compact is usable for removing an epoxide from a solution containing an anthraquinone compound in the process of producing the hydrogen peroxide by the oxidation and reduction of the anthraquinone compound. The method for producing the activated alumina compact for the production of the hydrogen peroxide comprises compacting activated alumina powder having rehydration, and 0.5-1.2 g/cm3 bulk density, rehydrating the obtained compact, and baking the rehydrated compact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an activated alumina compact for producing hydrogen peroxide and a method for producing the same. More specifically, the present invention relates to an activated alumina molded body for producing hydrogen peroxide used for removing epoxide from a solution containing an anthraquinone compound in a process for producing hydrogen peroxide by redox of an anthraquinone compound, and a method for producing the same.

[0002]

2. Description of the Related Art As a conventionally known method for producing hydrogen peroxide, there is a method utilizing an anthraquinone compound such as an alkylanthraquinone. In the production method, the above-mentioned compound or the like is dissolved in a solvent to obtain a solution containing an anthraquinone compound (referred to as an operation liquid). Turn into a body. Thereafter, in the oxidation step, hydrogen peroxide is generated by converting the anthraquinone compound into a quinone compound. The generated hydrogen peroxide is separated from the working fluid by a method such as water extraction. On the other hand, the remaining working fluid is circulated again to the reduction step. In this way, anthraquinone compounds are repeatedly redox-reduced, but it is known that epoxides and the like are produced as by-products in the reaction process. The epoxide is a compound in which an oxygen atom is bridged between two carbon atoms adjacent to a carbonyl group of anthraquinone. The accumulation of epoxide as an impurity in the working fluid reduces the yield of hydrogen peroxide, so the epoxide concentration must be kept as low as possible. As a method of removing epoxide from working fluid,
A method using activated alumina is known.

[0003]

However, when activated alumina used as a catalyst carrier or an adsorbent is applied, although some performance can be obtained at the initial stage of filling, the performance is easily deteriorated and the life is short. Therefore, it was necessary to replace them in a short period of time.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve such problems, and as a result, the initial removal performance for removing epoxide from the working fluid is equal to or higher than that of the working fluid. The present inventors have found an activated alumina molded body having a long service life that can be easily removed, and have completed the present invention. That is, in the present invention, (1) the average particle diameter is 0.5 mm or more and less than 2.0 mm, the BET specific surface area is 250 m ² / g or more, and the SiO ₂ concentration is 0.01% by weight to 15% by weight. In the process of producing hydrogen peroxide by redox of an anthraquinone compound, characterized in that it is an active alumina molded body for producing hydrogen peroxide used for removing epoxide from a solution containing an anthraquinone compound,

(2) The average particle diameter is 0.5 mm or more and 2.0
mm, a BET specific surface area of 250 m ² / g or more, a SiO ₂ concentration of 0.01 wt% to 15 wt%, and a water content of 0.5 wt% to 10 wt%. In a process for producing hydrogen peroxide by redox of an anthraquinone compound, an activated alumina molded body for producing hydrogen peroxide used for removing epoxide from a solution containing an anthraquinone compound,

(3) It has rehydration properties and has a bulk density of 0.1.
The activity for producing hydrogen peroxide according to (1) or (2), wherein activated alumina powder having a weight of 5 g / cm ^{3 to} 1.2 g / cm ³ g is molded, rehydrated, and fired. A method for producing an alumina molded body,

(4) In a process for producing hydrogen peroxide by oxidation-reduction of an anthraquinone compound, the working liquid is space-filled on a bed filled with the activated alumina molded article for producing hydrogen peroxide according to (1) or (2). A method for purifying a working fluid for producing hydrogen peroxide, comprising removing epoxide by passing the solution at a rate of 0.5 to 50 h ^-1 .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The activated alumina compact for producing hydrogen peroxide of the present invention has an average particle diameter of 0.5 mm or more and less than 2.0 mm, and a BET
The specific surface area is 250 m ² / g or more, and the SiO ₂ concentration is 0.01% by weight to 15% by weight.

The average particle size of the activated alumina molded article for producing hydrogen peroxide of the present invention is 0.5 mm or more and less than 2.0 mm,
Preferably it is 1.0 mm or more and 1.8 mm or less. When the average particle diameter is 2.0 mm or more, the deterioration of the removal performance is accelerated. If the average particle size is less than 0.5 mm, the resistance during passage through a column or the like increases, and sufficient removal performance cannot be obtained. The particle size distribution may be the same as that of activated alumina powder used in general industrial use, that is, the ratio of 90% diameter to 10% diameter is about 1.1 to about 2.

[0010] BET specific surface area of the hydrogen peroxide produced for the activated alumina formed body, 250 meters ² / g or more, preferably 300m ² / g~400m ² / g. If the BET specific surface area is lower than the above lower limit, the initial removal activity will be low.

The activated alumina molded body for producing hydrogen peroxide has a SiO ₂ concentration of 0.01 to 15% by weight, preferably 1 to 10% by weight. If the SiO ₂ concentration is less than 0.01% by weight, the initial removal performance will be low. When the amount is more than 15% by weight, although the removal performance is obtained, the strength of the activated alumina molded body tends to decrease.

The activated alumina molded article for producing hydrogen peroxide of the present invention can suppress the heat generation when the working liquid is first passed through the bed filled with the activated alumina molded article. % To about 10% by weight. When the water content is less than about 0.5% by weight, there is no effect of suppressing heat generation, and when the water content is more than about 10% by weight, water may be desorbed to contaminate the working fluid. In addition, it is recommended that the active alumina molded body for producing hydrogen peroxide has Na ₂ O of about 1% or less, preferably about 0.5% or less, since the purity of the product hydrogen peroxide and coloration of the product can be prevented. You.

In order to purify the working liquid using the activated alumina molded article for producing hydrogen peroxide of the present invention, for example, the working liquid is passed through a bed filled with the activated alumina molded article for producing hydrogen peroxide. In order to continuously remove epoxide in the working fluid for a long time, a temperature of about 50 ° C. to about 100 ° C.
C. and a space velocity of 0.5 to 50 h ^-1 are preferred. Also, non-rehydrating alumina such as α-alumina, aluminum salt, silica, talc, cordierite, titania,
It may be used by mixing with an inorganic compound such as an alkaline earth salt, a rare earth metal salt, zirconia, mullite, silica alumina, and ceramic fiber. When a compound other than an oxide is added, it is necessary to calcine the compound at a decomposition temperature or higher before use. As other conditions, the same conditions as those of the working liquid refining step in the usually performed hydrogen peroxide production process can be applied.

The process for producing an activated alumina compact for producing hydrogen peroxide according to the present invention has rehydration properties and a bulk density of 0.1.
It is characterized in that activated alumina powder of 5 g / cm ^{3 to} 1.2 g / cm ³ g is molded, rehydrated, and fired.

The activated alumina powder used in the production method has rehydration properties and has a bulk density of 0.5 g / cm ³ to 0.5 g / cm ³ .
What is necessary is just 1.2 g / cm < ³ >, and a well-known thing can be applied. The bulk density of the activated alumina powder is 0.5 g / cm ³
If it is smaller, molding becomes difficult, and the activated alumina molded article for producing hydrogen peroxide of the present invention cannot be obtained. When the bulk density is more than 1.2 g / cm ³ , the activated alumina molded body having high removal performance cannot be obtained, although the reason is not clear. Specific examples of the rehydratable activated alumina powder include alumina whose crystal form is at least one selected from the group consisting of χ, ρ, γ, and η.

As a method for obtaining the activated alumina powder, for example, a method of calcining gibbsite-type aluminum hydroxide (hereinafter sometimes referred to as a gibbsite calcining method), a method of neutralizing an aluminum salt and forming a gel. Of aluminum hydroxide, calcining, neutralizing aluminum salt to obtain alumina sol, calcining, hydrolyzing organic aluminum compounds to obtain gelled aluminum hydroxide, calcining, etc. There is. Among these methods, the gibbsite calcination method is recommended from the viewpoint of obtaining a high-strength molded article and economical efficiency. As a specific example, the average particle diameter obtained in the buyer step or the like is 0.1 to 200 μm
Aluminum hydroxide at a temperature of about 500 ° C. to about 12 ° C.
There is a method of contacting in an air stream at 00 ° C. and a linear velocity of about 5 m to about 50 m for about 0.1 second to about 10 seconds (flash calcination method).

The activated alumina powder generally has a loss on ignition of about 3% by weight to about 10% by weight and an average particle size of about 1 μm to about 20 μm, preferably about 3 μm to 10 μm.
m and the SiO ₂ content is about 0.01% to about 15% by weight.
And Na ₂ O is less than about 1% by weight, preferably 0.5% by weight.
% By weight or less. When the average particle diameter of the activated alumina powder exceeds about 20 μm, it is preferable to carry out pulverization in order to facilitate molding and increase the strength of the activated alumina compact. When Na ₂ O of the activated alumina powder is higher than about 1% by weight, the obtained activated alumina molded body tends to have a high Na ₂ O, which may cause a reduction in purity and coloring of the hydrogen peroxide product. If necessary, a silicon-containing substance may be added to aluminum hydroxide or a rehydratable activated alumina powder so that the SiO ₂ content of the obtained activated alumina molded body is about 0.01% to about 15% by weight. It may be added. The silicon-containing substance is, for example, silica powder or silica alumina powder, and preferably has an acid point of H0-5.6 or less.

In the production method of the present invention, for example, dish-shaped granulation, extrusion molding, compression molding, flow molding, crushing molding and the like can be applied. In particular, dish granulation, extrusion molding, and crushing molding are recommended. The shape is not particularly limited, spherical, cylindrical, ring, plate, honeycomb,
It may be in any form such as lump or crushed. In the case of dish-type granulation, it is particularly effective to add granulation nuclei together with activated alumina powder and water in order to reduce the particle size distribution of the obtained activated alumina compact. As the granulation nucleus, small particles of activated alumina, crushed products by-produced during the production of an activated alumina molded body, and the like can be used.

The rehydration can be carried out, for example, by a method in which the rehydration is carried out in steam at room temperature to about 200 ° C., preferably about 50 ° C. to about 150 ° C. or in a steam-containing gas for about 10 minutes to 1 week.

The firing is performed, for example, at a temperature of about 200 ° C. to about 50 ° C.
The heating may be performed at 0 ° C. for a time within the range of about 10 minutes to about 100 hours. Examples of the firing apparatus include a box-type electric furnace, a tunnel furnace, a far-infrared firing machine, a microwave heater, a ventilation firing apparatus, a shaft furnace, and a reflection furnace. Furnace etc. can be applied. In order to uniformly bake the rehydrated activated alumina molded body, a method in which the activated alumina molded body is thinly spread on a sheath and fired, and a method in which contact with a heated gas is enhanced are recommended.

[0021] In preparing the hydrogen peroxide manufacturing activated alumina formed body of the present invention, first, a re-hydration, and the bulk density is 0.5g / cm ³ ~1.2g / cm ³ Water and granulation nuclei are added to the activated alumina powder, and a molded body is obtained by a dish-type granulator or the like.Then, the obtained molded body is placed in a container with a lid, and the molded body is rehydrated with steam or the like. Next, the rehydrated molded body is sieved and then fired in a box-type electric furnace or the like to obtain an activated alumina molded body. Further, as a method for adjusting the water content of the activated alumina compact to about 0.5% by weight to about 10% by weight, there is a method of contacting with a humidified gas or / and water after firing. Specific examples include a method of supplying moist air to the fired activated alumina molded body, and a method of spraying a predetermined amount of water with a spray. Further, as a method of increasing the pore volume of the activated alumina molded body, for example, a method of reducing the particle size distribution of the activated alumina powder to be used, a method of lowering the processing temperature at the time of rehydration, stearic acid at the time of rehydration, etc. Examples thereof include a method of adding, a method of shortening the treatment time at the time of rehydration, a method of adding an organic pore former at the time of molding, and a method of combining them.
The obtained activated alumina compact may be used after further sieving and / or sorting.

The activated alumina molded article obtained by the production method of the present invention has an average particle diameter of 0.5 mm or more and 2.0 mm or more.
Less, preferably not less than 1.0mm 1.8mm or less, BET specific surface area of 250 meters ² / g or more, preferably from ^{300m 2 / g~400m 2 / g,} SiO 2 concentration of 0.01% to 15 % By weight, preferably 1% by weight to 1%
It is 0% by weight, and can be suitably used for removing epoxide from a solution containing an anthraquinone compound in a process for producing hydrogen peroxide by redox of an anthraquinone compound.

The activated alumina molded article obtained by the production method of the present invention usually has a packing density of 0.5 g / cm.
^{3 ~1.0g / cm 3, 0.1%} ~2.0% wear rate, pressure resistance 1Kg～20kg, more pore volume radius 10Å is 0.1cm ³ / g~1cm ³ / g, the radius 250Å or more of the pore volume is 0.01cm ³ /g~0.2cm ³ / g.

[0024]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

Physical Properties of Activated Alumina Powder Average Particle Diameter (μm): Laser Scattering Type Particle Size Distribution Analyzer [LEED & NORTHHR
UP), a 50% by weight diameter was measured. Loss on ignition (%): 2 g of activated alumina powder is placed in a platinum crucible and heated at 1100 ° C. for 2 hours. Weight loss during heating Δ
The burning loss (= Δw / 2 × 100) was determined from w. Bulk density (g / cm ³ ): 100 g of activated alumina powder is put in a 200 cm ³ cylinder, and the cylinder is 30 mm
From the height of 100 times repeatedly. The bulk density (= 100 / V) was determined from the volume V of the activated alumina powder. Crystal form: measured by X-ray diffraction method.

Physical Properties of Activated Alumina Molded Body Average Particle Diameter (μm): A 50% by weight diameter was determined by a sieving method. BET specific surface area (m ² / g): Measured by a nitrogen adsorption method. SiO ₂ (%): Measured according to JIS H1901. Na ₂ O (%): Measured according to JIS H1901. Moisture (%): Calculated from weight loss when heated at 200 ° C. Packing density (g / cm ³ ): Activated alumina molded body 100
Put the g to 200cm ³ cylinder, 30 cylinder
It was repeatedly dropped 100 times from a height of mm. The packing density (= 100 / V) was determined from the volume V of the activated alumina compact. Wear rate (%): Measured according to JIS-K1464. Compressive strength (kg): The breaking strength of ten samples was measured by a strength tester, and the average strength was determined. Pore volume (cm ³ / g): Measured by the Hg intrusion method (manufactured by Cantachrome, Autoscan 33, porosimeter).

Initial removal performance (%): 180 g of the activated alumina compact was added to 600 g of the hydrogen peroxide plant working solution after the reduction step, and the mixture was contacted for 6 hours while stirring at 200 rpm in a heated state. . The epoxide concentration in the liquid before and after the contact was measured by gas chromatography.
(Initial solution concentration—concentration after 6 hours) / initial solution concentration was defined as the removal performance (%).

200 hours removal performance (%): 30 ml of the activated alumina compact was packed in a jacketed glass column for heating. The liquid after the reduction step of the working liquid of the hydrogen peroxide plant was passed at SV 0.6 h ^-1 , and the concentration of epoxide at the inlet and the concentration of epoxide at the outlet of the column were measured by gas chromatography. The removal performance (%) was defined as (inlet epoxide concentration-outlet epoxide concentration) / inlet epoxide concentration, and the change over time in the removal performance was examined. The removal performance after passing for 200 hours was defined as the removal performance for 200 hours.

Temperature at the start of liquid passing (° C.): After 180 g of the activated alumina compact was placed in a thermos bottle, 600 g of the hydrogen peroxide plant working liquid after the oxidation step was added and the temperature change was examined. The maximum temperature was defined as the temperature (° C.) at the start of the liquid supply.

Example 1 Gibbsite (aluminum hydroxide, containing 0.02% of SiO _{2 with} respect to Al ₂ O ₃ ) obtained by the Bayer method was charged into a heating gas at about 700 ° C., and then calcined instantaneously. A hydratable activated alumina powder (having a loss on ignition of 6%, an average particle size of 8 μm, a bulk density of 0.7 g / cm ³ and crystal forms of χ and ρ alumina) was obtained. Was.

About 0.7 kg of water and about 0.15 kg of a granulation nucleus (activated alumina) having a diameter of 0.4 to 1.4 mm are added to 1 kg of the activated alumina powder, and a diameter of about 0.15 kg is added by a dish granulator. A 1-2 mm spherical molded body was obtained. The spherical molded body was placed in a lidded container, sealed, and kept at a temperature of 80 ° C. for 16 hours to partially rehydrate. Next, after the rehydrated spherical compact was sieved, the compact was placed in an electric furnace, heated to 400 ° C. and maintained for 2 hours to obtain an activated alumina compact.
The yield with a particle size of 1.18 to 2.36 mm was 85%.

The activated alumina compact has an average particle size of 1.5
mm, BET specific surface area 347 m ² / g, SiO ₂ 0.0
2% Na ₂ O 0.27% water 0% packing density 0.
67 g / cm ³ , wear rate 0.2%, compressive strength 2 kg, pore volume with a radius of 10 ° or more 0.60 cm ³ / g, radius 25
The pore volume of 0 ° or more was 0.16 cm ³ / g. The 200-hour removal performance of the activated alumina molded body was 40%.

Example 2 Gibbsite obtained by the Bayer method was poured into a heated gas at about 700 ° C. and calcined instantaneously to be rehydrated. An activated alumina powder (having a loss on ignition of 6% and having an average particle diameter of 6%) Is 15μ
m and the bulk density was 1.0 g / cm ³ . ) Got.

About 1 kg of the activated alumina powder, about 0.5 kg of water and about 0.15 kg of a granulation nucleus (activated alumina) having a diameter of 0.4 to 1.4 mm are added, and the diameter of the granulated powder is adjusted by a dish granulator. A 1-2 mm spherical molded body was obtained. The spherical molded body was placed in a lidded container, sealed, and kept at a temperature of 80 ° C. for 16 hours to partially rehydrate. Next, after the rehydrated spherical compact was sieved, the compact was placed in an electric furnace, heated to 400 ° C. and maintained for 2 hours to obtain an activated alumina compact.
The yield with a particle size of 1.18 to 2.36 mm was 80%.

The activated alumina compact has an average particle size of 1.6.
mm, BET specific surface area is 323 m ² / g, SiO ₂
02%, Na ₂ O 0.27%, moisture 0%, packing density 0.78 g / cm ³ , wear rate 0.8%, pressure resistance 5k
g, pore volume with a radius of 10 ° or more was 0.48 cm ³ / g, and pore volume with a radius of 250 ° or more was 0.08 cm ³ / g. The activated alumina molded body has an initial removal performance of 28%, 2
The 00 hour removal performance was 30%. The temperature at the start of the liquid passing was 80 ° C.

Example 3 A commercial silica alumina powder (SiO ₂ content of 15 kg) was added to 1 kg of the same rehydratable activated alumina powder as in Example 1.
%, The strongest acid point was H0-5.6, and the total acid amount was 0.14 mmol / g). Next, about 0.7 kg of water and about 0.15 kg of granulation nuclei (activated alumina) having a diameter of 0.4 to 1.4 mm are added to 1 kg of the mixed powder, and the diameter of about 1 to 1 kg is added by a dish granulator. A 2 mm spherical molded body was obtained. The spherical molded body was placed in a lidded container, sealed, and kept at a temperature of 80 ° C. for 16 hours to partially rehydrate. Next, after the rehydrated spherical compact was sieved, the compact was placed in an electric furnace, heated to 400 ° C. and maintained for 2 hours to obtain an activated alumina compact. The yield with a particle size of 1.18 to 2.36 mm was 80%.

The activated alumina compact had an average particle size of 1.5
mm, BET specific surface area 271 m ² / g, SiO ₂ 3%,
Na ₂ O 0.35% water content 0%, the packing density 0.68g
/ Cm ³ , wear rate 0.6%, pressure resistance 1kg, radius 10
Å or more pore volume 0.15 cm ³ / g, were radius 250Å or more pore volume 0.15 cm ³ / g. The initial removal performance of the activated alumina compact was 90%.

Example 4 500 g of the activated alumina molded body of Example 2 was spread in a metal vat, and the weight change was measured while flowing air having a relative humidity of 90% over the metal vat. Humidification was stopped when it reached 523 g. The water content of the obtained activated alumina compact was 3.
8%. The 200-hour removal performance of the activated alumina molded body was 33%, and the temperature at the start of liquid passage was 55 ° C.

Comparative Example 1 Gibbsite obtained by the Bayer method was charged into a heated gas at about 700 ° C. and calcined instantaneously to be rehydrated. An activated alumina powder (loss on ignition was 6%, average particle size Is 14μ
m, and the bulk density was 1.4 g / cm ³ . ) Got.

About 1 kg of the activated alumina powder, about 0.5 kg of water and about 0.15 kg of a granulation nucleus (activated alumina) having a diameter of 1.2 to 2.4 mm are added, and the diameter of the granulated powder is adjusted by a dish granulator. A 2-5 mm spherical compact was obtained. The spherical molded body was placed in a lidded container, sealed, and kept at a temperature of 80 ° C. for 16 hours to partially rehydrate. Next, after the rehydrated spherical compact was sieved, the compact was placed in an electric furnace, heated to 400 ° C. and maintained for 2 hours to obtain an activated alumina compact.
The yield with a particle size of 2.36 to 4.75 mm was 92%.

The activated alumina compact had an average particle size of 3.5.
mm, BET specific surface area 285 m ² / g, SiO ₂ 0.0
2% Na ₂ O 0.32% water 0% packing density 0.
84 g / cm ³ , wear rate 0.2%, pressure resistance 20 kg,
Pore volume 0.35 cm ³ / g with a radius of 10 ° or more, radius 2
The pore volume at 50 ° or more was 0.03 cm ³ / g. The 200-hour removal performance of the activated alumina molded body was 15%.

Comparative Example 2 Gibbsite obtained by the Bayer method was poured into a heated gas at about 700 ° C., and calcined instantaneously to be rehydrated. An activated alumina powder (having a loss on ignition of 6% and having an average particle diameter of 6%) Is 14μ
m and the bulk density was 1.4 g / cm ³ ).

About 1 kg of the activated alumina powder, about 0.5 kg of water and about 0.15 kg of a granulation nucleus (activated alumina) having a diameter of 0.4 to 1.4 mm were added, and the diameter of the granulated powder was increased by a dish granulator. A 2-5 mm spherical compact was obtained. The spherical molded body was placed in a lidded container, sealed, and kept at a temperature of 80 ° C. for 16 hours to partially rehydrate. Next, after the rehydrated spherical compact was sieved, the compact was placed in an electric furnace, heated to 700 ° C. and maintained for 2 hours to obtain an activated alumina compact.

The activated alumina compact has an average particle size of 1.6.
mm, BET specific surface area 130 m ² / g, SiO ₂ 0.0
2% Na ₂ O 0.32% water 0% packing density 0.
80 g / cm ³ , wear rate 1.3%, pressure resistance 3 kg, pore volume of radius 10 ° or more 0.40 cm ³ / g, radius 25
The pore volume of 0 ° or more was 0.03 cm ³ / g. The initial removal performance of the activated alumina compact was 10%.

[0045]

As described above in detail, the activated alumina molded body for producing hydrogen peroxide of the present invention has an initial removal performance for removing epoxide from the working liquid as compared with the conventional activated alumina molded body. Is equal to or greater than the above, and the service life that can be sufficiently removed is long. Further, the method for producing an activated alumina molded article for producing hydrogen peroxide of the present invention can easily provide the activated alumina molded article for producing hydrogen peroxide. Further, the method for purifying the working liquid for hydrogen peroxide production using the activated alumina molded body for producing hydrogen peroxide of the present invention can remove epoxide in the working liquid continuously for a long time.

Claims (4)

[Claims] An average particle diameter of 0.5 mm or more and 2.0 mm or more
A process for producing hydrogen peroxide by oxidation-reduction of an anthraquinone compound, characterized by having a BET specific surface area of at least 250 m ² / g and a SiO ₂ concentration of 0.01 to 15% by weight. The activated alumina compact for producing hydrogen peroxide used for removing epoxide from a solution containing an anthraquinone compound according to the above. 2. An average particle size of 0.5 mm or more and 2.0 mm or more
Less than BET specific surface area of 250 m ² / g or more, SiO ₂ concentration of 0.01 to 15% by weight, and water of 0.5 to 10% by weight. An activated alumina molded body for producing hydrogen peroxide used for removing epoxide from a solution containing an anthraquinone compound in a process for producing hydrogen peroxide by redox of an anthraquinone compound. 3. It has a rehydration property and has a bulk density of 0.5 g.
/ Cm ³ by molding the active alumina powder is to 1.2 g / cm ³ g, after rehydration, and firing, activated alumina molding production of hydrogen peroxide according to claim 1 or 2 How to make the body. 4. A process for producing hydrogen peroxide by oxidation-reduction of an anthraquinone compound, wherein a working liquid is applied to a bed filled with the activated alumina compact for producing hydrogen peroxide according to claim 1 or 2 at a space velocity of 0. A method for purifying a working liquid for producing hydrogen peroxide, comprising removing epoxide by passing the solution at 5 to 50 h ^-1 .