TW201836973A - Method and system for producing hydrogen peroxide by anthraquinone method - Google Patents

Abstract

The present invention is to provide a highly safe method for producing hydrogen peroxide by the anthraquinone method and a production system. The present invention provides a method for producing hydrogen peroxide comprising: (A) a hydrogenation step of supplying a working solution comprising a solvent and anthraquinone, a hydrogenation catalyst, and a hydrogen-containing gas into a hydrogenation reaction vessel, reducing the anthraquinone, and producing anthrahydroquinone; (B) an oxidation step of producing hydrogen peroxide by converting the anthrahydroquinone contained in the working solution from step (A) into anthraquinone in an oxidation tower; (C) an extraction step of separating the hydrogen peroxide, which is contained in the working solution from step (B), from the working solution; (D) a finishing step of purifying and concentrating the hydrogen peroxide from step (C); and (E) a circulating step of returning at least a part of the working solution from step (C) to step (A); the method further comprising: (F) a step of withdrawing an oxidation drain and a part of the working solution generated in step (B) from a bottom part of an oxidation tower as a withdrawn liquid, separating the withdrawn liquid into a working solution and hydrogen peroxide, and sending the separated working solution into step (B).

Description

Method and system for producing hydrogen peroxide using anthraquinone method

The present invention relates to a hydrogen peroxide manufacturing method and a manufacturing system using the anthraquinone method, and more particularly, to a safety management method for hydrogen peroxide manufacturing processing.

Hydrogen peroxide has oxidizing power and strong bleaching and bactericidal effects. Therefore, it is used as a bleaching agent and fungicide for paper, pulp, and fibers, and is widely used in oxidation reactions mainly based on epoxidation and hydroxylation. Important industrial products used.

As far as the production method of hydrogen peroxide is concerned, the anthraquinone method, the electrolytic method, and the method using the oxidation of isopropyl alcohol are known. The anthraquinone method is mainly used in the industry. In this method, anthraquinone is often referred to as the reaction carrier or working substance, and the anthraquinone-solvent mixture is referred to as the working solution. After the reduction, the catalyst is removed, and the hydroquinone is oxidized to anthraquinone by an oxygen-containing gas (usually air), and hydrogen peroxide is generated at the same time. Hydrogen peroxide is extracted and purified with water and concentrated to the desired concentration. The anthraquinone working solution is returned to the hydrogenation reactor and recycled. The anthraquinone system includes multiple stages in this way, so proficiency is required for the safe and stable commercial operation of the manufacturing plant.

In terms of safety of the manufacturing plant, an important note is that the hydrogen peroxide produced by the reaction in the oxidation step contacts the working solution or the moisture blown into the air to become a high concentration of hydrogen peroxide and accumulates at the bottom of the oxidation tower. This phenomenon is called Drain for normal oxidation. If this oxidative drainage is not properly managed, it may come into contact with working solutions, airborne dirt, fine particles of catalyst, etc., and there is a potential danger of explosion. [Prior Art Literature] [Patent Literature]

[Patent Document 1] CN201592986U [Patent Document 2] CN202625852U

(Problems to be Solved by the Invention)

The lower part of the oxidation tower of the anthraquinone method hydrogen peroxide production equipment is liable to collect the generated hydrogen peroxide called oxidized drainage. When impurities are mixed in, the hydrogen peroxide may decompose and explode, and a serious accident may occur. (The way to solve the problem)

The inventors of the present case worked hard to solve the above problems, and found that the oxidation tower can be improved by extracting the oxidized wastewater collected at the bottom of the oxidation tower, cooling the temperature below a certain temperature, and optionally adding a stabilizer to the oxidation tower. And surrounding security. In addition, it was found that the working solution and hydrogen peroxide, which have been discarded together with the oxidizing wastewater, were separated and sent back to the manufacturing process, which can be effectively used.

That is, the present invention includes the following matters. [1] A method for producing hydrogen peroxide, including the following steps: (A) A hydrogenation step, supplying a hydrogenation reactor with a working solution containing anthraquinones and a solvent, a hydrogenation catalyst, and a hydrogen-containing gas, and applying anthraquinones Reduction and generation of anthrahydroquinones; (B) An oxidation step, which converts anthrahydroquinones contained in the working solution from step (A) into anthraquinones in an oxidation tower and generates hydrogen peroxide; (C) an extraction step To separate the hydrogen peroxide contained in the working solution from step (B) from the working solution; (D) the Seiko step, to refine and concentrate the hydrogen peroxide from step (C); (E) the circulation step to At least a part of the working solution in step (C) returns to step (A); it further includes step (F), and a part of the oxidizing drainage and working solution generated in step (B) is extracted from the lower part of the oxidation tower, and the circulation flow rate is preferably 0.05 % ~ 3% is used as the extraction liquid, the extraction liquid is separated into a working solution and hydrogen peroxide, and the separated working solution is sent to step (B). The following steps may also be included: the separated hydrogen peroxide is further separated into an optional sub-step of the first part and the second part (but the second part may not exist), and the aforementioned first part is sent to any of the steps (D) The selected sub-step, the aforementioned second part is sent to an arbitrarily selected sub-step of the decomposition process. [2] The method for producing hydrogen peroxide according to [1], wherein in step (F), the extraction liquid is made to be 40 ° C. or less within 1 minute after the extraction liquid is extracted. [3] The method for producing hydrogen peroxide according to [2], in step (F), add a stabilizer to the extraction solution. [4] A hydrogen peroxide manufacturing system, including: (A) a hydrogenation reactor, supplying a working solution containing anthraquinones and a solvent, a hydrogenation catalyst, and a hydrogen-containing gas to reduce anthraquinones and generate anthracene hydrogen Quinones; (B) An oxidation tower that converts anthrahydroquinones contained in the working solution from the hydrogenation reactor into anthraquinones and generates hydrogen peroxide; (C) an extraction device that contains The hydrogen peroxide is separated from the working solution; (D) a refining device for refining the hydrogen peroxide from the extraction device and a concentrator for concentration; (E) a circulation conduit for returning at least a portion of the working solution from the extraction device To the hydrogenation reactor; further comprising: (F) a part of the oxidizing wastewater and working solution generated in the oxidation tower (B), preferably 0.05% to 3% of the circulating flow, withdrawn from the lower part of the oxidation tower as the extraction liquid Conduit for guiding the extracted liquid to the oil-water separator, an oil-water separator for separating the extracted liquid into a working solution and hydrogen peroxide, and sending the separated working solution to the oxidation tower (B) Catheter. It may also include: optionally, a conduit for sending the first part of the separated hydrogen peroxide to the refining device and / or a concentrator, and a conduit for sending the second part of the separated hydrogen peroxide to the decomposition treatment. [5] The manufacturing system of hydrogen peroxide according to [4], wherein, in the oil-water separator, or between the bottom of the oxidation tower and the oil-water separator, there is a method for making the extracted liquid less than 40 ° C within 1 minute after the extraction. Cooling device. [6] The hydrogen peroxide production system according to [4] or [5], further comprising a stabilizer tank for adding a stabilizer to the extracted liquid. (Effect of the invention)

According to the present invention, a plant can be safely operated by appropriately managing a high-risk place. In addition, the produced hydrogen peroxide can be used without waste, and the produced working solution can be used.

<Step (A)> In step (A), a hydrogenation reactor is supplied with a working solution containing anthraquinones and a solvent, a hydrogenation catalyst, and a hydrogen-containing gas, and the anthraquinones are reduced to produce anthrahydroquinones.

As for the hydrogenation reactor used in the method of the present invention, a general gas-liquid solid-phase catalyst reactor can be used, that is, a reactor such as a fixed bed type, a fluidized bed type, a mechanical stirring type, and a bubble column type. The hydrogenation reactor may be one or two or more hydrogenation reactors may be connected in parallel or in parallel.

The working solution used in the method of the present invention contains at least anthraquinones and a solvent.

The anthraquinones used in the present invention are not particularly limited, and alkylanthraquinone, alkyltetrahydroanthraquinone or a mixture thereof is preferred. Alkyl anthraquinone and alkyl tetrahydroanthraquinone can be a mixture of most alkyl anthraquinones or alkyl tetrahydroanthraquinones, respectively. When a mixture of alkylanthraquinone and alkyltetrahydroanthraquinone is used as anthraquinones, the mixed mole ratio is preferably 2: 1 to 50: 1.

Alkyl anthraquinone refers to 9,10-anthraquinone obtained by replacing at least one of the 1, 2 or 3 positions with a linear or branched aliphatic substituent containing at least one carbon atom. Generally, these alkyl substituents contain 9 or less carbon atoms, preferably 6 or less carbon atoms. Specific examples of such an alkylanthraquinone include 2-methylanthraquinone, 1,3-, 2,3-, 1,4-, or 2,7-dimethylanthraquinone and 2-ethylanthraquinone. , 2-isopropylanthraquinone, 2-second or 2-third butylanthraquinone, 2-second or 2-third pentylanthraquinone, and the like. The concentration of alkyl anthraquinones in the working solution can be controlled according to the processing conditions, and it is usually used at 0.4 to 1.0 mol / l.

The solvent used in the working solution of the present invention is preferably a mixed solution of a non-polar solvent capable of dissolving anthraquinones and a polar solvent capable of dissolving anthrahydroquinones. Non-polar solvents are aromatic hydrocarbons substituted with at least one alkyl group, especially alkylbenzenes containing 8 to 12 carbon atoms, or mixtures thereof. In the case of a polar solvent, it is an alcohol (eg, diisobutyl methanol, 2-octanol), a tetra-substituted urea, a phosphate, a 2-pyrrolidone, or a cyclohexyl acetate. Preferred combinations of solvents include aromatic hydrocarbons and alcohols, aromatic hydrocarbons and cyclohexyl alkyl acetate, aromatic hydrocarbons and phosphate esters, and combinations of aromatic hydrocarbons and tetra-substituted urea.

The hydrogenation catalyst used in the present invention generally contains an active metal element or a mixture of active metal elements that are physically or chemically adsorbed on a support. The active metal element is usually selected from one or more of nickel, osmium, ruthenium, rhodium, palladium, or platinum. The active metal element preferably contains at least palladium. The content of the active metal element is usually not more than 10% by weight, preferably not more than 5% by weight, and more preferably not more than 3% by weight. As the support, silicon dioxide, silica alumina, alumina, alumina magnesia, magnesia, titania, titania, zirconia, zeolite, activated carbon, or the like that are commonly used as catalyst supports can be used. Organic polymers, or mixtures thereof. Among them, silica, silica alumina, alumina magnesia, and γ-alumina are preferable, and silica and silica alumina are more preferable.

The particle diameter, particle size distribution, and particle shape of the support are not particularly limited, and can be selected according to the shape of the reactor using the hydrogenation catalyst. Examples include irregular, spherical, cylindrical, three-leaf, four-leaf, and ring shapes. For example, for a carrier for a mechanically stirred or suspended bubble tower reactor, the median diameter of the carrier is usually 1 μm to 200 μm, preferably 20 to 180 μm, and more preferably 30 to 150 μm. Its particle shape is irregular. Or spherical. The support for a fixed-bed or fluidized-bed hydrogenation reactor is spherical particles or crushed particles with a median diameter of 0.1 to 10 mm, preferably 0.5 to 3 mm, and is preferably pellets.

The amount of hydrogenation catalyst used can be controlled to an appropriate concentration range according to the processing conditions, and it is usually used in the range of 5 to 100 g / l.

In addition to the above, the working solution may contain additional components such as tertiary amine compounds such as trioctylamine, and ammonium compounds such as N, N-dialkylcarboxylic acid amidine.

The means for supplying the working solution and the hydrogenation catalyst to the hydrogenation reactor may be conventional means, and there is no particular limitation.

Then, a hydrogen-containing gas is supplied to the hydrogenation reactor, and anthraquinones contained in the working solution are reduced to produce anthrahydroquinones. The means for supplying the hydrogen-containing gas to the hydrogenation reactor may be a conventional means, and there is no particular limitation.

In the method of the present invention, the hydrogen-containing gas used for hydrogenating anthraquinones may be 100% hydrogen, or may be hydrogen obtained by diluting hydrogen with a passive gas. Examples of the inert gas include rare gases such as nitrogen, fluorinated gas, and argon. Usually the cheapest nitrogen is used.

The reaction of reducing anthraquinones with hydrogen to generate anthrahydroquinones is well known. In the method of the present invention, the temperature of the hydrogenation step is usually 10 to 100 ° C, preferably 20 to 80 ° C, and more preferably 25 to 70 ° C. In the method of the present invention, the pressure of the hydrogenation reactor is usually set to 100 kPa to 500 kPa.

Then, a working solution containing anthrahydroquinones and a solvent and a gas consumed by hydrogenation are discharged from the hydrogenation reactor.

The means for discharging the working solution and the gas consumed by the hydrogenation from the hydrogenation reactor may be conventional means, and there is no particular limitation.

<Step (B)> Step (B) is an oxidation step of converting anthrahydroquinones contained in the working solution from step (A) into anthraquinones in an oxidation tower and generating hydrogen peroxide.

In the method of the present invention, the oxidation step can be performed by conventional means. That is, the working solution containing 2-alkylanthrahydroquinone is guided to the oxidation step, and oxygen or air is used for oxidation in the oxidation tower to regenerate the 2-alkylanthraquinone and simultaneously generate hydrogen peroxide.

The temperature of the oxidation step is usually 10 to 100 ° C, preferably 20 to 80 ° C, and more preferably 25 to 70 ° C. The pressure range of the oxidation step is not particularly limited, and it is preferable to perform it within a range of 0.01 to 1.0 MPa. Considering the load of the reaction device and compressor, it is more economical to perform at low pressure.

The oxidation tower may be a conventional one without special restrictions. For example, there is no particular limitation on the flow oxidation, the co-current oxidation, and the like, and it can be adopted by taking advantage of the respective technical characteristics. Generally speaking, a multi-segment flow oxidation tower divided into 2 to 6 parts can be cited. Such an oxidation tower can be operated in a forward flow, and a perforated tray can be horizontally arranged at the central portion to perform a gas-liquid reaction. In order to fully mix the parts, they can be provided with appropriate access devices such as sieve plates or nets, or filled with a filler.

<Step (C)> Step (C) is an extraction step of separating hydrogen peroxide contained in the working solution from step (B) from the working solution.

In the method of the present invention, the extraction step can be performed using conventional means. The extraction device may be a conventional person, without special restrictions. It is usually carried out using water, and the temperature of the extraction step is usually 10 to 100 ° C, preferably 20 to 80 ° C, and more preferably 25 to 70 ° C.

<Step (D)> Step (D) is a precision step of refining and concentrating hydrogen peroxide from step (C).

Methods for refining hydrogen peroxide, such as solvent washing, distillation, extraction using various organic solvents, adsorption of impurities on activated carbon, alumina, magnesium oxide, or polymer resins, An ion exchange method using a anion exchange resin or a cation exchange resin, a reverse osmosis membrane method, and the like.

For example, the distillation method, which is a method for refining hydrogen peroxide, includes the step of removing hydrogen to increase the concentration of hydrogen peroxide, which is effective for removing organic impurities, especially for compounds used in the automatic oxidation manufacturing method, and is therefore widely implemented. This method is a method of evaporating an aqueous hydrogen peroxide solution as a raw material, separating the generated vapor from the liquid, and supplying it to a distillation column and concentrating to obtain a concentrated refined liquid.

The crude aqueous hydrogen peroxide (H ₂ O ₂ concentration: 15 to 35%) from the extraction stage is guided to a crude product storage tank through a refining device. Aqueous hydrogen peroxide is sent from the crude product storage tank to a concentration device, where it is distilled. Here, most of the impurities of hydrogen peroxide are removed, concentrated to a concentration of about 25 to 70% by weight, and stored in a storage container.

In addition, there are a method of removing organic impurities and inorganic impurities by distillation, and refining hydrogen peroxide by vacuum distillation, a method of combining ion exchange resin and membrane filtration, a combination of membrane filtration, activated carbon adsorption, and multi-stage purification. Distillation method and so on.

<Step (E)> Step (E) is a step in which at least a part of the working solution from step (C) is returned to step (A).

The means for returning the working solution from step (E) to step (A) may be conventional means, and there is no particular limitation. For example, it can implement by providing the circulation duct which returns at least one part of the working solution from an extraction apparatus to an oxidation tower.

The circulation rate of the working solution can be arbitrarily set between 0 and 100%.

<Step (F)> Step (F) includes: extracting a part of the oxidizing wastewater and working solution generated in step (B), preferably 0.05% to 3% of the circulating flow rate, and extracting it from the lower part of the oxidation tower for extraction. A sub-step of liquid, a sub-step of separating the extracted liquid into a working solution and hydrogen peroxide, and a sub-step of sending the separated working solution to step (B). In step (F), a duct for extracting a part of the oxidizing drainage and working solution generated from the oxidation tower (B) from the lower part of the oxidation tower as an extraction liquid, a duct for guiding the extraction liquid to an oil-water separator, An oil-water separator for separating the extracted liquid into a working solution and hydrogen peroxide, and a conduit for sending the separated working solution to the oxidation tower (B). Step (F) may also include the optional sub-step of further separating the separated hydrogen peroxide into the first part and the second part (but the second part may not exist), and sending the aforementioned first part to step (D) Arbitrarily selected sub-steps of the, and the aforementioned second part is sent to the arbitrarily selected sub-steps of the decomposition process. The above-mentioned optional sub-steps may use a filter for further separating the separated hydrogen peroxide into the first part and the second part (but the second part may not exist), and the first part may be sent to a refining device and And / or a tube of the concentrator, which is used to send the aforementioned second part to a tube for decomposition treatment.

It is also possible that there is no second part of the separated hydrogen peroxide. That is, all the separated hydrogen peroxide can be sent to step (D).

The extraction liquid should preferably be 40 ° C or less within 1 minute after extraction. Cooling can be performed by providing a cooling device in the oil-water separator or between the bottom of the oxidation tower and the oil-water separator. A heat exchanger can also be used as a cooling device.

It is better to add a stabilizer to the extract. The stabilizer can be provided by providing a stabilizer tank for adding the stabilizer, and the pump can be used to transport the stabilizer from here.

Hereinafter, embodiments of the present invention will be described more specifically, but the present invention is not limited thereto. The meaning of the symbols in FIGS. 1 and 2 is as follows.

Implementation Example 1-Addition of Stabilizing Agent for Oxidation and Drainage in Oil-water Separator Implementation System 1 is shown in Figure 1. From the bottom of the oxidation tower (not shown), the oxidizing wastewater containing hydrogen peroxide and the working solution of 0.2% of the circulating flow rate were extracted together as an extraction liquid (4). The extracted liquid is sent to the oil-water separator (1) and immediately cooled with a refrigerant to bring the temperature to 0 ° C to 40 ° C. Then, a predetermined stabilizer is added from the stabilizer tank (2). Stabilizers are selected from organic phosphonic acids such as phosphoric acid, pyrophosphoric acid and their sodium salts, ammonium nitrate, organic phosphonates, sodium stannates, etidronic acid, and the like One or more of the sodium salts may be used in combination. The addition amount of the stabilizer is preferably 0.1 mg / L to 500 mg / L relative to the oxidized wastewater. The extracted liquid is separated into a residual working solution and hydrogen peroxide in an oil-water separator, and the separated working solution (6) is returned to the upper part of the oxidation tower. The separated hydrogen peroxide (5) is sent to a concentration step or a purification step through a filter (3).

Implementation Example 2-Addition of Stabilizing Agent to Oxidation and Drainage in the Piping in Front of the Oil-Water Separator Fig. 2 shows the system of Implementation Example 2. From the bottom of the oxidation tower (not shown), the oxidizing wastewater containing hydrogen peroxide and the working solution of 0.2% of the circulating flow rate are extracted together as the extraction liquid (4). A predetermined stabilizer is added to the extraction liquid from the stabilizer tank (2). As the stabilizer, one selected from the group consisting of stannates such as phosphoric acid, pyrophosphate and their sodium salts, ammonium nitrate, organic phosphonates, sodium stannate, and organic phosphonic acids such as hydroxyethylidene diphosphonic acid and their sodium salts is used. More than one species may be mixed. The addition amount of the stabilizer is 0.1 mg / L to 1,000 mg / L, preferably 1 mg / L to 500 mg / L, relative to the oxidized wastewater. The drawn-out liquid to which the stabilizer has been added is sent to the oil-water separator (1), and is immediately cooled with a refrigerant to a temperature of 0 ° C to 40 ° C. In the oil-water separator, the extracted liquid is separated into the remaining working solution and hydrogen peroxide, and the separated working solution (6) is returned to the upper part of the oxidation tower. The separated hydrogen peroxide (5) is sent to a concentration step, a purification step, or a decomposition treatment through a filter (3). [Industrial availability]

According to the present invention, the safety of the oxidation tower and its surroundings in the anthraquinone method can be improved. In addition, it can be effectively used by separating the working solution and hydrogen peroxide that have been discarded together with the oxidizing wastewater.

1‧‧‧oil-water separator

2‧‧‧ stabilizer tank

3‧‧‧ filter

4‧‧‧ extraction fluid

5‧‧‧ hydrogen peroxide

6‧‧‧working solution

CW‧‧‧ cooling water

T‧‧‧Temperature sensor

FIG. 1 illustrates the system of the first aspect. FIG. 2 discloses a system of an implementation aspect 2.

Claims (6)

A method for producing hydrogen peroxide, including the following steps: (A) a hydrogenation step, supplying a hydrogenation reactor with a working solution containing anthraquinones and a solvent, a hydrogenation catalyst, and a hydrogen-containing gas to reduce and generate anthraquinones Anthrahydroquinones; (B) an oxidation step, which converts anthrahydroquinones contained in the working solution from step (A) into anthraquinones in an oxidation tower and generates hydrogen peroxide; (C) an extraction step, which The hydrogen peroxide contained in the working solution of step (B) is separated from the working solution; (D) the Seiko step, which refines and concentrates the hydrogen peroxide from step (C); (E) the recycling step, which results from step (C) At least a part of the working solution is returned to step (A); further including step (F), extracting a part of the oxidizing drainage and working solution generated in step (B) from the lower part of the oxidation tower as the extraction liquid, and separating the extraction liquid into work The solution and hydrogen peroxide, and the separated working solution is sent to step (B). For example, in the method for producing hydrogen peroxide according to item 1 of the scope of patent application, in step (F), the extraction liquid is made to be 40 ° C. or less within 1 minute after the extraction liquid is extracted. For example, in the method for manufacturing hydrogen peroxide according to item 2 of the scope of patent application, in step (F), a stabilizer is added to the extraction solution. A hydrogen peroxide manufacturing system includes: (A) a hydrogenation reactor that supplies a working solution containing anthraquinones and a solvent, a hydrogenation catalyst, and a hydrogen-containing gas to reduce anthraquinones and generate anthrahydroquinones; (B) An oxidation tower that converts anthrahydroquinones contained in the working solution from the hydrogenation reactor into anthraquinones and generates hydrogen peroxide; (C) an extraction device that converts the peroxide contained in the working solution from the oxidation tower Hydrogen is separated from the working solution; (D) a refining device for refining hydrogen peroxide from the extraction device and a concentrator for concentration; (E) a circulation duct to return at least a portion of the working solution from the extraction device to the hydrogenation reaction The device further comprises: (F) a conduit for extracting a part of the oxidizing drainage and working solution generated in the oxidation tower (B) from the lower part of the oxidation tower as an extraction liquid, a conduit for guiding the extraction liquid to an oil-water separator, An oil-water separator for separating the extracted liquid into a working solution and hydrogen peroxide, and a conduit for sending the separated working solution to the oxidation tower (B). For example, the manufacturing system of hydrogen peroxide in the fourth scope of the patent application, which has an oil-water separator, or between the bottom of the oxidation tower and the oil-water separator, which has an extraction liquid that becomes 40 ° C or less within 1 minute after extraction. Cooling device. For example, a manufacturing system for hydrogen peroxide in the scope of patent application No. 4 or 5, which has a stabilizer tank for adding a stabilizer to the extraction liquid.