阅读说明：本技术 2-烷基蒽醌工作液的预处理方法以及过氧化氢的生产方法 (Pretreatment method of 2-alkyl anthraquinone working solution and production method of hydrogen peroxide ) 是由 郑博 潘智勇 唐晓津 朱振兴 刘铮 胡立峰 宗保宁 毛俊义 于 2018-09-10 设计创作，主要内容包括：本发明涉及原料预处理领域,公开了一种2-烷基蒽醌工作液的预处理方法以及一种过氧化氢的生产方法,该方法包括：将所述2-烷基蒽醌工作液与吸附剂在碱液中接触进行吸附脱硫和除杂,分离出经过吸附脱硫和除杂的2-烷基蒽醌工作液并进行洗涤,所述吸附剂为非晶态合金,且所述非晶态合金含有镍。本发明提供的2-烷基蒽醌工作液的预处理方法能够显著降低工作液中杂质以及硫含量,并有效解决将所述工作液进行过氧化氢生产的加氢过程中贵金属钯催化剂中毒失活的问题,具有良好的工业应用前景。(The invention relates to the field of raw material pretreatment, and discloses a pretreatment method of 2-alkylanthraquinone working solution and a production method of hydrogen peroxide, wherein the method comprises the following steps: and (2) contacting the 2-alkylanthraquinone working solution with an adsorbent in alkali liquor to perform adsorption desulfurization and impurity removal, separating the 2-alkylanthraquinone working solution subjected to adsorption desulfurization and impurity removal, and washing, wherein the adsorbent is an amorphous alloy, and the amorphous alloy contains nickel. The pretreatment method of the 2-alkylanthraquinone working solution provided by the invention can obviously reduce the content of impurities and sulfur in the working solution, effectively solves the problem of poisoning and inactivation of the noble metal palladium catalyst in the hydrogenation process of hydrogen peroxide production of the working solution, and has good industrial application prospect.)

1. A method for pretreating a 2-alkylanthraquinone working solution, which is characterized by comprising the following steps: and (2) contacting the 2-alkylanthraquinone working solution with an adsorbent in alkali liquor to perform adsorption desulfurization and impurity removal, separating the 2-alkylanthraquinone working solution subjected to adsorption desulfurization and impurity removal, and washing, wherein the adsorbent is an amorphous alloy, and the amorphous alloy contains nickel.

2. The pretreatment method according to claim 1, wherein the nickel is contained in an amount of 35 to 95 wt%, preferably 50 to 90 wt%, based on the total weight of the amorphous alloy.

3. The pretreatment method according to claim 1 or 2, wherein the amorphous alloy further contains one or more metals of aluminum, iron, chromium, copper, zinc, molybdenum, and cobalt.

4. The pretreatment method according to any one of claims 1 to 3, wherein the content of nickel is 35 to 95 wt% and the total content of other metals is 5 to 65 wt%, based on the total weight of the amorphous alloy,

preferably, the content of nickel is 50 to 90 wt% and the total content of other metals is 10 to 50 wt%, based on the total weight of the amorphous alloy.

5. The pretreatment method according to any one of claims 1 to 3, wherein the amorphous alloy contains nickel and aluminum, and at least one metal selected from one or more of iron, chromium, copper, zinc, molybdenum, and cobalt, preferably a combination of chromium and iron, a combination of chromium and copper, a combination of chromium and molybdenum, and a combination of chromium and cobalt;

35-95 wt% nickel, 0.5-40 wt% aluminum, and 0.1-50 wt% total of one or more metals selected from iron, chromium, copper, zinc, molybdenum, and cobalt, based on the total weight of the amorphous alloy;

preferably, the content of nickel is 50-90 wt%, the content of aluminum is 1-30 wt%, and the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum, and cobalt is 1-40 wt%, based on the total weight of the amorphous alloy;

more preferably, the content of nickel is 50 to 90 wt%, the content of aluminum is 1 to 15 wt%, and the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum, and cobalt is 5 to 40 wt%, based on the total weight of the amorphous alloy.

6. The pretreatment method according to any one of claims 1 to 5, wherein a diffusion peak appears at 45 ± 1 ° in a range of 20 to 80 ° in 2 θ angle in an X-ray diffraction pattern of the adsorbent.

7. The pretreatment method according to any one of claims 1 to 6, wherein the conditions for contacting the 2-alkylanthraquinone working solution with the adsorbent in the alkaline solution comprise: the temperature is 10-200 ℃, preferably 25-170 ℃, and the pressure is 0-3MPa, preferably 0-2 MPa;

preferably, the number of contacts is from 1 to 5, more preferably from 2 to 4, and the time for each contact is from 0.01 to 24 hours, more preferably from 0.5 to 8 hours;

preferably, the contacting is performed under agitation, with the rotation speed of the agitation being 500-.

8. The pretreatment method according to any one of claims 1 to 7, wherein the adsorbent is used in an amount of 0.01 to 40% by weight, preferably 1 to 10% by weight, based on the weight of the 2-alkylanthraquinone working solution.

9. The pretreatment method according to any one of claims 1 to 7, wherein the base in the alkali solution is an inorganic base selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate, preferably sodium hydroxide, and the alkali solution is preferably an aqueous solution of a base;

the volume ratio of the alkali liquor to the 2-alkyl anthraquinone working solution is 0.1-10, preferably 0.5-2.

10. The pretreatment method according to claim 1, wherein the washing conditions are such that the pH of the washed 2-alkylanthraquinone working solution is neutral, and preferably, the washing comprises acid washing and water washing in this order.

11. The pretreatment method according to claim 10, wherein an acid used for acid washing is an inorganic acid selected from at least one of sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid, preferably phosphoric acid, and the acid is used in the form of an acid solution, preferably an aqueous acid solution;

the pickling conditions include: the temperature is 5-100 ℃, preferably 20-60 ℃, and the pressure is 0-1MPa, preferably 0-0.5 MPa;

the volume ratio of the acid liquid to the 2-alkyl anthraquinone working solution is 0.1-10, preferably 0.5-2;

the acid washing times are 1-5 times, preferably 2-4 times, and the time of each acid washing is 0.01-24h, preferably 0.5-8 h;

preferably, the acid washing is carried out under stirring, and the rotation speed of the stirring is 500-2000 rpm, more preferably 800-1200 rpm.

12. The pretreatment method according to claim 10, wherein the conditions of the water washing include: the pressure is 0-1MPa, preferably 0-0.5MPa, the temperature is 5-100 ℃, and preferably 20-60 ℃;

the volume ratio of water to the 2-alkyl anthraquinone working solution is 0.1-10, preferably 0.5-2;

the washing times are 1-5 times, preferably 2-4 times, and the washing time is 0.01-24h, preferably 0.5-8 h;

preferably, the water washing is performed under stirring, and the rotation speed of the stirring is 500-.

13. A process for the production of hydrogen peroxide, which comprises subjecting a 2-alkylanthraquinone working fluid to hydrogenation, oxidation and extraction, characterized in that it further comprises pretreating the 2-alkylanthraquinone working fluid before the hydrogenation, said pretreatment being carried out by the process as claimed in any one of claims 1 to 12.

Technical Field

The invention relates to raw material pretreatment, in particular to a pretreatment method of a 2-alkylanthraquinone working solution for producing hydrogen peroxide and a production method of the hydrogen peroxide.

Background

Hydrogen peroxide is an important green basic chemical and has high industrial relevance. Since 2008, China has become the first major country for hydrogen peroxide production, and consumption has exceeded 1000 million t/a (by 27.5%) in 2015. At present, the production method of hydrogen peroxide is mainly an anthraquinone method, and 2-alkylanthraquinone (mainly comprising 2-ethylanthraquinone, 2-butylanthraquinone and 2-amylanthraquinone) is used as a 'carrier' of the process, so that the quality and the yield of the hydrogen peroxide are directly influenced. The 2-alkyl anthraquinone and mixed solvent (composed of non-polar solvent and polar solvent) are mixed according to a certain proportion to prepare working solution, and the working solution can be recycled after the processes of hydrogenation, oxidation, extraction, drying, refining and the like.

The 2-alkyl anthraquinone working solution contains impurities, which seriously affects the process operation and the product index. However, the pretreatment technology of the 2-alkylanthraquinone working solution is not reported, and therefore, a new pretreatment method of the 2-alkylanthraquinone working solution needs to be developed.

Disclosure of Invention

The invention aims to provide a novel pretreatment method of a 2-alkylanthraquinone working solution, which can obviously reduce impurities and sulfur content of the working solution.

The inventor of the invention finds that in the hydrogenation process for preparing hydrogen peroxide by using 2-alkyl anthraquinone working solution, a noble metal palladium catalyst is generally used, and in the catalytic hydrogenation process in the form of a fixed bed, the activity stability of the catalyst is better because the loading amount of palladium in the catalyst is higher. However, in the case of catalytic hydrogenation in the form of slurry bed or fluidized bed, the amount of palladium supported in the fine powder catalyst can be significantly reduced, but the catalyst is easily chemically deactivated, and the continuous stability of the production process and the quality of the product cannot be guaranteed. The inventor of the invention finds through research that the preparation method of the 2-alkylanthraquinone is a phthalic anhydride method, which needs to use a large amount of concentrated sulfuric acid, so that the sulfur content of the product is as high as 10-20mg/kg, and in addition, the sulfur content of the finally prepared 2-alkylanthraquinone working solution is about 1-6mg/kg due to the problems of the source and the purity of the mixed solvent. These sulfides can lead to the deactivation of the noble metal palladium catalyst in the hydrogenation process of the working solution, thus leading to the reduction of the service life of the catalyst, not only increasing the use cost, but also seriously affecting the process efficiency. Therefore, in order to improve the efficiency of the whole process and purify the reaction environment, the 2-alkylanthraquinone working solution needs to be pretreated for desulfurization and impurity removal.

At present, liquid-phase desulfurization technology can be divided into hydrodesulfurization technology and non-hydrodesulfurization technology, and the hydrodesulfurization technology is not suitable for the desulfurization treatment process of 2-alkylanthraquinone working solution because hydrogen can react with 2-alkylanthraquinone. Non-hydrodesulfurization techniques include oxidative desulfurization, extractive desulfurization, alkylation desulfurization, and adsorptive desulfurization, among others. The adsorption desulfurization technology has the advantages of simple operation, mild condition, small equipment investment, good desulfurization effect, no impurity introduction and the like, and is particularly suitable for the desulfurization process of the 2-alkylanthraquinone working solution.

According to the present invention, since prior art reports on adsorption desulfurization of 2-alkylanthraquinone working fluids have not been made before the inventors' studies, there has been no report on the use of amorphous alloys as adsorbents for 2-alkylanthraquinone working fluids.

In order to achieve the above object, one aspect of the present invention provides a method for pretreating a 2-alkylanthraquinone working solution, wherein the method comprises: and (2) contacting the 2-alkylanthraquinone working solution with an adsorbent in alkali liquor to perform adsorption desulfurization and impurity removal, separating the 2-alkylanthraquinone working solution subjected to adsorption desulfurization and impurity removal, and washing, wherein the adsorbent is an amorphous alloy, and the amorphous alloy contains nickel.

Preferably, the amorphous alloy further contains one or more metals of aluminum, iron, chromium, copper, zinc, molybdenum, and cobalt.

Preferably, the content of nickel is 35-95 wt% and the total content of other metals is 5-65 wt% based on the total weight of the amorphous alloy, and more preferably, the content of nickel is 50-90 wt% and the total content of other metals is 10-50 wt% based on the total weight of the amorphous alloy.

Preferably, the amorphous alloy contains nickel and aluminum, and one or more metals selected from iron, chromium, copper, zinc, molybdenum, and cobalt, more preferably at least one of a combination of chromium and iron, a combination of chromium and copper, a combination of chromium and molybdenum, and a combination of chromium and cobalt; the content of nickel is 35-95 wt% based on the total weight of the amorphous alloy, the content of aluminum is 0.5-40 wt%, the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum and cobalt is 0.1-50 wt%, more preferably, the content of nickel is 50-90 wt%, the content of aluminum is 1-30 wt%, the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum and cobalt is 1-40 wt%, further preferably, the content of nickel is 50-90 wt%, the content of aluminum is 1-15 wt%, and the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum and cobalt is 5-40 wt%, based on the total weight of the amorphous alloy.

Preferably, the conditions for contacting the 2-alkylanthraquinone working solution with the adsorbent in the alkaline solution include: the temperature is 10-200 deg.C, preferably 25-170 deg.C, and the pressure is 0-3MPa, preferably 0-2 MPa; more preferably, the number of contacts is from 1 to 5, more preferably from 2 to 4, each contact for a period of from 0.01 to 24 hours, preferably from 0.5 to 8 hours; further preferably, the contacting is performed under stirring, with a rotation speed of 500-.

In a second aspect, the invention provides a method for producing hydrogen peroxide, which comprises the steps of hydrogenating, oxidizing and extracting a 2-alkylanthraquinone working solution, wherein the method further comprises the step of pretreating the 2-alkylanthraquinone working solution before hydrogenation, and the pretreatment method is a pretreatment method of the 2-alkylanthraquinone working solution provided by the invention.

The pretreatment method of the 2-alkylanthraquinone working solution provided by the invention comprises the step of contacting the 2-alkylanthraquinone working solution with an adsorbent in an alkali liquor for adsorption desulfurization and impurity removal, namely, the working solution, the alkali liquor and the adsorbent are simultaneously contacted for alkali liquor washing and adsorption desulfurization, and the adsorbent is a nickel-based amorphous alloy. The nickel-based amorphous alloy shows excellent stability in alkali liquor and has good desulfurization activity, the invention creatively provides the coupling of the alkali washing and the adsorption desulfurization of the 2-alkylanthraquinone working solution, not only can shorten the pretreatment process flow and improve the process efficiency, but also has better effects of removing impurities and reducing the sulfur content, thereby effectively solving the problem of poisoning and inactivation of the noble metal palladium catalyst in the hydrogenation process when the 2-alkylanthraquinone working solution is used for preparing hydrogen peroxide, and having good industrial application prospect.

Drawings

FIG. 1 is a process flow diagram of the pretreatment method of 2-alkylanthraquinone working solution provided by the present invention.

Detailed Description

According to the invention, the pretreatment method of the 2-alkylanthraquinone working solution comprises the following steps: and (2) contacting the 2-alkylanthraquinone working solution with an adsorbent in alkali liquor to perform adsorption desulfurization and impurity removal, separating the 2-alkylanthraquinone working solution subjected to adsorption desulfurization and impurity removal, and washing, wherein the adsorbent is an amorphous alloy, and the amorphous alloy contains nickel.

According to the present invention, each component in the amorphous alloy exists in an amorphous form. Can be verified by XRD methods. When the XRD pattern shows broadened diffraction peaks, it can be confirmed that the alloy has an amorphous form. Specifically, the present invention uses an amorphous material in which an amorphous alloy adsorbent contains nickel as a main active component and exhibits a diffusion peak at 45 ± 1 ° in an X-ray diffraction pattern in a range of 20 to 80 ° in 2 θ.

According to the invention, the adsorbent is an amorphous alloy and the amorphous alloy contains nickel as the main active component of the amorphous alloy, the content of nickel may be 35 to 95 wt%, preferably 50 to 90 wt%, based on the total weight of the amorphous alloy.

Preferably, the amorphous alloy further contains one or more metals of aluminum, iron, chromium, copper, zinc, molybdenum, and cobalt. The content of nickel is 35-95 wt% based on the total weight of the amorphous alloy, and the total content of other metals is 5-65 wt%, more preferably, the content of nickel is 50-90 wt% and the total content of other metals is 10-50 wt% based on the total weight of the amorphous alloy. Here, if the other metal is selected from one of aluminum, iron, chromium, copper, zinc, molybdenum and cobalt, the total content of the other metal refers to the content of one of the metals, and if the other metal is selected from two or more of aluminum, iron, chromium, copper, zinc, molybdenum and cobalt, the total content of the other metal refers to the total content of the plurality of metals.

According to an embodiment of the present invention, from the viewpoint of further improving the effect of adsorption desulfurization, the amorphous alloy contains nickel and aluminum, and one or more metals selected from iron, chromium, copper, zinc, molybdenum, and cobalt, preferably at least one of a combination of chromium and iron, a combination of chromium and copper, a combination of chromium and molybdenum, and a combination of chromium and cobalt; the content of nickel is 35-95 wt% based on the total weight of the amorphous alloy, the content of aluminum is 0.5-40 wt%, the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum and cobalt is 0.1-50 wt%, preferably, the content of nickel is 50-90 wt%, the content of aluminum is 1-30 wt%, the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum and cobalt is 1-40 wt%, more preferably, the content of nickel is 50-90 wt%, the content of aluminum is 1-15 wt%, the total content of one or more metals selected from iron, chromium, copper, zinc, molybdenum and cobalt is 5-40 wt%, based on the total weight of the amorphous alloy.

According to the present invention, the preparation method of the amorphous alloy may be performed with reference to a conventional method in the art, except that the composition of the amorphous alloy is selected according to the present invention. Preferably, the method for preparing the amorphous alloy comprises the following steps: a mixture containing nickel and one or more other metals selected from the group consisting of aluminum, iron, chromium, copper, zinc, molybdenum and cobalt in the above-mentioned content range, preferably a mixture of nickel, aluminum and one or more other metals selected from the group consisting of iron, chromium, copper, zinc, molybdenum and cobalt in the above-mentioned content range is alloyed in vacuum at a temperature higher than their melting points, the alloy is rapidly quenched by a vacuum quenching method under conditions that the rotation speed of a copper roll is 600 and 1000 revolutions per minute (in a specific embodiment, 800 revolutions per minute is preferred), the injection pressure is 0.05 to 0.1MPa, a scaly strip is formed, and the obtained alloy abrasive grain diameter is 60 to 80 μm, to obtain a master alloy. And subjecting the master alloy to constant temperature heat treatment in a reducing atmosphere, such as a hydrogen atmosphere, under conditions including a temperature of 500-800 deg.C (in embodiments, preferably 600 deg.C), for a period of 2-5 hours (in embodiments, preferably 3 hours). The heat-treated master alloy is subjected to alkali treatment in an aqueous solution of an inorganic alkali, typically sodium hydroxide, typically at a concentration of 20 to 30% by weight, in an aqueous solution of an inorganic alkali, typically sodium hydroxide at a concentration of typically 20 to 30% by weight, at a temperature of 80 to 120 ℃ (embodiment preferably 100 ℃), for a constant temperature treatment time of 30 minutes to 2 hours (embodiment preferably 1 hour), and then washed with distilled water to neutrality, i.e., a pH of 7, and then water is removed. The washing temperature is preferably equivalent to the temperature of the alkali treatment, and may be, for example, 80 to 100 ℃ (80 ℃ is preferred in the embodiment). The water removal process can be carried out by reference to conventional treatment methods in the alloy field, for example, by placing the washed master alloy in benzene, carrying out azeotropic distillation at atmospheric pressure, and then storing it in benzene for later use.

According to the invention, the conditions for contacting the 2-alkylanthraquinone working fluid with the adsorbent in the lye generally comprise: temperature, pressure and time. Wherein the temperature range may be 10 to 200 ℃, preferably 25 to 170 ℃, and the pressure and time may be appropriately adjusted depending on the contact temperature, for example, the pressure range may be 0 to 3MPa, preferably 0 to 2 MPa. The number of times of contacting the 2-alkylanthraquinone working solution with the adsorbent in the alkali solution is not particularly limited, and from the viewpoint of ensuring sufficient dissolution and precipitation of impurities and sufficient adsorption of sulfides in the 2-alkylanthraquinone working solution, the number of times of contacting the 2-alkylanthraquinone working solution with the adsorbent in the alkali solution is 1 to 5 times, more preferably 2 to 4 times, and the time for each contact is 0.01 to 24 hours, preferably 0.5 to 8 hours. After each contact is carried out with the alkali washing and the desulfurization process, only the waste alkali liquor needs to be discharged, the adsorbent still continues to be used, and after the alkali washing and the adsorption desulfurization process are completed, the waste alkali liquor and the adsorbent are discharged. The contact mode is preferably as follows: in the alkali liquor, the 2-alkylanthraquinone working solution and the adsorbent are fully mixed, preferably, the contact is also carried out under stirring, and the stirring speed can be 500-2000 rpm, preferably 800-1200 rpm.

According to the invention, the base in the lye is typically an inorganic base which may be selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate, preferably sodium hydroxide. The alkali solution is usually an aqueous solution of alkali, the concentration of the alkali solution is not particularly limited, and those skilled in the art can appropriately select the alkali solution according to the solubility of different inorganic bases at different temperatures, as long as impurities can be sufficiently removed. According to one embodiment of the invention, the concentration of the aqueous sodium hydroxide solution may be between 0.1 and 70% by weight, preferably between 1 and 50% by weight. The amount of the alkali solution to be used is not particularly limited as long as impurities in the 2-alkylanthraquinone working solution are sufficiently dissolved and precipitated, and the volume ratio of the alkali solution to the 2-alkylanthraquinone working solution is preferably 0.1 to 10, more preferably 0.5 to 2.

According to the present invention, although the adsorption desulfurization of the working fluid can be achieved by bringing the 2-alkylanthraquinone working fluid into contact with the adsorbent in the alkali solution, the adsorbent is used in an amount of 0.01 to 40% by weight, preferably 1 to 10% by weight, based on the weight of the 2-alkylanthraquinone working fluid, from the viewpoint of further improving the adsorption desulfurization effect, in order to achieve the object of the present invention more preferably.

The invention completes the two processes of washing impurities, such as non-substituted anthraquinone, anthraquinone dimer and the like, and adsorption desulfurization by the alkali liquor by contacting the 2-alkylanthraquinone working solution with the adsorbent in the alkali liquor, greatly saves the cost and simplifies the process by the alkali washing and desulfurization coupling treatment method. In addition, the nickel-based amorphous alloy adopted by the invention is stored in the alkali liquor, so that the performance of the nickel-based amorphous alloy can be more stable, and the desulfurization and impurity removal effects of the 2-alkylanthraquinone working solution can be further improved.

According to the invention, in order to further remove impurities in the 2-alkylanthraquinone working solution and make the pH value of the 2-alkylanthraquinone working solution neutral, the method also comprises separating the 2-alkylanthraquinone working solution subjected to adsorption desulfurization and alkali washing impurity removal and washing. Preferably, the washing comprises acid washing and water washing in sequence. The method for separating the 2-alkylanthraquinone working solution subjected to adsorption desulfurization and impurity removal after the adsorption desulfurization and the alkali washing impurity removal can adopt a conventional separation method in the field, for example, the method for separating the alkali solution from the 2-alkylanthraquinone working solution can be centrifugation or standing layering, the lower layer is the alkali solution containing impurities, the upper layer is the 2-alkylanthraquinone working solution, and then the lower alkali solution phase is removed. The method for separating the 2-alkylanthraquinone working solution from the adsorbent may be a conventional solid-liquid separation method, such as filtration.

According to the invention, the acid used for acid washing and the acid washing conditions are such that the alkali remaining in the 2-alkylanthraquinone working solution after adsorption desulfurization and alkali washing for impurity removal is neutralized.

According to the present invention, the method of pickling may be referred to a conventional method in the art. For example, the acid used for the acid washing is usually an inorganic acid, which may be selected from at least one of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid, and is preferably phosphoric acid. The acid is used in the form of an acid solution, and is usually an aqueous acid solution, and the concentration of the acid solution is not particularly limited as long as it can sufficiently neutralize the alkali/alkali solution remaining in the 2-alkylanthraquinone working solution. According to one embodiment of the invention, the concentration of the aqueous phosphoric acid solution may be in the range of 0.1 to 83% by weight, preferably 0.5 to 20% by weight.

The pickling conditions according to the present invention can also be referred to the conventional conditions in the art. For example, the conditions for pickling include: temperature and pressure. The pickling temperature is 5 to 100 ℃, preferably 20 to 60 ℃ from the viewpoint of ensuring sufficient neutralization of the alkali/alkali solution remaining in the 2-alkylanthraquinone working solution, and the pickling pressure can be appropriately adjusted depending on the pickling temperature, and is usually 0 to 1MPa, preferably 0 to 0.5 MPa.

According to the invention, the amount of acid solution used, the number of acid pickings and the time of each acid picking are not particularly limited as long as sufficient neutralization of the residual alkali/alkaline solution in the 2-alkylanthraquinone working solution is ensured, and preferably the volume ratio of acid solution to the 2-alkylanthraquinone working solution is 0.1 to 10, more preferably 0.5 to 2. The number of acid solutions may be 1-5, preferably 2-4, and the time for each acid solution is generally 0.01-24h, preferably 0.5-8 h.

According to the invention, the pickling is preferably also carried out with stirring. The rotation speed of the stirring can be 500-2000 rpm, preferably 800-1200 rpm.

The method and conditions for water washing according to the present invention can be also referred to the conventional methods and conditions in the art. As long as the pH value of the 2-alkylanthraquinone working solution is ensured to be neutral.

According to the present invention, the conditions of the water washing generally include temperature and pressure. The temperature of the acid washing is 5 to 100 ℃ and preferably 20 to 60 ℃ from the viewpoint of sufficiently removing the residual acid solution in the 2-alkylanthraquinone working solution to ensure that the pH of the working solution is neutral, and the pressure of the water washing may be appropriately adjusted depending on the temperature of the water washing, and is usually 0 to 1MPa and preferably 0 to 0.5 MPa. More preferably, the same conditions as in the acid washing are used.

According to the present invention, the amount of washing with water and the number of times of washing with water and the time of each washing with water are not particularly limited as long as sufficient neutralization of the residual acid/acid solution in the 2-alkylanthraquinone working solution is ensured, and preferably, the volume ratio of water to the 2-alkylanthraquinone working solution is 0.1 to 10, more preferably 0.5 to 2. The number of washing with water may be 1-5, preferably 2-4, and the time for each washing with water is generally 0.01-24h, preferably 0.5-8 h.

According to the invention, the water washing is preferably also carried out with stirring. The rotation speed of the stirring can be 500-2000 rpm, preferably 800-1200 rpm.

In addition, the acid solution and the water can be respectively and fully mixed with the 2-alkylanthraquinone working solution, then the mixture is centrifuged or stood for layering, the lower layer is the acid solution/water containing impurities, the upper layer is the 2-alkylanthraquinone working solution, and then the lower washing liquid phase is removed to obtain the washed 2-alkylanthraquinone working solution.

The pretreatment method provided by the invention has no special limitation on the 2-alkylanthraquinone working solution, the sulfur content (based on the weight of elemental sulfur) can be 1-6mg/kg, and the sulfides mainly comprise inorganic sulfide sulfates, organic sulfide thiophenes and the like.

The composition and preparation method of the 2-alkylanthraquinone working solution are not particularly limited, and the conventional composition and preparation method in the field can be referred. For example, the 2-alkylanthraquinone working solution is prepared by mixing 2-alkylanthraquinone with a mixed solvent composed of a nonpolar solvent and a polar solvent, wherein the content of the 2-alkylanthraquinone in the mixed solvent is 100-300g/L, the ratio of the nonpolar solvent to the polar solvent in the mixed solvent is generally 1-3:1, the nonpolar solvent can be selected from one or more of high boiling point mixed alkylbenzene with a boiling range of 160-240 ℃, alkylbenzene with a carbon atom number of 9-10 and a mixture thereof, and the polar solvent can be selected from one or more of trioctyl phosphate, methylcyclohexyl acetate and diisobutyl methanol. Wherein the alkyl substituent of the 2-alkylanthraquinone is located at the 2-position of the anthraquinone ring, and the number of carbon atoms of the alkyl substituent is not particularly limited, and may be, for example, C₁-C₅Specific examples thereof may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl.

The method for pretreating the 2-alkylanthraquinone working solution according to the present invention will be described in detail with reference to FIG. 1.

The pretreatment process of the 2-alkylanthraquinone working solution is carried out as the process shown in the attached figure 1. The pretreatment process of the 2-alkylanthraquinone working solution specifically comprises the following steps: the 2-alkylanthraquinone working solution is contacted with the alkali liquor and the adsorbent simultaneously to finish two processes of washing the alkali liquor and adsorbing desulfurization. Standing and layering the mixed solution, discharging the waste alkali liquor at the lower layer, and continuously using the adsorbent. And when the alkali washing and the desulfurization are completed according to the required times, standing and layering the mixed solution, discharging the lower-layer waste alkali liquor, performing solid-liquid separation, such as filtration, discharging the adsorbent, and then sending the separated working solution to an acid washing process. According to the pickling method for washing, after the pickling process is finished each time, the mixed solution is kept stand for layering, and the waste acid liquor on the lower layer is discharged. And when the pickling process is completed according to the required times, standing and layering the mixed solution, discharging the waste acid solution on the lower layer, and sending the separated working solution to a washing process. According to the washing method disclosed by the invention, after the washing process is finished each time, the mixed liquid is subjected to standing and layering, and the washing waste liquid at the lower layer is discharged. And when the washing process is completed according to the required times and the indexes of impurities and sulfur content of the working solution meet the requirements, finishing the pretreatment process of the working solution, and sending the separated working solution to the next procedure.

The invention also provides a production method of hydrogen peroxide, which comprises the steps of hydrogenating, oxidizing and extracting the 2-alkylanthraquinone working solution, wherein the method also comprises the step of pretreating the 2-alkylanthraquinone working solution before hydrogenation, and the pretreatment method is the pretreatment method of the 2-alkylanthraquinone working solution provided by the invention.

According to the invention, the production process for producing hydrogen peroxide generally comprises the following steps:

(1) a hydrogenation step, under the condition of hydrogenation reaction and in the presence of a catalyst, contacting the 2-alkyl anthraquinone working solution with hydrogen to obtain a hydrogenation solution containing 2-alkyl anthraquinone and 2-alkyl anthraquinone;

(2) an oxidation step of contacting the hydrogenated liquid with oxygen under oxidation reaction conditions to obtain an oxidation liquid containing hydrogen peroxide and 2-alkylanthraquinone;

(3) and an extraction step, namely extracting the hydrogen peroxide from the oxidizing solution to obtain an extraction liquid containing the hydrogen peroxide and a raffinate.

The method also comprises the step of pretreating the 2-alkylanthraquinone working solution by using the method before hydrogenating the 2-alkylanthraquinone working solution. Preferably, after the 2-alkylanthraquinone working solution is pretreated and before hydrogenation, conventional method can be adopted for dehydration, so as to ensure that the water content of the 2-alkylanthraquinone working solution is less than 3000 mg/kg.

The method for producing hydrogen peroxide is characterized in that before the 2-alkylanthraquinone working solution is hydrogenated, the pretreatment is carried out to remove impurities and remove sulfur, so that the activity stability of the catalyst is better, and the aim of the invention is fulfilled.

The present invention will be described in detail below by way of examples.

In the following examples, the 2-amylanthraquinone working solution is prepared by mixing 2-amylanthraquinone with a non-polar solvent mesitylene and a polar solvent diisobutylcarbinol, wherein the content of 2-amylanthraquinone in the mixed solvent of the non-polar solvent and the polar solvent is 220g/L, and the volume ratio of the non-polar solvent to the polar solvent in the mixed solvent is 3: 2.

In the following examples, the method for determining the sulfur content in the 2-amylanthraquinone working solution is a total sulfur method: the total sulfur content, SHT0689-2000, was determined by UV fluorescence.

In the following examples, the method for determining the content of impurities in the 2-amylanthraquinone working solution is a chromatography method, and the analysis conditions are as follows: agilent 7890A, column DB-1(50 m.times.0.25 mm. times.0.25 μm). Sample inlet temperature: 330 ℃, sample introduction: 0.2 mu L, the split ratio of 20:1, nitrogen as carrier gas, the flow rate of constant flow mode of 0.7mL/min, temperature programming: keeping the temperature at 110 ℃ for 10min, then increasing the temperature to 320 ℃ at the speed of 5 ℃/min, and keeping the temperature for 18 min. FID detector: temperature 350 ℃, hydrogen flow: 35mL/min, air flow: 350mL/min, tail gas blowing is nitrogen, and the flow is as follows: 25 mL/min. Area normalization method: the peak areas of anthraquinone substances except the solvent are normalized, and the mass fraction is expressed by the chromatographic peak-area integral rate of impurities.

Preparation example 1

This preparation example is used to illustrate the preparation of an amorphous alloy Ni-Fe-Al adsorbent.

Adding 25 g of nickel, 50 g of aluminum and 15 g of iron into a quartz tube, heating the quartz tube to above 1300 ℃ for melting in a high-frequency furnace, alloying, then spraying the alloy liquid onto a copper roller with the rotating speed of 800 revolutions per minute from a nozzle below the quartz tube (the spraying pressure is 0.08MPa), introducing cooling water into the copper roller, rapidly cooling the alloy liquid, throwing out the alloy liquid along the tangent line of the copper roller to form a scaly strip, grinding the scaly strip to the particle diameter of 60-80 micrometers to obtain a master alloy, and carrying out XRD analysis on the obtained master alloy by using an X-ray powder diffractometer (Japanese science D/MAX-2500 type X-ray diffractometer, Cu K α ray and current of 100mA, the same below), wherein the obtained XRD diagram shows that a diffusion peak appears at 45 +/-1 DEG within the range of 20-80 DEG of 2 theta angle and is a typical characteristic of amorphous alloy, and the obtained Ni-Fe-Al alloy product is in the form.

And (3) carrying out heat treatment on the master alloy in a hydrogen environment, wherein the heat treatment temperature is 600 ℃, and the constant temperature time is 3 hours. The heat-treated master alloy was slowly added to a three-necked flask containing 1000 g of a 20% by weight aqueous solution of sodium hydroxide, and the mixture was stirred at a constant temperature of 100 ℃ for 1 hour. After stopping heating and stirring, the liquid was decanted and washed with distilled water at 80 ℃ to a pH of 7. Benzene was then added and the water was removed by azeotropic distillation at atmospheric pressure and stored in benzene until use, the resulting adsorbent composition being shown in table 1.

Preparation examples 2 to 6

An amorphous alloy adsorbent was prepared according to the method of preparation example 1, except that the amount and composition of the metal were changed, and the composition of the prepared adsorbent is shown in table 1.

TABLE 1