JP2008023452A - Method for evaluating hydrogenation catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for simply, quickly and simultaneously evaluating the activity and hydrogenation selectivity of a hydrogenation catalyst which is used in hydrogen peroxide production by means of an anthraquinone method. <P>SOLUTION: While a hydraulic solution is being added at a certain flow rate and hydrogen is also being added to a mixture of a hydrogenation catalyst, which is used in hydrogen peroxide production by means of an anthraquinone method, and a solvent used in the hydraulic solution, a hydrogenation reaction is carried out, so that hydrogen absorption per time unit may be constant, to evaluate not only the activity of the hydrogenation from an amount of a catalyst and an amount of absorbed hydrogen but also the selectivity from a change in the reaction solution component. Thus, a hydrogenation catalyst used in hydrogen peroxide production by means of an anthraquinone method is evaluated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for simultaneously and simply evaluating the activity and hydrogenation selectivity of a hydrogenation catalyst used for anthraquinone method hydrogen peroxide production.

  At present, the main production method of industrial hydrogen peroxide is a method using anthraquinones as a reaction medium and is called an anthraquinone method. In general, anthraquinones are used after being dissolved in a suitable organic solvent. The organic solvent is used alone or as a mixture, but usually a mixture of two organic solvents is used. A solution prepared by dissolving anthraquinones in an organic solvent is called a working solution.

  Since the working solution is recycled and reused, by-products that do not produce hydrogen peroxide such as alkyloxyanthrone and alkyltetrahydroanthraquinone epoxide produced by hydrogenation of anthraquinones are gradually accumulated in the working solution. The production of these by-products is an undesirable reaction that not only loses the supplied hydrogen but also loses expensive anthraquinones, thereby increasing the production cost of hydrogen peroxide. Therefore, catalyst activity and hydrogenation selectivity are important for a catalyst used for hydrogenation of anthraquinones. Among them, hydrogenation selectivity is a particularly important factor.

  As a method for evaluating the catalytic performance of a hydrogenation catalyst, a solution of 2-alkylanthraquinones and 2-alkyltetrahydroanthraquinones dissolved in a solvent composed of diisobutylcarbinol and mixed alkyl aromatics is contacted with a small amount of catalyst. A method of measuring a hydrogen absorption amount of a solution at the time of heating (see Patent Document 1), a method of reacting an organic solvent mixture containing a mixture of alkylanthraquinone and a working solution containing a hydrogenation catalyst in a stirred reactor (Patent Document 2) And a method in which the reaction is carried out using a working solution containing an organic solvent mixture containing 2-ethylanthraquinone and a hydrogenation catalyst, and the amount of hydrogen peroxide recovered from the working solution is evaluated (see Patent Document 3), in the reactor The working solution and hydrogenation catalyst were added to the catalyst to monitor the reduction level of anthraquinone to hydroanthraquinone. How to evaluate the activity (see Patent Document 4) are disclosed. In these methods, only the catalytic activity of the hydrogenation catalyst can be evaluated.

Patent Documents 5 and 6 disclose a method using a device for circulating a working solution similar to the industrialized anthraquinone method. In these methods, the catalytic activity can be evaluated simultaneously with the hydrogen partial pressure, the hydrogenation selectivity based on the by-product concentration, and the catalyst strength closer to the plant than the filter differential pressure. However, in order to evaluate using this apparatus, it is necessary to prepare a certain amount of working solution and hydrogenation catalyst, and in order to obtain the evaluation result, it is necessary to operate for several days to several weeks. is there. Further, since the apparatus is complicated, a great deal of labor is required for operation management.
Japanese Patent Publication No.63-29588 JP-A-5-238703 JP-A-6-292830 Japanese Patent Laid-Open No. 10-510796 JP-A-9-271671 Japanese Patent Laid-Open No. 2001-170485

  The object of the present invention is to solve the above-mentioned problems in the prior art, and newly developed hydrogenation catalysts and hydrogenation catalyst activity and hydrogenation selectivity during or after continuous use in plants. It is intended to provide a method for simultaneously and simply evaluating the above.

As a result of diligent studies to solve the above problems, the present inventors have determined that the hydrogen absorption amount per unit time is constant for the addition rate of the solvent containing anthraquinones added to the hydrogenation catalyst dispersed in the solvent in advance. The hydrogenation catalyst activity and hydrogen are characterized by adjusting the ratio of hydrogenation among the added anthraquinones (hereinafter referred to as hydrogenation ratio) by the amount of hydrogenation catalyst dispersed in the solvent. The present inventors have found a method for simultaneously and rapidly evaluating the selectivity of crystallization, and have reached the present invention.

  That is, the present invention adds a working solution at a constant flow rate to a mixed solution of a hydrogenation catalyst used for the production of hydrogen peroxide by the anthraquinone method and a solvent used for the working solution, and while adding hydrogen. The hydrogenation reaction is performed so that the hydrogen absorption amount per unit time is constant, the hydrogenation activity is evaluated from the catalyst amount and the hydrogen absorption amount, and the selectivity is evaluated from the change in the reaction solution composition. The present invention relates to a method for evaluating a hydrogenation catalyst used for hydrogen peroxide production by the anthraquinone method.

According to the evaluation method of the present invention, the activity of the hydrogenation catalyst and the selectivity of the hydrogenation can be simultaneously and simply evaluated before performing the measurement using an industrially complex circulation device, and the cost for catalyst development can be reduced. Development can be accelerated. In addition, according to the present invention, by evaluating the activity and hydrogenation selectivity of the hydrogenation catalyst during or after continuous use in the circulation process, it can be used for plant maintenance. In addition, according to the present invention, the combination of organic solvents constituting the working solution can be changed to evaluate the activity of the hydrogenation catalyst and the selectivity of hydrogenation, which can also be used for studying solvent types.

  In the present invention, the form of the hydrogenation catalyst is not particularly limited. Examples of the homogeneous catalyst include those having hydrogenation activity such as Raney nickel catalyst and Pd black. In a heterogeneous catalyst in which a metal compound is supported on a support, silica, alumina, titania, zirconia, silica-alumina composite oxide, silica-titania composite oxide, silica-alumina-titania composite oxide and their physics are used as the catalyst support. And at least one oxide selected from the group consisting of chemical mixtures. Further, the supported metal compound is not particularly limited as long as it usually has hydrogenation activity, but examples thereof include metal compounds including one or more kinds including palladium, rhodium, ruthenium or platinum.

  In the present invention, the hydrogenation catalyst is previously dispersed in a solvent in a measuring apparatus, and a solvent containing anthraquinones (hereinafter referred to as a working solution) is added thereto. This addition rate is adjusted so that the amount of hydrogen absorbed per unit time is constant. The ratio of hydrogenation among the added anthraquinones (hereinafter referred to as hydrogenation ratio) is adjusted by the amount of hydrogenation catalyst dispersed in the solvent in advance. The solvent is preferably a combination of an aromatic hydrocarbon and a higher alcohol, a combination of an aromatic hydrocarbon and a cyclohexanol or a carboxylic acid ester of an alkylcyclohexanol, an aromatic hydrocarbon and a tetrasubstituted urea, or a preferable organic solvent. A combination with trisphosphate (2-ethylhexyl) phosphate is exemplified.

In the present invention, the concentration of anthraquinones in the working solution and the ratio of the solvent used to disperse the hydrogenation catalyst and the working solution are not particularly limited, but the solubility of the anthraquinones and reactants in the solvent is a standard. It is desirable to specify. The solvent used for dispersing the hydrogenation catalyst and the solvent containing anthraquinones may be the same or different.

  In the present invention, the reaction time for hydrogenation is not particularly limited, but is preferably 0.1 to 10 hours, more preferably 0.3 to 3 hours. The advantage of this evaluation method is not obtained much over 24 hours. The reaction temperature and pressure for hydrogenation are not particularly specified, but the temperature and pressure used in commercial processes are preferred. In the present invention, the hydrogenation reaction pressure can be sufficiently evaluated even at normal pressure.

  In the present invention, the evaluation apparatus is preferably a batch reaction type in which the inside of the system can be replaced with gas and a stirring blade is provided in order to perform the hydrogenation reaction quickly. The rate of addition of the working solution is important in controlling the amount of hydrogenation reaction. Therefore, a high-performance precision pump or a micro syringe pump that can precisely control the addition rate of the working solution is desirable.

  The hydrogenation rate is a ratio between the hydrogen absorption amount and the theoretical hydrogen absorption amount obtained from the theoretical addition amount of anthraquinones obtained from the working solution amount added to the reactor. In the present invention, the hydrogenation catalyst amount is changed for one sample, that is, the hydrogenation rate is changed, multiple points are measured, and an approximate expression of the hydrogenation rate, the amount of hydrogen absorbed per catalyst amount, and the selectivity of hydrogenation is prepared. It is preferable to evaluate the performance of the hydrogenation catalyst. Therefore, it is more preferable to measure 3 or more points per sample.

  The catalytic activity is evaluated by the hydrogen absorption amount per unit catalyst amount obtained from the hydrogen absorption amount after the reaction and the catalyst amount. To compare the catalyst activity between the catalysts, an approximate expression between the hydrogenation rate after the reaction and the hydrogen absorption amount per catalyst amount was prepared, and the hydrogen per unit catalyst amount obtained from this approximate equation at the same hydrogenation rate was obtained. This is done by comparing the amount of absorption.

  The selectivity of hydrogenation is evaluated by measuring the concentration of by-products in the working solution after the reaction and comparing the amount of by-products after the reaction with the hydrogenated anthraquinones. These anthraquinones are measured with an analyzer such as high performance liquid chromatography. Comparison of hydrogenation selectivity between catalysts is obtained from this approximate expression by preparing an approximate expression between the hydrogenation rate after the reaction and the ratio of by-products / anthraquinones, and the same hydrogenation rate. This is done by comparing the ratio of the amount of by-products produced / anthraquinones.

The invention is illustrated in detail by the following examples. In the examples, “%” means “% by weight” unless otherwise specified.
The hydrogenation catalyst used for the production of hydrogen peroxide was used. The evaluation method will be described below. A batch type measuring apparatus (SUS 300 cc) was charged with 60 parts by weight of a solvent and an amount of hydrogenation catalyst necessary to obtain a predetermined hydrogenation rate. The solvent for dispersing the hydrogenation catalyst and the working solution containing the anthraquinones (hereinafter referred to as working solution) was a mixed solvent consisting of 60% by volume of 1,2,4-trimethylbenzene and 40% by volume of diisobutylcarbinol. . A SUS stirring blade, a Teflon (registered trademark) tube (φ3 mm) for charging the working solution, and a SUS tube for introducing hydrogen were attached to the reaction vessel, and the reaction system was purged with hydrogen. Hydrogen was previously placed in a glass container with a scale of 2 cc and having a scale of 2 cc, and supplied to the reaction tank through a SUS tube for introducing hydrogen.

  Next, a precision metering pump [Nippon Seimitsu Co., Ltd.] was prepared by dissolving a working solution dissolved in a mixed solvent of 60% by volume of 1,2,4-trimethylbenzene and 40% by volume of diisobutylcarbinol so that the concentration of amylanthraquinone was 1.5 mol / L. Using a chemical pump SP-Y-3201], it was added at a rate of 5 parts by weight and reacted for 60 minutes while stirring at 1100 rpm. The reaction temperature was controlled at 30 ° C., and the reaction pressure was controlled at normal pressure.

Example 1
1.0 part by weight of a silica-supported palladium catalyst (see Patent Document 1) continuously used in the circulation process and 60 parts by weight of a solvent constituting the working solution were added to the batch type measuring apparatus. A SUS stirrer blade and a Teflon (registered trademark) tube for charging the working solution were attached to the reaction tank, and the reaction system was purged with hydrogen. A working solution having an amylanthraquinone concentration of 1.5 mol / L was added at 5 parts by weight / minute, and the mixture was reacted for 60 minutes while stirring at 1100 rpm. The reaction temperature was controlled at 30 ° C., and the reaction pressure was controlled at normal pressure. The hydrogenation rate was 87.4%, the catalytic activity was 44.0 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/130. The total reaction time for the evaluation was 3 hours.

Example 2
The hydrogenation catalyst was evaluated in the same manner as in Example 1. However, 0.35 parts by weight of the same silica-supported palladium catalyst (see Patent Document 1) used continuously and repeatedly in the circulation process was used. The hydrogenation rate was 66.3%, the catalytic activity was 110.1 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/530. The total reaction time for the evaluation was 3 hours.

Example 3
The hydrogenation catalyst was evaluated in the same manner as in Example 1. However, 0.15 parts by weight of the same silica-supported palladium catalyst (see Patent Document 1) used continuously and repeatedly in the circulation process was used. The hydrogenation rate was 44.7%, the catalytic activity was 149.8 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/1340. The total reaction time for the evaluation was 3 hours.

Example 4
The hydrogenation catalyst was evaluated in the same manner as in Example 1. However, 1.0 part by weight of a silica-supported palladium catalyst (see Patent Document 1) that was continuously used in a circulation process and collected at a different time from Example 1 was used. The hydrogenation rate was 81.9%, the catalytic activity was 41.3 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/200. The total reaction time for the evaluation was 3 hours.

Example 5
The hydrogenation catalyst was evaluated in the same manner as in Example 4. However, 0.35 parts by weight of a silica-supported palladium catalyst (see Patent Document 1) used continuously and repeatedly in the circulation process was used. The hydrogenation rate was 57.9%, the catalytic activity was 83.3 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/550. The total reaction time for the evaluation was 3 hours.

Example 6
The hydrogenation catalyst was evaluated in the same manner as in Example 4. However, 0.22 parts by weight of a silica-supported palladium catalyst (see Patent Document 1) used continuously and repeatedly in the circulation process was used. The hydrogenation rate was 39.2%, the catalytic activity was 89.6 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/1350. The total reaction time for the evaluation was 3 hours.

Example 7
The hydrogenation catalyst was evaluated in the same manner as in Example 1. However, 1.2 parts by weight of a silica-supported palladium catalyst (see Patent Document 1) that was continuously used in a circulation process and collected at a different time from Examples 1 and 4 was used. The hydrogenation rate was 87.5%, the catalytic activity was 36.7 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/130. The total reaction time for the evaluation was 3 hours.

Example 8
The hydrogenation catalyst was evaluated in the same manner as in Example 7. However, 0.35 parts by weight of a silica-supported palladium catalyst (see Patent Document 1) used continuously and repeatedly in the circulation process was used. The hydrogenation rate was 62.6%, the catalytic activity was 90.1 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/420. The total reaction time for the evaluation was 3 hours.

Example 9
The hydrogenation catalyst was evaluated in the same manner as in Example 7. However, 0.18 parts by weight of a silica-supported palladium catalyst (see Patent Document 1) that was continuously used in a circulation process and collected at a different time from Examples 1 and 4 was used. The hydrogenation rate was 41.8%, the catalytic activity was 116.4 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/970. The total reaction time for the evaluation was 3 hours.

Example 10
The hydrogenation catalyst was evaluated in the same manner as in Example 1. However, 0.80 parts by weight of a new catalyst of silica-supported palladium catalyst (see Patent Document 1) was used as the hydrogenation catalyst. The hydrogenation rate was 94.8%, the catalytic activity was 59.7 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/260. The total reaction time for the evaluation was 3 hours.

Example 11
The hydrogenation catalyst was evaluated in the same manner as in Example 10. However, 0.50 part by weight of a new catalyst of silica-supported palladium catalyst (see Patent Document 1) was used as the hydrogenation catalyst. The hydrogenation rate was 88.6%, the catalytic activity was 89.2 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/690. The total reaction time for the evaluation was 3 hours.

Example 12
The hydrogenation catalyst was evaluated in the same manner as in Example 10. However, 0.18 parts by weight of a new catalyst of a silica-supported palladium catalyst (see Patent Document 1) was used as the hydrogenation catalyst. The hydrogenation rate was 71.8%, the catalytic activity was 200.6 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/1680. The total reaction time for the evaluation was 3 hours.

Example 13
The hydrogenation catalyst was evaluated in the same manner as in Example 1. However, instead of the silica-supported palladium catalyst continuously used in the circulation process (see Patent Document 1), the silica-alumina-supported palladium catalyst [K-0290 manufactured by Heraeus Co., Ltd.] 1.0 used in the circulation process in the same manner. Part by weight was used. The hydrogenation rate was 81.5%, the catalytic activity was 82.0 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/470. The total reaction time for the evaluation was 3 hours.

Example 14
The hydrogenation catalyst was evaluated in the same manner as in Example 13. However, instead of the silica-supported palladium catalyst continuously used in the circulation process (see Patent Document 1), the silica-alumina-supported palladium catalyst [K-0290 manufactured by Heraeus Co., Ltd.] 0.50 which was also used repeatedly in the circulation process was similarly used. Part by weight was used. The hydrogenation rate was 64.0%, the catalytic activity was 128.8 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/1160. The total reaction time for the evaluation was 3 hours.

Example 15
The hydrogenation catalyst was evaluated in the same manner as in Example 13. However, instead of the silica-supported palladium catalyst continuously used in the circulation process (see Patent Document 1), the silica-alumina-supported palladium catalyst [K-0290 manufactured by Heraeus Co., Ltd.] 0.30 which was used continuously and repeatedly in the circulation process. Part by weight was used. The hydrogenation rate was 42.8%, the catalytic activity was 143.3 Nml / mg-Pd * hr, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/3050. The total reaction time for the evaluation was 3 hours.

Comparative Example 1
The reaction was performed using a batch-type reaction tank (SUS 100 cc). The reaction vessel was charged with 0.1 parts by weight of the catalyst used in Example 1 and 20 parts by weight of the working solution. A SUS stirring blade was attached to the reaction vessel, and after air-tightness, the reaction system was replaced with hydrogen. The amount of hydrogen absorbed per unit catalyst amount was measured for 30 minutes with stirring at 1000 rpm. The reaction temperature was controlled at 30 ° C., and the reaction pressure was controlled at normal pressure. Hydrogen was put in advance in a glass container with a scale of 2 cc and having a capacity of 500 CC, and supplied to the reaction tank through a SUS tube for introducing hydrogen.
The hydrogenation selectivity of the hydrogenation catalyst was evaluated by a circulation device in which the reaction solvent circulates the reduction process, the oxidation process, and the extraction process to generate hydrogen peroxide. 200 parts by weight of the hydrogenation catalyst used in Example 1 was charged into the hydrogenation reactor in the reduction process of the circulation device, and anthraquinones were continuously hydrogenated to produce hydrogen peroxide. The working solution in the hydrogenation reactor was kept at about 4 liters, and 0.25 liter / min working solution and 1.8 liter / min hydrogen were supplied. The working solution in which anthraquinones were hydrogenated was separated from the catalyst through a candle filter and extracted from the hydrogenation reactor. Stirring was performed with inclined turbine blades so that sufficient mixing was obtained by baffles attached to the inner wall of the reactor. The reaction temperature of the hydrogenation reaction was 40 ° C. The working solution used was a solution prepared by dissolving 60% by volume of 1,2,4-trimethylbenzene and 40% by volume of diisobutylcarbinol so that the concentration of amylanthraquinone was 0.6 mol / L. The total amount of working solution in the circulation device was about 40 liters. The hydrogenation selectivity was determined by measuring the concentration of amylanthraquinone and amyltetrahydroanthraquinone in the working solution using liquid chromatography after producing hydrogen peroxide in a circulating reactor for 200 hours. The production amount of amylanthraquinone, amyltetrahydroanthraquinone and other by-products in the process was calculated and obtained as a ratio to the production amount of the main product.
The hydrogenation rate was 48%, the catalytic activity was 82.8 Nml / mg-Pd * 30 min, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/1150. The total reaction time for the evaluation was 200 hours.

Comparative Example 2
The hydrogenation catalyst was evaluated in the same manner as in Comparative Example 1. However, 200 parts by weight of the silica-supported palladium catalyst used in Example 4 (see Patent Document 1) was used as the hydrogenation catalyst. The hydrogenation rate was 41%, the catalytic activity was 57.4 Nml / mg-Pd * 30 min, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/1420. The total reaction time for the evaluation was 200 hours.

Comparative Example 3
The hydrogenation catalyst was evaluated in the same manner as in Comparative Example 1. However, 200 parts by weight of the silica-supported palladium catalyst used in Example 7 (see Patent Document 1) was used as the hydrogenation catalyst. The hydrogenation rate was 46%, the catalytic activity was 69.3 Nml / mg-Pd * 30 min, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/890. The total reaction time for the evaluation was 200 hours.

Comparative Example 4
The hydrogenation catalyst was evaluated in the same manner as in Comparative Example 1. However, as a hydrogenation catalyst, 100 parts by weight of a new catalyst of the silica-supported palladium catalyst used in Example 10 (see Patent Document 1) was used. The hydrogenation rate was 50%, the catalytic activity was 162.0 Nml / mg-Pd * 30 min, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was <1/5000. The total reaction time for the evaluation was 200 hours.

Comparative Example 5
The hydrogenation catalyst was evaluated in the same manner as in Comparative Example 1. However, the hydrogenation catalyst used was 200 parts by weight of the silica / alumina supported palladium catalyst used in Example 13 [K-0290 manufactured by Heraeus Co., Ltd.]. The hydrogenation rate was 38%, the catalytic activity was 38.2 Nml / mg-Pd * 30 min, and the ratio of amyltetrahydroanthraquinone / amylanthrahydroquinone was 1/4100. The total reaction time for the evaluation was 200 hours.
In the evaluation method of the present invention, almost the same result could be obtained simultaneously in a short time compared with the conventional method for measuring the activity of hydrogenation catalyst and hydrogenation selectivity.

Claims (3)

  While adding the working solution at a constant flow rate to the mixed solution of the hydrogenation catalyst used for the production of hydrogen peroxide by the anthraquinone method and the solvent used for the working solution, hydrogen per unit time is added while adding hydrogen. A method for evaluating a hydrogenation catalyst used in hydrogen peroxide production by an anthraquinone method, wherein the analysis is carried out by performing a hydrogenation reaction so that the amount of absorption is constant.   2. The method for evaluating a hydrogenation catalyst used in the production of hydrogen peroxide by the anthraquinone method according to claim 1, wherein the hydrogenation activity is evaluated from the catalyst amount and the hydrogen absorption amount. The method for evaluating a hydrogenation catalyst for use in the production of hydrogen peroxide by the anthraquinone method according to claim 1, wherein the selectivity is evaluated from a change in the composition of the reaction solution.