Method for preparing bis(aminomethyl)cyclohexane

Abstract

A method for producing bis(aminomethyl)cyclohexane by hydrogenating xylylenediamine in the presence of a solvent and a catalyst, wherein a catalyst whose activity has been reduced due to use is treated in a catalyst regeneration process comprising the following process (1) and process (2) and then reused in a reaction system. Process (1): The amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) is maintained at 20 mass% or less. Process (2): The catalyst is heated to 100 to 500°C and brought into contact with a hydrogen-containing gas.

Description

Technology Field

[0001] The present invention relates to a method for producing bis(aminomethyl)cyclohexane. Background Technology

[0002] Bis(aminomethyl)cyclohexane is an industrially important compound as a raw material for bis(isocyanatemethyl)cyclohexane, etc. Bis(aminomethyl)cyclohexane can be obtained, for example, by catalytic hydrogenation treatment of xylylenediamine. Patent Document 1 describes a method for producing bis(aminomethyl)cyclohexane by catalytic hydrogenation using a ruthenium catalyst and a solvent selected from alkylamines and alkylenediamines.

[0003] Patent Document 2 relates to the regeneration treatment of a catalyst used for the hydrogenation of dicyanobenzene, an aromatic dinitrile. Specifically, it is disclosed that a catalyst (nickel catalyst) used for the hydrogenation of dicyanobenzene in a liquid phase can be regenerated by contacting it with a hydrogen-containing gas in a temperature range of 200 to 500°C. Prior art literature

[0004] Japanese Patent No. 3974198, Japanese Patent Publication No. 2004-107327 The problem to be solved

[0005] In the production of bis(aminomethyl)cyclohexane, as in Patent Document 2, there is a problem in that the catalytic activity gradually decreases with use, making it impossible to obtain a satisfactory yield.

[0006] However, a problem arose in which catalyst regeneration could not be sufficiently performed even when the catalyst used for the hydrogenation of xylylenediamine was treated by the regeneration method disclosed in Patent Document 2. Upon investigating this problem, it was discovered that when the catalyst used for the hydrogenation of xylylenediamine is regenerated using a hydrogen-containing gas, the precipitates generated cause the following problems. For example, in a fixed-bed type reaction apparatus, problems occur in heat exchangers or filters on the manufacturing line due to the precipitates, making continued operation impossible. Furthermore, there are cases where precipitates form on the catalyst, and there is also a problem in that these precipitates hinder catalyst regeneration. Patent Document 1 does not disclose the regeneration of the catalyst used in the reaction.

[0007] The present invention aims to provide a method for producing bis(aminomethyl)cyclohexane by hydrogenation of xylylenediamine, wherein the catalyst whose activity has been reduced by the reaction can be regenerated and reused as a catalyst. means of solving the problem

[0008] As a result of careful consideration, the inventors have discovered that the above problem can be solved by maintaining the amount of bis(aminomethyl)cyclohexane in the liquid prior to the contact process with the hydrogen-containing gas at a specific amount in the catalyst regeneration process using a hydrogen-containing gas. That is, the present invention relates to the following.

[0009] A method for producing bis(aminomethyl)cyclohexane by hydrogenating xylylenediamine in the presence of a solvent and a catalyst, wherein a catalyst whose activity has been reduced due to use is treated by a catalyst regeneration process comprising the following process (1) and process (2) and then reused in a reaction system.

[0010] Process (1): The amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) is maintained at 20 mass% or less.

[0011] Process (2): The catalyst is heated to 100 to 500°C and brought into contact with a hydrogen-containing gas. Effects of the invention

[0012] According to the present invention, a method for producing bis(aminomethyl)cyclohexane can be provided, which allows for the regeneration of a catalyst whose activity has been reduced due to use, even in the production of bis(aminomethyl)cyclohexane by hydrogenation of xylylenediamine. According to the method of the present invention, it is possible to restore catalytic activity to enable reuse, and at the same time, prevent the precipitation of solid components in the manufacturing apparatus during catalyst regeneration. Therefore, it is possible to avoid the inability to control the apparatus or catalyst degradation during production, and bis(aminomethyl)cyclohexane can be produced safely and efficiently. Specific details for implementing the invention

[0013] The present invention relates to a method for producing bis(aminomethyl)cyclohexane by hydrogenating xylylenediamine in the presence of a solvent and a catalyst, wherein a catalyst whose activity has been reduced due to use is treated by a catalyst regeneration process comprising the following process (1) and process (2) and then reused in a reaction system.

[0014] Process (1): The amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) is maintained at 20 mass% or less.

[0015] Process (2): The catalyst is heated to 100 to 500°C and brought into contact with a hydrogen-containing gas.

[0016] Hereinafter, forms for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The present embodiment is an example for explaining the present invention and is not intended to limit the present invention to the contents below. The present invention may be carried out with appropriate modifications within the scope of its gist. In this specification, the notation "XX~YY" means "XX or more and YY or less."

[0017] Preparation of Bis(aminomethyl)cyclohexane

[0018] Bis(aminomethyl)cyclohexane is prepared by using at least one solvent selected from the group consisting of, for example, alkylamines and alkylenediamines, and hydrogenating xylylenediamine in the presence of a catalyst.

[0019] 1. Xylylenediamine

[0020] Xylylenediamine, which is a raw material, exists in three isomers: ortho, meta, and para, and these alone or a mixture thereof can all be used as raw materials. In the present embodiment, it is preferable to use at least one selected from the meta isomer and the para isomer as a raw material, and it is more preferable to use the meta isomer as a raw material.

[0021] 2. Solvent

[0022] In the preparation of bis(aminomethyl)cyclohexane of the present embodiment, it is preferable to use at least one selected from the group consisting of alkylamines and alkylenediamines as a solvent.

[0023] In the present embodiment, it is desirable to select a solvent that can be recycled. For example, it is desirable to select a solvent that can be recycled by distillation separation from the reaction product, or bis(aminomethyl)cyclohexane as an alkylenediamine solvent. As described below, bis(aminomethyl)cyclohexane has the advantage of not requiring distillation separation. Specifically, using at least one solvent selected from the group consisting of alkylamines and alkylenediamines having 1 to 18 carbon atoms, which is liquid at room temperature, is effective for suppressing the formation of by-products and increasing the yield of the target product.

[0024] Specific alkylamines include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, butylamine, dibutylamine, tributylamine, hexylamine, cyclohexylamine, and 2-ethylhexylamine. Specific alkylenediamines include ethylenediamine, propylenediamine, 1,4-butylenediamine, hexamethylenediamine, or bis(aminomethyl)cyclohexane.

[0025] Among these, bis(aminomethyl)cyclohexane is particularly advantageous in terms of process because the product obtained by the hydrogenation of xylylenediamine can also be reused as a solvent, and there is no need for solvent removal in subsequent processes. It is preferable that the bis(aminomethyl)cyclohexane used as a solvent be the same isomer as the product bis(aminomethyl)cyclohexane. For example, if the product is 1,3-bis(aminomethyl)cyclohexane, it is preferable that the bis(aminomethyl)cyclohexane used as a solvent be 1,3-bis(aminomethyl)cyclohexane.

[0026] As for the solvent, as described above, it is required to use at least one selected from the group consisting of alkylamines and alkylenediamines, which may be a single solvent or a mixture. A mixture of at least one selected from the group consisting of alkylamines and alkylenediamines and another organic solvent may also be used.

[0027] Other organic solvents to be mixed include alcohols such as methanol, ethanol, isopropyl alcohol, and n-propyl alcohol.

[0028] The weight ratio (xylylenediamine:solvent) between the raw material xylylenediamine and the solvent is preferably 1:100 to 1:1, more preferably 1:80 to 1:3, and even more preferably 1:50 to 1:10. When a mixed solvent is used as the solvent, the total weight of the mixed solvent satisfies the range of the above weight ratio.

[0029] 3. Catalyst

[0030] The catalyst used in the production of bis(aminomethyl)cyclohexane according to the present embodiment is not limited and may include known supported and unsupported metal catalysts and Rainey catalysts. Among these, a catalyst containing at least one metal selected from the group consisting of ruthenium, rhodium, nickel, cobalt, palladium, and platinum as an active metal component is preferred, and among these, a ruthenium-containing catalyst is preferred.

[0031] In the case of the supported catalyst, the carrier may be alumina, silica, diatomite, carbon, titania, zirconia, etc. If necessary, the catalyst may be modified by adding at least one component selected from the group consisting of Li, Na, K, Rb, Cs, Be, Ca, Ba, Ti, Cu, Cr, Zn, Mn, Mg, Fe, Ga, Ge, Nb, Ir, Pt, Bi, Al, Si, In, Sr, Ce, and Mo.

[0032] Examples of raw materials for ruthenium-containing catalysts include metallic ruthenium, ruthenium oxide, ruthenium hydroxide, etc., and it is preferable to use them in a form supported on alumina, diatomaceous earth, carbon, etc.

[0033] The loading amount of the ruthenium-containing catalyst is appropriately selected according to the type and shape of the catalyst, the type of ruthenium raw material, the reaction temperature, the amount of hydrogen supplied, etc. For example, when using an alumina support, a ruthenium-containing catalyst supported at a mass of about 2% on crushed alumina with a size of 1 mmφ to 2 mmφ can be used.

[0034] Among these, a ruthenium-supported alumina catalyst is preferred as a ruthenium-containing catalyst.

[0035] During the hydrogenation reaction, additives may be added for purposes such as promoting the reaction or improving the yield. Examples of additives include hydroxides or alcoholates of alkali metals or alkaline earth metals, and specifically, lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.

[0036] 4. Hydrogenation of xylylenediamine

[0037] The hydrogenation reaction can be performed in both fixed-bed and suspended forms, and either batch or continuous methods are possible; however, the fixed-bed continuous flow method is preferable due to its simplicity.

[0038] The hydrogen pressure in the hydrogenation of xylylenediamine is preferably 0.4 MPaG or higher, and industrially 5 to 14 MPaG is preferred. The reaction temperature is preferably 50 to 150°C, more preferably 80 to 130°C.

[0039] The amount of catalyst used in the hydrogenation of xylylenediamine is, for example, when using a catalyst supported with about 2 mass% of the above-mentioned ruthenium, the WHSV relative to the supply amount of the raw material xylylenediamine is preferably 0.001 to 5.0, more preferably 0.001 to 2.0.

[0040] In the hydrogenation reaction, it is desirable to select conditions such as reaction temperature and raw material supply amount so that the conversion rate of xylylenediamine is preferably 95 mol% or more, more preferably 98 mol% or more, and even more preferably substantially 100 mol%, in terms of the productivity of bis(aminomethyl)cyclohexane.

[0041] Separation of the target product from the reaction product can be easily carried out by removing alkylamines, alkylenediamines, and organic solvents at atmospheric pressure and vacuum distillation.

[0042] When hydrogenating xylylenediamine continuously using a solvent, there are methods such as separating the dissolved gas from the solution containing the reaction product using a gas-liquid separator, recovering it in a solvent recovery facility, and then separating it by distillation in the recovery facility to recycle the solvent, and methods such as separating a portion of the bis(aminomethyl)cyclohexane obtained by hydrogenation and recycling it as a solvent.

[0043] When using bis(aminomethyl)cyclohexane obtained by catalytic hydrogenation by the method of the present embodiment as a solvent, the dissolved gas can be separated from the reaction product in a gas-liquid separator and then directly circulated for use.

[0044] Catalyst Regeneration

[0045] In this embodiment, in the production of bis(aminomethyl)cyclohexane as described above, a catalyst whose activity has decreased due to use is regenerated by contacting it with a hydrogen-containing gas and then reused in the reaction system. The catalyst regeneration treatment in this embodiment is characterized by including a process (1) of maintaining the amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) at 20 mass% or less, and a process (2) of heating the catalyst to 100 to 500°C and contacting it with a hydrogen-containing gas. It is preferable to carry out this catalyst regeneration treatment within the reactor used for the hydrogenation reaction of bis(aminomethyl)cyclohexane, as this is simple and industrially advantageous.

[0046] Process (1)

[0047] In process (1), the amount of bis(aminomethyl)cyclohexane in the liquid prior to the subsequent process (2) is maintained at 20 mass% or less. If the amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) exceeds 20 mass%, solid precipitation occurs in the catalyst during process (2), making it impossible to regenerate the catalyst. The adjustment of the amount of bis(aminomethyl)cyclohexane in the liquid during process (1) can be performed, for example, by washing the catalyst using a washing solution.

[0048] Specifically, if the amount of bis(aminomethyl)cyclohexane in the liquid before process (2) exceeds 20 mass%, the catalyst can be cleaned using a cleaning solution until the amount of bis(aminomethyl)cyclohexane in the liquid after cleaning becomes 20 mass% or less, thereby maintaining the amount of bis(aminomethyl)cyclohexane in the liquid before process (2) at the amount specified in process (1).

[0049] The amount of bis(aminomethyl)cyclohexane in the liquid can be measured by taking a portion of the cleaning solution before and after cleaning and using known methods such as gas chromatography.

[0050] In this embodiment, the amount of bis(aminomethyl)cyclohexane in the liquid is the concentration of bis(aminomethyl)cyclohexane in the cleaning solution after cleaning when a cleaning solution is used, and the concentration of bis(aminomethyl)cyclohexane in the solution containing the reaction product obtained from the reactor when a cleaning solution is not used. The total mass of the liquid containing bis(aminomethyl)cyclohexane (provided that the mass of solid components such as catalysts mixed in the liquid is excluded) is set to 100 mass%.

[0051] I will explain it in more detail.

[0052] When bis(aminomethyl)cyclohexane is used as the reaction solvent, the amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) usually exceeds 20 mass%. Therefore, according to one aspect of the present embodiment, in process (1), the catalyst is washed using a washing solution until the amount of bis(aminomethyl)cyclohexane in the liquid becomes 20 mass% or less. If the amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) is 20 mass% or less, the washing process may not be performed and the process may proceed to process (2).

[0053] When a solvent other than bis(aminomethyl)cyclohexane is used as a reaction solvent in the production of bis(aminomethyl)cyclohexane, if the amount of bis(aminomethyl)cyclohexane specified in process (1) is satisfied, the process proceeds to the subsequent process (2) without performing the washing treatment, etc. Even when a solvent other than bis(aminomethyl)cyclohexane is used, if the amount of bis(aminomethyl)cyclohexane before process (2) exceeds 20 mass%, as described above, the amount of bis(aminomethyl)cyclohexane in the liquid can be adjusted to satisfy the requirements of process (1) by washing treatment with a washing solution.

[0054] As the above cleaning solution, at least one selected from the group consisting of water, aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and alcohols may be used, and these may be alone or as a mixture. Examples of aliphatic hydrocarbons include n-hexane, n-heptane, cyclohexane, etc. Examples of aromatic hydrocarbons include metaxylene, paraxylene, orthoxylene, benzene, toluene, etc. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Examples of alcohols include methanol, ethanol, isopropyl alcohol, normal propyl alcohol, isobutyl alcohol, normal butyl alcohol, etc. Among these, at least one selected from the group consisting of water, aliphatic hydrocarbons with 5 to 15 carbon atoms, aromatic hydrocarbons with 6 to 15 carbon atoms, ketones with 3 to 15 carbon atoms, and alcohols with 1 to 15 carbon atoms is preferred, and from the perspective of safety, environment, and cost, it is more preferable that the cleaning solution be water alone or contain water.

[0055] The cleaning solution may be at room temperature or heated. When heating the cleaning solution, for example, if the cleaning solution is water, it is preferable to heat it to 30 to 90°C so that it does not volatilize at atmospheric pressure.

[0056] The inventors have detected that when hydrogen regeneration treatment of a catalyst is performed in a bis(aminomethyl)cyclohexane manufacturing line, solid precipitation occurs in the catalyst layer or in the heat exchanger used in the subsequent process, causing manufacturing trouble. This phenomenon is not observed in the regeneration treatment of a catalyst used for the hydrogenation of dicyanobenzene as described in Patent Document 2. As a result of careful examination, it was discovered that the above trouble is resolved by maintaining the amount of bis(aminomethyl)cyclohexane in the liquid before contacting the catalyst with a hydrogen-containing gas in process (2) at 20 mass% or less. According to one aspect of the present embodiment, the amount of bis(aminomethyl)cyclohexane in process (1) can be adjusted by washing the catalyst using a washing solution as described above.

[0057] In process (1), the amount of bis(aminomethyl)cyclohexane in the liquid prior to process (2) is preferably maintained at 18 mass% or less, more preferably 15 mass% or less, and even more preferably 10 mass% or less.

[0058] The cleaning method is not particularly limited; the catalyst may be cleaned within the reactor used to produce bis(aminomethyl)cyclohexane, or the catalyst may be removed from the production reactor and cleaned separately. It is not particularly limited. Cleaning within the production reactor is preferable as it allows for process simplification and is industrially advantageous.

[0059] As cleaning methods, examples include (i) a method of filling the catalyst layer with a cleaning solution and repeatedly expelling the solution, and (ii) a method of circulating the cleaning solution through the catalyst layer. In either case (i) or (ii) as a cleaning method, the cleaning solution may be circulated to increase cleaning efficiency.

[0060] When circulating the cleaning solution, the circulation time varies depending on the amount of catalyst, but generally, about 0.5 to 10 hours is desirable. To increase cleaning efficiency, in the case of the cleaning type of (i) above, after circulating the solution once, a new cleaning solution may be filled, and this may be repeated.

[0061] Process (2)

[0062] In the process, the catalyst is heated to 100 to 500°C and brought into contact with a hydrogen-containing gas to regenerate the catalyst with reduced activity. If the treatment temperature is lower than 100°C, the effect of the regeneration treatment is insufficient, and if it exceeds 500°C, there is a risk that the catalyst will deteriorate.

[0063] The regeneration treatment of the catalyst may be carried out in the reactor in which bis(aminomethyl)cyclohexane was produced, or it may be carried out when the catalyst is discharged from the reactor. Since it is simple and also industrially advantageous, it is preferable to carry out the treatment in the reactor in which bis(aminomethyl)cyclohexane was produced. As described above, this reactor is preferably a fixed-bed reactor.

[0064] In the present embodiment, the regeneration treatment is performed at a rate of temperature rise of the catalyst while in contact with a hydrogen-containing gas, preferably 40°C / min or less (including zero), more preferably 30°C / min or less, and even more preferably 20°C / min or less. As described above, it is preferable to perform the regeneration treatment with a hydrogen-containing gas in the range of 100 to 500°C; however, even when the catalyst is in contact with the hydrogen-containing gas at a temperature below 100°C prior to the regeneration treatment in this temperature range, it is preferable to control the rate of temperature rise of the catalyst to 40°C / min or less. During the regeneration treatment of the catalyst with a hydrogen-containing gas, the temperature of the catalyst may rise rapidly during the treatment and become uncontrollable. A rapid rise in the temperature of the catalyst is undesirable in terms of safety and stability of manufacturing operations, and it must be avoided as it causes deterioration of catalyst performance.

[0065] According to the findings of the present invention, the temperature rise of the catalyst is closely related to the supply rate of the hydrogen-containing gas during the regeneration process. Therefore, by controlling the supply rate of the hydrogen-containing gas during the regeneration process, a rapid rise in the temperature of the catalyst can be avoided. That is, by setting the supply rate of the hydrogen-containing gas low, it becomes possible to avoid a rapid rise in the temperature of the catalyst that may occur. It is preferable to adjust the supply rate of the hydrogen-containing gas to a rate such that the rate of temperature rise of the catalyst is 40°C / min or less. The specific supply rate of the hydrogen-containing gas varies depending on the type of catalyst, its usage history, and the temperature of the catalyst, but is preferably 0.001 to 2000 NL / h (N: standard conditions (0°C, 1 atm)), more preferably 0.001 to 1000 NL / h per 1 kg of catalyst.

[0066] The hydrogen-containing gas used for catalyst regeneration may contain inert impurities that do not interfere with catalyst regeneration, such as methane and nitrogen. The hydrogen pressure is preferably 0.01 kPa to 30 MPa, and more preferably 0.1 kPa to 15 MPa. When setting the hydrogen pressure low (e.g., 0.1 MPa or less), it is convenient and preferable to use an inert diluent gas such as nitrogen.

[0067] In the present embodiment, it is preferable to perform the regeneration process (2) using a hydrogen-containing gas in the following two steps. That is, it is more preferable to perform the regeneration treatment of the catalyst using a hydrogen-containing gas by two steps: (2-1) a process of contacting the catalyst with a hydrogen-containing gas for, for example, 1 hour or more at a temperature in the range of 100 to 200°C and an average temperature of 180°C or less (hereinafter referred to as a low-temperature treatment process), and (2-2) a process of additionally contacting the catalyst contacted in the above step (2-1) with a hydrogen-containing gas at a temperature in the range of 200°C to 500°C (hereinafter referred to as a high-temperature treatment process). By performing the regeneration treatment in the above two steps, the catalyst can be regenerated more sufficiently. Furthermore, by performing the regeneration treatment in two steps, the heat generation and gas generation caused by the regeneration treatment can be slowed down, which is particularly desirable for industrial-scale equipment.

[0068] (2-1) Low-temperature processing

[0069] In the low-temperature treatment process (2-1), the temperature during catalyst regeneration is in the range of 100 to 200°C, preferably 120 to 180°C, and the average temperature is 180°C or lower. This average temperature represents the time-averaged temperature in the low-temperature treatment process carried out at 100 to 200°C, and is defined by the value obtained by integrating the temperature over time and dividing it by the length of the treatment time. In the low-temperature treatment process (2-1), the temperature during treatment may be varied as long as it is in the range of 100 to 200°C. For example, it is possible to have a process that combines a constant temperature maintenance process with a temperature increase or decrease process.

[0070] The processing time of the low-temperature treatment process is typically 1 hour or more, and preferably 1 to 200 hours.

[0071] In the low-temperature treatment process (2-1), hydrogen is supplied so that the rate of increase of the catalyst temperature is preferably 40°C / min or less (including zero), more preferably 30°C / min or less, and particularly preferably 20°C / min or less.

[0072] (2-2) High-temperature treatment process

[0073] The temperature during catalyst regeneration in the high-temperature treatment process (2-2) is in the range of 200°C to 500°C, preferably 210°C to 400°C, and more preferably 220°C to 350°C. In the high-temperature treatment process (2-2), the temperature being treated may be changed within the above range. For example, it is possible to have a process that combines a constant temperature maintenance process with a temperature increase or decrease process.

[0074] The processing time of the high-temperature treatment process can typically be selected from a range of 3 to 300 hours. The processing time and temperature depend on the type of catalyst or the degree of activity degradation. In cases where the degree of activity degradation is severe, it is desirable to take a longer processing time.

[0075] In the high-temperature treatment process (2-2), it is preferable to supply hydrogen while controlling the rate of temperature increase of the catalyst to preferably be 40°C / min or less (including zero), more preferably 30°C / min or less, and particularly preferably 20°C / min or less.

[0076] As described above, the rise in the temperature of the catalyst is closely related to the hydrogen supply rate during the regeneration process. Therefore, in the low-temperature treatment process (2-1) and the high-temperature treatment process (2-2), a rapid rise in the temperature of the catalyst can be avoided by controlling the hydrogen supply rate in the low-temperature treatment process and the high-temperature treatment process.

[0077] The hydrogen supply rate is adjusted while monitoring the temperature of the catalyst so that the rate of temperature increase of the catalyst is 40°C / min or less. The specific hydrogen supply rate varies depending on the type of catalyst, usage history, and the temperature of the catalyst, but is preferably 0.001 to 2000 NL / h (N: standard conditions (0°C, 1 atm)), more preferably 0.001 to 1000 NL / h per 1 kg of catalyst.

[0078] The hydrogen-containing gas used in the low-temperature treatment process (2-1) and the high-temperature treatment process (2-2) may contain inert impurities that do not hinder catalyst regeneration, such as methane and nitrogen. The hydrogen pressure in the low-temperature treatment process (2-1) and the high-temperature treatment process (2-2) is preferably 0.01 kPa to 30 MPa, more preferably 0.1 kPa to 15 MPa. When the hydrogen pressure is set low (e.g., 0.1 MPa or less), it is convenient and preferable to use an inert diluent gas such as nitrogen. The composition of the hydrogen-containing gas used in the low-temperature treatment process (2-1) and the high-temperature treatment process (2-2) may be the same or different.

[0079] Through the regeneration treatment described above, catalyst regeneration can be performed while preventing the precipitation of solids on the catalyst, and the catalyst activity reduced by use can be restored. For example, if the regeneration treatment is performed in a fixed-bed format, the precipitation of solids on the catalyst layer can be prevented, so the regeneration treatment can be performed without problems.

[0080] By regeneration treatment, the catalyst recovers its activity and can be reused as a catalyst for the hydrogenation reaction of xylylenediamine, making it possible to produce bis(aminomethyl)cyclohexane.

[0081] Examples

[0082] The present invention will be described in detail based on the embodiments shown below, but the present invention is not limited by these embodiments.

[0083] Example 1

[0084] Hydrogenation of Xylylendiamine

[0085] As a catalyst, a commercially available 2 mass% ruthenium-supported alumina catalyst was used.

[0086] 130 kg of catalyst was loaded into a fixed-bed continuous flow tubular reactor (inner diameter 34 cm, packing height 200 cm). After activating the catalyst by reducing it at 260°C under a hydrogen stream, a mixture consisting of 5 mass% of metaxylylenediamine as a raw material and 95 mass% of 1,3-bis(aminomethyl)cyclohexane as a solvent was supplied to the reactor under conditions of a reaction pressure of 8 MPaG and a reaction temperature of 100°C. The raw material supply rate (representing the mixture of the raw material and the solvent) was set to 11 kg / h.

[0087] As a result of analyzing the obtained reactor outlet liquid by gas chromatography, the conversion rate of metaxylylenediamine was 99.5 mol%. After carrying out the reaction for 90 days, the conversion rate of metaxylylenediamine decreased to 98.8 mol%, so the reaction was stopped.

[0088] The conversion rate of metaxylylendiamine (hereinafter also referred to as "MXDA") was calculated by the following method.

[0089] Conversion rate (mol%) = ((Mass of MXDA in feed liquid - Mass of MXDA in reactor outlet liquid) / Molecular weight of MXDA) / (Mass of MXDA in feed liquid / Molecular weight of MXDA) × 100

[0090] The conditions for gas chromatography are as follows.

[0091] Device: Product name "GC-2010 plus" manufactured by Shimadzu Corporation

[0092] Column: DB-1, Agilent Technologies, Inc. (inner diameter 0.53 mm, length 30 m, film thickness 1.50 μm)

[0093] Carrier gas: He gas was distributed at a flow rate of 2.3 mL / min.

[0094] Sample injection volume: 1.0μL

[0095] Detector: Hydrogen Flame Ionization Detector (FID)

[0096] Detector temperature: 280℃

[0097] Vaporization chamber temperature: 280℃

[0098] Temperature increase conditions: Maintained at 100℃ for 18 minutes, then increased to 120℃ at a rate of 5℃ / min and maintained for 20 minutes. Afterwards, increased to 280℃ at a rate of 10℃ / min and maintained for 10 minutes.

[0099] Sample preparation method: For 0.1g of sample, 0.1g of diphenylmethane was added as an internal standard and diluted with 10g of methanol.

[0100] Catalyst Regeneration Treatment

[0101] After setting the pressure of the reactor to atmospheric pressure, the catalyst layer was washed with water until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was 15 mass% (Process (1)).

[0102] The amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was quantified by gas chromatography after collecting the wash solution. The conditions for gas chromatography are as follows.

[0103] (Gas chromatography measurement conditions)

[0104] Device: Product name "GC-2010 plus" manufactured by Shimadzu Corporation

[0105] Column: CP-Volamine, Agilent Technologies, Inc. (inner diameter 0.32 mm, length 60 m)

[0106] Carrier gas: He gas was circulated at a flow rate of 1.5 mL / min.

[0107] Sample injection volume: 1.0μL

[0108] Detector: Hydrogen Flame Ionization Detector (FID)

[0109] Detector temperature: 260℃

[0110] Vaporization chamber temperature: 230℃

[0111] Temperature increase conditions: Maintained at 230℃ for 35 minutes.

[0112] Sample preparation method: For 0.1g of sample, 0.1g of diphenylmethane was added as an internal standard and diluted with 10g of methanol.

[0113] Next, hydrogen gas was supplied to the catalyst layer after cleaning at a rate of 240 NL / h per 1 kg of catalyst, heated from room temperature to 150°C, and then maintained hydrogen flow at 150°C for 2 hours (low temperature heating process (2-1)). Next, the temperature was raised to 260°C at a rate of 0.1°C / min, and then maintained hydrogen flow at 260°C for 10 hours (high temperature heating process (2-2)), and then lowered to room temperature. Meanwhile, in process (2), no increase in the catalyst temperature of 40°C / min or more was observed, and the rate of increase in the catalyst temperature was 1°C / min or less.

[0114] Hydrogenation reaction using a regenerative catalyst

[0115] Using the regenerated catalyst, the hydrogenation reaction of xylylenediamine was carried out under the same conditions as above. At a reaction temperature of 100°C, the conversion rate of metaxylylenediamine was 99.8 mol%, showing results almost equivalent to those obtained using an unused catalyst.

[0116] Example 2

[0117] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 1. After stopping the hydrogenation reaction, catalyst regeneration treatment was performed in the same manner as in Example 1, except that the catalyst layer was washed with water until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was 1 mass% (Process (1)). The catalyst after regeneration treatment could be reused in the same manner as in Example 1. In Example 2 as well, no increase in the catalyst temperature of 40°C / min or more was observed in Process (2), and the rate of increase in the catalyst temperature was 1°C / min or less.

[0118] Example 3

[0119] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 1. After stopping the hydrogenation reaction, catalyst regeneration treatment was performed in the same manner as in Example 1, except that the catalyst layer was washed with water until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was 5 mass% (Process (1)). The catalyst after regeneration treatment could be reused in the same manner as in Example 1. In Example 3 as well, no increase in the catalyst temperature of 40°C / min or more was observed in Process (2), and the rate of increase in the catalyst temperature was 1°C / min or less.

[0120] Comparative Example 1

[0121] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 1. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 1, except that the catalyst layer was not cleaned. However, about 7 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

[0122] Comparative Example 2

[0123] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 1. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 1, except that the catalyst layer was washed with water until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid reached 50 mass%. However, about 11 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

[0124] Comparative Example 3

[0125] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 1. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 1, except that the catalyst layer was washed with water until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid reached 30 mass%. However, about 13 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

[0126] Example 4

[0127] As a catalyst, a 2 mass% ruthenium-supported alumina catalyst was used.

[0128] Catalyst 0.14m 3 The catalyst was charged into a tubular reactor (inner diameter 34 cm, charging height 200 cm). After activating the catalyst by reducing it at 260°C under a hydrogen stream, a mixture consisting of 5 mass% of metaxylylenediamine as a raw material and 95 mass% of 1,3-bis(aminomethyl)cyclohexane as a solvent was supplied to the reactor under conditions of a reaction pressure of 8 MPaG and a reaction temperature of 100°C. The raw material supply rate (representing the mixture of the raw material and the solvent) was set to 11 kg / h.

[0129] After carrying out the reaction for 90 days, the reaction was stopped. After setting the pressure of the reactor to atmospheric pressure, the catalyst layer was washed with methanol until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was 15 mass% (Process (1)).

[0130] Hydrogen gas was supplied at a rate of 240 NL / h per 1 kg of catalyst, heated from room temperature to 150°C, and then maintained hydrogen flow at 150°C for 2 hours (low-temperature heating process (2-1)). Subsequently, the temperature was raised to 260°C at a rate of 0.1°C / min, and then maintained hydrogen flow at 260°C for 10 hours (high-temperature heating process (2-2)), after which the temperature was lowered to room temperature. The catalyst after the regeneration treatment could be reused in the same way as in Example 1. Meanwhile, in process (2), no increase in the catalyst temperature of 40°C / min or more was observed, and the rate of increase in the catalyst temperature was 1°C / min or less.

[0131] Comparative Example 4

[0132] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 4. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 4, except that the catalyst layer was washed with methanol until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid reached 50 mass%. However, about 12 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

[0133] Comparative Example 5

[0134] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 4. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 4, except that the catalyst layer was washed with methanol until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid reached 30 mass%. However, about 18 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

[0135] Example 5

[0136] As a catalyst, a 2 mass% ruthenium-supported alumina catalyst was used.

[0137] Catalyst 0.14m 3 The catalyst was charged into a tubular reactor (inner diameter 34 cm, charging height 200 cm). After activating the catalyst by reducing it at 260°C under a hydrogen stream, a mixture consisting of 5 mass% of metaxylylenediamine as a raw material and 95 mass% of 1,3-bis(aminomethyl)cyclohexane as a solvent was supplied to the reactor under conditions of a reaction pressure of 8 MPaG and a reaction temperature of 100°C. The raw material supply rate (representing the mixture of the raw material and the solvent) was set to 11 kg / h.

[0138] After carrying out the reaction for 90 days, the reaction was stopped. After setting the pressure of the reactor to atmospheric pressure, the catalyst layer was washed with metaxylene until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was 15 mass% (Process (1)).

[0139] Hydrogen gas was supplied at a rate of 240 NL / h per 1 kg of catalyst, heated from room temperature to 150°C, and then maintained hydrogen flow at 150°C for 2 hours (low-temperature heating process (2-1)). Subsequently, the temperature was raised to 260°C at a rate of 0.1°C / min, and then maintained hydrogen flow at 260°C for 10 hours (high-temperature heating process (2-2)), after which the temperature was lowered to room temperature. The catalyst after the regeneration treatment could be reused in the same way as in Example 1. Meanwhile, in process (2), no increase in the catalyst temperature of 40°C / min or more was observed, and the rate of increase in the catalyst temperature was 1°C / min or less.

[0140] Comparative Example 6

[0141] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 5. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 5, except that the catalyst layer was washed with metaxylene until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid reached 30 mass%. However, about 23 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

[0142] Example 6

[0143] As a catalyst, a 2 mass% ruthenium-supported alumina catalyst was used.

[0144] Catalyst 0.14m 3 The catalyst was charged into a tubular reactor (inner diameter 34 cm, charging height 200 cm). After activating the catalyst by reducing it at 260°C under a hydrogen stream, a mixture consisting of 5 mass% of metaxylylenediamine as a raw material and 95 mass% of 1,3-bis(aminomethyl)cyclohexane as a solvent was supplied to the reactor under conditions of a reaction pressure of 8 MPaG and a reaction temperature of 100°C. The raw material supply rate (representing the mixture of the raw material and the solvent) was set to 11 kg / h.

[0145] After carrying out the reaction for 90 days, the reaction was stopped. After setting the pressure of the reactor to atmospheric pressure, the catalyst layer was washed with acetone until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was 15 mass% (Process (1)).

[0146] Hydrogen gas was supplied at a rate of 240 NL / h per 1 kg of catalyst, heated from room temperature to 150°C, and then maintained hydrogen flow at 150°C for 2 hours (low-temperature heating process (2-1)). Subsequently, the temperature was raised to 260°C at a rate of 0.1°C / min, and then maintained hydrogen flow at 260°C for 10 hours (high-temperature heating process (2-2)), after which the temperature was lowered to room temperature. The catalyst after the regeneration treatment could be reused in the same way as in Example 1. Meanwhile, in process (2), no increase in the catalyst temperature of 40°C / min or more was observed, and the rate of increase in the catalyst temperature was 1°C / min or less.

[0147] Comparative Example 7

[0148] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 6. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 6, except that the catalyst layer was washed with acetone until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid reached 30 mass%. However, about 19 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

[0149] Example 7

[0150] As a catalyst, a 2 mass% ruthenium-supported alumina catalyst was used.

[0151] Catalyst 0.14m 3 The catalyst was charged into a tubular reactor (inner diameter 34 cm, charging height 200 cm). After activating the catalyst by reducing it at 260°C under a hydrogen stream, a mixture consisting of 5 mass% of metaxylylenediamine as a raw material and 95 mass% of 1,3-bis(aminomethyl)cyclohexane as a solvent was supplied to the reactor under conditions of a reaction pressure of 8 MPaG and a reaction temperature of 100°C. The raw material supply rate (representing the mixture of the raw material and the solvent) was set to 11 kg / h.

[0152] After carrying out the reaction for 90 days, the reaction was stopped. After setting the pressure of the reactor to atmospheric pressure, the catalyst layer was washed with n-heptane until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid was 15 mass% (Process (1)).

[0153] Hydrogen gas was supplied at a rate of 240 NL / h per 1 kg of catalyst, heated from room temperature to 150°C, and then maintained hydrogen flow at 150°C for 2 hours (low-temperature heating process (2-1)). Subsequently, the temperature was raised to 260°C at a rate of 0.1°C / min, and then maintained hydrogen flow at 260°C for 10 hours (high-temperature heating process (2-2)), after which the temperature was lowered to room temperature. The catalyst after the regeneration treatment could be reused in the same way as in Example 1. Meanwhile, in process (2), no increase in the catalyst temperature of 40°C / min or more was observed, and the rate of increase in the catalyst temperature was 1°C / min or less.

[0154] Comparative Example 8

[0155] Hydrogenation of metaxylylenediamine was performed in the same manner as in Example 7. After stopping the hydrogenation reaction, a catalyst regeneration treatment was attempted by contacting the catalyst with hydrogen gas in the same manner as in Example 7, except that the catalyst layer was washed with heptane until the amount of 1,3-bis(aminomethyl)cyclohexane in the liquid reached 30 mass%. However, about 18 hours after the supply of hydrogen gas, the flow rate of hydrogen gas decreased by about 35%. Solid products precipitated on the catalyst layer, and the heat exchanger used in the subsequent process became clogged, making it impossible to perform the catalyst regeneration treatment.

Claims

Claim 1 A method for producing bis(aminomethyl)cyclohexane by hydrogenating xylylenediamine in a fixed-bed reactor in the presence of a solvent and a catalyst, wherein the solvent comprises at least one selected from the group consisting of alkylamines and alkylenediamines, and the catalyst whose activity has been reduced due to use is reused in a reaction system after being treated by a catalyst regeneration process comprising the following process (1) and process (2), and the catalyst regeneration process is performed in the fixed-bed reactor. Process (1): Before process (2), the catalyst is washed using at least one selected from the group consisting of water, aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and alcohols as a washing solution, and the catalyst is washed until the amount of bis(aminomethyl)cyclohexane in the washing solution after washing becomes 20 mass% or less. Process (2): The catalyst is heated to 100 to 500°C and brought into contact with a hydrogen-containing gas. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A method for producing bis(aminomethyl)cyclohexane according to claim 1, wherein the process (2) comprises the following processes (2-1) and (2-2). (2-1) A process of contacting the catalyst with a hydrogen-containing gas at a temperature in the range of 100 to 200°C, wherein the average temperature is 180°C or lower. (2-2) A process of further contacting the catalyst contacted in the process (2-1) with a hydrogen-containing gas at a temperature in the range of greater than 200°C to 500°C. Claim 6 A method for producing bis(aminomethyl)cyclohexane according to claim 1, wherein the contact with the hydrogen-containing gas of the above process (2) is performed under conditions where the rate of increase of the catalyst temperature is 40°C / min or less. Claim 7 A method for producing bis(aminomethyl)cyclohexane according to claim 1, wherein in the process (2) above, the supply rate of hydrogen-containing gas is controlled so that the rate of increase of the catalyst temperature is 40℃ / min or less. Claim 8 A method for producing bis(aminomethyl)cyclohexane according to claim 1, wherein the hydrogen-containing gas supply rate in the process (2) is 0.001 to 1000 L / h per 1 kg of catalyst at standard conditions of 0°C and 1 atm. Claim 9 delete Claim 10 A method for producing bis(aminomethyl)cyclohexane according to any one of claims 1 and 5 to 8, wherein the catalyst comprises at least one selected from the group consisting of a ruthenium-containing catalyst, a rhodium-containing catalyst, a nickel-containing catalyst, a palladium-containing catalyst, and a platinum-containing catalyst. Claim 11 A method for producing bis(aminomethyl)cyclohexane according to any one of claims 1 and 5 to 8, wherein the catalyst is a ruthenium-containing catalyst.

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