Post-treatment method of product mixture for producing methyl isoamyl ketone

Abstract

The invention relates to a post-treatment method of a product mixture for producing methyl isoamyl ketone. The post-treatment method comprises the following steps: measuring the contents of methyl isoamyl ketone and methyl isobutyl ketone in the product mixture; determining the ratio of the dosage of p-aminodiphenylamine to the product mixture according to the measured contents of methyl isoamyl ketone and methyl isobutyl ketone; adding p-aminodiphenylamine according to the determined proportion; the method comprises the following steps: under the action of a hydrogenation catalyst, carrying out condensation hydrogenation reaction in hydrogen to obtain a phenyl p-phenylenediamine mixture of N-(1, 3-dimethyl butyl)-N '-phenyl p-phenylenediamine and N-(1, 4-dimethyl amyl)-N'-phenyl p-phenylenediamine. According to the method disclosed by the invention, the ratio of methyl isoamyl ketone to methyl isobutyl ketone can be flexibly adjusted according to the content of each component in the required phenyl p-phenylenediamine mixture by utilizing the composition characteristic that the product of a methyl isoamyl ketone production process comprises methyl isoamyl ketone and methyl isobutyl ketone; therefore, the target p-aminophenylenediamine mixture can be directly obtained from the product mixture.

Description

Technical Field

[0001] The present invention relates to the technical field of compound preparation, and particularly to a post-treatment method for a product mixture in the production of Methyl Isoamyl Ketone (MIAK). Background Art

[0002] Methyl Isoamyl Ketone, also known as 5-methyl-2-hexanone, is an important organic compound. It can be used as an organic solvent in the coating field, or as a raw material or intermediate for synthesizing other compounds or drugs. It can also be used as an extractant and a cleaning agent in the electronics industry.

[0003] For the product mixture generated during the production of Methyl Isoamyl Ketone, the traditional post-treatment method usually involves separating and purifying each product in the product mixture. This method often has problems such as complex processes, high energy consumption, and large product losses. For example, the separation efficiency is low, and it is difficult to precisely control the product ratio. These limitations not only affect the production efficiency and economic benefits but also may cause certain pressure on the environment. Therefore, a post-treatment method is needed that can provide an efficient, economical, and environmentally friendly post-treatment process to improve the product quality and yield and achieve the effective utilization of resources. Summary of the Invention

[0004] The present invention provides a post-treatment method for a product mixture in the production of Methyl Isoamyl Ketone. According to the characteristics that the main components of the product mixture are Methyl Isoamyl Ketone and Methyl Isobutyl Ketone (MIBK), without performing complex product separation processes, it is directly used to react with p-phenylenediamine to prepare a phenyl-p-phenylenediamine mixture.

[0005] According to one aspect of the present invention, a post-treatment method for a product mixture in the production of Methyl Isoamyl Ketone is provided, including the following steps:

[0006] Determine the contents of Methyl Isoamyl Ketone and Methyl Isobutyl Ketone in the product mixture;

[0007] Determine the ratio of the dosage of p-phenylenediamine to the product mixture according to the determined contents of Methyl Isoamyl Ketone and Methyl Isobutyl Ketone;

[0008] Add p-phenylenediamine to the product mixture according to the determined ratio;

[0009] Under the action of a hydrogenation catalyst, carry out a condensation hydrogenation reaction in a hydrogen atmosphere to obtain a phenyl-p-phenylenediamine mixture including N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine.

[0010] According to one embodiment, the ratio of the total molar amount of methyl isopentyl ketone and methyl isobutyl ketone to the molar amount of p-aminodiphenylamine is (1 to 3):1.

[0011] According to one embodiment, the post-treatment method further includes comparing the measured content ratio of methyl isopentyl ketone and methyl isobutyl ketone with the required ratio of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine in the target phenyl-p-phenylenediamine mixture, and determining whether to add methyl isopentyl ketone and / or methyl isobutyl ketone to the product mixture and the corresponding addition amount according to the comparison result.

[0012] According to one embodiment, the post-treatment method further includes pre-recovering the solvent in the product mixture.

[0013] Among them, pre-recovering the solvent in the product mixture includes recovering acetone by vacuum distillation at 55°C.

[0014] According to one embodiment, the hydrogenation catalyst is a noble metal catalyst, and the dosage is 0.1 to 5% of the total mass of methyl isopentyl ketone and methyl isobutyl ketone. Among them, the noble metal catalyst is one or more of platinum-carbon catalyst and palladium-carbon catalyst.

[0015] According to one embodiment, the post-treatment method further includes a purification step to obtain a purified phenyl-p-phenylenediamine mixture.

[0016] Among them, the purification step includes filtration, liquid separation, and distillation steps.

[0017] According to one embodiment, the reaction temperature of the condensation hydrogenation reaction is 60 to 120°C; the reaction pressure is 0.5 to 3.0 MPa.

[0018] According to the post-treatment method of the present invention, complex separation and purification steps for the product mixture for producing methyl isopentyl ketone are avoided. By utilizing the characteristics that the main components of the product mixture are MIAK and MIBK, the product mixture is directly used for synthesizing downstream products, that is, for carrying out a condensation hydrogenation reaction with p-aminodiphenylamine, thereby preparing a phenyl-p-phenylenediamine mixture for use as an antioxidant. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a process flow chart of the post-treatment method according to the present invention;

[0020] Figure 2 is a gas chromatogram of the product mixture solution according to Example 1 of the present invention;

[0021] Figure 3is the gas chromatogram of the product mixture according to Embodiment 2 of the present invention;

[0022] Figure 4 is the gas chromatogram of the product mixture according to Embodiment 3 of the present invention;

[0023] Figure 5 is the gas chromatogram of the product mixture according to Embodiment 4 of the present invention. Detailed implementation manners

[0024] The conventional methods for treating the product mixture of producing methyl isopentyl ketone usually include separating and purifying each component therein. The separation methods are carried out through steps such as filtration, liquid separation, and multi-stage rectification. Since there are multiple components in the product mixture, the processes of separating and purifying them separately are relatively complex, energy-consuming, and the yield of the product will decrease.

[0025] The present invention provides a post-treatment method for the product mixture of producing methyl isopentyl ketone, without separately separating and purifying the components in the product mixture, but using the whole as a synthesis raw material for the preparation of phenyl-p-phenylenediamine mixture, thereby improving the raw material utilization rate and reducing the production cost.

[0026] The present invention mainly aims at the product mixture of preparing methyl isopentyl ketone with acetone and isobutyraldehyde as starting materials. Its main components include methyl isopentyl ketone and methyl isobutyl ketone. For example, it may include about 92% of MIAK and about 5% of MIBK. In this application, the proportions of methyl isopentyl ketone and methyl isobutyl ketone can be adjusted according to actual needs.

[0027] See Figure 1 , the post-treatment method for the product mixture of producing methyl isopentyl ketone according to the present invention includes the following steps:

[0028] Determine the contents of methyl isopentyl ketone and methyl isobutyl ketone in the product mixture;

[0029] Determine the ratio of the dosage of p-phenylenediamine to the product mixture according to the determined contents of methyl isopentyl ketone and methyl isobutyl ketone;

[0030] Add p-phenylenediamine to the product mixture according to the determined ratio;

[0031] Under the action of a hydrogenation catalyst, carry out a condensation hydrogenation reaction in a hydrogen atmosphere to obtain a phenyl-p-phenylenediamine mixture (also called EPPD) including N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (also called 6PPD) and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine (also called 7PPD).

[0032] Among them, the contents of methyl isopentyl ketone and methyl isobutyl ketone in the product mixture can be accurately determined by gas chromatography, high performance liquid chromatography or gas chromatography-mass spectrometry. Then, according to the determined contents of methyl isopentyl ketone and methyl isobutyl ketone, the ratio of the dosage of p-phenylenediamine to the product mixture is determined.

[0033] To facilitate the accurate determination of the contents of methyl isopentyl ketone and methyl isobutyl ketone, the product mixture is usually filtered first to remove the catalyst therein; further, the filtrate is rectified to recover the solvent, for example, acetone is recovered by vacuum rectification at 55°C.

[0034] The reaction formulas of methyl isobutyl ketone and methyl isopentyl ketone with p-phenylenediamine are shown as Formula 1 and Formula 2 respectively as follows:

[0035]

[0036] According to the above Formula 1 and Formula 2, the total added molar amount of methyl isobutyl ketone and methyl isopentyl ketone should be greater than or equal to the molar amount of p-phenylenediamine. Preferably, the total added molar amount of methyl isobutyl ketone and methyl isopentyl ketone is greater than the molar amount of p-phenylenediamine so that p-phenylenediamine reacts completely. p-Phenylenediamine is added to the above product mixture according to the amount determined thereby. According to one embodiment, the ratio of the total molar amount of methyl isopentyl ketone and methyl isobutyl ketone to the molar amount of p-phenylenediamine is (1-3):1, for example, it can be 2:1.

[0037] Under the action of a hydrogenation catalyst, a condensation hydrogenation reaction is carried out in a hydrogen atmosphere to obtain a phenylenediamine mixture including N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine (7PPD), that is, EPPD.

[0038] The hydrogenation catalyst is a noble metal catalyst, for example, it can be one or more of platinum-carbon catalyst and palladium-carbon catalyst, and the dosage is 0.1-5% of the total mass of methyl isopentyl ketone and methyl isobutyl ketone, preferably 0.5-4.5%, for example, 1%, 2%, 3% or 4%. Among them, the mass percentage content of the noble metal in the noble metal catalyst can be 1.5-3.0%, preferably 1.8-2.6%, for example, it can be 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4% or 2.5%.

[0039] Moreover, the reaction temperature in the condensation hydrogenation step can be 60 to 120°C, preferably 60 to 79°C, such as 65°C, 70°C, 75°C, 79°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or 115°C; the reaction pressure can be 0.5 to 3.0 MPa, preferably 0.5 to 0.9 MPa, such as 0.6 MPa, 0.7 MPa or 0.8 MPa.

[0040] Furthermore, if the ratio of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine directly synthesized from the above product mixture does not conform to the expected composition ratio of the phenyl-p-phenylenediamine mixture, the composition of the product mixture can be adjusted before the condensation hydrogenation step. Specifically, the measured content ratio of methyl isopentyl ketone and methyl isobutyl ketone can be compared with the ratio of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine required in the target phenyl-p-phenylenediamine mixture, and it is determined whether it is necessary to add methyl isopentyl ketone and / or methyl isobutyl ketone to the product mixture according to the comparison result.

[0041] For example, if the content ratio of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) required in the target phenyl-p-phenylenediamine mixture is higher than the content ratio of MIBK in the product mixture, an appropriate proportion of MIBK can be added to the product mixture before the condensation hydrogenation step, so that the product after the condensation hydrogenation step has an ideal ratio of 6PPD and 7PPD.

[0042] The above method further includes a purification step of purifying the phenyl-p-phenylenediamine mixture synthesized in the condensation hydrogenation step to obtain a purified phenyl-p-phenylenediamine mixture. Specifically, the purification step can include filtration, liquid separation, and rectification. The filtration step can remove the hydrogenation catalyst in the reaction solution of the condensation hydrogenation step. The liquid separation step can divide the filtrate into an oil phase and a water phase, and the separated oil phase is used for the rectification step. The rectification step is used to further purify the product to obtain a phenyl-p-phenylenediamine mixture with high purity, and at the same time, unreacted raw materials (such as mixed ketones, etc.) can be recovered, improving the utilization rate of raw materials and reducing costs.

[0043] The method of the present invention has the following advantages:

[0044] The amount of catalyst used is significantly reduced, and the controllability of the reaction and the selectivity of the product are improved. Specifically, the addition amount and ratio of the reaction raw materials can be flexibly adjusted according to the content of each component in the product mixture, realizing precise control of the target product;

[0045] The temperature and pressure conditions of the reaction are mild. Specifically, the reaction temperature can be 60 - 120 °C, especially 60 - 79 °C, and the reaction pressure can be 0.5 - 3.0 MPa, especially 0.5 - 0.9 MPa, reducing the requirements for equipment and energy consumption;

[0046] When the reaction occurs at low temperature (60 - 79 °C) and low pressure (0.5 - 0.9 MPa), there are fewer by-products in the reaction process, the selectivity of the target product is high, and the molar ratio of the components of the target product can be kept basically the same as that of the raw materials, so that the product can more accurately meet the customer requirements;

[0047] Reduce the material loss occurring in the multi-step process;

[0048] The purity of the target product is high, improving the quality of the product mixture.

[0049] The present invention will be specifically described below in conjunction with the embodiments, and the advantages and various effects of the present invention will be presented more clearly therefrom. Those skilled in the art should understand that these specific embodiments and examples are used to illustrate the present invention, rather than limiting the present invention.

[0050] All percentages used in the following examples are mass percentages.

[0051] Among them, the operating conditions for gas chromatography analysis are as follows:

[0052] Gas chromatograph: Agilent 7890B

[0053] Capillary chromatographic column HP-5: 30 m × 0.320 mm × 0.25 μm (column length × column inner diameter × liquid film thickness)

[0054] Detector temperature: 250 °C

[0055] Vaporization chamber temperature: 220 °C

[0056] Carrier gas: nitrogen

[0057] Carrier gas flow rate: 1.0 mL / min

[0058] Split ratio: 80:1

[0059] Hydrogen: 30 mL / min

[0060] Column temperature: initial temperature 60 °C, rising to 220 °C at a heating rate of 5 °C / min and holding for 2 min

[0061] Solvent: ethanol

[0062] Injection volume: 1 μL.

[0063] Example 1

[0064] Using a 1L laboratory hydrogenation autoclave, 320 g of the product mixture for producing methyl isopentyl ketone after removing the solvent (wherein, the molar ratio of methyl isopentyl ketone to methyl isobutyl ketone is measured as 16.1:1) and 250 g of p-aminodiphenylamine were charged, that is, the molar ratio of the mixed ketone of MIAK and MIBK to p-aminodiphenylamine is 2:1. 10 g (3.1%) of platinum-carbon catalyst was charged and poured into the autoclave, and the reaction kettle was sealed; after purging with hydrogen, the pressure was increased to 0.5 MPa, the temperature was raised to 79 °C and stirred, and the crude EPPD was obtained in about 3 hours.

[0065] Sampling the crude product for gas chromatography analysis, removing the solvent peaks of MIAK and MIBK. Among them, see Figure 2 , the content of 6PPD is 6.25%, the content of 7PPD is 92.48%, the conversion rate of p-aminodiphenylamine is 100%, and the selectivity is 99.13%.

[0066] The crude product reaction solution was filtered, the filtrate was phase-separated, and the separated oil phase was used for rectification. The rectification temperature was 80-90 °C, and the excess mixed ketone was recovered to obtain EPPD with a purity of 99.9%.

[0067] Example 2

[0068] Using a 1L laboratory hydrogenation autoclave, 205 g of the product mixture for producing methyl isopentyl ketone after removing the solvent (wherein, the molar ratio of methyl isopentyl ketone to methyl isobutyl ketone is measured as 16.1:1) and 100 g of 99.9% fresh MIBK (the molar ratio of MIAK:MIBK after preparation is 3:2), and 250 g of p-aminodiphenylamine were charged, that is, the molar ratio of the mixed ketone of MIAK and MIBK to p-aminodiphenylamine is 2:1. 10 g (3.3%) of platinum-carbon catalyst was charged and poured into the autoclave, and the reaction kettle was sealed; after purging with hydrogen, the pressure was increased to 0.9 MPa, the temperature was raised to 60 °C and stirred, and the crude EPPD was obtained in about 3 hours.

[0069] Sampling the crude product for gas chromatography analysis, removing the solvent peaks of MIAK and MIBK. Among them, see Figure 3 , the content of 6PPD is 37.95%, the content of 7PPD is 61.14%, the conversion rate of p-aminodiphenylamine is 100%, and the selectivity is 99.21%.

[0070] The crude product reaction solution was filtered, the filtrate was phase-separated, and the separated oil phase was used for rectification. The rectification temperature was 80-90 °C, and the excess mixed ketone was recovered to obtain EPPD with a purity of 99.9%.

[0071] Example 3

[0072] Using a 1L laboratory hydrogenation autoclave, charge 67.5 g of the product mixture for producing methyl isopentyl ketone after removing the solvent (wherein, the molar ratio of methyl isopentyl ketone to methyl isobutyl ketone is measured as 16.1:1) and 215 g of 99.9% fresh MIBK (the molar ratio of MIAK:MIBK after preparation is 1:4), and 250 g of p-phenylenediamine, that is, the molar ratio of the mixed ketone of MIAK and MIBK to p-phenylenediamine is 2:1. Charge 10 g (3.5%) of platinum-carbon catalyst, pour it into the autoclave, and seal the reaction kettle; after purging with hydrogen, increase the pressure to 0.7 MPa, heat up to 70 °C and stir. After about 3 hours, obtain the crude EPPD.

[0073] Take a sample of the crude product for gas chromatography analysis, removing the solvent peaks of MIAK and MIBK. Among them, refer to Figure 4 , the content of 6PPD is 78.63%, the content of 7PPD is 20.42%, the conversion rate of p-phenylenediamine is 100%, and the selectivity is 99.16%.

[0074] Filter the crude product reaction solution, separate the phases of the filtrate, and separate the oil phase for rectification. The rectification temperature is 80 - 90 °C, recover the excess mixed ketone, and obtain EPPD with a purity of 99.9%.

[0075] Example 4

[0076] Feed the product mixture for synthesizing MIAK into a rectification column, carry out vacuum rectification at 55 °C to recover acetone. After the acetone recovery is complete, put the bottom liquid of the column into a 5000L reaction kettle, charge 410 kg of the mixed ketone (wherein, the molar ratio of methyl isopentyl ketone to methyl isobutyl ketone is measured as 16.1:1) and 200 kg of 99.9% fresh MIBK (the molar ratio of MIAK:MIBK after preparation is 3:2), 500 kg of p-phenylenediamine and 10 kg (1.7%) of platinum-carbon catalyst, that is, the molar ratio of the mixed ketone of MIAK and MIBK to p-phenylenediamine is 2:1. After purging with hydrogen, increase the pressure to 1.5 MPa, heat up to 100 °C and react for 4 hours to obtain the crude EPPD.

[0077] Take a sample of the crude product for gas chromatography analysis, removing the solvent peaks of MIAK and MIBK. Among them, refer to Figure 5 , the content of 6PPD is 35.29%, the content of 7PPD is 63.16%, the conversion rate of p-phenylenediamine is 100%, and the selectivity is 98.52%.

[0078] Filter the crude product, separate the phases of the filtrate, and separate the oil phase for rectification. The rectification temperature is 80 - 90 °C, recover the excess mixed ketone, and obtain EPPD with a purity of 99.8%.

[0079] The crude product of the above-mentioned embodiment was subjected to gas chromatography analysis, and the approximate position information of the characteristic peaks in the obtained chromatogram is shown in Table 1 below.

[0080] Table 1

[0081]

[0082] The composition ratios of the synthetic raw material ketone in the above-mentioned Examples 1 to 4 and the ratios of 7PPD and 6PPD in the product EPPD are summarized in Table 2 as follows.

[0083] Table 2

[0084] MIAK:MIBK molar ratio 7PPD:6PPD mass ratio 7PPD:6PPD molar ratio Selectivity Example 1 16.1:1 62.48％:6.25％ 14.8:1 99.13％ Example 2 3:2 (i.e., 1.5:1) 61.14％:37.95％ 1.61:1 99.21％ Example 3 1:4 20.42％:78.63％ 1:3.85 99.16％ Example 4 3:2 (i.e., 1.5:1) 63.16％:35.29％ 1.79:1 98.52％

Claims

1. A post-treatment method for a product mixture for producing methyl isoamyl ketone, characterized in that: The following steps are involved: determining the contents of methyl isoamyl ketone and methyl isobutyl ketone in the product mixture; Determining the ratio of the amount of p-aminodiphenylamine to the product mixture according to the measured contents of methyl isoamyl ketone and methyl isobutyl ketone; adding p-aminodiphenylamine to the product mixture in a determined ratio; Under the action of a hydrogenation catalyst, a condensation hydrogenation reaction is carried out in a hydrogen atmosphere to obtain a phenyl-p-phenylenediamine mixture including N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine.

2. The post-processing method according to claim 1, wherein: The ratio of the total molar amount of methyl isoamyl ketone and methyl isobutyl ketone to the molar amount of p-aminodiphenylamine is (1-3):

1.

3. The post-treatment method according to claim 1 further comprises comparing the measured content ratio of methyl isoamyl ketone and methyl isobutyl ketone with the required ratio of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine in the target phenyl-p-phenylenediamine mixture, and determining whether it is necessary to add methyl isoamyl ketone and / or methyl isobutyl ketone to the product mixture and the corresponding addition amount according to the comparison result.

4. The post-treatment method according to claim 1 further comprises recovering the solvent in the product mixture in advance.

5. The post-treatment method according to claim 1, wherein the hydrogenation catalyst is a noble metal catalyst, and the amount used is 0.1 to 5% of the total mass of methyl isoamyl ketone and methyl isobutyl ketone.

6. The post-treatment method according to claim 5, wherein the noble metal catalyst is one or more of a platinum-carbon catalyst and a palladium-carbon catalyst.

7. The post-treatment method according to claim 5, wherein the amount of the hydrogenation catalyst used is 0.5 to 3% of the total mass of methyl isoamyl ketone and methyl isobutyl ketone.

8. The post-treatment method according to claim 1, wherein the reaction temperature of the condensation hydrogenation reaction is 60 to 120°C; and the reaction pressure is 0.5 to 3.0 MPa.

9. The post-treatment method according to claim 4, wherein the pre-recovery of the solvent in the product mixture comprises recovering acetone by vacuum distillation at 55°C.

10. The post-treatment method according to claim 8, wherein the reaction temperature of the condensation hydrogenation reaction is 60-79°C; and the reaction pressure is 0.5-0.9 MPa.

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