Method for reducing content of aldehyde compounds in styrene

Abstract

The invention relates to the technical field of dealdehyding treatment, in particular to a method for reducing the content of aldehyde compounds in styrene, which at least comprises the following steps: S1, stirring crude styrene and alcohol compounds in a mixing kettle at normal temperature to obtain a mixed solution; and S2, standing the mixed solution in a liquid separation kettle, and taking an upper-layer solution, so as to obtain dealdehyded styrene. The method for reducing the content of aldehyde compounds in styrene provided by the invention is simple in process and high in production efficiency; the specific alcohol compound and the crude styrene are adopted for extraction, the mass ratio of the alcohol compound to the crude styrene, the stirring time and the standing time are further controlled, the content of aldehyde compounds in the styrene can be effectively reduced to 50 mg / kg or below, the chromaticity of the styrene can be reduced, and high economic value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of dealdehyde treatment, and in particular to a method for reducing the content of aldehyde compounds in styrene. Background Art

[0002] In the standards for industrial styrene, total aldehyde content is a key indicator, especially for high-quality styrene, the benzaldehyde content must be controlled below 0.01%. The presence of aldehyde impurities has an adverse effect on the subsequent processing of styrene. They will aggravate the corrosion of styrene monomers on metals, reduce the molecular weight of polymers, and react with catalysts to form complexes, interfering with the polymerization process of styrene.

[0003] Styrene products produced by the extractive distillation process have great differences in conditions at different olefin cracking plants. The aldehyde content in crude styrene is closely related to the quality of cracking gasoline. In the actual production process, the total aldehyde content at the styrene distillation outlet often exceeds 200 mg / kg, affecting the quality grade of styrene.

[0004] Chinese patent CN115504852A discloses a method for reducing the content of aldehyde substances in styrene products, wherein crude styrene is subjected to alkali washing, water washing, dehydration, refining and aldehyde removal reflux treatment to obtain refined styrene, and the aldehyde content of the refined styrene does not exceed 100 mg / kg; Chinese patent CN107814680A discloses a method for removing aldehyde from crude styrene obtained from cracked gasoline, comprising adding a dealdehyde agent to the crude styrene for reaction to convert the aldehyde in the crude styrene into aldoxime, and then removing the aldoxime by distillation to obtain refined styrene after dealdehyde removal, and the aldehyde content in the styrene obtained by this method is less than 100 μg / g; However, the treatment process in the above technology is complicated, and the dealdehyde effect needs to be further improved. Summary of the invention

[0005] In order to solve the problems in the prior art, the present invention provides a method for reducing the content of aldehyde compounds in styrene, which comprises at least the following steps:

[0006] S1, placing crude styrene and alcohol compounds in a mixing kettle and stirring at room temperature to obtain a mixed solution;

[0007] S2. After the mixed solution is allowed to stand in a separatory kettle, the upper layer of solution is taken to obtain the styrene after dealdehyde removal.

[0008] In one embodiment, the crude styrene is crude styrene produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd.

[0009] In a preferred embodiment, the purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0010] In one embodiment, the alcohol compound includes ethylene glycol.

[0011] In one embodiment, the ethylene glycol is industrial ethylene glycol with a purity of ≥99%.

[0012] In one embodiment, the mass ratio of the crude styrene to the alcohol compound is (0.5-4):1.

[0013] In a preferred embodiment, the mass ratio of the crude styrene to the alcohol compound is any one of 0.5:1, 1:1, 2:1, 3:1, and 4:1.

[0014] In a more preferred embodiment, the mass ratio of the crude styrene to the alcohol compound is 0.5:1.

[0015] In one embodiment, the stirring time at room temperature in step S1 is 20-50 min.

[0016] In a preferred embodiment, the stirring time at room temperature in step S1 is 20-40 min, which can be 20 min, 30 min, 40 min, or 50 min.

[0017] In a more preferred embodiment, the stirring time at room temperature in step S1 is 20 min.

[0018] In one embodiment, the standing time in step S2 is 5-20 min.

[0019] In a preferred embodiment, the standing time in step S2 is 5-10 min, which can be 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0020] In a more preferred embodiment, the standing time in step S2 is 5 minutes.

[0021] In one embodiment, the total aldehyde content of the styrene after the dealdehydeation is less than 50 mg / kg.

[0022] In a preferred embodiment, the total aldehyde content of the styrene after the dealdehydeation is less than 45 mg / kg.

[0023] In the present application, after standing still, the ethylene glycol solution after extracting the aldehyde compounds is separated from the bottom, and the ethylene glycol solution can be recycled.

[0024] Beneficial Effects

[0025] 1. The present invention adopts the principle of similar compatibility, uses specific alcohol compounds and crude styrene for extraction, and further controls the mass ratio of the two, which can not only effectively reduce the content of aldehyde compounds in styrene to less than 50 mg / kg, but also reduce the chromaticity of styrene.

[0026] 2. The method for reducing the content of aldehyde compounds in styrene provided by the present invention improves production efficiency while effectively reducing the content of aldehyde compounds in styrene by controlling the stirring time during extraction to 20-50 minutes and the standing time to 5-20 minutes.

[0027] 3. The method for reducing the content of aldehyde compounds in styrene provided by the present invention has simple process, high production efficiency and high economic value. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The experimental methods in the examples without specifying specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without specifying the manufacturer are all conventional products that can be purchased commercially.

[0029] Example 1

[0030] This embodiment provides a method for reducing the content of aldehyde compounds in styrene, comprising the following steps:

[0031] S1. Place 500 g crude styrene and 1000 g alcohol compound in a mixing kettle and stir at room temperature for 20 min to obtain a mixed solution;

[0032] S2. After the mixed solution is allowed to stand in the separatory kettle for 5 minutes, the upper layer of solution is taken out to obtain the styrene after dealdehyde removal.

[0033] The crude styrene is produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd. The purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0034] The alcohol compound is industrial ethylene glycol with a purity of ≥99%.

[0035] The total aldehyde content of the styrene after the dealdehyde treatment is 34.5 mg / kg.

[0036] Example 2

[0037] This embodiment provides a method for reducing the content of aldehyde compounds in styrene, comprising the following steps:

[0038] S1. Place 1000 g crude styrene and 1000 g alcohol compound in a mixing kettle and stir at room temperature for 30 min to obtain a mixed solution;

[0039] S2. After the mixed solution is allowed to stand in a separatory kettle for 10 minutes, the upper layer of solution is taken out to obtain the styrene after dealdehyde removal.

[0040] The crude styrene is produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd. The purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0041] The alcohol compound is industrial ethylene glycol with a purity of ≥99%.

[0042] The total aldehyde content of the styrene after the dealdehyde treatment is 39.8 mg / kg.

[0043] Example 3

[0044] This embodiment provides a method for reducing the content of aldehyde compounds in styrene, comprising the following steps:

[0045] S1. Place 1000 g crude styrene and 500 g alcohol compound in a mixing kettle and stir at room temperature for 40 min to obtain a mixed solution;

[0046] S2. After the mixed solution is allowed to stand in a separatory kettle for 10 minutes, the upper layer of solution is taken out to obtain the styrene after dealdehyde removal.

[0047] The crude styrene is produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd. The purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0048] The alcohol compound is industrial ethylene glycol with a purity of ≥99%.

[0049] The total aldehyde content of the styrene after the dealdehyde treatment is 43.2 mg / kg.

[0050] Example 4

[0051] This embodiment provides a method for reducing the content of aldehyde compounds in styrene, comprising the following steps:

[0052] S1, placing 2000g crude styrene and 500g alcohol compound in a mixing kettle and stirring at room temperature for 50min to obtain a mixed solution;

[0053] S2. After the mixed solution is allowed to stand in a separatory kettle for 20 minutes, the upper layer of solution is taken out to obtain the styrene after dealdehyde removal.

[0054] The crude styrene is produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd. The purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0055] The alcohol compound is industrial ethylene glycol with a purity of ≥99%.

[0056] The total aldehyde content of the styrene after the dealdehyde treatment is 44.7 mg / kg.

[0057] Comparative Example 1

[0058] This comparative example provides a method for reducing the content of aldehyde compounds in styrene, comprising the following steps:

[0059] S1, placing 1000g crude styrene and 200g alcohol compound in a mixing kettle and stirring at room temperature for 50min to obtain a mixed solution;

[0060] S2. After the mixed solution is allowed to stand in a separatory kettle for 20 minutes, the upper layer of solution is taken out to obtain the styrene after dealdehyde removal.

[0061] The crude styrene is produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd. The purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0062] The alcohol compound is industrial ethylene glycol with a purity of ≥99%.

[0063] The total aldehyde content of the styrene after the dealdehyde treatment is 105.6 mg / kg.

[0064] Comparative Example 2

[0065] This comparative example provides a method for reducing the content of aldehyde compounds in styrene, comprising the following steps:

[0066] S1, placing 2000g crude styrene and 500g alcohol compound in a mixing kettle and stirring at room temperature for 10min to obtain a mixed solution;

[0067] S2. After the mixed solution is allowed to stand in a separatory kettle for 20 minutes, the upper layer of solution is taken out to obtain the styrene after dealdehyde removal.

[0068] The crude styrene is produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd. The purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0069] The alcohol compound is industrial ethylene glycol with a purity of ≥99%.

[0070] The total aldehyde content of the styrene after the dealdehyde treatment is 112.5 mg / kg.

[0071] Comparative Example 3

[0072] This comparative example provides a method for reducing the content of aldehyde compounds in styrene, comprising the following steps:

[0073] S1. Place 1000 g crude styrene and 1000 g alcohol compound in a mixing kettle and stir at room temperature for 20 min to obtain a mixed solution;

[0074] S2. After the mixed solution is allowed to stand in a separatory kettle for 3 minutes, the upper layer of solution is taken out to obtain the styrene after dealdehyde removal.

[0075] The crude styrene is produced by the styrene extraction device of Guangdong Xinhua Yue Resin Technology Co., Ltd. The purity of the crude styrene is 99.8%, the platinum cobalt color is 9.6#, and the total aldehyde content is 155.1 mg / kg (calculated as styrene).

[0076] The alcohol compound is industrial ethylene glycol with a purity of ≥99%.

[0077] The total aldehyde content of the styrene after the dealdehyde treatment is 114.2 mg / kg.

[0078] Performance Testing

[0079] The chromaticity and total aldehyde content of the styrene after dealdehydeation prepared in the examples and comparative examples were tested.

[0080] The test method for styrene color is GB / T 605-2006;

[0081] The test method for total styrene formaldehyde content is GB / T 12688.5-2019;

[0082] The test data are listed in Table 1.

[0083] Table 1

[0084] sample Chroma(Platinum-Cobalt Color Number) Total aldehyde mg / kg (calculated as benzaldehyde) Example 1 7.2 34.5 Example 2 8.1 39.8 Example 3 8.3 43.2 Example 4 8.6 44.7 Comparative Example 1 9.3 105.6 Comparative Example 2 9.4 112.5 Comparative Example 3 9.6 114.2

Claims

1. A method for reducing the content of aldehyde compounds in styrene, characterized in that: At least the following steps are included: S1, placing crude styrene and alcohol compounds in a mixing kettle and stirring at room temperature to obtain a mixed solution; S2. After the mixed solution is allowed to stand in a separatory kettle, the upper layer of solution is taken to obtain the styrene after dealdehyde removal.

2. The method for reducing the content of aldehyde compounds in styrene according to claim 1, characterized in that: The alcohol compound includes ethylene glycol.

3. The method for reducing the content of aldehyde compounds in styrene according to claim 2, characterized in that: The ethylene glycol is industrial ethylene glycol with a purity of ≥99%.

4. The method for reducing the content of aldehyde compounds in styrene according to claim 1, characterized in that: The mass ratio of the crude styrene to the alcohol compound is (0.5-4):

1.

5. The method for reducing the content of aldehyde compounds in styrene according to any one of claims 1 to 4, characterized in that: The mass ratio of the crude styrene to the alcohol compound is 0.5:

1.

6. The method for reducing the content of aldehyde compounds in styrene according to claim 1, characterized in that: The stirring time at room temperature in step S1 is 20-50 min.

7. The method for reducing the content of aldehyde compounds in styrene according to claim 6, characterized in that: The stirring time at room temperature in step S1 is 20-40 min.

8. The method for reducing the content of aldehyde compounds in styrene according to claim 1, characterized in that: The standing time in the step S2 is 5-20 min.

9. The method for reducing the content of aldehyde compounds in styrene according to claim 8, characterized in that: The standing time in step S2 is 5-10 min.

10. The method for reducing the content of aldehyde compounds in styrene according to claim 1, characterized in that: The total aldehyde content of the styrene after the dealdehyde treatment is less than 50 mg / kg.