Purification reagent and purification method of 1-amino-2-cyano-cyclopentene

Abstract

The invention belongs to separation and purification of by-products in the field of chemical engineering, and discloses a purification reagent and a purification method of 1-amino-2-cyano-cyclopentene.The purification reagent comprises the steps that a decolorizing auxiliary agent is added into molten ACCP, and after stirring is conducted for a certain time, suction filtration is conducted to obtain high-purity ACCP; wherein the decolorizing auxiliary agent is selected from at least one of activated carbon, activated clay, a molecular sieve, bentonite and diatomite, preferably activated carbon and / or activated clay. According to the technical scheme, at least one of benzene, chloroform, diethyl ether, absolute ethyl alcohol, absolute methanol, acetone and water is adopted as a solvent component, and the interaction force between crystal molecules can be increased through hydrogen bonds formed between solvents, so that the crystal is more stable, and recrystallization of ACCP is facilitated; meanwhile, the activated carbon, the activated clay, the molecular sieve, the bentonite and the diatomite have very strong adsorbability, so that impurities and pigments in the ACCP can be removed, and the purity of the ACCP is improved.

Description

Technical Field

[0001] The present invention belongs to the separation and purification of by-products in the chemical industry, and relates to a purification reagent and a purification method for 1-amino-2-cyano-cyclopentene. More specifically, it relates to a purification method for by-product 1-imino-2-cyano-cyclopentene during the synthesis of adiponitrile by the adipic acid method or the butadiene method. Background Art

[0002] Adiponitrile is an important chemical product and can be used in the production of nylon 66. During the production of adiponitrile, at a certain temperature, a cyclization reaction occurs within the adiponitrile molecule to form ACCP. Moreover, whether it is the adipic acid catalytic ammoniation process technology or the butadiene hydrocyanation process technology, during the production of adiponitrile, ACCP will be produced as a by-product in the product.

[0003] As a by-product of adiponitrile, ACCP has not been effectively utilized at present and is only burned as waste residue, which is a waste of energy. If ACCP can be used as a raw material and separated and purified by relevant technologies to obtain a product ACCP that meets the standards, and a series of high-value-added downstream products are developed, it can not only solve the environmental pollution caused by the discharge of ACCP and the comprehensive utilization problem, extend the adiponitrile industrial chain, but also improve the overall benefit of the adiponitrile device, which is of great significance for improving the enterprise benefit and enhancing the enterprise competitiveness.

[0004] There are few patented technologies for recycling the by-product ACCP of adiponitrile. CN202945188U proposes a device that directly introduces liquid ammonia into a crystallizer to exchange heat with an ACCP solution to crystallize ACCP, and then filters to recover the ACCP crystals. Actually, the ACCP content in the ACCP residue recovered by this device is only 60% - 70%, and it still contains 15% - 20% of adiponitrile, 10 - 15% of other impurities such as 4-amino-2-methyl-5,6-trimethylenepyridine. This ACCP with low purity cannot be directly used downstream and still needs to be purified, which increases the overall operation process and energy consumption and has low economic benefits.

[0005] Therefore, how to purify ACCP efficiently and with low energy consumption is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] The main purpose of the present invention is to provide a purification method for 1-amino-2-cyano-cyclopentene (ACCP) to solve the problem of low purity of ACCP in the prior art. This method uses solvent dissolution - recrystallization - decolorization treatment to increase the purity of the crude ACCP to more than 95%. The product ACCP has high purity and good color, laying a good foundation for direct application and further synthesis of fine chemical products.

[0007] To achieve the above object, according to one aspect of the present invention, there is provided a purification reagent for 1-amino-2-cyanocyclopentene (ACCP), comprising:

[0008] a solvent, the solvent component is selected from at least one of benzene, chloroform, ether, absolute ethanol, absolute methanol, acetone, and water;

[0009] a decolorizing aid, selected from at least one of activated carbon, activated clay, molecular sieve, bentonite, and diatomaceous earth, and the dosage of the decolorizing aid is 3% - 30% by mass fraction.

[0010] Further, the solvent is a mixed solution of alcohols and water, preferably ethanol and water; the mass fraction of ACCP in the solvent is 10% - 55%, preferably 10% - 35%.

[0011] Further, the water content of the solvent is 0% - 80% by mass fraction; preferably, the water content of the solvent is 40% - 65% by mass fraction.

[0012] According to the second aspect of the present application, there is also provided a purification method for 1-amino-2-cyanocyclopentene (ACCP), and the purification method comprises:

[0013] Adding the decolorizing aid to the molten ACCP, filtering by suction after stirring for a certain time to obtain high-purity ACCP; wherein, the decolorizing aid is selected from at least one of activated carbon, activated clay, molecular sieve, bentonite, and diatomaceous earth, preferably activated carbon and / or activated clay.

[0014] Further, the mass ratio of the decolorizing aid to the ACCP sample is 0.2 - 0.6:1; the preferred mass ratio is 0.3 - 0.5:1.

[0015] Further, the decolorizing temperature after mixing the decolorizing aid and the ACCP sample is 150 - 170°C; the preferred temperature is 155 - 165°C.

[0016] Further, the recrystallization temperature of ACCP is -15°C to 10°C; the preferred recrystallization temperature is -10°C to 5°C.

[0017] Except for still containing a small amount of ACCP, the remaining in the solvent after recrystallization filtration of ACCP is mainly the solvent component, which is recycled by rectification.

[0018] The beneficial effects of the present invention compared with the prior art are:

[0019] Applying the technical solution of the present invention, by using at least one of benzene, chloroform, ether, absolute ethanol, absolute methanol, acetone, and water as a solvent component, the hydrogen bonds formed between the solvents can increase the intermolecular interaction force of the crystal molecules, making the crystal more stable and facilitating the recrystallization of ACCP; at the same time, activated carbon, activated clay, molecular sieve, bentonite, and diatomaceous earth have strong adsorption properties, which can remove impurities and pigments in ACCP and improve the purity of ACCP. Detailed implementation mode

[0020] The beneficial effects of the present invention will be further described below in conjunction with specific embodiments. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0021] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0022] The following percentage contents represent mass fractions.

[0023] Example 1

[0024] Add 40.0 g of ACCP crude product (purity 70.3%) to 150 g of absolute ethanol, stir at -15 °C for 1 h, filter by suction after standing for 1 h to obtain pure ACCP product. After melting the pure ACCP product, add 5% activated carbon, and the weight ratio of activated carbon to ACCP sample is 0.3:1. Stir well at 155 °C for 1 h and then filter by suction to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0025] Example 2

[0026] Add 80.0 g of ACCP crude product (purity 70.3%) to 150 g of absolute ethanol, stir at -15 °C for 1 h, filter by suction after standing for 1 h to obtain pure ACCP product. After melting the pure ACCP product, add 5% activated carbon, and the weight ratio of activated carbon to ACCP sample is 0.3:1. Stir well at 155 °C for 1 h and then filter by suction to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0027] Example 3

[0028] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution is 50%. Stir at -15°C for 1 h, let it stand for 1 h, then filter to obtain pure ACCP. After melting the pure ACCP, add 5% activated carbon, and the weight ratio of activated carbon to the ACCP sample is 0.3:1. Stir thoroughly at 155°C for 1 h and then filter to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0029] Example 4

[0030] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution is 50%. Stir at 0°C for 1 h, let it stand for 1 h, then filter to obtain pure ACCP. After melting the pure ACCP, add 5% activated carbon, and the weight ratio of activated carbon to the ACCP sample is 0.3:1. Stir thoroughly at 155°C for 1 h and then filter to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0031] Example 5

[0032] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution is 50%. Stir at -10°C for 1 h, let it stand for 1 h, then filter to obtain pure ACCP. After melting the pure ACCP, add 5% activated carbon, and the weight ratio of activated carbon to the ACCP sample is 0.3:1. Stir thoroughly at 155°C for 1 h and then filter to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0033] Example 6

[0034] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution is 50%. Stir at -10°C for 1 h, let it stand for 1 h, then filter to obtain pure ACCP. After melting the pure ACCP, add 5% activated carbon, and the weight ratio of activated carbon to the ACCP sample is 0.2:1. Stir thoroughly at 155°C for 1 h and then filter to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0035] Example 7

[0036] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution is 50%. Stir at 5 °C for 1 h, let it stand for 1 h, then filter by suction to obtain pure ACCP. After melting the pure ACCP, add 5% activated carbon. The weight ratio of activated carbon to the ACCP sample is 0.2:1. Stir well at 155 °C for 1 h and then filter by suction to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0037] Example 8

[0038] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution is 50%. Stir at 5 °C for 1 h, let it stand for 1 h, then filter by suction to obtain pure ACCP. After melting the pure ACCP, add 5% activated clay. The weight ratio of activated carbon to the ACCP sample is 0.2:1. Stir well at 155 °C for 1 h and then filter by suction to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0039] Example 9

[0040] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute methanol and water, where the water content in the mixed solution is 60%. Stir at -10 °C for 1 h, let it stand for 1 h, then filter by suction to obtain pure ACCP. After melting the pure ACCP, add 5% activated carbon. The weight ratio of activated carbon to the ACCP sample is 0.2:1. Stir well at 155 °C for 1 h and then filter by suction to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0041] Example 10

[0042] Add 40.0 g of crude ACCP (purity 70.3%) to 150 g of a mixed solution of absolute methanol and water, where the water content in the mixed solution is 60%. Stir at -10 °C for 1 h, let it stand for 1 h, then filter by suction to obtain pure ACCP. After melting the pure ACCP, add 5% activated carbon. The weight ratio of activated carbon to the ACCP sample is 0.2:1. Stir well at 155 °C for 1 h and then filter by suction to obtain the purified ACCP sample, and analyze the purity of the ACCP sample. See Table 1.

[0043] Example 11

[0044] 40.0 g of crude ACCP (purity 70.3%) was added to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution was 60%. It was stirred at -10°C for 1 h, filtered by suction after standing for 1 h to obtain pure ACCP. After melting the pure ACCP, 5% activated clay was added, and it was stirred thoroughly at 155°C for 1 h and then filtered by suction to obtain the purified ACCP sample, and the purity of the ACCP sample was analyzed. See Table 1.

[0045] Example 12

[0046] 40.0 g of crude ACCP (purity 70.3%) was added to 150 g of a mixed solution of absolute ethanol and water, where the water content in the mixed solution was 60%. It was stirred at -10°C for 1 h, filtered by suction after standing for 1 h to obtain pure ACCP. After melting the pure ACCP, 5% Y-type molecular sieve was added, and it was stirred thoroughly at 155°C for 1 h and then filtered by suction to obtain the purified ACCP sample, and the purity of the ACCP sample was analyzed. See Table 1.

[0047] Table 1 Purity of ACCP Sample

[0048] Serial number Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Purity, % 99.3 99.6 99.8 93.7 98.9 95.6 Serial number Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Purity, % 95.8 94.7 95.2 90.5 98.2 94.6

Claims

1. A purification reagent for 1-amino-2-cyanocyclopentene, characterized in that, it comprises a solvent and a decolorizing aid, and the decolorizing aid is at least one of activated carbon, activated clay, molecular sieve, bentonite, and diatomaceous earth, and the dosage mass fraction is 3% - 30%.

2. The purification reagent for 1-amino-2-cyanocyclopentene according to claim 1, characterized in that, the solvent is at least one of benzene, chloroform, ether, absolute ethanol, absolute methanol, acetone, and water.

3. The purification reagent for 1-amino-2-cyanocyclopentene according to claim 1, characterized in that, the solvent is ethanol and water, and the mass fraction of ACCP in the solvent is 10% - 55%.

4. The purification reagent for 1-amino-2-cyanocyclopentene according to claim 1, characterized in that, the water content mass fraction of the solvent is 0% - 80%.

5. A purification method for 1-amino-2-cyanocyclopentene, characterized in that, it comprises the following steps: adding a decolorizing aid to molten ACCP, stirring for a certain time and then filtering to obtain high-purity ACCP; wherein, the decolorizing aid is activated carbon and / or activated clay.

6. The purification method for 1-amino-2-cyanocyclopentene according to claim 5, characterized in that, the mass ratio of the decolorizing aid to the ACCP sample is 0.2 - 0.6:

1.

7. The purification method for 1-amino-2-cyanocyclopentene according to claim 5, characterized in that, the decolorizing temperature after mixing the decolorizing aid and the ACCP sample is 150 - 170 °C.

8. The purification method for 1-amino-2-cyanocyclopentene according to claim 5, characterized in that, the recrystallization temperature of ACCP is -15 °C to 10 °C.