阅读说明：本技术 用于合成己二胺中间体6-氨基己腈的催化剂的制备方法及6-氨基己腈的合成方法 (Preparation method of catalyst for synthesizing hexamethylene diamine intermediate 6-aminocapronitrile and synthesis method of 6-aminocapronitrile ) 是由 王根林 王刚 丁克鸿 徐林 王铖 殷剑虎 聂庆超 于 2020-06-10 设计创作，主要内容包括：本发明提供了一种用于合成己二胺中间体6-氨基己腈的催化剂的制备方法及6-氨基己腈的合成方法。该制备方法包括步骤S1,将载体、粘结剂、水和胶溶剂进行混合,得混合物；步骤S2,将混合物进行成型,得成型载体；以及步骤S3,将成型载体在改性剂酸性溶液中进行改性,得到用于合成己二胺中间体6-氨基己腈的催化剂,改性剂与成型载体的质量比为0.1～1:1,改性剂选自磷酸钙、磷酸镁、磷酸铝、偏磷酸钙、偏磷酸镁、偏磷酸铝、亚磷酸铝中的一种或多种。使催化剂具有更优良的强度、活性和选择性。且上述制备方法简单,原料来源广泛,成本较低。(The invention provides a preparation method of a catalyst for synthesizing a hexamethylene diamine intermediate 6-aminocapronitrile and a synthesis method of 6-aminocapronitrile. The preparation method comprises the step S1 of mixing a carrier, a binder, water and a peptizing agent to obtain a mixture; step S2, molding the mixture to obtain a molded carrier; and step S3, modifying the formed carrier in a modifier acid solution to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, wherein the mass ratio of the modifier to the formed carrier is 0.1-1: 1, and the modifier is selected from one or more of calcium phosphate, magnesium phosphate, aluminum phosphate, calcium metaphosphate, magnesium metaphosphate, aluminum metaphosphate and aluminum phosphite. The catalyst has better strength, activity and selectivity. The preparation method is simple, the raw materials are widely available, and the cost is low.)

1. A method for preparing a catalyst for synthesizing hexamethylene diamine intermediate 6-aminocapronitrile, which is characterized by comprising the following steps:

step S1, mixing the carrier, the adhesive, the water and the peptizing agent to obtain a mixture;

step S2, molding the mixture to obtain a molded carrier; and

step S3, modifying the formed carrier in a modifier acid solution to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, wherein the mass ratio of the modifier to the formed carrier is 0.1-1: 1, and the modifier is selected from one or more of calcium phosphate, magnesium phosphate, aluminum phosphate, calcium metaphosphate, magnesium metaphosphate, aluminum metaphosphate and aluminum phosphite.

2. The preparation method according to claim 1, wherein the mass concentration of the modifier in the modifier acid solution is 5-50%, preferably the modifier acid solution is formed by dissolving the modifier in an acid solution, preferably the acid solution is one or more selected from phosphoric acid aqueous solution, nitric acid aqueous solution, hydrochloric acid and sulfuric acid aqueous solution.

3. The method according to claim 1, wherein the step S3 comprises immersing the shaped carrier in the acidic solution of the modifier, preferably for 10-300 min.

4. The method for preparing a composite material according to claim 1, wherein the step S3 includes:

modifying the molded carrier in the acidic solution of the modifier to obtain a modified system containing the modified carrier;

and carrying out solid-liquid separation, secondary drying and secondary roasting on the modified system to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, preferably carrying out solid-liquid separation to obtain a vacuum removal solvent, preferably carrying out the vacuum removal solvent with the minimum absolute pressure of 0.01MPa, preferably carrying out the vacuum removal at the temperature of 10-200 ℃, preferably carrying out the secondary drying at the temperature of 5-200 ℃, preferably carrying out the secondary drying at the temperature of 1-100 h, preferably carrying out the secondary roasting at the temperature of 200-1100 ℃, and preferably carrying out the secondary roasting at the time of 2-50 h.

5. The method according to claim 1, wherein the mass ratio of the water to the carrier is 0.4 to 0.9: 1.

6. The preparation method according to claim 1, wherein the mass ratio of the binder to the carrier is 0.01-1: 1, and the binder is preferably one or more selected from pseudo-boehmite, alumina, polyvinyl alcohol and sesbania powder.

7. The preparation method according to claim 1, wherein the peptizing agent is selected from one or more of aqueous nitric acid, aqueous phosphoric acid, aqueous sulfuric acid, aqueous acetic acid and hydrochloric acid, and the mass ratio of the peptizing agent to the carrier is preferably 0.01-0.3: 1.

8. The method according to claim 1, wherein the carrier is selected from one or more of silica, silica gel, pseudoboehmite, alumina, kaolin, titanium dioxide, calcium oxide, magnesium oxide, and zeolite molecular sieves.

9. The production method according to claim 1, wherein the step S2 includes,

kneading and extruding the mixture to form a formed mixture;

drying and roasting the formed mixture for the first time to obtain a formed carrier;

the kneading time is preferably 10-300 min, the extrusion molding time is preferably 1-10 times, the first drying temperature is preferably 5-200 ℃, the first drying time is preferably 1-100 h, the first roasting temperature is preferably 250-1000 ℃, and the first roasting time is preferably 1-40 h.

10. A method for synthesizing 6-aminocapronitrile, which comprises catalyzing ammoniation of caprolactam to synthesize 6-aminocapronitrile by using a catalyst, wherein the catalyst is obtained by the preparation method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of 6-aminocapronitrile preparation, in particular to a preparation method of a catalyst for synthesizing a hexamethylene diamine intermediate 6-aminocapronitrile and a synthesis method of 6-aminocapronitrile.

Background

6-aminocapronitrile is a key raw material for synthesizing hexamethylene diamine and is obtained by catalytic ammoniation reaction of caprolactam.

In U.S. Pat. No. US2234566, copper was supported on a silica gel support as a dehydration catalyst, 6-aminocapronitrile was synthesized at an ammonia/caprolactam molar ratio of 6 and a reaction temperature of 360 ℃ with a caprolactam conversion of 21.7% and a 6-aminocapronitrile yield of only 25%, which was problematic in that the catalyst activity was low.

In U.S. patent application publication No. US3855267, aluminum phosphate is dissolved in hot water to form a saturated solution, and undissolved aluminum phosphate solids are removed by filtration. 15g of active alumina, alpha-alumina or molecular sieve is dipped into 120g of the saturated solution, and the catalyst loaded with the aluminum phosphate is obtained after the moisture is removed in vacuum at 100 ℃. After ammonia gas at 375 ℃ contacts molten caprolactam, the mixed gas passes through a catalyst bed filled with 100mL at the flow rate of 1.9g/min, and under the conditions that the temperature of a reactor is 375 ℃ and the molar ratio of ammonia gas to caprolactam is 75-100, caprolactam is catalyzed and aminated to prepare 6-aminocapronitrile, the conversion rate of caprolactam reaches 65 percent at most, and the selectivity of 6-aminocapronitrile is only 87 percent.

In Chinese patent with patent application publication No. CN107739318, a method and apparatus for preparing 6-aminocapronitrile by a liquid phase method of caprolactam are developed, phosphoric acid or phosphate is used as a catalyst, the conversion rate of caprolactam is 55%, and the selectivity of 6-aminocapronitrile is 97%. The intermittent process has the defects of complex catalyst separation and recycling process and low productivity.

Disclosure of Invention

The invention mainly aims to provide a preparation method of a catalyst for synthesizing a hexamethylene diamine intermediate 6-aminocapronitrile and a synthesis method of 6-aminocapronitrile, so as to solve the problem that the activity and selectivity of the catalyst for preparing 6-aminocapronitrile by ammoniation of caprolactam in the prior art are low.

In order to achieve the above object, according to one aspect of the present invention, there is provided a method for preparing a catalyst for synthesizing hexamethylenediamine intermediate 6-aminocapronitrile, the method comprising: step S1, mixing the carrier, the adhesive, the water and the peptizing agent to obtain a mixture; step S2, molding the mixture to obtain a molded carrier; and step S3, modifying the formed carrier in a modifier acid solution to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, wherein the mass ratio of the modifier to the formed carrier is 0.1-1: 1, and the modifier is selected from one or more of calcium phosphate, magnesium phosphate, aluminum phosphate, calcium metaphosphate, magnesium metaphosphate, aluminum metaphosphate and aluminum phosphite.

Further, the mass concentration of the modifier in the modifier acid solution is 5-50%, preferably the modifier acid solution is formed by dissolving the modifier in an acid solution, and the acid solution is preferably one or more selected from phosphoric acid aqueous solution, nitric acid aqueous solution, hydrochloric acid and sulfuric acid aqueous solution.

Further, the step S3 includes immersing the shaped carrier in an acidic solution of a modifier, preferably for 10-300 min.

Further, the step S3 includes: modifying the formed carrier in a modifier acid solution to obtain a modified system containing the modified carrier; and carrying out solid-liquid separation, secondary drying and secondary roasting on the modified system to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, preferably carrying out solid-liquid separation to obtain a vacuum removal solvent, preferably carrying out the vacuum removal solvent with the minimum absolute pressure of 0.01MPa, preferably carrying out the vacuum removal at the temperature of 10-200 ℃, preferably carrying out the secondary drying at the temperature of 5-200 ℃, preferably carrying out the secondary drying for 1-100 h, preferably carrying out the secondary roasting at the temperature of 200-1100 ℃, and preferably carrying out the secondary roasting for 2-50 h.

Further, the mass ratio of the water to the carrier is 0.4-0.9: 1.

Furthermore, the mass ratio of the binder to the carrier is 0.01-1: 1, and the binder is preferably one or more selected from pseudo-boehmite, alumina, polyvinyl alcohol and sesbania powder.

The peptizing agent is one or more selected from nitric acid aqueous solution, phosphoric acid aqueous solution, sulfuric acid aqueous solution, acetic acid aqueous solution and hydrochloric acid, and the mass ratio of the peptizing agent to the carrier is preferably 0.01-0.3: 1.

Further, the carrier is selected from one or more of silica, silica gel, pseudo-boehmite, alumina, kaolin, titanium dioxide, calcium oxide, magnesium oxide and zeolite molecular sieves.

Further, the step S2 includes kneading the mixture, extruding the mixture into strips, and forming a formed mixture; drying and roasting the formed mixture for the first time to obtain a formed carrier; the kneading time is preferably 10-300 min, the extrusion molding time is preferably 1-10 times, the first drying temperature is preferably 5-200 ℃, the first drying time is preferably 1-100 h, the first roasting temperature is preferably 250-1000 ℃, and the first roasting time is preferably 1-40 h.

According to another aspect of the invention, a synthesis method of 6-aminocapronitrile is provided, the synthesis method comprises catalyzing ammoniation of caprolactam to synthesize 6-aminocapronitrile by using a catalyst, and the catalyst is obtained by the preparation method.

By applying the technical scheme of the invention, the carrier, the binder, water and the peptizing agent are molded, the molded carrier is soaked in an acidic modifier solution of which the active ingredient is phosphate or metaphosphate, and the molded modified catalyst is obtained after roasting, so that the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile is obtained. On one hand, the molding treatment enables the catalyst to have better strength, and on the other hand, the modification of the acidic solution of the modifier modifies the surface of the molded carrier, so that the effect of adjusting the active sites of the catalyst is achieved, and the activity and the selectivity of the catalyst are improved. The preparation method is simple, the raw materials are widely available, and the cost is low.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

As analyzed by the background technology, the catalyst for preparing 6-aminocapronitrile by ammoniation of caprolactam in the prior art has the problem of low activity and selectivity, and in order to solve the problem, the invention provides a preparation method of the catalyst for synthesizing hexamethylene diamine intermediate 6-aminocapronitrile and a synthesis method of 6-aminocapronitrile.

In an exemplary embodiment of the present application, there is provided a method for preparing a catalyst for synthesizing hexamethylenediamine intermediate 6-aminocapronitrile, the method comprising the steps of S1, mixing a support, a binder, water and a peptizing agent to obtain a mixture; step S2, molding the mixture to obtain a molded carrier; and step S3, modifying the formed carrier in a modifier acid solution to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, wherein the mass ratio of the modifier to the formed carrier is 0.1-1: 1, and the modifier is selected from one or more of calcium phosphate, magnesium phosphate, aluminum phosphate, calcium metaphosphate, magnesium metaphosphate, aluminum metaphosphate and aluminum phosphite.

The method comprises the steps of forming a carrier, a binder, water and a peptizing agent, dipping the obtained formed carrier in an acidic modifier solution of which the active ingredient is phosphate or metaphosphate, roasting to obtain a formed modified catalyst, and obtaining the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile. On one hand, the molding treatment enables the catalyst to have better strength, and on the other hand, the modification of the acidic solution of the modifier modifies the surface of the molded carrier, so that the effect of adjusting the active sites of the catalyst is achieved, and the activity and the selectivity of the catalyst are improved. The preparation method is simple, the raw materials are widely available, and the cost is low.

In order to improve the modification effect of the modification and obtain a catalyst with better performance for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, the mass concentration of the modifier in the modifier acid solution is preferably 5-50%, the modifier acid solution is preferably formed by dissolving the modifier in an acid solution, and the acid solution is preferably selected from one or more of phosphoric acid aqueous solution, nitric acid aqueous solution, hydrochloric acid and sulfuric acid aqueous solution. Preferably, the modifier has better solubility in the acid solution, so that the modification effect of the modifier on the carrier is better facilitated, and the mass concentration of the modifier in the modifier solution is beneficial to increasing the content of active ingredients in the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, so that the catalytic activity of the catalyst is improved.

In an embodiment of the present application, the step S3 includes immersing the shaped carrier in an acidic solution of the modifier, preferably for 10 to 300 min.

The modifier is an active component of the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, and the impregnation time is controlled within the range, so that the impregnation effect is improved, and the catalytic activity of the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile is improved.

In an embodiment of the present application, the step S3 includes: modifying the formed carrier in a modifier acid solution to obtain a modified system containing the modified carrier; and carrying out solid-liquid separation, secondary drying and secondary roasting on the modified system to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile, preferably carrying out solid-liquid separation to obtain a vacuum removal solvent, preferably carrying out the vacuum removal solvent with the minimum absolute pressure of 0.01MPa, preferably carrying out the vacuum removal at the temperature of 10-200 ℃, preferably carrying out the secondary drying at the temperature of 5-200 ℃, preferably carrying out the secondary drying for 1-100 h, preferably carrying out the secondary roasting at the temperature of 200-1100 ℃, and preferably carrying out the secondary roasting for 2-50 h.

The method for carrying out solid-liquid separation on the modified system can refer to the conventional solid-liquid separation method in the prior art, such as the method for achieving solid-liquid separation by filtering, heating and evaporating a solvent and the like, the method is used for improving the effect of solid-liquid separation, so that the solvent in the modified system is removed as efficiently as possible, and further the subsequent treatment of secondary drying and secondary roasting is facilitated, the solid-liquid separation is preferably a vacuum removal solvent, the minimum absolute pressure of the vacuum removal solvent is preferably 0.01MPa, the temperature of the vacuum removal is preferably 10-200 ℃, the treatment conditions of the secondary drying and the secondary roasting are favorable for removing the solvent as far as possible, and simultaneously, the binder is decomposed, so that the content of effective active ingredients in the catalyst is improved.

In order to improve the uniformity of the mixture and obtain a molded carrier as uniform as possible, the mass ratio of the water to the carrier is preferably 0.4 to 0.9: 1.

In order to improve the bonding effect of the binder on the carrier and obtain the formed carrier with improved strength, the mass ratio of the binder to the carrier is preferably 0.01-1: 1, and the binder is preferably selected from one or more of pseudo-boehmite, alumina, polyvinyl alcohol and sesbania powder.

In one embodiment of the present application, the peptizing agent is one or more selected from a nitric acid aqueous solution, a phosphoric acid aqueous solution, a sulfuric acid aqueous solution, an acetic acid aqueous solution, and hydrochloric acid, and the mass ratio of the peptizing agent to the carrier is preferably 0.01 to 0.3: 1.

The mass of the peptizer refers to the mass after the water in the peptizer is removed. The peptizing agent and the binder are used in a matching manner, and the mass ratio of the mass of the peptizing agent to the mass of the carrier is controlled within the range, so that the bonding effect among the particles of the carrier in the mixture can be further improved, and the carrier molding is facilitated.

In one embodiment of the present application, the above-mentioned carrier is selected from one or more of silica, silica gel, pseudoboehmite, alumina, kaolin, titania, calcium oxide, magnesium oxide, and zeolite molecular sieves.

The present application selects the above-mentioned carrier as a supporting framework for the catalyst active ingredient, which contributes more to improving the strength of the formed catalyst and at the same time improving the activity of the catalyst.

In an embodiment of the present application, the step S2 includes kneading and extruding the mixture to obtain a molded mixture; drying and roasting the formed mixture for the first time to obtain a formed carrier; the kneading time is preferably 10-300 min, the extrusion molding time is preferably 1-10 times, the first drying temperature is preferably 5-200 ℃, the first drying time is preferably 1-100 h, the first roasting temperature is preferably 250-1000 ℃, and the first roasting time is preferably 1-40 h.

The relevant parameters in the forming process of the formed carrier are controlled, so that the forming efficiency of the formed carrier is improved, the strength of the formed carrier is enhanced, and the strength of the obtained catalyst is improved.

In another exemplary embodiment of the present application, a method for synthesizing 6-aminocapronitrile is provided, the method comprising catalyzing the amination of caprolactam to synthesize 6-aminocapronitrile using a catalyst obtained by any one of the aforementioned methods.

The method comprises the steps of forming a carrier, a binder, water and a peptizing agent, soaking the obtained formed carrier in an acidic modifier solution of which the active ingredient is phosphate or metaphosphate, and roasting to obtain a formed modified catalyst, so as to obtain the catalyst for synthesizing the hexamethylene diamine intermediate 6-aminocapronitrile. The catalyst has better strength, activity and selectivity. The catalyst is used in a catalytic system for synthesizing 6-aminocapronitrile by ammoniation of caprolactam, and the reaction efficiency can be greatly improved.

The advantageous effects of the present application will be described below with reference to specific examples and comparative examples.