阅读说明：本技术 一种用于提高二聚酸产率和产品质量的催化合成方法 (Catalytic synthesis method for improving yield and product quality of dimer acid ) 是由 张小杰 代晓东 刘清源 苏宁馨 石会龙 刘博文 刘焕荣 李雷 李舰 于 2019-09-26 设计创作，主要内容包括：本发明涉及一种用于提高二聚酸产率和产品质量的催化合成方法。其技术方案是：采用N<Sub>2</Sub>充填维持反应釜内高压条件,同时采用鼓泡法使N<Sub>2</Sub>分散在原料中,可以提高目标产物-二聚酸的转化率,降低副产物转化；用十六烷基三甲基溴化铵改性白土催化剂,可以使两者之间发生阳离子交换反应,使有机基团覆盖白土催化剂表面或插入其层间,使白土催化剂表面微观结构发生变化,增大了层间距,使白土催化剂由原来的亲水性转变为亲油性；通过在二聚酸聚合过程中加入双酸型离子液体与白土催化剂形成复合催化剂,催化油酸聚合制备二聚酸产品。本发明可以进一步提高二聚酸产率和产品质量,并且降低活性白土催化剂的用量和催化剂对产物的吸附,提高催化剂的利用率。(The invention relates to a catalytic synthesis method for improving yield and product quality of dimer acid. The technical scheme is as follows: by using N 2 Filling and maintaining high pressure condition in the reaction kettle, and simultaneously adopting a bubbling method to make N 2 The dimer acid is dispersed in the raw materials, so that the conversion rate of the target product, namely dimer acid, can be improved, and the conversion of byproducts is reduced; the hexadecyl trimethyl ammonium bromide is used for modifying the clay catalyst, so that a cation exchange reaction can be generated between the hexadecyl trimethyl ammonium bromide and the clay catalyst, organic groups cover the surface of the clay catalyst or are inserted into the interlayer of the clay catalyst, the microstructure of the surface of the clay catalyst is changed, the interlayer spacing is increased, and the clay catalyst is changed from original hydrophilicity to lipophilicity; the dimer acid product is prepared by adding a double-acid ionic liquid and a clay catalyst into the polymerization process of the dimer acid to form a composite catalyst and catalyzing the polymerization of oleic acidAnd (5) preparing the product. The invention can further improve the yield of dimer acid and the product quality, reduce the dosage of the activated clay catalyst and the adsorption of the catalyst to the product, and improve the utilization rate of the catalyst.)

1. A catalytic synthesis method for improving yield and product quality of dimer acid is characterized by comprising the following steps:

firstly, cleaning a reaction kettle until the reaction kettle is dry, clean and free of impurities, checking that each feeding pipeline and each discharging pipeline are unblocked, closing the reaction kettle, and vacuumizing for 60min until the pressure in the kettle is below 0.02 MPa;

secondly, opening a gas feeding pipeline of the reaction kettle, and sucking high-purity N in vacuum₂Closing the gas feeding pipeline when the pressure in the kettle reaches 0.04 MPa;

thirdly, starting an oleic acid feeding pipeline, sucking 10% of oleic acid raw materials in the total feeding amount each time, slowly heating the reaction kettle to 80 ℃, and stirring at a constant speed by a stirrer in the kettle in the process;

fourthly, injecting a mixture of the oleic acid raw material accounting for 80 percent of the rest and the activated clay catalyst accounting for 10 percent of the total weight of the oleic acid raw material by an injection pump, and slowly stirring at a constant speed in the process to keep the temperature in the kettle at 80 ℃;

fifthly, weighing LiCl cocatalyst according to 4% of the total amount of the oleic acid, and mixing the LiCl cocatalyst into 10% of the oleic acid;

sixthly, adding the mixture of the LiCl cocatalyst and the oleic acid obtained in the fifth step into a reaction kettle, and continuously stirring for more than 60min at 80 ℃ to ensure that the clay catalyst, the LiCl cocatalyst and the oleic acid raw material are fully mixed;

seventhly, after the raw materials in the sixth step are mixed, introducing high-purity N from a gas feeder at the bottom of the reaction kettle₂Stopping gas inlet until the upper pressure of the reaction kettle reaches 2.8 MPa;

eighthly, controlling the temperature of the reaction kettle to rise to 240 ℃ within 4 hours, keeping stirring at a uniform and slow speed in the process, and keeping the temperature at 240 ℃ for 4 hours so as to facilitate the catalytic polymerization reaction of the raw materials in the kettle;

ninth step, after the reaction of the eighth step, controlling the temperature of the reaction kettle to be reduced to 150 ℃ for 2h, adding phosphoric acid accounting for 2 percent of the total amount of the oleic acid, and continuing to react for 1h, wherein the process is continuously stirred at a constant speed;

the tenth step, naturally cooling the reaction kettle to 110 ℃, starting a gas feeder at the bottom of the reactor, introducing high-purity nitrogen and a gas pipeline at the top, closing after 30min, and enabling N to be in a state of₂Fully contacting with a white clay catalyst in the kettle;

and step eleven, opening a discharge port at the bottom of the reaction kettle, discharging to obtain a dimer acid product, and allowing the dimer acid product to enter a subsequent separation process.

2. A catalytic synthesis method for improving yield and product quality of dimer acid is characterized by comprising the following steps:

firstly, cleaning a reaction kettle until the reaction kettle is dry, clean and free of impurities, checking that each feeding pipeline and each discharging pipeline are unblocked, closing the reaction kettle, and vacuumizing for 60min until the pressure in the kettle is below 0.02 MPa;

secondly, opening a gas feeding pipeline of the reaction kettle, and sucking high-purity N in vacuum₂Closing the gas feeding pipeline when the pressure in the kettle reaches 0.04 MPa;

thirdly, starting an oleic acid feeding pipeline, sucking 10% of oleic acid raw materials in the total feeding amount each time, slowly heating the reaction kettle to 80 ℃, and stirring at a constant speed by a stirrer in the kettle in the process;

fourthly, injecting a mixture of the oleic acid raw material accounting for 80 percent of the rest and the activated clay catalyst accounting for 5 percent of the total weight of the oleic acid raw material by an injection pump, and slowly stirring at a constant speed in the process to keep the temperature in the kettle at 80 ℃;

fifthly, weighing LiCl cocatalyst according to 2% of the total amount of oleic acid, weighing Bronsted-Lewis double-acid ionic liquid according to 0.5% of the total amount of oleic acid, and mixing the Bronsted-Lewis double-acid ionic liquid into 10% of oleic acid;

sixthly, adding the mixture of the LiCl cocatalyst, the Bronsted-Lewis double-acid type ionic liquid catalyst and the oleic acid in the fifth step into a reaction kettle, and continuously stirring for more than 60min at 80 ℃ to ensure that the carclazyte catalyst, the LiCl cocatalyst and the oleic acid raw material are fully mixed;

seventhly, after the raw materials in the sixth step are mixed, introducing high-purity N from a gas feeder at the bottom of the reaction kettle₂Stopping gas inlet until the upper pressure of the reaction kettle reaches 2.8 MPa;

eighthly, controlling the temperature of the reaction kettle to rise to 240 ℃ within 4 hours, keeping stirring at a uniform and slow speed in the process, and keeping the temperature at 240 ℃ for 4 hours so as to facilitate the catalytic polymerization reaction of the raw materials in the kettle;

ninth step, after the reaction of the eighth step, controlling the temperature of the reaction kettle to be reduced to 150 ℃ for 2h, adding phosphoric acid accounting for 2 percent of the total amount of the oleic acid, and continuing to react for 1h, wherein the process is continuously stirred at a constant speed;

the tenth step, naturally cooling the reaction kettle to 110 ℃, starting a gas feeder at the bottom of the reactor, introducing high-purity nitrogen and a gas pipeline at the top, closing after 30min, and enabling N to be in a state of₂Fully contacting with a white clay catalyst in the kettle;

and step eleven, opening a discharge port at the bottom of the reaction kettle, discharging to obtain a dimer acid product, and allowing the dimer acid product to enter a subsequent separation process.

3. The catalytic synthesis method according to claim 1 or 2 for improving yield and product quality of dimer acid, characterized by: the Bronsted-Lewis double-acid ionic liquid catalyst adopts (3-sulfonic acid) -propyl triethyl ammonium zinc chloride salt- [ HSO₃-(CH₂)₃-NEt₃]Cl-ZnCl₂。

4. The catalytic synthesis method according to claim 1 or 2 for improving yield and product quality of dimer acid, characterized by: the activated clay catalyst is modified by cetyl trimethyl ammonium bromide, and the using amount of the clay catalyst is 0.8% of the mass of the clay catalyst.

Technical Field

The invention relates to a catalytic reaction process method for synthesizing dimer acid, in particular to a catalytic synthesis method for improving yield and product quality of dimer acid.

Background

Dimer acid is mainly a dimer of octadecanoic unsaturated monocarboxylic acid, which is polymerized from straight-chain unsaturated fatty acids or unsaturated fatty acid esters, the main components of which are soybean oleic acid, tall oil acid or linoleic acid of other natural oils. The high-quality dimer acid product has the characteristics of high dimer acid content, light color, stable quality and the like, can be used for synthesizing polyamide resin, corrosion inhibitors, lubricants, fuel additives, coatings, vegetable oil stabilizers and the like in petroleum processing equipment, and has good market prospect, along with the continuous development of new materials and new processes, the application field of the dimer acid product is continuously expanded and extended.

The polymerization process generally used for the production of dimer acid is (1) a fatty acid direct polymerization process: the method mainly takes the cotton oleic acid and the furoic acid as raw materials, and carries out catalytic polymerization under the condition of inert gas, but fatty acid is very easy to carry out oxidative decarboxylation reaction at high temperature in the process, so that the product color is deepened, the saponification value is reduced, and the dosage of a catalyst is larger; (2) fatty acid methyl ester polymerization process: the microcrystalline kaolin is used as a catalyst, an intermittent methanol deoxygenation polymerization process is adopted, the requirement on the purity of methanol is high, the using amount of the catalyst is large, polymers are easy to generate in the synthesis process of dimer acid, and the iron and phosphorus content is high, so that the using effect and the grade of a product are influenced. (3) And (3) a pressure polymerization process: and (3) removing air in the high-pressure reaction kettle by filling inert gas, and carrying out polymerization reaction under the pressure of 2-3 MPa. The pressurizing method reduces the oxygen in the reaction system to the maximum extent, avoids the oxidation of raw materials, has lighter product color, but has high energy consumption, higher requirement on the purity of the introduced inert gas, higher requirement on reaction equipment and operation and larger equipment investment.

The dimer acid is obtained by polymerizing unsaturated fatty acid under the conditions of high temperature and certain pressure by using acid clay as a catalyst, the reaction conditions are harsh, polymers (the content of the dimer is only 50-60 percent), the content of iron and phosphorus in the product is high (the chroma is high by 12 #), and a large amount of waste clay (20 percent of the raw material) polluting the environment can be generated after the reaction.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a catalytic synthesis method for improving the yield and the product quality of dimer acid, which can realize the quality grade of the dimer acid product, reduce the oil adsorption amount in a catalyst and improve the environmental effect and the economic value of the dimer acid synthesis technology.

The catalytic synthesis method for improving the yield and the product quality of the dimer acid comprises the following steps:

firstly, cleaning a reaction kettle until the reaction kettle is dry, clean and free of impurities, checking that each feeding pipeline and each discharging pipeline are unblocked, closing the reaction kettle, and vacuumizing for 60min until the pressure in the kettle is below 0.02 MPa;

secondly, opening a gas feeding pipeline of the reaction kettle, and sucking high-purity N in vacuum₂Closing the gas feeding pipeline when the pressure in the kettle reaches 0.04 MPa;

thirdly, starting an oleic acid feeding pipeline, sucking 10% of oleic acid raw materials in the total feeding amount each time, slowly heating the reaction kettle to 80 ℃, and stirring at a constant speed by a stirrer in the kettle in the process;

fourthly, injecting a mixture of the oleic acid raw material accounting for 80 percent of the rest and the activated clay catalyst accounting for 10 percent of the total weight of the oleic acid raw material by an injection pump, and slowly stirring at a constant speed in the process to keep the temperature in the kettle at 80 ℃;

fifthly, weighing LiCl cocatalyst according to 4% of the total amount of the oleic acid, and mixing the LiCl cocatalyst into 10% of the oleic acid;

sixthly, adding the mixture of the LiCl cocatalyst and the oleic acid obtained in the fifth step into a reaction kettle, and continuously stirring for more than 60min at 80 ℃ to ensure that the clay catalyst, the LiCl cocatalyst and the oleic acid raw material are fully mixed;

seventhly, after the raw materials in the sixth step are mixed, introducing high-purity N from a gas feeder at the bottom of the reaction kettle₂Stopping gas inlet until the upper pressure of the reaction kettle reaches 2.8 MPa;

eighthly, controlling the temperature of the reaction kettle to rise to 240 ℃ within 4 hours, keeping stirring at a uniform and slow speed in the process, and keeping the temperature at 240 ℃ for 4 hours so as to facilitate the catalytic polymerization reaction of the raw materials in the kettle;

ninth step, after the reaction of the eighth step, controlling the temperature of the reaction kettle to be reduced to 150 ℃ for 2h, adding phosphoric acid accounting for 2 percent of the total amount of the oleic acid, and continuing to react for 1h, wherein the process is continuously stirred at a constant speed;

the tenth step, naturally cooling the reaction kettle to 110 ℃, starting a gas feeder at the bottom of the reactor, introducing high-purity nitrogen and a gas pipeline at the top, closing after 30min, and enabling N to be in a state of₂Fully contacting with a white clay catalyst in the kettle;

and step eleven, opening a discharge port at the bottom of the reaction kettle, discharging to obtain a dimer acid product, and allowing the dimer acid product to enter a subsequent separation process.

In addition, the invention also provides another catalytic synthesis method for improving the yield and the product quality of the dimer acid, which comprises the following steps:

firstly, cleaning a reaction kettle until the reaction kettle is dry, clean and free of impurities, checking that each feeding pipeline and each discharging pipeline are unblocked, closing the reaction kettle, and vacuumizing for 60min until the pressure in the kettle is below 0.02 MPa;

secondly, opening a gas feeding pipeline of the reaction kettle, and sucking high-purity N in vacuum₂Closing the gas feeding pipeline when the pressure in the kettle reaches 0.04 MPa;

thirdly, starting an oleic acid feeding pipeline, sucking 10% of oleic acid raw materials in the total feeding amount each time, slowly heating the reaction kettle to 80 ℃, and stirring at a constant speed by a stirrer in the kettle in the process;

fourthly, injecting a mixture of the oleic acid raw material accounting for 80 percent of the rest and the activated clay catalyst accounting for 5 percent of the total weight of the oleic acid raw material by an injection pump, and slowly stirring at a constant speed in the process to keep the temperature in the kettle at 80 ℃;

fifthly, weighing LiCl cocatalyst according to 2% of the total amount of oleic acid, weighing Bronsted-Lewis double-acid ionic liquid according to 0.5% of the total amount of oleic acid, and mixing the Bronsted-Lewis double-acid ionic liquid into 10% of oleic acid;

sixthly, adding the mixture of the LiCl cocatalyst, the Bronsted-Lewis double-acid type ionic liquid catalyst and the oleic acid in the fifth step into a reaction kettle, and continuously stirring for more than 60min at 80 ℃ to ensure that the carclazyte catalyst, the LiCl cocatalyst and the oleic acid raw material are fully mixed;

seventhly, after the raw materials in the sixth step are mixed, introducing high-purity N from a gas feeder at the bottom of the reaction kettle₂Stopping gas inlet until the upper pressure of the reaction kettle reaches 2.8 MPa;

eighthly, controlling the temperature of the reaction kettle to rise to 240 ℃ within 4 hours, keeping stirring at a uniform and slow speed in the process, and keeping the temperature at 240 ℃ for 4 hours so as to facilitate the catalytic polymerization reaction of the raw materials in the kettle;

ninth step, after the reaction of the eighth step, controlling the temperature of the reaction kettle to be reduced to 150 ℃ for 2h, adding phosphoric acid accounting for 2 percent of the total amount of the oleic acid, and continuing to react for 1h, wherein the process is continuously stirred at a constant speed;

the tenth step, naturally cooling the reaction kettle to 110 ℃, starting a gas feeder at the bottom of the reactor, introducing high-purity nitrogen and a gas pipeline at the top, closing after 30min, and enabling N to be in a state of₂Fully contacting with a white clay catalyst in the kettle;

and step eleven, opening a discharge port at the bottom of the reaction kettle, discharging to obtain a dimer acid product, and allowing the dimer acid product to enter a subsequent separation process.

Preferably, the Bronsted-Lewis double-acid type ionic liquid catalyst adopts (3-sulfonic acid) -propyl triethyl ammonium zinc chloride salt- [ HSO [ ]₃-(CH₂)₃-NEt₃]Cl-ZnCl₂。

Preferably, the activated clay catalyst is modified by cetyl trimethyl ammonium bromide, and the amount of the clay catalyst is 0.8% of the mass of the clay catalyst.

The invention has the beneficial effects that:

the invention aims atThe problem of catalytic synthesis of polyacid by using N₂Filling and maintaining high pressure condition in the reaction kettle, and simultaneously adopting a bubbling method to make N₂The dimer acid is dispersed in the raw materials, so that the conversion rate of the target product, namely dimer acid, can be improved, and the conversion of byproducts is reduced; and can prevent oxidation and carbonization reaction caused by over-high local temperature in the liquid; after the reaction is finished, reducing the adsorption of the catalyst to the product by utilizing the interfacial tension and entrainment of the nitrogen bubbles produced by the bubbling method;

the invention adopts cetyl trimethyl ammonium bromide (0.8 percent of the dosage of the clay catalyst) to modify the clay catalyst, and the cetyl trimethyl ammonium bromide is used to modify the clay catalyst, so that the cation exchange reaction can be generated between the cetyl trimethyl ammonium bromide and the clay catalyst, organic groups cover the surface of the clay catalyst or are inserted between the layers of the clay catalyst, the microstructure of the surface of the clay catalyst is changed, the interlayer spacing is increased, and the original hydrophilicity of the clay catalyst is changed into lipophilicity. The clay catalyst can be more fully contacted with the dimer acid raw material, the catalytic efficiency of the clay catalyst is obviously improved, the using amount of the clay catalyst is greatly reduced, and the product quality and the economic competitiveness of the dimer acid are improved;

the invention adopts the ionic liquid and the clay catalyst to carry out composite catalysis, and has the advantages that: the ionic liquid as a novel catalyst has the advantages of high polymerization reaction catalytic performance, repeated and cyclic use, environment-friendly production process and the like. The method is characterized in that Bronsted-Lewis double-acid ionic liquid and a clay catalyst are added in the process of dimer acid polymerization to form a composite catalyst, and oleic acid polymerization is catalyzed to prepare a dimer acid product. Not only greatly reduces the dosage of the clay catalyst in the production process of the dimer acid, but also improves the purity of the dimer acid product and the quality of the dimer acid product.

Through the measures, the method can further improve the yield of the dimer acid and the product quality, reduce the using amount of the activated clay catalyst and the adsorption of the catalyst on the product, improve the utilization rate of the catalyst, and have good environmental significance and economic value.

Detailed Description

The following description is presented in conjunction with the preferred embodiments of the present invention, and it is to be understood that the preferred embodiments described herein are presented only for the purpose of illustrating and explaining the present invention, and are not intended to limit the present invention.