阅读说明：本技术 一种脂肪叔胺的生产方法 (Production method of fatty tertiary amine ) 是由 张远军 刘盛华 陈红星 赵竹元 谌建新 于 2021-08-04 设计创作，主要内容包括：本发明提供了一种脂肪叔胺的生产方法,它包括催化剂的制备、脂肪叔胺的合成、脂肪叔胺的后处理及储存。本方法着重于脂肪叔胺质量的改善,通过采用限定的催化剂及反应条件,在胺化阶段降低脂肪叔胺中的羟醛缩合物,并将一甲胺或二甲胺回收利用；在后处理阶段通过用惰性气体置换去除产品中溶解的活性气体,阻止白色絮状物的产生,得到的脂肪叔胺,大大改善其反应外观和存储外观,整体上改善脂肪叔胺的品质。(The invention provides a production method of fatty tertiary amine, which comprises the preparation of a catalyst, the synthesis of the fatty tertiary amine, the post-treatment and the storage of the fatty tertiary amine. The method focuses on the improvement of the quality of the fatty tertiary amine, and reduces the aldol condensation compound in the fatty tertiary amine in the amination stage by adopting a limited catalyst and reaction conditions, and recycles monomethylamine or dimethylamine; the active gas dissolved in the product is removed by replacement with inert gas in the post-treatment stage, the generation of white floccule is prevented, and the obtained fatty tertiary amine greatly improves the reaction appearance and the storage appearance, and improves the quality of the fatty tertiary amine as a whole.)

1. A method for producing a tertiary fatty amine, characterized by comprising the steps of:

1) preparation of the catalyst

1.1) preparing a nitrate mixed solution with the weight percent of 10-15 by using deionized water for copper nitrate, nickel nitrate, chromium nitrate, platinum chloride and magnesium nitrate, and preparing a sodium carbonate solution with the weight percent of 10-15 by using deionized water for anhydrous sodium carbonate for later use;

1.2) adding deionized water into diatomite, stirring and heating to 50-60 ℃, simultaneously dropwise adding a nitrate mixed solution and a sodium carbonate solution to form a precipitate, keeping the pH value of 6-8, adjusting the pH value of 8-10 by using the sodium carbonate solution after the nitrate mixed solution is completely dripped, ageing the precipitate for 3-4 hours, washing, filtering, drying, roasting at the temperature of 500-600 ℃ for 3-4 hours, and grinding to obtain a finished catalyst Cat-M;

2) synthesis of fatty tertiary amines

2.1) pumping the dried fatty alcohol into an amination kettle (1), connecting a gas compressor (3) to the amination kettle (1), circulating the gas in the amination kettle (1) in the kettle, adding the catalyst Cat-M obtained in the step 1), respectively replacing the catalyst with nitrogen and hydrogen for 3 times, heating to 190 ℃ with 160-;

2.2) after the catalyst is reduced, heating to 190 ℃, starting to introduce metered monomethylamine or dimethylamine to carry out amination reaction, introducing monomethylamine or dimethylamine while heating to 200-230 ℃, controlling the pressure to 0.1-0.4Mpa, and simultaneously separating water generated by the reaction through a water separator and pressing the water into an amine recovery kettle (2);

2.3) adding an alkaline substance into the amine recovery kettle (2), adjusting the alkali concentration in the aqueous solution in the amine recovery kettle (2) to 1-10%, heating, opening a valve of the amine recovery kettle, returning monomethylamine or dimethylamine dissolved in water to the amination kettle (1) for continuous reaction, after the monomethylamine or dimethylamine recovery reaction in the amine recovery kettle (2) is finished, continuing the heat preservation reaction of the amination kettle (1) until the pressure is not reduced, and stopping the reaction after sampling and analyzing are qualified;

3) working up of tertiary fatty amines

3.1) transferring the reaction liquid to a settling kettle (4) for cooling and settling;

3.2) transferring the settled product to a rectifying still (5), vacuumizing before rectification, replacing the rectifying still (5) for a plurality of times by using nitrogen, keeping the vacuum degree between-0.095 and-0.1 Mpa, and collecting fractions at the corresponding temperature at the outlet of the rectifying still according to the boiling point of the obtained aliphatic tertiary amine to obtain the aliphatic tertiary amine product;

4) storage of fatty tertiary amines

Adding strong alkali solution into the finished product obtained by rectification, transferring the finished product into a finished product storage tank (6), vacuumizing the finished product storage tank (6) before use, and replacing the finished product storage tank with nitrogen for a plurality of times.

2. The method for producing the aliphatic tertiary amine according to claim 1, wherein in the catalyst Cat-M in the step 1), the mass ratio of copper oxide, nickel oxide, chromium oxide, platinum oxide and magnesium oxide is 2-4: 0.5-1: 0.01-0.05: 0.005-0.02: 0.1 to 0.5.

3. The method for producing a tertiary aliphatic amine according to claim 1, wherein the ratio of the mass of diatomaceous earth to the total mass of all metal oxides in step 1) is 1-1.5:1, preferably 1: 1.

4. the method for producing a tertiary aliphatic amine according to claim 1, wherein the catalyst reduction time in step 2.1) is 30 to 60 minutes.

5. The method for producing a tertiary aliphatic amine according to claim 1, wherein the aliphatic alcohol is a C8-14 aliphatic alcohol.

6. The method for producing a tertiary aliphatic amine according to claim 1, wherein the basic substance in step 2.3) is sodium hydroxide, potassium hydroxide, sodium methoxide or potassium methoxide, preferably sodium hydroxide or potassium hydroxide.

7. The method for producing aliphatic tertiary amine according to claim 1, wherein the heating temperature of the amine recovery kettle in the step 2) is 20-100 ℃, the temperature is raised to 100 ℃, and the reaction is carried out for 30-60min under the condition of heat preservation; adding alkali until the pH value of water is 12-14.

8. The method for producing tertiary aliphatic amine according to claim 1, wherein in step 3) and step 4), air is replaced with nitrogen until the oxygen content in the rectifying still and the finished product storage tank is less than 1%, and the carbon dioxide content is less than 100ppm calculated according to the proportion of oxygen, carbon dioxide and acid gas in the air.

9. The method for producing fatty tertiary amine according to claim 1, wherein the concentration of the strong alkali solution used in step 4) is 30-50%, the addition amount is 0.01-0.1% of the mass of the fatty tertiary amine, and the strong alkali used is sodium hydroxide or potassium hydroxide.

Technical Field

The invention relates to the technical field of fatty tertiary amine production, in particular to a production method of fatty tertiary amine capable of effectively improving the quality of fatty tertiary amine.

Background

Fatty tertiary amines are important intermediates in the domestic and industrial fields. The quaternary ammonium salt derived from the quaternary ammonium salt, the amphoteric surfactant and the like are widely applied to textile softeners, antistatic agents, bactericides, cleaning agents and the like. The fatty tertiary amine can be prepared by a fatty acid two-step method and a fatty alcohol one-step method, wherein the fatty alcohol one-step method is the most important method for preparing the tertiary amine industrially at present. At present, the overall process for preparing the fatty tertiary amine by the fatty alcohol one-step method is basically mature, and each manufacturer only carries out further research and optimization on the aspects of product yield and quality improvement, so that the product is more refined and high in quality. The quality of the fatty tertiary amine is influenced mainly by the following aspects: 1) the impurities formed during the reaction include alkyl polyamines and aldol condensates, which are difficult to dissolve in water and affect the appearance of the product after quaternization of the tertiary amine. 2) White floccule is generated during the storage of the fatty tertiary amine, and the appearance of the fatty tertiary amine is seriously affected. In addition, ammonia gas and hydrogen gas are continuously introduced in the amination process, and if excessive ammonia and hydrogen are not collected, certain waste and environmental pollution are caused.

The literature, "control of tertiary amine production process by alcohol one-step method" discusses the control of tertiary monoalkyl amine as a byproduct of tertiary amine and monitors the production process of byproduct aldol condensate, and the content is usually about 2%, but some high-end customers in the market often require the aldol condensate to be controlled below 1%. In patent CN110498746A, excess monomethylamine is introduced to convert fatty alcohol into intermediate fatty secondary amine, and then the fatty alcohol is supplemented to continue to react with the fatty secondary amine, so that the aldol condensation product is reduced to below 1%. However, the production process reduces the production efficiency to a certain extent due to the need of further fatty alcohol supplementation.

Disclosure of Invention

In view of the above problems in the prior art, it is an object of the present invention to provide a method for producing a tertiary aliphatic amine, focusing on improvement in quality of the tertiary aliphatic amine, by reducing an aldol condensate in the tertiary aliphatic amine in a synthesis stage and preventing generation of white flocs in a post-treatment and storage stage.

The invention discloses a method for producing fatty tertiary amine, which is characterized by comprising the following steps:

1) preparation of the catalyst

1.1) preparing a nitrate mixed solution with the weight percent of 10-15 by using deionized water for copper nitrate, nickel nitrate, chromium nitrate, platinum chloride and magnesium nitrate, and preparing a sodium carbonate solution with the weight percent of 10-15 by using deionized water for anhydrous sodium carbonate for later use;

1.2) adding deionized water into diatomite, stirring and heating to 50-60 ℃, simultaneously dropwise adding a nitrate mixed solution and a sodium carbonate solution to form a precipitate, keeping the pH value of 6-8, adjusting the pH value of 8-10 by using the sodium carbonate solution after the nitrate mixed solution is completely dripped, aging the precipitate for 3-4 hours, washing, filtering, drying, roasting at the temperature of 500-600 ℃ for 3-4 hours, and grinding to obtain a finished catalyst Cat-M which contains metal oxides;

2) synthesis of fatty tertiary amines

2.1) putting the dried fatty alcohol into an amination kettle, wherein a gas compressor is connected on the amination kettle to circulate the gas in the amination kettle in the kettle, adding the catalyst Cat-M obtained in the step 1), respectively replacing the catalyst with nitrogen and hydrogen for 3 times, heating to 190 ℃ plus materials, introducing the hydrogen to the pressure of 0.1Mpa, and carrying out catalyst reduction reaction, namely reducing the metal oxide into a metal simple substance;

2.2) after the catalyst is reduced, heating to 190 ℃, starting to introduce metered monomethylamine or dimethylamine to carry out amination reaction, introducing monomethylamine or dimethylamine while heating to 200-230 ℃, controlling the pressure to 0.1-0.4Mpa, and simultaneously separating water generated by the reaction through a water separator and pressing the water into an amine recovery kettle;

2.3) adding an alkaline substance into the amine recovery kettle, adjusting the concentration of the alkali in the aqueous solution in the amine recovery kettle to 1-10%, heating, opening a valve of the amine recovery kettle, returning the monomethylamine or dimethylamine dissolved in the water to the amination kettle for continuous reaction, after the monomethylamine or dimethylamine recovery reaction in the amine recovery kettle is finished, continuing the heat preservation reaction of the amination kettle until the pressure is not reduced, and stopping the reaction after sampling and analyzing are qualified;

3) working up of tertiary fatty amines

3.1) transferring the reaction liquid to a settling kettle for cooling and settling;

3.2) transferring the settled product to a rectifying still, vacuumizing before rectification, replacing the rectifying still for a plurality of times by using nitrogen, keeping the vacuum degree between-0.095 and-0.1 Mpa, and collecting fractions at the corresponding temperature at the outlet of the rectifying still according to the boiling point of the obtained aliphatic tertiary amine to obtain the product aliphatic tertiary amine; if the fraction with the outlet temperature of 108-112 ℃ of the rectifying still is collected, the product C12/14 alkyl dimethyl tertiary amine is obtained;

4) storage of fatty tertiary amines

Adding strong alkali solution into the finished product obtained by rectification, transferring the finished product into a finished product storage tank, vacuumizing the finished product storage tank before use, and replacing the finished product storage tank with nitrogen for several times.

Further, the invention also defines that in the catalyst Cat-M in the step 1), the mass ratio of copper oxide, nickel oxide, chromium oxide, platinum oxide and magnesium oxide is 2-4: 0.5-1: 0.01-0.05: 0.005-0.02: 0.1 to 0.5.

Further, the invention also defines the feeding ratio of the mass of the diatomite to the total mass of all the metal oxides in the step 1) to be 1-1.5:1, preferably 1: 1.

further, the invention also limits the catalyst reduction time in the step 2.1) to 30-60 minutes.

Further, the invention also defines the fatty alcohol as C8-14 fatty alcohol.

Further, the invention also defines that the alkaline substance in the step 2.3) is sodium hydroxide, potassium hydroxide, sodium methoxide or potassium methoxide, and preferably sodium hydroxide or potassium hydroxide.

Furthermore, the invention also limits the heating temperature of the amine recovery kettle in the step 2) to be 20-100 ℃, and the temperature is raised to 100 ℃ for heat preservation reaction for 30-60 min; adding alkali until the pH value of water is 12-14.

Furthermore, the invention also limits that in the step 3) and the step 4), the air is replaced by nitrogen until the oxygen content in the rectifying still and the finished product storage tank is less than 1 percent, and the carbon dioxide content is less than 100ppm according to the proportion of oxygen, carbon dioxide and acid gas in the air.

Further, the invention also limits the concentration of the strong alkali solution used in the step 4) to be 30-50%, and the adding amount of the strong alkali solution is 0.01-0.1% of the mass of the fatty tertiary amine.

The production method of the fatty tertiary amine adopts a one-step reaction, can prepare the monoalkyl fatty tertiary amine or the polyalkyl fatty tertiary amine according to the requirement, and has the following reaction principle:

1) main reaction

Monoalkyl tertiary amines:

a bisalkyl tertiary amine:

wherein R-OH is C8-14 fatty alcohol;

2) side reactions

2.1) aldol condensates

2.2) white floc generated in the storage process is mainly analyzed to be fatty tertiary amine salt, such as fatty tertiary amine carbonate and the like.

The white floccule is mainly formed by the reaction of acid gas in the air and alkaline fatty amine to generate salt, particularly carbon dioxide in the air and a small amount of other acid gas, and in addition, the existence of oxygen can change tertiary amine into amine oxide;

carbonate of fatty tertiary amine

The invention recovers monomethylamine and dimethylamine by strengthening alkali, and the principle is such as recovering NH by strong alkali₃，NH₃With NH4 in water⁺Exist of CH₂NH₂With CH₂NH₃ ⁺In order to facilitate understanding, NH is used in the invention for explaining the reaction principle₃For example, the details are as follows:

the ammonia nitrogen is mainly in waterWith ammonium ions (NH)₄ ⁺) And free ammonia (NH)₃) The states exist, with the equilibrium relationship as follows:

NH₃+H₂O＝NH₄ ⁺+OH^-

this relationship is influenced by the pH, which, when high, shifts the equilibrium to the left and the proportion of free ammonia increases; at room temperature, most of ammonia nitrogen exists in the state of ammonium ion at a pH of about 7, whereas free ammonia accounts for about 98% at a pH of about 11.

The invention utilizes the principle that the solubility of ammonia in water is reduced under the alkaline heating condition, namely the final temperature of actual heating is raised to 100 ℃, and recovered water obtained by reaction is added with liquid alkali and heated, namely, the pH is adjusted, and the temperature is raised simultaneously to ensure that amine dissolved in water is fully resolved out and then enters an amination kettle for continuous reaction:

NH⁴⁺+OH^-＝NH₃·H₂O

NH₃·H₂O＝H₂O+NH₃× (high temperature).

By adopting the technology, compared with the prior art, the invention has the following beneficial effects:

1) according to the invention, by changing the composition of the catalyst, a platinum oxide component is added into the catalyst, and the feed ratio of each oxide is changed, namely the mass ratio of copper oxide, nickel oxide, chromium oxide, platinum oxide and magnesium oxide is defined as 2-4: 0.5-1: 0.01-0.05: 0.005-0.02: 0.1-0.5, obtaining a novel catalyst, and under the action of the catalyst, greatly reducing the generation of an aldol condensation compound, wherein the rate of oxidizing fatty alcohol into fatty aldehyde and the rate of dehydrating and hydrogenating an intermediate fatty aldehyde after further amination with monomethylamine or dimethylamine are mainly adjusted by adjusting the proportion of each component of the catalyst, so that the generation of the aldol condensation compound is reduced;

2) according to the invention, a gas compressor is directly added on the amination kettle, so that gasified monomethylamine, dimethylamine and hydrogen in the amination kettle are recycled in a reaction system, the cost is reduced, and the reaction efficiency is improved;

3) during reaction, water generated by the reaction is separated by a water separator and then enters an amine recovery kettle for recovery, alkali is added into the amine recovery kettle, the heating is carried out, ammonia dissolved in the water is resolved out and returns to an amination kettle for continuous reaction, so that the waste and the environmental pollution are reduced, and by adopting the method, the content of the aldol condensation compound in the obtained product can be reduced to be below 0.5 percent;

4) in the distillation process and the storage process, the active gases dissolved in the product, mainly oxygen, carbon dioxide, nitrogen dioxide and the like, are replaced by the inert gases, and meanwhile, a trace amount of strong base solution is added into the finished product storage tank, so that the reaction of the product with acidic gases in the air and the like is effectively avoided, and the condition that tertiary amine is changed into amine oxide due to the existence of oxygen is also avoided; therefore, the method can ensure that the fatty tertiary amine product does not generate white floccule in a longer time, improve the quality of the product and the storage time, and ensure the quality of the product because the finished product is still transparent and clear liquid after being stored for 60 days without generating the white floccule after being stored by the method.

Drawings

FIG. 1 is a process flow diagram of example 1 of the present invention.

In the figure: 1. an amination kettle; 2. an amine recovery kettle; 3. a gas compressor; 4. settling the kettle; 5. a rectifying still; 6. and (5) a finished product storage tank.

Detailed Description

The invention is further described with reference to the accompanying drawings, but the scope of the invention is not limited thereto:

EXAMPLE 1 production of monoalkyl Tertiary amine

First step, preparation of the catalyst

The weight portions are as follows: 300 parts of copper nitrate, 100 parts of nickel nitrate, 3 parts of chromium nitrate, 1 part of platinum chloride and 30 parts of magnesium nitrate are prepared into a nitrate mixed solution with the concentration of 10 wt% by using deionized water, and anhydrous sodium carbonate is prepared into a sodium carbonate solution with the concentration of 10 wt% by using deionized water; adding deionized water into diatomite (the ratio of the diatomite to the total metal oxide is 1: 1), stirring and heating to 50-60 ℃, simultaneously dropwise adding the prepared nitrate mixed solution and sodium carbonate solution to form a precipitate, keeping the pH to be 6-8, after the nitrate mixed solution is completely dripped, adjusting the pH to 8-10 by using the sodium carbonate solution, after the precipitate is aged for 3-4 hours, washing, filtering and drying, roasting at the temperature of 500-600 ℃ for 3-4 hours, and grinding to obtain a finished catalyst Cat-A;

second step, amination

As shown in figure 1, 10000kg of dodecatetraol with the moisture of 0.09% after being dried is transferred into an amination kettle 1, a gas compressor 3 is started to circulate the gas in the amination kettle 1 in the kettle, 100kg of catalyst Cat-A is used, the amination kettle 1 is replaced by nitrogen for 3 times and hydrogen for 3 times, then the temperature is raised, hydrogen is used for reduction for 1 hour at the temperature of 160 plus 190 ℃, the hydrogen pressure is maintained at 0.1MPa in the process, and the metal oxide in the catalyst is reduced into a metal simple substance; and (2) introducing dimethylamine into the amination kettle 1 for amination reaction after the reduction is finished, heating to 220 ℃ while introducing dimethylamine, and introducing 2335kg of dimethylamine within 3-4 hours, wherein the total molar ratio of the dodecatetradecanol to the dimethylamine is 1: 1, maintaining the pressure of the reaction kettle at 0.2-0.3Mpa in the process, if the pressure is higher, properly slowing down the speed of introducing dimethylamine, opening a valve 2 of an amine recovery kettle after the introduction of the dimethylamine is finished, adding sodium hydroxide to adjust the concentration of sodium hydroxide in the aqueous solution in the amine recovery kettle 2 to 5%, and then heating to recover the dimethylamine dissolved in the generated water to the amination kettle 1 for continuous reaction. After the dimethylamine recovery reaction is finished, sampling and analyzing when the temperature is kept for 2-3 hours and the pressure is not reduced basically, the content of the monoalkyl tertiary amine is 95.2 percent, the content of the dialkyl amine is 3.2 percent, the content of the trialkyl tertiary amine is 0.5 percent, and the content of the aldol condensation compound is 0.4 percent.

Third, distillation and working up

Transferring the crude reaction liquid in the amination kettle 1 to a settling kettle 4 for cooling and settling, transferring to a rectifying kettle 5 after settling, vacuumizing the rectifying kettle 5 and replacing the crude reaction liquid with nitrogen for three times, measuring the oxygen content by 0.98%, then gradually heating and continuously vacuumizing, keeping the vacuum degree at-0.095 to-0.1 Mpa, starting to collect the finished product C12/14 alkyl dimethyl tertiary amine at the top temperature of 108-.

EXAMPLE 2 Process for producing Dialkyltertiary amine

First step, preparation of the catalyst

Preparing 400 parts of copper nitrate, 100 parts of nickel nitrate, 2 parts of chromium nitrate, 0.5 part of platinum chloride and 40 parts of magnesium nitrate into a 12 wt% mixed solution by using deionized water, and preparing a 12 wt% solution of anhydrous sodium carbonate by using deionized water; adding deionized water into diatomite (the ratio of the diatomite to the total metal oxide is 1: 1), stirring and heating to 50-60 ℃, simultaneously dropwise adding a nitrate mixed solution and a sodium carbonate solution to form a precipitate, keeping the pH value of 6-8, adjusting the pH value of 8-10 by using the sodium carbonate solution after the nitrate mixed solution is completely dripped, aging the precipitate for 3-4 hours, washing, filtering, drying, roasting at the temperature of 500-600 ℃ for 3-4 hours, and grinding to obtain a finished catalyst Cat-B;

second step, amination

Transferring 10000kg of dried decanol with the water content of 0.08 percent into an amination kettle 1, starting a gas compressor 3 to circulate gas in the amination kettle 1 in the kettle, using 100kg of catalyst Cat-B, using nitrogen to replace the amination kettle 1 for 3 times, using hydrogen to replace for 3 times, then heating, using hydrogen to reduce at 180 ℃ for 1 hour, reducing metal oxide into metal simple substance, and maintaining the hydrogen pressure at 0.1MPa in the process; after the reduction is finished, introducing monomethylamine into an amination kettle 1 for amination reaction, heating to 225 ℃ while introducing monomethylamine, and introducing 980kg monomethylamine in 3-4 hours, wherein the total molar ratio of decanol to monomethylamine is 2: 1, maintaining the pressure of a reaction kettle at 0.3Mpa, if the pressure is higher, properly slowing down the speed of introducing monomethylamine, opening an amine recovery kettle valve after introducing the monomethylamine, adding potassium hydroxide to adjust the concentration of potassium hydroxide in an aqueous solution in an amine recovery kettle 2 to 10%, then heating to recover the monomethylamine dissolved in generated water to an amination kettle for continuous reaction, and after finishing the monomethylamine recovery reaction, keeping the temperature for 2-3 hours and sampling and analyzing when the pressure is not reduced basically, wherein the content of the monoalkyl tertiary amine is 3.2%, the content of the dialkyl amine is 95.1%, the content of the trialkyl tertiary amine is 0.8%, and the content of the aldol condensation compound is 0.3%;

third, distillation and working up

Transferring the crude reaction liquid of the amination kettle 1 to a settling kettle 4 for cooling and settling, transferring to a rectifying kettle 5 after settling, vacuumizing the rectifying kettle 5 and replacing with nitrogen for three times, measuring the oxygen content by 0.95%, then gradually heating, continuously vacuumizing, keeping the vacuum degree at-0.095 to-0.1 Mpa, collecting a finished product at the top temperature of about 185 ℃, adding a KOH solution of 0.05 percent of the total amount of the finished product into the finished product after rectification, wherein the concentration of the KOH solution is 30 percent, transferring the product to a finished product storage tank, and replacing the finished product storage tank with vacuum and nitrogen for three times. The product in the finished product storage tank is sampled to be transparent clear liquid without white floccule after 60 days.

Comparative example 1

First step, preparation of the catalyst

Preparing 400 parts of copper nitrate, 100 parts of nickel nitrate, 100 parts of zinc nitrate and 100 parts of magnesium nitrate into a 10% mixed solution by using deionized water, and preparing 10% solution of anhydrous sodium carbonate by using the deionized water; adding deionized water into diatomite (the ratio of the diatomite to the total metal oxide is 1: 1), stirring and heating to 50-60 ℃, simultaneously dropwise adding a nitrate mixed solution and a sodium carbonate solution to form a precipitate, keeping the pH value of 6-8, adjusting the pH value of 8-10 by using the sodium carbonate solution after the nitrate mixed solution is completely dripped, aging the precipitate for 3-4 hours, washing, filtering, drying, roasting at the temperature of 500-600 ℃ for 3-4 hours, and grinding to obtain a finished catalyst Cat-C;

second step, amination

8000kg of dried dodecatetradecanol with the water content of 0.09 percent and 100kg of catalyst Cat-C are transferred into an amination kettle, the reaction kettle is replaced by nitrogen for 3 times and hydrogen for 3 times, then the temperature is raised, hydrogen is used for reduction for 1 hour at the temperature of 190 ℃ plus materials, and the process maintains the hydrogen pressure at 0.1 MPa. And (3) introducing dimethylamine into the reaction kettle for amination reaction after the reduction is finished, heating to 220 ℃ while introducing dimethylamine, and introducing 1865kg of dimethylamine within 3-4 hours, wherein the total molar ratio of the dodecatetradecanol to the dimethylamine is 1: 1, maintaining the pressure of the reaction kettle to be 0.2-0.3Mpa in the process, if the pressure is higher, properly slowing down the speed of introducing dimethylamine, opening a valve of an amine recovery kettle after the introduction of the dimethylamine is finished, adding sodium hydroxide to adjust the concentration of the sodium hydroxide in the aqueous solution in the amine recovery kettle to 3%, and then heating to recover the dimethylamine dissolved in the generated water to the amination kettle for continuous reaction. After the dimethylamine recovery reaction is finished, sampling and analyzing when the temperature is kept for 2-3 hours and the pressure is not reduced basically, wherein the content of the monoalkyl tertiary amine is 95.3 percent, the content of the dialkyl amine is 2.2 percent, the content of the trialkyl tertiary amine is 0.6 percent, and the content of the aldol condensation compound is 1.5 percent;

third, distillation and working up

And (2) settling the crude product of the amination kettle, transferring the crude product to a rectifying kettle, vacuumizing the rectifying kettle until the crude product is replaced by nitrogen for three times, detecting the oxygen content of 0.95%, gradually heating the rectifying kettle, continuously vacuumizing the rectifying kettle, keeping the vacuum degree between-0.095 and-0.1 Mpa, collecting the finished product when the top temperature is about 110 ℃, transferring the product to a finished product storage tank after the rectification is finished, wherein the finished product storage tank is not replaced by vacuum and nitrogen, no alkali solution is added into the finished product, and sampling the finished product storage tank after 15 days to obtain a small amount of white floccule.