阅读说明：本技术 一种正丁基异氰酸酯釜残处理方法 (Method for treating n-butyl isocyanate kettle residue ) 是由 严绘 林洋 孟海娟 赵芙蓉 廖强 龚正福 殷恒志 赵升榕 于 2021-08-25 设计创作，主要内容包括：本申请公开了一种正丁基异氰酸酯釜残处理方法,正丁基异氰酸酯含盐固体釜残得到有效资源化处理,降低了三废排放量,提高了产品附加值。通过中和及加压碱解工艺、釜残中正丁基异氰酸酯自聚体、副产1,3二丁基脲、正丁胺盐酸盐等组分,反应后的产物组成较为单一,大幅降低后处理难度,产品纯度高。通过萃取精馏工艺,实现正丁胺有效回收,釜残资源化工艺流程短、制备的产品纯度高,真正实现了釜残的有效利用。(The application discloses a method for treating n-butyl isocyanate kettle residue, which is characterized in that n-butyl isocyanate salt-containing solid kettle residue is effectively recycled, the discharge amount of three wastes is reduced, and the added value of products is improved. Through the neutralization and pressurization alkaline hydrolysis process, the n-butyl isocyanate self-polymerization in the kettle residue, the by-product 1, 3-dibutyl urea, n-butylamine hydrochloride and other components, the composition of the product after reaction is single, the post-treatment difficulty is greatly reduced, and the product purity is high. The effective recovery of the n-butylamine is realized through the extraction and rectification process, the recycling process flow of the kettle residue is short, the purity of the prepared product is high, and the effective utilization of the kettle residue is really realized.)

1. The n-butyl isocyanate kettle residue treatment method is characterized by comprising the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

2. The n-butyl isocyanate kettle residue treatment method of claim 1, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

3. The n-butyl isocyanate kettle residue treatment method as claimed in claim 1, wherein the extraction agent is one of n-butanol, n-pentanol, n-hexanol and heptanol.

4. The n-butyl isocyanate kettle residue treatment method as claimed in claim 1, wherein the vacuum degree of the negative pressure distillation process is 1-100 KPa.

5. The method for treating the n-butyl isocyanate kettle residue as recited in claim 1, wherein the recovered solvent in the negative pressure distillation process is repeatedly fed to the extraction step.

6. The method for treating n-butyl isocyanate kettle residue according to claim 1, wherein the water layer in the layering step is sent to a wastewater treatment system.

Technical Field

The application relates to the field of chemical waste treatment, in particular to a n-butyl isocyanate kettle residue treatment method.

Background

N-butyl isocyanate (hereinafter referred to as FNC) is mainly used for synthesizing pesticides such as benomyl and the like and is also used as a catalyst for synthesizing sulfonylurea herbicides. As an important intermediate, the compound can be used for synthesizing products such as medicines, pesticides and the like. At present, the FNC preparation method mainly comprises the steps of reacting phosgene with n-butylamine, and preparing a finished product from a synthetic liquid through the working procedures of light dispelling, rectification and the like. In order to improve the reaction yield, the FNC preparation process is generally adopted by salifying n-butylamine and hydrochloric acid and then carrying out phosgenation. If the salt forming process is insufficient, the n-butylamine and the reaction product FNC continue to react to generate the byproduct 1, 3-dibutylurea, the salt forming solution is subjected to phosgenation reaction, if the phosgene is insufficient, the reaction is incomplete, part of n-butylamine hydrochloride suspended matters enter a post-treatment process, and finally the suspended matters exist in a kettle residue form. Meanwhile, a small amount of n-butyl isocyanate is self-polymerized in the rectification process to form polymers which exist in the rectification kettle residue. Therefore, the residue is mainly n-butylamine hydrochloride, byproduct 1, 3-dibutylurea and polymer. Because the components are complex, the kettle residue is used as solid waste by part of enterprises to be sent to qualification manufacturers for treatment, and no report related to FNC kettle residue resource treatment is found at present. Therefore, a method for treating the n-butyl isocyanate kettle residue is needed to solve the problems.

Disclosure of Invention

The application provides a method for treating residual n-butyl isocyanate in a kettle, which solves the problem of inconvenient treatment of residual n-butyl isocyanate in the prior art.

The application provides a n-butyl isocyanate kettle residue treatment method, which comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Further, the n-butyl isocyanate kettle residue treatment method is characterized in that the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Further, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptanol.

Further, the vacuum degree in the negative pressure distillation process is 1-100 KPa.

Further, in the method for treating the n-butyl isocyanate kettle residue, the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Further, in the method for treating the n-butyl isocyanate kettle residue, a water layer in the layering step is sent into a wastewater treatment system.

According to the technical scheme, the application provides a n-butyl isocyanate kettle residue treatment method, and aims to solve the problems that a kettle residue treatment scheme is not provided in the existing process, salt-containing solid kettle residues are difficult to treat and the like. The process has the following advantages:

(1) the salt-containing solid still residue of the n-butyl isocyanate is effectively recycled, the discharge amount of three wastes is reduced, and the added value of the product is improved.

(2) Through the neutralization and pressurization alkaline hydrolysis process, the n-butyl isocyanate self-polymerization in the kettle residue, the by-product 1, 3-dibutyl urea, n-butylamine hydrochloride and other components, the composition of the product after reaction is single, the post-treatment difficulty is greatly reduced, and the product purity is high.

(3) The effective recovery of the n-butylamine is realized through the extraction and rectification process, the recycling process flow of the kettle residue is short, the purity of the prepared product is high, and the effective utilization of the kettle residue is really realized.

Drawings

In order to more clearly illustrate the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without any creative effort.

FIG. 1 is a process flow diagram of the present application;

FIG. 2 is a reaction equation of n-butylamine hydrochloride with base according to the present application;

FIG. 3 is a reaction equation of byproduct 1, 3-dibutylurea of the present application with a base;

FIG. 4 shows the reaction equation of the n-butyl isocyanate self-assembly substance with a base.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

See FIGS. 1-4

Example 1

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent to a wastewater treatment system.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

500g of n-butyl isocyanate rectification kettle residue is added into a 2L high pressure kettle, 10 percent NaOH solution with the same weight as the kettle residue is added, the mixture is stirred for 3 hours at the temperature of 30 ℃, and the pH value of the solution is 14 after the stirring is finished. Introducing nitrogen into the system for replacement, filling nitrogen to 3MPa after the replacement is qualified, and heating to 150 ℃ for alkaline hydrolysis. After 6 hours of reaction, the temperature is reduced and the pressure is relieved, and the kettle material is homogeneous liquid. Adding 500g of n-butanol, extracting for three times at 30 ℃, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under vacuum of 10 KPa. The normalized content of n-butylamine in the fraction was 99.5%, and the yield of n-butylamine was 95.1%.

Example 2

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent to a wastewater treatment system.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

500g of n-butyl isocyanate rectification residue was added to a 2L autoclave, 1000g of 5% KOH solution was added, and the mixture was stirred at 50 ℃ for 2 hours, after which the pH of the solution was measured to be 14. Introducing nitrogen into the system for replacement, filling nitrogen to 5MPa after the replacement is qualified, and heating to 120 ℃ for alkaline hydrolysis. After 4 hours of reaction, the temperature is reduced and the pressure is relieved, and the kettle material is homogeneous liquid. Adding 1000g of n-butanol, extracting for three times at 20 ℃, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under vacuum of 20 KPa. The normalized content of n-butylamine in the fraction was 99.3%, and the yield of n-butylamine was 96.3%.

Example 3

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent to a wastewater treatment system.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

300g of n-butyl isocyanate rectifying still residue is added into a 2L high pressure kettle, 1500g of 1% ammonia water solution is added, stirring is carried out for 5h at the temperature of 40 ℃, and the pH value of the solution is measured to be 9 after stirring. Introducing nitrogen into the system for replacement, filling nitrogen to 10MPa after the replacement is qualified, and heating to 100 ℃ for alkaline hydrolysis. After 8 hours of reaction, the temperature is reduced and the pressure is relieved, and the kettle material is homogeneous liquid. Adding 900g of n-heptanol, extracting for three times at 60 ℃, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under vacuum of 30 KPa. The normalized content of n-butylamine in the fraction was 99.7%, and the yield of n-butylamine was 88.3%.

Example 4

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent to a wastewater treatment system.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

500g of n-butyl isocyanate rectification kettle residue is added into a 2L autoclave, 1500g of 50 percent NaOH solution is added, the mixture is stirred for 5 hours at the temperature of 60 ℃, and the pH value of the solution is 14 after the stirring is finished. Introducing nitrogen into the system for replacement, filling nitrogen to 2MPa after the replacement is qualified, and heating to 100 ℃ for alkaline hydrolysis. After reacting for 2h, cooling and decompressing, and the kettle material is homogeneous liquid. Adding 250 n-amyl alcohol, extracting for three times at 30 ℃, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under the vacuum of 5 KPa. The normalized content of n-butylamine in the fraction was 99.5%, and the yield of n-butylamine was 90.5%.

Example 5

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent to a wastewater treatment system.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

500g of medium-n-butyl isocyanate residue was added to a 2L autoclave, 1500g of a 30% NaOH solution were added, and the mixture was stirred at 10 ℃ for 10 hours, after which the pH of the solution was measured to be 14. Introducing nitrogen into the system for replacement, filling nitrogen to 3MPa after the replacement is qualified, and heating to 170 ℃ for alkaline hydrolysis. After 4 hours of reaction, the temperature is reduced and the pressure is relieved, and the kettle material is homogeneous liquid. Adding 500g of n-hexanol, extracting for three times at 50 ℃, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under vacuum of 70 KPa. The normalized content of n-butylamine in the fraction is 99.5 percent, and the yield of the n-butylamine is 91.8 percent

Example 6

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent to a wastewater treatment system.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

300g of n-butyl isocyanate rectifying still residue is added into a 2L autoclave, 1500g of 20 percent NaOH solution is added, the mixture is stirred for 6 hours at the temperature of 40 ℃, and the pH value of the solution is 14 after the stirring is finished. Introducing nitrogen into the system for replacement, filling nitrogen to 4MPa after the replacement is qualified, and heating to 160 ℃ for alkaline hydrolysis. After 7h of reaction, the temperature is reduced and the pressure is relieved, and the kettle material is homogeneous liquid. Adding 1500g of n-butanol, extracting at 30 ℃ for three times, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under vacuum of 100 KPa. The normalized content of n-butylamine in the fraction is 99.6 percent, and the yield of the n-butylamine is 91.5 percent

Example 7

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: adding n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14, and neutralizing n-butylamine hydrochloride in the kettle residue into n-butylamine through a neutralization reaction;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent into a wastewater treatment system

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

500g of n-butyl isocyanate rectification residue was added to a 2L autoclave, 500g of 10% KOH solution was added thereto, and the mixture was stirred at 80 ℃ for 5 hours, after which the pH of the solution was measured to be 14. Introducing nitrogen into the system for replacement, filling nitrogen to 7MPa after the replacement is qualified, and heating to 130 ℃ for alkaline hydrolysis. After 8 hours of reaction, the temperature is reduced and the pressure is relieved, and the kettle material is homogeneous liquid. Adding 500g of n-butanol, extracting for three times at 30 ℃, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under vacuum of 5 KPa. The normalized content of n-butylamine in the fraction was 99.4%, and the yield of n-butylamine was 91.1%.

Example 8

According to the technical scheme, the n-butyl isocyanate kettle residue treatment method comprises the following steps:

s1: rectifying the n-butyl isocyanate kettle residues, and adding the rectified n-butyl isocyanate kettle residues into a clean reaction kettle;

s2: maintaining the temperature of the reaction system at 20-50 ℃, adding dilute alkali liquor into the reaction kettle, and continuously stirring for 3-5 hours to keep the pH value in the reaction kettle at 13-14;

s3: introducing nitrogen into the system for replacement, then boosting the pressure of the system to 2-5MPa, lifting the system to 100-200 ℃, and carrying out alkaline hydrolysis reaction for 1-20 hours;

s4: and cooling and decompressing the system, adding an extracting agent for extraction, layering the extract liquor, and carrying out negative pressure distillation and collection on an oil layer.

Preferably, the method for treating the n-butyl isocyanate kettle residue comprises the step of treating the n-butyl isocyanate kettle residue with dilute alkali solution, wherein the dilute alkali solution comprises one of NaOH, KOH and ammonia water.

Preferably, the n-butyl isocyanate kettle residue treatment method is characterized in that the extracting agent is one of n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol and heptyl alcohol.

Preferably, the vacuum degree of the negative pressure distillation process is 1-100 KPa.

Preferably, the method for treating the n-butyl isocyanate kettle residue is characterized in that the recovered solvent in the negative pressure distillation process is repeatedly sent to the extraction step.

Preferably, in the n-butyl isocyanate kettle residue treatment method, the water layer in the layering step is sent to a wastewater treatment system.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

According to the method, kettle residues left by n-butyl isocyanate production are put into a reaction kettle, dilute alkali liquor is added, n-butylamine hydrochloride in the kettle residues is subjected to neutralization reaction with alkali, the diluted alkali liquor is added, stirring is carried out until the n-butylamine hydrochloride is completely reacted with the alkali, then nitrogen gas replacement and the like are conducted in a specific environment to enable byproducts 1, 3-dibutyl urea and n-butyl isocyanate to be hydrolyzed from a polymer, after the alkaline hydrolysis, negative pressure distillation is carried out on an oil layer through extraction and layering, and n-butylamine finished products are collected.

400g of n-butyl isocyanate rectifying still residue is added into a 2L high pressure kettle, 800g of 5 percent NaOH solution is added, the mixture is stirred for 10 hours at the temperature of 50 ℃, and the pH value of the solution is 14 after the stirring is finished. Introducing nitrogen into the system for replacement, filling nitrogen to 9MPa after the replacement is qualified, and heating to 190 ℃ for alkaline hydrolysis. After 6 hours of reaction, the temperature is reduced and the pressure is relieved, and the kettle material is homogeneous liquid. Adding 400g of n-butanol, extracting for three times at 40 ℃, layering the extract, rectifying the oil layer under negative pressure, and collecting the fraction under vacuum of 10 KPa. The normalized content of n-butylamine in the fraction was 99.6%, and the yield of n-butylamine was 92.5%.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The above-described embodiments of the present application do not limit the scope of the present application.