Method for treating n-butyl isocyanate kettle residues

Abstract

The invention discloses a method for treating n-butyl isocyanate kettle residues, which is used for effectively resourcefully treating the n-butyl isocyanate salt-containing solid kettle residues, reducing the discharge of three wastes and improving the added value of the product. Through neutralization and pressurized alkaline hydrolysis processes, components such as an n-butyl isocyanate self-polymer, a byproduct 1, 3-dibutyl urea and n-butylamine hydrochloride are contained in kettle residues, and the reacted product is relatively single in composition, so that the post-treatment difficulty is greatly reduced, and the product purity is high. The n-butylamine is effectively recycled through the extractive distillation process, the kettle residue recycling process flow is short, the prepared product is high in purity, and effective utilization of the kettle residues is truly achieved.

Description

technical field

[0001] The application relates to the field of chemical waste treatment, in particular to a method for treating n-butyl isocyanate still residue. Background technique

[0002] N-butyl isocyanate (hereinafter referred to as FNC) is mainly used to synthesize insecticides such as benomyl, and is also used as a catalyst for the synthesis of sulfonylurea herbicides. As an important intermediate, it can be used to synthesize medicines, pesticides and other products. At present, the preparation method of FNC is mainly the reaction of phosgene and n-butylamine, and the synthetic liquid is prepared through processes such as lightening and rectification. In order to improve the reaction yield, generally, n-butylamine is firstly salted with hydrochloric acid, and then phosgenated to prepare FNC. If the salt-forming process is insufficient, n-butylamine and the reaction product FNC will continue to react to produce 1,3 dibutylurea as a by-product, and the salt-forming ...

Examples

Embodiment 1

[0026] As can be seen from the above technical scheme, a kind of n-butyl isocyanate still residue treatment method comprises the steps:

[0027] S1: Add n-butyl isocyanate residue in a clean reactor;

[0028] S2: Maintain the temperature of the reaction system at 20-50°C, add dilute lye to the reactor and continue to stir for 3-5 hours, so that the pH in the reactor is kept at 13-14, and the neutralization reaction will remove the n-butane in the residue Amine hydrochloride is neutralized to n-butylamine;

[0029] S3: After nitrogen replacement in the system, the system is boosted to 2-5MPa, and the system is raised to 100-200°C, and the alkali hydrolysis reaction is performed for 1-20 hours. The alkali hydrolysis reaction converts the trimer into n-butylamine. This process Add a certain amount of alkali to maintain the alkali concentration at 1%-50%;

[0030] S4: After cooling down the system and releasing the pressure, add an extractant for extraction, layer the extract, a...

Embodiment 2

[0039] As can be seen from the above technical scheme, a kind of n-butyl isocyanate still residue treatment method comprises the steps:

[0040] S1: Add n-butyl isocyanate residue in a clean reactor;

[0041] S2: Maintain the temperature of the reaction system at 20-50°C, add dilute lye to the reactor and continue to stir for 3-5 hours, so that the pH in the reactor is kept at 13-14, and the neutralization reaction will remove the n-butane in the residue Amine hydrochloride is neutralized to n-butylamine;

[0042] S3: After nitrogen replacement in the system, the system is boosted to 2-5MPa, and the system is raised to 100-200°C, and the alkali hydrolysis reaction is performed for 1-20 hours. The alkali hydrolysis reaction converts the trimer into n-butylamine. This process Add a certain amount of alkali to maintain the alkali concentration at 1%-50%;

[0043] S4: After cooling down the system and releasing the pressure, add an extractant for extraction, layer the extract, a...

Embodiment 3

[0052] As can be seen from the above technical scheme, a kind of n-butyl isocyanate still residue treatment method comprises the steps:

[0053] S1: Add n-butyl isocyanate residue in a clean reactor;

[0054] S2: Maintain the temperature of the reaction system at 20-50°C, add dilute lye to the reactor and continue to stir for 3-5 hours, so that the pH in the reactor is kept at 13-14, and the neutralization reaction will remove the n-butane in the residue Amine hydrochloride is neutralized to n-butylamine;

[0055] S3: After nitrogen replacement in the system, the system is boosted to 2-5MPa, and the system is raised to 100-200°C, and the alkali hydrolysis reaction is performed for 1-20 hours. The alkali hydrolysis reaction converts the trimer into n-butylamine. This process Add a certain amount of alkali to maintain the alkali concentration at 1%-50%;

[0056] S4: After cooling down the system and releasing the pressure, add an extractant for extraction, layer the extract, a...

technical field

[0001] The application relates to the field of chemical waste treatment, in particular to a method for treating n-butyl isocyanate still residue. Background technique

[0002] N-butyl isocyanate (hereinafter referred to as FNC) is mainly used to synthesize insecticides such as benomyl, and is also used as a catalyst for the synthesis of sulfonylurea herbicides. As an important intermediate, it can be used to synthesize medicines, pesticides and other products. At present, the preparation method of FNC is mainly the reaction of phosgene and n-butylamine, and the synthetic liquid is prepared through processes such as lightening and rectification. In order to improve the reaction yield, generally, n-butylamine is firstly salted with hydrochloric acid, and then phosgenated to prepare FNC. If the salt-forming process is insufficient, n-butylamine and the reaction product FNC will continue to react to produce 1,3 dibutylurea as a by-product, and the salt-forming ...

Examples

Embodiment 1

[0026] As can be seen from the above technical scheme, a kind of n-butyl isocyanate still residue treatment method comprises the steps:

[0027] S1: Add n-butyl isocyanate residue in a clean reactor;

[0028] S2: Maintain the temperature of the reaction system at 20-50°C, add dilute lye to the reactor and continue to stir for 3-5 hours, so that the pH in the reactor is kept at 13-14, and the neutralization reaction will remove the n-butane in the residue Amine hydrochloride is neutralized to n-butylamine;

[0029] S3: After nitrogen replacement in the system, the system is boosted to 2-5MPa, and the system is raised to 100-200°C, and the alkali hydrolysis reaction is performed for 1-20 hours. The alkali hydrolysis reaction converts the trimer into n-butylamine. This process Add a certain amount of alkali to maintain the alkali concentration at 1%-50%;

[0030] S4: After cooling down the system and releasing the pressure, add an extractant for extraction, layer the extract, a...

Embodiment 2

[0039] As can be seen from the above technical scheme, a kind of n-butyl isocyanate still residue treatment method comprises the steps:

[0040] S1: Add n-butyl isocyanate residue in a clean reactor;

[0041] S2: Maintain the temperature of the reaction system at 20-50°C, add dilute lye to the reactor and continue to stir for 3-5 hours, so that the pH in the reactor is kept at 13-14, and the neutralization reaction will remove the n-butane in the residue Amine hydrochloride is neutralized to n-butylamine;

[0042] S3: After nitrogen replacement in the system, the system is boosted to 2-5MPa, and the system is raised to 100-200°C, and the alkali hydrolysis reaction is performed for 1-20 hours. The alkali hydrolysis reaction converts the trimer into n-butylamine. This process Add a certain amount of alkali to maintain the alkali concentration at 1%-50%;

[0043] S4: After cooling down the system and releasing the pressure, add an extractant for extraction, layer the extract, a...

Embodiment 3

[0052] As can be seen from the above technical scheme, a kind of n-butyl isocyanate still residue treatment method comprises the steps:

[0053] S1: Add n-butyl isocyanate residue in a clean reactor;

[0054] S2: Maintain the temperature of the reaction system at 20-50°C, add dilute lye to the reactor and continue to stir for 3-5 hours, so that the pH in the reactor is kept at 13-14, and the neutralization reaction will remove the n-butane in the residue Amine hydrochloride is neutralized to n-butylamine;

[0055] S3: After nitrogen replacement in the system, the system is boosted to 2-5MPa, and the system is raised to 100-200°C, and the alkali hydrolysis reaction is performed for 1-20 hours. The alkali hydrolysis reaction converts the trimer into n-butylamine. This process Add a certain amount of alkali to maintain the alkali concentration at 1%-50%;

[0056] S4: After cooling down the system and releasing the pressure, add an extractant for extraction, layer the extract, a...

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