Equipment and method for preparing hexamethylene diisocyanate through pyrolysis in mixed solvent

A technology of hexamethylene diisocyanate and mixed solvents, which is applied in the field of pyrolysis to prepare hexamethylene diisocyanate, can solve the problems of high energy consumption and large investment, and achieve the effects of avoiding energy waste, solving potential safety hazards, and improving yield and purity

Pending Publication Date: 2022-05-10
CHINA PETROLEUM & CHEM CORP +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The first technical problem to be solved by the present invention is to provide a method for preparing hexamethylene diisocyanate by pyrolysis in a mixed solvent in view of the current situation of the prior art. The method adopts a mixed solvent system to overcome the problem of no solvent, and It can solve the problems of large investment and high energy consumption in solvents with light boiling point, and can reduce the secondary contact between product isocyanate and by-product alcohols, and improve the yield and purity of isocyanate in the reaction

Method used

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  • Equipment and method for preparing hexamethylene diisocyanate through pyrolysis in mixed solvent

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Effect test

Embodiment 1

[0038] In this embodiment, the method for preparing hexamethylene diisocyanate by pyrolysis in a mixed solvent comprises the following steps:

[0039]Add the raw material 1,6-hexamethylene dicarbamate methyl ester and the medium-boiling point solvent biphenyl into the batching tank 1 according to the mass ratio of 1 / 1, and the total amount of 1,6-hexamethylene dicarbamate methyl ester and the medium-boiling point solvent biphenyl is 2000g , mix 1,6-hexamethylene dicarbamate and biphenyl in batching tank 1 and preheat to 80°C to form solution A;

[0040] The thermal decomposition reactor 2 is pre-filled with 50g catalyst nano-zinc oxide and 1000g high boiling point solvent dioctyl sebacate, solution A is transported to the thermal decomposition reactor 2000mL by the feed pump at a flow rate of 10mL / min;

[0041] The thermal decomposition reactor 2, the product condenser 4, the by-product condenser 5, the product tank 6 and the by-product tank 7 are all pumped to a negative pres...

Embodiment 2

[0044] In this embodiment, the method for preparing hexamethylene diisocyanate by pyrolysis in a mixed solvent comprises the following steps:

[0045] Add the raw material 1,6-hexamethylene dicarbamate methyl ester and the medium-boiling point solvent biphenyl into the batching tank 1 according to the mass ratio of 1 / 1, and the total amount of 1,6-hexamethylene dicarbamate methyl ester and the medium-boiling point solvent biphenyl is 2000g , mix 1,6-hexamethylene dicarbamate and biphenyl in batching tank 1 and preheat to 80°C to form solution A;

[0046] The thermal decomposition reactor 2 is pre-filled with 100g catalyst nano-Zn and 1000g high boiling point solvent octyl phthalate, and solution A is transported to the thermal decomposition reactor 2000mL by the feed pump at a flow rate of 20mL / min;

[0047] The thermal decomposition reactor 2, the product condenser 4, the by-product condenser 5, the product tank 6 and the by-product tank 7 are all pumped to a negative pressur...

Embodiment 3

[0050] In this embodiment, the method for preparing hexamethylene diisocyanate by pyrolysis in a mixed solvent comprises the following steps:

[0051] Add the raw material 1,6-hexamethylene dicarbamate methyl ester and the medium-boiling point solvent biphenyl into the batching tank 1 according to the mass ratio of 1 / 1, and the total amount of 1,6-hexamethylene dicarbamate methyl ester and the medium-boiling point solvent biphenyl is 2000g , mix 1,6-hexamethylene dicarbamate and biphenyl in batching tank 1 and preheat to 80°C to form solution A;

[0052] Thermal decomposition reactor 2 is pre-filled with 500g catalyst Zn-ZSM and 1000g high boiling point solvent paraffin, and solution A is transported to thermal decomposition reactor 2000mL by feed pump at a flow rate of 50mL / min;

[0053] The thermal decomposition reactor 2, the product condenser 4, the by-product condenser 5, the product tank 6 and the by-product tank 7 are all evacuated to a micro-negative pressure state wit...

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Abstract

The invention relates to equipment and a method for preparing hexamethylene diisocyanate through pyrolysis in a mixed solvent, a thermal decomposition reactor and a product separator are organically combined together, hexamethylene diisocyanate is prepared through pyrolysis in the mixed solvent, and compared with an existing phosgene method for producing isocyanate, the problem of potential safety hazards of the phosgene method is solved; compared with a light-boiling-point solvent process, the energy consumption is reduced, the energy consumption required by a single separation solvent is 1 / 10 of the energy consumption required by the light-boiling-point solvent process, and the method is green, environment-friendly and energy-saving; compared with a high-boiling-point solvent process, secondary contact between the product and a by-product is avoided, the yield and purity of the product are greatly improved, and the problem of energy waste caused by the fact that a thermal decomposition intermediate is carried in the product is avoided; in addition, the method is simple in process, easy and convenient to operate and beneficial to industrial production.

Description

Technical field [0001] The invention relates to the technical field of isocyanate preparation, and specifically refers to an equipment and method for preparing hexamethylene diisocyanate by pyrolysis in a mixed solvent. Background technique [0002] Isocyanate is the main raw material for the production of polyurethane and is widely used in elastomers, coatings, plastics, pesticides and leather industries. At present, the domestic demand for isocyanates is increasing year by year, and a large amount of isocyanates needs to be imported from abroad every year to meet the demand, so the application prospects of isocyanates are very broad. The main isocyanate products on the market include phenyl isocyanate (PI), diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), etc. [0003] At present, low boiling point solvents, medium boiling point solvents and high boiling point solvents are mainly used to prepare isocyanates using non-phosge...

Claims

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Application Information

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IPC IPC(8): C07C263/04C07C265/14
CPCC07C263/04C07C265/14
Inventor 杨宏泉贺鹏孙志刚陈家强卲逸松李会泉杨彩云王利国张思嘉曹妍
Owner CHINA PETROLEUM & CHEM CORP
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