Method and equipment for preparing methyl carbamate

A technology of methyl carbamate and ammonia, which is applied in the preparation of carbamic acid derivatives, chemical instruments and methods, and the preparation of organic compounds, can solve problems such as equipment corrosion, reduce carbon emissions, be beneficial to environmental protection, and improve The effect of one-way conversion rate

Active Publication Date: 2015-12-23
ZHONGBEI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the catalyst used in the reaction is a compound of oxides or salts of transition metals and inorganic acids such as sulfuric acid, nitric acid, phosphoric acid, and polyphosphoric acid, and there is still a problem of corrosion to equipment.

Method used

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  • Method and equipment for preparing methyl carbamate
  • Method and equipment for preparing methyl carbamate
  • Method and equipment for preparing methyl carbamate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] exist figure 1 In the equipment shown, add 120g of urea and 560ml of methanol into the 1L reactor 1 (the molar ratio of feeding is about 1:7), close all the valves, and stir to dissolve. Heat urea and methanol to 160°C, correspondingly, the pressure inside the reactor 1 will gradually rise to about 1.7MPa, and react under this condition for 3 hours. Then open the valves 10, 12, and then open the valve 3. At this time, the ammonia gas is exported to the ammonia recovery device 11 through the condensing device 9, and the pressure and temperature in the reactor 1 tend to decline. After exporting the ammonia gas, close the valves 10 and 12, open the valve 8, gradually raise the temperature in the reactor 1 to about 100°C, and recover the unreacted methanol to the methanol recovery device 7. The reaction product in the reaction kettle 1 was discharged to another vacuum distillation kettle while it was hot, and 88.5 g of methyl carbamate was obtained after vacuum distillatio...

Embodiment 2

[0045] exist figure 1 In the equipment shown, add 120g of urea and 560ml of methanol into the 1L reactor 1 (the molar ratio of feeding is about 1:7), close all the valves, and stir to dissolve. Heat urea and methanol to 160°C, correspondingly, the pressure inside the reactor 1 will gradually rise to about 1.7MPa, and react under this condition for 3 hours. Then open the valves 10, 12, and then open the valve 3. At this time, the ammonia gas is exported to the ammonia recovery device 11 through the condensing device 9, and the pressure and temperature in the reactor 1 tend to decline. When the temperature drops to 60°C, close the valve 3 and continue heating until the temperature and pressure return to the original level, and react for 3 hours. Repeat this operation to export ammonia gas three times (about 1 hour each time). After exporting the ammonia gas for the last time, close the valves 10 and 12, open the valve 8, heat the temperature of the reactor 1 to about 100°C gra...

Embodiment 3

[0047] exist figure 1 In the equipment shown, add 120g of urea and 560ml of methanol into the 1L reactor 1 (the molar ratio of feeding is about 1:7), close all the valves, and stir to dissolve. Heat urea and methanol to 160°C, correspondingly, the pressure inside the reactor 1 will gradually rise to about 1.7MPa, and react under this condition for 3 hours. Then open the valves 10, 12, and then open the valve 3. At this time, the ammonia gas is exported to the ammonia recovery device 11 through the condensing device 9, and the pressure and temperature in the reactor 1 tend to decline. When the temperature drops to 60°C, close the valve 3 and continue heating until the temperature and pressure return to the original level, and react for 3 hours. Repeated operations in this way, ammonia gas is exported six times (each time takes about 1h). After exporting the ammonia gas for the last time, close the valves 10 and 12, open the valve 8, heat the temperature of the reactor 1 to ab...

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Abstract

A method for preparing methyl carbamate, comprising the steps of: reacting urea and methanol in a reactor to generate a reaction product comprising methyl carbamate and ammonia; deriving the ammonia in batches from the reactor, and simultaneously The exported ammonia gas is input into the urea synthesis plant as a raw material, and reacts with carbon dioxide to regenerate urea. The molar ratio of urea and methanol in the reactor is 1:6-10, the reaction in the reactor is carried out at a temperature of 150-200°C, and the pressure in the reactor is correspondingly 1.5-2.0MPa. The method is characterized by preparing methyl carbamate with urea and methanol as raw materials at medium temperature and medium pressure without the participation of a catalyst, which improves the conversion rate of urea into methyl carbamate and reduces production costs. The reaction of converting ammonia gas into urea consumes the greenhouse gas carbon dioxide and is beneficial to environmental protection. The invention also provides a device for preparing methyl carbamate.

Description

technical field [0001] The invention relates to the technical field of basic organic synthesis, in particular to a method and equipment for preparing methyl carbamate under medium temperature, medium pressure and catalyst-free conditions. Background technique [0002] Methods for the preparation of methyl carbamate using methanol and urea as raw materials can generally be classified into three types: (1) catalyst-free high-temperature and high-pressure synthesis methods; (2) normal temperature and pressure catalytic synthesis methods; and (3) medium temperature and medium pressure synthesis methods Catalytic synthesis method. The first type of catalyst-free high-temperature and high-pressure synthesis method was adopted by many countries as early as the 1950s and 1960s. The process requires a temperature as high as 200°C and a pressure as high as tens of MPa, and the yield is not high (<60%). The second category is the normal temperature and pressure catalytic synthesis...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C271/12C07C269/00
Inventor 刘亚青袁团刘俊杰任福德朱福田赵贵哲
Owner ZHONGBEI UNIV
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