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A material separation method and device in the process of preparing dimethyl carbonate by urea alcoholysis

A technology for separation of dimethyl carbonate and substances, which is applied in the purification/separation, fractionation, and organic chemistry of carbonate/haloformate, and can solve the problems of low working temperature, loss of dimethyl carbonate, and crystallization blocking the top of the tower Working temperature and other issues to achieve efficient separation and improve separation recovery

Active Publication Date: 2017-07-28
YASHENTECH CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The present invention effectively solves the dilemma of crystallization blockage caused by the low working temperature at the top of the product separation tower in the process of preparing dimethyl carbonate by urea alcoholysis or the loss of dimethyl carbonate caused by high working temperature at the top of the tower

Method used

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  • A material separation method and device in the process of preparing dimethyl carbonate by urea alcoholysis
  • A material separation method and device in the process of preparing dimethyl carbonate by urea alcoholysis
  • A material separation method and device in the process of preparing dimethyl carbonate by urea alcoholysis

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Experimental program
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Effect test

Embodiment 1

[0043] Combined reference figure 2 As shown, a material separation device in the process of preparing dimethyl carbonate by alcoholysis of urea includes a product separation tower 201, a reboiler 213, a feed buffer tank 222, a feed pressure reducing valve 241, a feed heat exchanger 212, Methanol tank 221, methanol pump 231, methanol heat exchanger 211.

[0044] The middle part of the product separation tower is provided with a mixture feed inlet, and the upper end of the tower is provided with an alternative reflux liquid inlet. The outlet of the feed tank 222 is in communication with the inlet of the feed decompression valve 241, the outlet of the feed decompression valve 241 is in communication with the inlet of the feed heat exchanger 212, and the outlet of the feed heat exchanger 212 is in communication with the product separation tower. The feed inlet is connected. The outlet of the methanol tank 221 is in communication with the inlet of the methanol pump 231, the outlet o...

Embodiment 2

[0049] Same reference figure 2 As shown, the mixture material of the product separation tower is a high temperature and pressure mixture from the reaction section. The material separation device in the process for preparing dimethyl carbonate by direct urea alcoholysis in this embodiment is the same as that in the first embodiment.

[0050] The separation method of the second embodiment is as follows:

[0051] The mixture material from the outlet of the direct urea alcoholysis reactor, the temperature is 185℃, the pressure is 0.75MPa(A), the mass flow is 12.5Ton / h, and the mass composition: methanol 75%, dimethyl carbonate 8%, methyl carbamate 9 %, ammonia 5%, carbon dioxide 1.5%, dimethyl ether 1.5%, after passing through the feed pressure reducing valve 241, they are sent to the feed heat exchanger 212 for preheating to 75°C, and then sent to the middle of the product separation tower 201. The product separation tower 201 is a plate tower with an operating pressure of 0.3 MPa (...

Embodiment 3

[0053] Same reference figure 2 As shown, the product separation tower mixture material is a high temperature, pressure mixture from the reaction section. The material separation device in the process for preparing dimethyl carbonate by the direct urea alcoholysis method in this embodiment is the same as the first embodiment.

[0054] The separation method of the third embodiment is as follows:

[0055] The mixed material from the outlet of the direct urea alcoholysis reactor, temperature 185℃, pressure 0.75MPa(A), mass flow rate 68Ton / h, mass composition: methanol 76%, dimethyl carbonate 10%, methyl carbamate 7% , 3% of ammonia, 2% of carbon dioxide, and 2% of dimethyl ether. After passing through the feed pressure reducing valve 241, they are sent to the feed heat exchanger 212 to be preheated to 70°C, and then sent to the middle of the product separation tower 201. The product separation tower 201 is a plate tower with an operating pressure of 0.2 MPa (A). The alternative refl...

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Abstract

The invention relates to a substance separation method in a technology for preparing dimethyl carbonate by an urea alcoholysis method and an apparatus. The substance separation method comprises the following steps: a mixing material containing methanol, dimethyl carbonate, ammonia and carbon dioxide is sent to a products separating tower, a rectification technology is used to obtain a gas phase mixture (low-boiling-point substances such as ammonia and carbon dioxide)at tower top and a tower liquid phase mixture (high boiling products such as dimethyl carbonate and methanol), appropriate operating temperature at the tower top is selected, crystal substance formed by ammonia and carbon dioxide is avoided, methanol liquid or a methanol solution introduced at the upper end of the tower is taken as a substitute of backflow liquid, and the separation recovery rate of dimethyl carbonate is increased. The substance separation method in the technology for preparing dimethyl carbonate by the urea alcoholysis method and the apparatus solve a dilemma that in the technology for preparing dimethyl carbonate by using the urea alcoholysis method, the operating temperature at the tower top of the products separating tower is low, so that the crystallization obstruction or high work temperature at tower top is generated, so that dimethyl carbonate loses.

Description

[0001] 【Technical Field】 [0002] The invention relates to a mixture separation process, in particular to a material separation method and device in the dimethyl carbonate process. [0003] 【Background technique】 [0004] Dimethyl Carbonate (DMC for short, structural formula: ), is a new type of green chemical that has attracted much attention at home and abroad in recent years, because its molecule contains CH 3 -, CH 3 O-, CH 3 O-CO-, -CO- and other functional groups have good reactivity and can undergo methylation, carbonylation, methyl esterification and transesterification with alcohol, phenol, amine, hydrazine, ester and other compounds. It can replace highly toxic methylation reagents and carbonylation reagents (such as phosgene) and meets the era requirements of clean production and green chemical industry. It is used in many fields including chemical synthesis, environmentally friendly solvents, lithium ion electrolytes, especially fuel additives, etc. widely used. Due to ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C69/96C07C68/08B01D3/14B01D3/32
CPCB01D3/14B01D3/32C07C68/08C07C69/96
Inventor 王讯文李志坚韩晖刘丹王尤崎
Owner YASHENTECH CORP