Method for continuous gas phase synthesis of oxamide

A gas-phase synthesis and oxamide technology, which is applied in the preparation of carboxylic acid amide, chemical instruments and methods, and the preparation of organic compounds, can solve the problems of unreachable industrial production, long reaction time, and high toxicity of hydrocyanic acid, etc., and eliminate Harm to the environment and human health, continuous and stable industrial production, and the effect of high conversion rate of ammonia decomposition

Active Publication Date: 2013-09-11
江苏丹化煤制化学品工程技术有限公司
View PDF4 Cites 21 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method can be divided into Degussa method, Sagami method, Asahi Kasei method and Hoechat method. The difference between the four methods is that the oxidant, catalyst and process are different. The disadvantage of this preparation method is that hydrocyanic acid is highly toxic and costly. There are reports of industrialization;
[0005] (2) Pyrolysis method, that is, ammonium oxalate or urea oxalate is used for pyrolysis to obtain oxamide, but this method is costly and has no practical value, and there are few studies at present
[0006] (3) Ammonolysis method of dialkyl oxalate (US6348626, US5393319, CN102267921A), in which dialkyl oxalate reacts with ammonia gas under the dissolution of corresponding fatty alcohol to generate oxamide and

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for continuous gas phase synthesis of oxamide
  • Method for continuous gas phase synthesis of oxamide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A method for continuous gas-phase synthesis of oxamide, the steps are as follows: (1) Dimethyl oxalate is heated to 170°C by a steam heater and a heat-conducting oil heater to be vaporized, and then enters the gas-phase reactor from the upper part of the gas-phase reactor through a tangential direction, The liquid ammonia is vaporized by the evaporator and the buffer tank and enters the gas distributor, and then enters the gas phase reactor from the bottom of the gas phase reactor. The two undergo ammonolysis reaction in the gas phase reactor. The molar ratio of ammonia gas to dimethyl oxalate 2.1︰1, the reaction temperature is 165°C, the reaction pressure is 1MPa, and the reaction residence time is 5min; (2) The powdery oxamide generated by the ammonolysis reaction, part of the excess ammonia in the reaction and the by-product methanol vapor are passed through the cyclone The separator and circulating gas filter realize the separation of the gas-solid phase, and the pow...

Embodiment 2

[0029] A method for continuous gas-phase synthesis of oxamide, the steps are as follows: (1) Dimethyl oxalate is heated to 170°C by a steam heater and a heat-conducting oil heater to be vaporized, and then enters the gas-phase reactor from the upper part of the gas-phase reactor through a tangential direction, The liquid ammonia is vaporized by the evaporator and the buffer tank and enters the gas distributor, and then enters the gas phase reactor from the bottom of the gas phase reactor. The two undergo ammonolysis reaction in the gas phase reactor. The molar ratio of ammonia gas to dimethyl oxalate 2.3︰1, the reaction temperature is 175°C, the reaction pressure is 1.3MPa, and the reaction residence time is 15min; The cyclone separator and circulating gas filter realize the separation of the gas-solid phase, and the powdery oxamide is collected from the bottom of the cyclone separator, and the purity of the oxamide product analyzed by liquid chromatography is 99.2%; (3) the se...

Embodiment 3

[0031]A method for continuous gas-phase synthesis of oxamide, the steps are as follows: (1) Diethyl oxalate is heated to 185°C by a steam heater and a heat-conducting oil heater to be vaporized, and then enters the gas-phase reactor from the upper part of the gas-phase reactor through a tangential direction, The liquid ammonia is vaporized by the evaporator and the buffer tank and enters the gas distributor, and then enters the gas phase reactor from the bottom of the gas phase reactor. The two undergo ammonolysis reaction in the gas phase reactor. The molar ratio of ammonia gas to diethyl oxalate 2.5︰1, the reaction temperature is 185°C, the reaction pressure is 1.5MPa, and the reaction residence time is 30min; The cyclone separator and circulating gas filter realize the separation of the gas-solid phase, and the powdery oxamide is collected from the bottom of the cyclone separator, and the purity of the oxamide product analyzed by liquid chromatography is 99.0%; (3) the separ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a method for continuous gas phase synthesis of oxamide. In a gas phase reactor, gas phase oxalic acid dialkyl ester and ammonia gas perform ammonolysis reaction under high temperature to generate oxamide product and corresponding fatty alcohol secondary product, and the oxamide product is collected by a cyclone separator. The method uses the gas phase continuous synthesis technology, and solves the defects of long reaction time and poor capacity of intermittent reaction in the existing oxamide preparation technology; by adopting the method, the reaction time is reduced remarkably, the reaction is continuous and steady, the oxalic ester aminolysis conversion rate is high, the quality of the obtained oxamide is high, and continuous steady industrial production of the oxamide is realized.

Description

technical field [0001] The invention relates to a method for synthesizing oxamide, in particular to a method for continuously gas-phase synthesizing oxamide, which belongs to the technical field of oxamide preparation. Background technique [0002] Oxamide is a non-toxic and stable colorless crystal or powder at room temperature. As a urea-formaldehyde slow-acting fertilizer with broad application prospects, its nitrogen content is 31.8%, and its solubility in water is 0.016%. It does not absorb moisture in the air, is non-toxic, and is easy to store. In the process of hydrolysis or biodegradation, ammoniacal nitrogen and carbon dioxide are gradually released, which meets the needs of crops for nitrogen throughout the growth period, and reduces the leaching, volatilization and loss of nitrogen. The loss caused by denitrification improves the utilization rate of chemical fertilizers, reduces the frequency of fertilization, and saves manpower and time. Its advantages as a slo...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C07C233/56C07C231/02C07C31/04C07C31/08C07C29/00
Inventor 吴晓金吴维果毛洪堂贺云辉
Owner 江苏丹化煤制化学品工程技术有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap