Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for treating melamine tail gas

A technology for melamine and tail gas treatment, applied in gas treatment, separation methods, chemical instruments and methods, etc., can solve problems such as poor operation stability, low urea conversion rate, unqualified, etc., and achieve the effect of increasing flexibility

Active Publication Date: 2017-01-25
青海黎明化工有限责任公司
View PDF7 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

During processing, if the concentration of liquid phase is high, the content of ammonia and carbon dioxide in the gas phase will increase, increasing the load of the ammonia scrubbing system, resulting in unqualified recycling water system or unqualified atmospheric emissions
In order to make the ammonia scrubbing system qualified, the lower temperature should be controlled, and the melamine tail gas is usually diluted to avoid crystallization causing blockage of pipelines and equipment. At this time, the obtained liquid phase has low component concentration and low urea conversion rate. Disadvantages of low energy consumption, poor operation stability, and increased energy consumption

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] A set of 10t / h high-pressure melamine production equipment, the tail gas produced is condensed into methyl ammonium liquid, without dilution of the process condensate of the urea recovery plant, the liquid phase of the methyl ammonium liquid gas-liquid separator is 40.6t / h to recover the formazan of the urea plant Ammonium separator, the mass percentage concentration of each component is: CO 2 32.02%, NH 3 44.19%, H 2 O 23.78%, which is relatively concentrated methylammonium liquid, the temperature is controlled at 100 °C, and the pressure is controlled at 2.4MPa (G); at this time, the gas phase of the methylammonium liquid gas-liquid separator is 359kg / h, and the mass percentage concentration of each component is: CO 2 0.16%, NH 3 78.48%, H 2 O 1.85%, air 19.51%, if it enters the ammonia scrubber of melamine, it is very different from the required component air of nearly 100%.

[0013] This gas phase is introduced into the second circulation and first cooling s...

Embodiment 2

[0016] A set of 10t / h high-pressure melamine production equipment, the tail gas produced is condensed into methylammonium liquid, which is diluted with the process condensate of the 10t / h urea recovery device, and the liquid phase of the methylammonium liquid gas-liquid separator is 50.9t / h to recover urea For the methylammonium separator of the device, the mass percent concentration of each component is: CO 2 26.13%, NH 3 36.51%, H 2 O 37.34%, is a relatively dilute methylammonium liquid, the temperature is controlled at 50 °C, and the pressure is controlled at 2.0MPa (G); at this time, the gas phase of the methylammonium liquid gas-liquid separator is 100kg / h, and the mass percentage concentration of each component is: CO 2 0%, NH 3 trace, H 2 A small amount of O, 100% air, enters the ammonia scrubber of melamine, and has no effect on the melamine system.

[0017] Because the methylammonium liquid phase concentration of the urea removal unit is relatively dilute, the...

Embodiment 3

[0019] A set of 10t / h high-pressure melamine production equipment, the tail gas produced is condensed into methylammonium liquid, which is diluted with the process condensate of the 5t / h urea recovery device, and the liquid phase of the methylammonium liquid gas-liquid separator is 45.9t / h to recover urea For the methylammonium separator of the device, the mass percent concentration of each component is: CO 2 28.29%, NH 3 39.66%, H 2 O 31.90%, is a relatively dilute methylammonium liquid, the temperature is controlled at 65 °C, and the pressure is controlled at 2.2MPa (G); at this time, the gas phase of the methylammonium liquid gas-liquid separator is 100kg / h, and the mass percentage concentration of each component is: CO 2 0.04%, NH 3 28.44%, H 2 O 0.48%, air 71.04%, enter the ammonia scrubber of melamine, and have no effect on the melamine system.

[0020] Because the methylammonium liquid phase concentration of the urea removal unit is relatively dilute, the synthe...

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 treating melamine tail gas. The method comprises the following steps: introducing the tail gas into an ammonium carbamate solution gas-liquid separator for condensing, wherein a liquid phase urea removal production device introduces a gase phase into a two-circulating one-cooling system of the urea device capable of recovering the melamine tail gas according to the specific components of the gas phase when the air mass percentage is low; recycling the formed dilute ammonium carbamate solution; and introducing the gas phase into an ammonium scrubber of melamine when the air mass percentage is high enough, and allowing the washed water to enter a recycling system. According to the arrangement, carbon dioxide can be prevented from entering a melamine scrubbing system, so that the content of the carbon dioxide in melamine recycled water is reduced, and the load of the ammonium scrubber of melamine is reduced; and selection is performed according to actual conditions, so that the production control flexibility is improved, and emptying up-to-standard release is guaranteed.

Description

technical field [0001] The invention belongs to the field of melamine production in chemical production, and in particular relates to a method for treating melamine tail gas. Background technique [0002] In the high-pressure method (7-10MPa) melamine production process, tail gas containing ammonia, carbon dioxide and water will be produced. There are many methods for the treatment of tail gas, among which the co-production of urea solution is reused as the raw material of melamine, which is a very Good method. Usually, the tail gas is directly condensed into methyl ammonium liquid, and the liquid phase is used to produce urea solution; the gas phase is washed with ammonia, and the washed water enters the recycling system. During the treatment, if the concentration of the liquid phase is high, the content of ammonia and carbon dioxide in the gas phase will increase, which will increase the load of the ammonia scrubbing system, resulting in unqualified recycling water system...

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
Patent Type & Authority Applications(China)
IPC IPC(8): C07C273/04C07C273/12B01D5/00B01D53/14
CPCB01D5/0057B01D53/002B01D53/145B01D2252/103B01D2257/406B01D2258/02C07C273/04C07C273/12Y02P20/141Y02P70/10
Inventor 蒋远华杨晓勤卢钢
Owner 青海黎明化工有限责任公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com