Method for removing sodium carbonate from hydrazine hydrate crude solution

A technology of hydrazine hydrate and sodium carbonate, applied in the directions of hydrazine, nitrogen and non-metallic compounds, can solve the problems of increasing consumption of acidic substances, blockage of heat exchange tubes, unfavorable evaporation, continuous production of rectification, etc., and achieve the effect of reducing consumption

Inactive Publication Date: 2015-08-26
HANGZHOU HI TECH FINE CHEM
View PDF1 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If this solution is used in the process of producing biurea, the remaining sodium carbonate needs to consume a large amount of acidic substances, which increases the consumption of acidic substances
If this solution is used in the process of producing hydrazine hydrate through evaporation and rectification, sodium carbonate monohydrate will be formed in the evaporation process due to the existence o

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

[0018] 1. Pass water into the urea preparation tank, drop into solid urea under stirring, magnesium sulfate heptahydrate catalyst, the magnesium sulfate addition is 1.5% of the urea amount, be mixed with 360g / L urea solution.

[0019] 2. Add 32% caustic soda to water to prepare 270-275g / L dilute alkali, feed chlorine gas to react to produce available chlorine 108g / L, and sodium hypochlorite with sodium hydroxide 124g / L.

[0020] 3. Mix the urea solution and sodium hypochlorite and heat to 130°C to react to form a crude solution containing hydrazine hydrate. The molar ratio of urea to sodium hypochlorite is 1.085. The crude solution produced by the reaction did not contain sodium hydroxide. The components in the crude solution are hydrazine hydrate 48g / L, sodium carbonate 125g / L, urea 25g / L, sodium chloride 180g / L, and the rest is water.

[0021] 4. Add strontium chloride to the crude hydrazine hydrate solution, and react with sodium carbonate to form insoluble strontium carbo...

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 removing sodium carbonate from a hydrazine hydrate crude solution. The method comprises the following steps: 1, a urea solution is mixed with sodium hypochlorite, wherein a molar ratio of the urea solution to sodium hypochlorite is 1-2, such that the crude solution obtained by a reaction does not contain sodium hydroxide; 2, a chloride is added into the hydrazine hydrate crude solution; and centrifugal separation is carried out, such that poorly soluble carbonate is separated; 3, the hydrazine hydrate solution with sodium carbonate removed is subjected to membrane filtration, such that cations in the solution are removed. With the method, sodium carbonate in the hydrazine hydrate crude solution is thoroughly removed. The produced poorly soluble carbonate can be directly sold after certain treatments, and can be subjected to a reaction with hydrochloric acid recovered from an ADC process for producing chloride for recycling. When the sodium-carbonate-removed hydrazine hydrate solution is used in a biurea production process, acidic substance addition can be greatly reduced. When the sodium-carbonate-removed hydrazine hydrate solution is used in a hydrazine hydrate production process through evaporation and rectification, evaporation and rectification continuous production is facilitated.

Description

technical field [0001] The invention relates to the technical field of removing sodium carbonate, in particular to a method for removing sodium carbonate in the thick solution of hydrazine hydrate. Background technique [0002] The crude solution for producing hydrazine hydrate by urea method contains hydrazine hydrate, sodium carbonate, urea, sodium chloride and water. The content of sodium carbonate is 110-150g / L. The conventional method is to pre-cool the crude solution of hydrazine hydrate and send it to the crystallization kettle, and cool it down to -2°C--0°C; centrifuge to remove 60--70% of sodium carbonate decahydrate , to obtain a hydrazine hydrate solution containing 35-60 / L sodium carbonate. If this solution is used in the process of producing biurea, the remaining sodium carbonate needs to consume a large amount of acidic substances, which increases the consumption of acidic substances. If this solution is used in the process of producing hydrazine hydrate thro...

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): C01B21/16
Inventor 陈海贤付永宽
Owner HANGZHOU HI TECH FINE CHEM
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