Process improvement for producing epichlorohydrin by using glycerin method dichloropropanol as raw material

A technology of epichlorohydrin and dichloropropanol, applied in the direction of organic chemistry, etc., can solve the problems of increasing the cost of wastewater treatment, increasing the TOC of brine, and decreasing the yield of ECH, and achieves short reaction residence time, increased reaction speed, and reduced The effect of TOC

Active Publication Date: 2017-05-10
JIANGSU YANGNONG CHEM GROUP +2
View PDF11 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] CN103709124B discloses raw materials DCH and NaOH through pipeline mixer and falling film tubular reactor, and ECH is removed from the reactor in a short time; Excellent mass transfer and heat transfer effects shorten the residence time of ECH in the system and reduce side reactions, but the above two patents have not fundamentally solved the problem of ECH hydrolysis in the alkaline system, resulting in low ECH yield , the total organic carbon content (abbreviation TOC) of brine is higher, which increases the cost of waste water treatment; CN102875494B and CN102603680B all adopt microchannel reactors to synthesize ECH, which has the characteristics of short residence time, mild reaction and high ECH yield, but the alkali consumption (actual use Alkali mol / theoretical mol) is as high as 1.3, and a third medium solvent needs to be introduced for brine extraction, which not only increases the cost of solvent recovery, but also inevitably has a small amount of solvent remaining in the brine, resulting in an increase in brine TOC
At the same time, the throughput of the microchannel reactor is small, which is not suitable for the production of 10,000-ton ECH
[0004] Glycerol method DCH is a mixture of 1,3-DCH and 2,3-DCH, of which 1,3-DCH accounts for about 95% (wt%), 2,3-DCH accounts for about 5% (wt%), the reaction of the former The speed is dozens of times that of the latter, and the reaction speed with alkali is 1,3-DCH>ECH>2,3-DCH, and a large amount of ECH is generated in the alkaline system and is prone to hydrolysis. If the alkaline system cannot be separated in time, the Glycidol, monochloropropanediol (hereinafter referred to as monochlorine), etc. will be generated, which will be further converted into glycerin, resulting in a decrease in ECH yield and an increase in brine TOC. The existing negative pressure saponification process brine TOC is about 10000ppm, resulting in huge environmental protection treatment pressure

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
  • Process improvement for producing epichlorohydrin by using glycerin method dichloropropanol as raw material
  • Process improvement for producing epichlorohydrin by using glycerin method dichloropropanol as raw material
  • Process improvement for producing epichlorohydrin by using glycerin method dichloropropanol as raw material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] 1. One-time atmospheric pressure layered saponification

[0029] Adopt two-stage continuous tank saponification under normal pressure, DCH (content 99.67%) and NaOH (15.11%) are continuously fed into the first-level tank, the flow rates are 0.645kg / h and 1.24kg / h respectively, and overflow to the second-level Still, the reaction residence time is 10 minutes, the temperature is 40 ° C, and it runs for 15 hours in total. It enters the stratifier and continuously separates 6.84 kg of oil phase and 21.44 kg of water phase. The saponified water layer was stripped under the conditions of 40-50°C and -0.1MPa, a total of 4.29kg was evaporated, and 4.05kg of the water phase and 0.24kg of the oil phase were separated; Distillation, reflux ratio R=1, collect 6.55kg of distillate at 116-118°C, separate out 0.05kg of water phase and 6.5kg of oil phase, and 0.52kg of residue in the kettle; from one saponification to the end of rectification, the conversion rate of DCH is 94.9%, and t...

Embodiment 2

[0038] 1. One-time atmospheric pressure layered saponification

[0039] Adopt two-stage continuous tank saponification under normal pressure, DCH (content 99.67%) and NaOH (18.5%) are continuously fed into the first-level tank, the flow rates are 0.645kg / h and 0.97kg / h respectively, and overflow to the second-level Still, the reaction residence time is 5 minutes, the temperature is 40 ° C, and it runs for 15 hours in total. It enters the stratifier to separate 6.95 kg of oil phase and 17.28 kg of water phase. The saponified water layer was stripped under the conditions of 40-50°C and -0.1MPa, a total of 3.19kg was distilled out, and 3.0kg of water phase and 0.19kg of oil phase were separated; the saponified oil layer and the stripped oil layer were combined, and a 1m glass packed column was used to fine-tune Distillation, reflux ratio R=1, collect 6.50kg of distillate at 116-118°C, separate out 0.03kg of water phase and 6.46kg of oil phase, and 0.67kg of residue in the kettle;...

Embodiment 3

[0048] 1. One-time atmospheric pressure layered saponification

[0049] 7.5kgDCH (content 99.67%) was dropped into a 20L kettle, stirred and heated to 40°C, and 15% NaOH aqueous solution was started to be added dropwise, the reaction temperature was maintained at 40°C, and the dropwise addition time was 5 minutes. Add 14.68kg of liquid caustic soda dropwise; after the reaction, pour it into a separatory funnel, let it stand for stratification, separate the upper layer into 5.24kg of oil phase, and the lower layer into 16.94kg of water phase; strip the water phase under negative pressure of -0.095MPa, 3.35kg is produced, oil and water are separated in the production liquid, and 3.15kg of the water phase is applied to the next batch of steam stripping. The 0.2kg of the oil phase is combined with the saponified oil layer and rectified under normal pressure. layer, the unreacted DCH collected in the tower kettle is 0.36kg. From the primary saponification to the end of rectificati...

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 aim at providing a method for producing epichlorohydrin by using glycerin method dichloropropanol as a raw material with step-by-step saponification. Compared with the prior art, the process has the characteristics of mild reaction conditions, simple process, low alkali consumption, low brine TOC, high ECH yield, and the like. Different reaction speeds of each component in DCH are used, the step-by-step saponification method is used, firstly primary normal pressure intermittent or continuous saponification is used, oil and water are layered, an oil layer is rectified in order to obtain an ECH product, and negative pressure secondary saponification is carried out for unreacted DCH in a column reactor. A washing process is used, most monochloropropanediol in a primary saponification rectifying still residue is separated, monochloropropanedio and DCH in a washing water layer return to a glycerin chlorination system for reusage. After washing, negative pressure high alkali ratio is used for the primary saponification rectifying still residue in order to carry out secondary saponification, and continuous industrial production is realized.

Description

technical field [0001] The invention relates to a process improvement method for producing epichlorohydrin by using glycerol method dichloropropanol as raw material. Background technique [0002] Epichlorohydrin (ECH for short) is a colorless and transparent liquid. It is an important chemical product and an intermediate in the synthesis of epoxy resins, elastomers, glycidyl ethers, etc. Chemical products also have important applications. At present, the main methods of producing epichlorohydrin are: propylene high-temperature chlorination method, propylene alcohol method and glycerin method. The first two methods use propylene as raw material. With the shortage of petroleum resources, the source and price of propylene are affected by the market. The glycerol method uses glycerol as a raw material, as a by-product of biodiesel, a renewable resource and green energy, so the production of epichlorohydrin by the glycerol method has very important significance. Disclosed in CN...

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): C07D303/08C07D301/26C07D301/32
CPCC07D301/26C07D301/32C07D303/08
Inventor 王怡明徐林丁克鸿邵波顾志强严绘卞辰超
Owner JIANGSU YANGNONG CHEM GROUP
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