Unlock instant, AI-driven research and patent intelligence for your innovation.

Efficient separation method of dimethyl ketene

A technology of dimethyl ketene and separation method, applied in the separation/purification of carbonyl compounds, chemical instruments and methods, preparation of carbon-based compounds, etc. Problems such as butyric acid distillation column load and reduction of space-time yield of DMK are achieved to shorten residence time, lower production cost and reduce loss

Active Publication Date: 2021-01-05
ZHEJIANG HENGYI PETROCHEMICAL RES INST CO LTD +1
View PDF11 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The methods for separating DMK disclosed in the above-mentioned patents are rapid condensation separation, but the reverse reaction between DMK and isobutyric acid to generate isobutyric anhydride during the condensation process will cause a large amount of DMK loss, thereby reducing the space-time yield of DMK and increasing production costs
[0004]In addition, the time for the gaseous products formed by cracking to pass through the condenser depends on the amount of carrier gas and raw materials fed, and it is often impossible to take into account the amount of raw materials in the cracking reaction tube in actual operation. The residence time and the residence time of cracked products in the condenser are both in the best operating range
At the same time, during the condensation process of the product, the temperature drop is conducive to the reverse reaction of the product DMK and isobutyric acid to form the raw material isobutyric anhydride, resulting in product loss, resulting in excessive circulation of anhydride and increasing the load of the rectifying tower for anhydride and isobutyric acid

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
  • Efficient separation method of dimethyl ketene
  • Efficient separation method of dimethyl ketene
  • Efficient separation method of dimethyl ketene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] like figure 1As shown, the feed rate of raw material liquid (isobutyric anhydride) is regulated to 1.6ml / min by liquid inlet pump and flowmeter, and the nitrogen flow rate is regulated to 160ml / min by gas flowmeter, isobutyric anhydride (purity 99%) After being mixed with nitrogen at room temperature, it enters the preheater, and after being heated and gasified by the preheater, the temperature rises to 320 °C, and then it is passed into the cracking reactor, and the high temperature cracking reaction is carried out under the high temperature cracking condition, wherein the temperature of the cracking reactor is 450 ℃. The pressure of the cracking reactor is controlled by a German Vacuubrand PC 3001 vacuum pump, and the pressure is in the range of 3-70Kpa. In Example 1, the total pressure of the reactor was controlled at 5kPa. After the pyrolysis product exits the reactor, it is mixed with a stream of low-temperature nitrogen, wherein the temperature of the low-temper...

Embodiment 2

[0037] like figure 1 As shown, the feed rate of raw material liquid (isobutyric anhydride) is regulated to 1.6ml / min by liquid inlet pump and flowmeter, and the nitrogen flow rate is regulated to 160ml / min by gas flowmeter, isobutyric anhydride (purity 99%) After being mixed with nitrogen at room temperature, it enters the preheater, and after being heated and gasified by the preheater, the temperature rises to 320 °C, and then it is passed into the cracking reactor, and the high temperature cracking reaction is carried out under the high temperature cracking condition, wherein the temperature of the cracking reactor is 450 ℃. The pressure of the cracking reactor is controlled by a German Vacuubrand PC 3001 vacuum pump, and the pressure is in the range of 3-70Kpa. In this embodiment, the total pressure of the reactor is controlled at 5kPa. After the pyrolysis product exits the reactor, it is mixed with a stream of low-temperature nitrogen, wherein the temperature of the low-...

Embodiment 3

[0039] like figure 1 As shown, the feed rate of raw material liquid (isobutyric anhydride) is regulated to 1.6ml / min by liquid inlet pump and flowmeter, and the nitrogen flow rate is regulated to 160ml / min by gas flowmeter, isobutyric anhydride (purity 99%) After being mixed with nitrogen, it enters the preheater, and after being heated and vaporized by the preheater, the temperature rises to 320°C, and then it is passed into the cracking reactor for high-temperature cracking reaction under high-temperature cracking conditions, wherein the temperature of the cracking reactor is 450°C . The pressure of the cracking reactor is controlled by a German Vacuubrand PC 3001 vacuum pump, and the pressure is in the range of 3-70Kpa. In this embodiment, the total pressure of the reactor is controlled at 5kPa. After the pyrolysis product exits the reactor, it is mixed with a stream of low-temperature nitrogen, wherein the temperature of the low-temperature nitrogen is 0° C., and the flo...

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 relates to the field of chemical engineering, and discloses an efficient separation method of dimethyl ketene, which comprises the following steps of: preheating isobutyric anhydride anda carrier, carrying out reaction in a cracking reactor, discharging a gas-phase cracking product, and mixing the gas-phase cracking product with a low-temperature inert gas; enabling the mixed gas toenter a heat exchanger to be condensed, the retention time of the mixed gas in the heat exchanger being 0.01-1.0 s, and the temperature of the mixed gas discharged out of the heat exchanger being 20-70 DEG C; enabling the mixed gas to enter a gas-liquid cyclone separator; collecting a liquid-phase product obtained by separation; and enabling a gas-phase product obtained through separation to enter an absorption tower to recover dimethyl ketene. Low-temperature inert gas is supplemented at the outlet of a cracking reactor to chill the cracking product, meanwhile, the retention time of the mixed gas in the heat exchanger is controlled, the loss of the product in the condensation separation process is reduced, and the yield of the target product is increased. According to the invention, thecracking reactor and the heat exchanger can be operated under different working conditions, and the separation efficiency of dimethyl ketene is higher.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a high-efficiency separation method for dimethyl ketene. Background technique [0002] Dimethylketene (DMK) is an important intermediate in organic synthesis. Its molecular structure is highly unsaturated and can undergo reactions such as addition, decomposition and polymerization. It is a raw material for the production of various fine chemicals. For the preparation of dimethyl ketene, currently, fatty acids or fatty acid anhydrides are produced by high-temperature pyrolysis in industry to prepare dimethyl ketene. However, the separation of dimethyl ketene has always been the key to limit its yield. How to improve the separation efficiency of dimethyl ketene and reduce its loss in the separation process is an important technical problem. [0003] Patents US2936324, US US3227764, US5169994 and US5258556 disclose the method for preparing dimethyl ketene (DMK) with isobutyric anhy...

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): C07C49/203C07C45/65C07C45/78
CPCC07C45/65C07C45/78C07C45/783C07C49/203
Inventor 时强成有为易磊刘严王韩张新平杨磊邱敏茜
Owner ZHEJIANG HENGYI PETROCHEMICAL RES INST CO LTD