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

A process for the integrated separation of dimethyl carbonate and methanol by pervaporation-pressurized rectification

A technology of dimethyl carbonate and pressure distillation, which is applied in the preparation of carbonates/haloformates, the preparation of organic carbonates, the separation/purification of hydroxyl compounds, etc., to reduce concentration polarization and low energy consumption , Improve the effect of permeation flux

Active Publication Date: 2016-03-30
JIANGSU JIUMO HIGH TECH CO LTD
View PDF4 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above patents only show that the pervaporation separation experiment shows high selectivity and large permeate flux, and does not involve industrial applications. It can be predicted that the collected permeate still needs to be further separated

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
  • A process for the integrated separation of dimethyl carbonate and methanol by pervaporation-pressurized rectification

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The azeotropic mixture of dimethyl carbonate and methanol was obtained at the top of the reactive distillation column 1 at a temperature of 64°C, the content of dimethyl carbonate was 30% (by mass fraction, the same below), and the content of methanol was 70%. Such as figure 1As shown, the azeotropic mixture first enters the buffer tank 2, and then is transported to the pervaporation membrane system 4 by the liquid delivery pump 3 at 40°C, where it is compounded with polydimethylsiloxane-polyvinylidene fluoride-nano-titanium dioxide membrane contact. The pervaporation membrane system 4 includes a membrane module, a condenser and a vacuum pump, and the downstream side of the membrane is evacuated by a vacuum pump to maintain a vacuum degree of 100Pa. Due to the difference in selectivity of pervaporation membranes for methanol and dimethyl carbonate adsorption, the pervaporation process breaks the methanol-dimethyl carbonate azeotropic equilibrium, and the concentration ...

Embodiment 2

[0026] Such as figure 1 As shown, the azeotropic mixture of dimethyl carbonate and methanol is obtained at the top of the reactive distillation column 1, and the temperature is 64°C. The azeotropic mixture first enters the buffer tank 2, and then uses the liquid delivery pump 3 to transport to In the pervaporation membrane system 4, it is in contact with polydimethylsiloxane-polyvinylidene fluoride-nano silica composite membrane. The pervaporation membrane system 4 includes a membrane module, a condenser and a vacuum pump, and the downstream side of the membrane is evacuated by a vacuum pump to maintain a vacuum degree of 1500Pa. Due to the difference in selectivity of pervaporation membranes for methanol and dimethyl carbonate adsorption, the pervaporation process breaks the methanol-dimethyl carbonate azeotropic equilibrium, and the retentate side is condensed by a condenser to obtain a concentration of dimethyl carbonate of 10.0wt % feed liquid a; feed liquid b with a dime...

Embodiment 3

[0028] Such as figure 1 As shown, the azeotropic mixture of dimethyl carbonate and methanol is obtained at the top of the reactive distillation column 1, and the temperature is 64 ° C. The azeotropic mixture first enters the buffer tank 2 and is then transported to In the pervaporation membrane system 4, it is in contact with polydimethylsiloxane-polyethersulfone-polyimide composite membrane. The pervaporation membrane system 4 includes a membrane module, a condenser and a vacuum pump, and the downstream side of the membrane is evacuated by a vacuum pump to maintain a vacuum degree of 10100Pa. Due to the difference in selectivity of pervaporation membranes for methanol and dimethyl carbonate adsorption, the pervaporation process breaks the methanol-dimethyl carbonate azeotropic equilibrium, and the retentate side is condensed by a condenser to obtain a concentration of dimethyl carbonate of 11.5wt % feed liquid a; feed liquid b with a dimethyl carbonate concentration of 42.4w...

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 provides a process for separating dimethyl carbonate and methanol by employing pervaporation and pressure distillation integration. The process is characterized by comprising the steps as follows: when azeotrope of dimethyl carbonate and methanol obtained by a reactive distillation column passes through a pervaporation membrane system, a pervaporation membrane effectively breaks through the azeotropic bottleneck of methanol-dimethyl carbonate; a dimethyl carbonate low-concentration side feed liquid returns to the reactive distillation column to be separated in cycle; a dimethyl carbonate high-concentration side feed liquid is conveyed to a pressurized distillation column; a dimethyl carbonate product of which the mass purity is over 99.6% is obtained from a tower after being separated by the pressurized distillation column; and a dimethyl carbonate and methanol mixed solution with relatively high content is obtained from the tower top, and is also returned to the reactive distillation column to enter the next cyclic separation. The energy consumption of the process disclosed by the invention in existing pervaporation-distillation integration processes is the lowest; the dimethyl carbonate product is relatively excellent in quality; the production process and equipment are simplified; and the process disclosed by the invention has the advantages of being convenient, adjustable, low in operation cost, high in integration and the like.

Description

technical field [0001] The invention relates to a process for the integrated separation of dimethyl carbonate and methanol through pervaporation-pressure rectification. The invention belongs to the technical field of separation of dimethyl carbonate. Background technique [0002] Dimethyl Carbonate (Dimethyl Carbonate, DMC for short) is an organic chemical product with environment-friendly characteristics, and is also an important intermediate and starting material for organic synthesis. With the gradual expansion of demand and application fields of dimethyl carbonate, the research on its production process is becoming more and more important. At present, the industrial production methods of dimethyl carbonate mainly use urea and methanol direct alcoholysis method, methanol oxidative carbonylation method, transesterification method, carbon dioxide and methanol direct synthesis method, etc., but no matter which method is used, due to thermodynamic limitations, DMC The azeot...

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 Patents(China)
IPC IPC(8): C07C31/04C07C29/76C07C69/96C07C68/06C07C68/08
CPCC07C29/128C07C29/76C07C68/065C07C68/08C07C31/04C07C69/96C07C31/205Y02P20/10
Inventor 丁晓斌王焕章杜运平王成
Owner JIANGSU JIUMO HIGH TECH CO LTD