Manufacturing Method of Ethylene Glycol Dimethyl Ether
Ethylene Glycol Dimethyl Ether (DME for short) is an important organic chemical raw material, which is widely used in solvents, fuels, pharmaceuticals, pesticides and other fields. In the field of chemical production raw materials, the manufacturing method of ethylene glycol dimethyl ether has attracted much attention. This article will introduce the manufacturing method of ethylene glycol dimethyl ether in detail.
I. Raw materials and equipment
1. Raw materials: ethylene glycol, methanol, sulfuric acid, sodium hydroxide and so on.
2. Equipment: reaction kettle, condenser, water separator, storage tank, pump and so on.
2. Manufacturing process
1. Esterification reaction
Mix ethylene glycol and methanol in the ratio of 1:2 by molar ratio, add appropriate amount of sulfuric acid as catalyst, and carry out the esterification reaction under the condition of atmospheric pressure and 80-90℃ to generate dimethyl ethylene glycol.
Note: The dosage of sulfuric acid and the reaction temperature need to be strictly controlled to avoid excessive esterification and the occurrence of side reactions.
2. Alcoholysis reaction
Mixing dimethyl ethylene glycol and methanol in the ratio of 1:1 in molar ratio, adding appropriate amount of sodium hydroxide as catalyst, and carrying out the alcoholysis reaction under the condition of atmospheric pressure and 80-90℃ to produce ethylene glycol dimethyl ether and methanol.
Note: The amount of sodium hydroxide and the reaction temperature need to be controlled to avoid excessive alcoholysis and the occurrence of side reactions. At the same time, the reaction solution needs to be neutralized to remove the remaining acid and base.
3. Distillation and purification
The reaction solution is subjected to distillation and purification, firstly, methanol and unreacted glycol are evaporated out, and then the fraction of ethylene glycol dimethyl ether is collected to obtain the product of ethylene glycol dimethyl ether with higher purity.
Note: It is necessary to control the distillation temperature and pressure to ensure the purity and yield of the product.
III. Safety and environmental protection
1. In the manufacturing process, it is necessary to strictly follow the safety operation procedures to avoid fire, explosion and other safety accidents.
2. Waste water, waste gas and other wastes need to be treated to minimize pollution to the environment.
4. Quality control
The quality of ethylene glycol dimethyl ether products needs to be strictly controlled, including purity, moisture, acidity, chromaticity and other indicators. The quality of the product can be tested and monitored by gas chromatography, mass spectrometry and other analytical means.
In short, the manufacturing method of ethylene glycol dimethyl ether involves several process steps and operation details, which need to strictly control the quality of raw materials, reaction conditions, equipment operation and other factors to ensure the quality and yield of the product. Meanwhile, safety and environmental protection management need to be strengthened, and relevant laws, regulations and standard requirements need to be complied with to ensure the smooth progress of the production process.
