Method for preparing dimethyl ether through methanol dehydration

A methanol dehydration and dimethyl ether technology, applied in the dehydration of hydroxyl-containing compounds to prepare ether, ether preparation, organic chemistry, etc., can solve the problems of serious equipment corrosion, serious environmental pollution, and harsh operating conditions, and achieve high operating flexibility. Simple process and high conversion rate

Active Publication Date: 2013-12-11
KAIRUI ENVIRONMENTAL PROTECTION TECH
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  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The sulfuric acid dehydration method was first used in the methanol dehydration method, and the reaction was carried out in the liquid phase. The main disadvantages were serious equipment corrosion, harsh operating conditions, and serious environmental pollution.
At present, the production methods of dimethyl ether mainly include: (1) using methanol vapor phase dehydration to produce dimethyl ether. Advantages: the purity of dimethyl ether can reach 99.9%. The purity of raw materials also has certain requirements; (2) DME is produced by catalytic distillation. Advantages: methanol dehydration reaction and product separation are carried out in a methanol rectification tower at the same time. Disadvantages: more plates, higher equipment investment less elastic

Method used

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  • Method for preparing dimethyl ether through methanol dehydration
  • Method for preparing dimethyl ether through methanol dehydration

Examples

Experimental program
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Effect test

Embodiment 1

[0023] Such as figure 1 As shown, 500kg / h of methanol with a content of 99.5% (mass ratio) enters the first heat exchanger 2 through the methanol feed pipe 1, and passes through the outlet pipe 3 of the first methanol heat exchanger after heat exchange, and the temperature is 50-60°C , into the second heat exchanger 4 for heat exchange, and then through the second heat exchanger outlet pipe 5, the temperature is 70 ~ 80 ° C, enters the heater 6, the heated methanol passes through the heater outlet pipe 7, the temperature is 140 ~ 150°C, enter dehydration reactor 8, operating pressure: 1.5-3.0MPa, operating temperature: 140-150°C, space velocity: 1h - , under the action of a catalyst, methanol is dehydrated to generate a dimethyl ether mixture, and the resulting reaction mixture enters the gas-liquid separator 10 through the outlet pipe 9 of the dehydration reactor, the operating pressure is 0.8-1.3 MPa, and the operating temperature is 120-130 ° C. The gas phase directly ente...

Embodiment 2

[0025] Such as figure 2 As shown, 500kg / h of methanol with a content of 99.5% (mass ratio) enters the first heat exchanger 2 through the methanol feed pipe 1, and passes through the outlet pipe 3 of the first methanol heat exchanger after heat exchange, and the temperature is 40-50°C , enter the second heat exchanger 4 for heat exchange, and then pass through the second heat exchanger outlet pipe 5, the temperature is 60 ~ 70 ° C, enter the heater 6, the heated methanol passes through the heater outlet pipe 7, the temperature is 120 ~ 130°C, enter dehydration reactor 8, operating pressure: 3.0-4.0MPa, operating temperature: 120-130°C, space velocity: 5h -, under the action of a catalyst, methanol is dehydrated to generate a dimethyl ether mixture, and the resulting reaction mixture enters the gas-liquid separator 10 through the outlet pipe 9 of the dehydration reactor, the operating pressure: 1.3-1.5MPa, and the operating temperature is 110-120°C, and the separation is obtain...

Embodiment 3

[0027] Such as figure 1 As shown, 500kg / h of methanol with a content of 99.5% (mass ratio) enters the first heat exchanger 2 through the methanol feed pipe 1, and passes through the outlet pipe 3 of the first methanol heat exchanger after heat exchange, and the temperature is 50-60°C , enter the second heat exchanger 4 for heat exchange, and then pass through the second heat exchanger outlet pipe 5, the temperature is 70 ~ 80 ° C, enter the heater 6, the heated methanol passes through the heater outlet pipe 7, the temperature is 150 ~ 160°C, enter dehydration reactor 8, operating pressure: 0.5-1.5MPa, operating temperature: 150-160°C, space velocity: 3h - , under the action of a catalyst, methanol is dehydrated to form a dimethyl ether mixture, and the resulting reaction mixture enters the gas-liquid separator 10 through the outlet pipe 9 of the dehydration reactor, the operating pressure: 0.5-0.8MPa, and the operating temperature is 140-150°C, and the obtained The gas phase ...

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Abstract

The invention relates to a method for preparing dimethyl ether through methanol dehydration. The method comprises the steps: enabling preheated methanol to be subjected to dehydration reaction under the action of a catalyst, so as to obtain a reaction mixture, and carrying out gas-liquid separation; enabling an obtained gas phase to directly enter a dimethyl ether rectification tower; removing anions and cations from an obtained liquid phase, and then, enabling the liquid phase to enter the dimethyl ether rectification tower; condensing an overhead of the dimethyl ether rectification tower, so as to obtain a qualified dimethyl ether product; obtaining alcohol-containing wastewater from the dimethyl ether rectification tower. According to the method disclosed by the invention, the process flow is simple, and methanol reacts in a liquid phase state, so that the method has the advantages of low reaction temperature, high conversion ratio, good selectivity and low energy consumption; in addition, corrosive anions and cations are removed by an ion exchanger, so that the problem of corrosion of liquid phase methods is solved effectively.

Description

technical field [0001] The invention relates to a production method of chemical products, in particular to a method for preparing dimethyl ether. Background technique [0002] Dimethyl ether is also called methyl ether, or DME for short. As a basic chemical raw material, dimethyl ether can be widely used in industry, agriculture, medical treatment, daily life and other fields due to its good characteristics of easy compression, condensation and vaporization. In the future, DME will be mainly used to replace automobile fuel, liquefied petroleum gas, city gas, etc., and the market prospect is extremely broad. [0003] The methanol dehydration method was the first to use the sulfuric acid method for dehydration, and the reaction was carried out in the liquid phase. The main disadvantages were severe equipment corrosion, harsh operating conditions, and serious environmental pollution. At present, the production methods of dimethyl ether mainly include: (1) using methanol vapor...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C43/04C07C41/09
Inventor 毛进池戴良国刘文飞王文学张勇葛立军
Owner KAIRUI ENVIRONMENTAL PROTECTION TECH
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