Alcohol oil extraction device in dimethyl ether production system and alcohol oil extraction method

Abstract

The invention discloses an alcohol oil extraction device in a dimethyl ether production system and an alcohol oil extraction method. A reaction product obtained by taking crude methanol as a raw material to prepare dimethyl ether enters a dimethyl ether rectifying tower; a kettle liquid buffer slot is formed in the flow of the rectified tower kettle liquid to a methanol vaporization tower; a valve controls the flow of the kettle liquid; a mining opening I is connected to the buffer slot in the upper part of a content gauge of the rectifying tower, and a mining opening II is connected with an atmospheric pressure buffer tank on the top of the buffer slot; dilute alkali lye is supplied to the buffer tank; an inverted U-shaped water seal is arranged at the outlet of the buffer tank, and connected with a methanol intermediate tank; an alcohol oil mining opening is formed in the upper part of the buffer tank. By adopting the alcohol oil extraction device and the alcohol oil extraction method, the target of continuously and automatically recovering alcohol oil in the dimethyl ether is achieved by an organic matter separation method. Thus, the quality of the dimethyl ether product is improved, and the dehydration catalyst is protected.

Description

technical field [0001] The invention relates to the technical field of dimethyl ether production, in particular to a method and device for recovering alcohol oil in the production process of dimethyl ether. Background technique [0002] The current domestic industrial production process of dimethyl ether is the dehydration reaction of methanol under the action of a catalyst. The temperature of the dehydration catalyst is generally controlled between 300-400°C. At present, the selectivity of the domestic dehydration catalyst in the early stage of use can reach 98%. The selectivity drops sharply, and the side reactions continue to increase. Under high temperature conditions, the by-product of methanol production of dimethyl ether is mainly C 5 -C 10 The hydrocarbons, that is, the so-called alcohol oil in the methanol rectification process, most of its components have a higher boiling point than dimethyl ether. [0003] The traditional dimethyl ether production process does...

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Problems solved by technology

[0003] The traditional dimethyl ether production process does not involve the production of alcohol oil. According to the principle of alcohol oil recovery in the methanol rectification unit, some manufacturers extract isobutyl oil in the methanol vaporization tower. However, due to the The concentration of vaporized methanol is not high, the reflux of the vaporization tower is close to 0, and the temperature control is higher than that of the methanol rectification tower. Many alcohol oils cannot be recovered in the methanol vaporization tower. In addition, during the production process The side reaction produced, and finally most of the alcohol oil enters the dimethyl ether rectification tower

[0004] The mixture of alcohol oil and dimethyl ether is not only related to the quality of the finished product of dimethyl ether, but also related to the service life of the dehydration catalyst. The catalyst of many manufacturers will find that the color of the catalyst turns gray or black after about one year of use. This is because the catalyst After the alcohol oil is adsorbed, it is caused by carbonization at a high temperature for a long time. The carbonized substance will block the micropores of the catalyst, resulting in the deactivation of the catalyst.

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