Apparatus for coproduction of refined methanol and dimethyl ether or production of each of refined methanol and dimethyl ether from coarse methyl alcohol

Abstract

The invention discloses a device for jointly or solely producing refined methanol and dimethyl ether by using crude methanol. The method is to use the crude methanol as a raw material, and produce the dimethyl ether by a method of methanol gas-phase catalytic dehydration, The method comprises the following steps: adding dilute alkali liquor and soft water into a primary tower to carry out pretreatment; regulating pH value; removing light component impurities; extracting primarily distilled impurities and treating the mixture in a vaporization tower. Heavy component impurities in the crude methanol enter a methanol recovery tower along with vaporization tower bottom liquor, and are extracted out from a fusel oil extraction port at the stripping section of the methanol recovery tower; the vaporization tower in the method is a rectifying tower, and the methanol recycled by the methanol recovery tower as backflow ensures purity of the methanol entering methanol vapor of a dehydration reaction system; and the method can jointly or solely produce the dimethyl ether or the refined methanol, and can produce the dimethyl ether and the refined methanol at the same time.

Description

technical field [0001] The invention relates to a method for preparing dimethyl ether by gas-phase dehydration of methanol, in particular to a method for preparing dimethyl ether by dehydrating crude methanol as a raw material. Background technique [0002] At present, dimethyl ether is prepared by methanol gas-phase dehydration. The production process of this method is: the raw material methanol is heated and vaporized by a vaporizer or a vaporization tower, and then sent to a methanol gas-phase dehydration reaction system for dehydration reaction, and the reaction product is sent to a dimethyl ether rectification tower for separation. , to obtain dimethyl ether from the top or top of the dimethyl ether distillation tower; the mixed solution of methanol and water discharged from the tower bottom is sent to the methanol recovery tower by self-pressure for rectification and separation, and methanol is recovered from the top of the tower as raw material, and The water obtaine...

AI Technical Summary

Problems solved by technology

[0005](2) The combination of the process flow is complex and the switching process is cumbersome, and when the single production of dimethyl ether and the single production of refined methanol are switched, the replacement of some equipment is unreasonable. The equipment design is complicated and the investment is large;

[0006](3) When producing dimethyl ether and co-producing refined methanol, the crude methanol has not been pretreated in the pre-column, and the quality of the co-produced refined methanol is not high

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