METHOD AND SYSTEM FOR PREPARING METHYL ACETOACETATE OR ETHYL ACETOACETATE BY USING TUBULAR CONTINUOUS FLOW REACTOR

摘要

The present invention relates to the field of chemical production, and relates to a method and system for preparing methyl acetoacetate or ethyl acetoacetate by using a tubular continuous flow reactor. In the method, methanol or ethanol and a catalyst are respectively injected into a catalyst mixing section; after the two are mixed, a diketene metering pump is started; then, the diketene and an alcohol solution are injected into a tubular continuous flow reactor; the reaction pressure is adjusted by means of a pressure regulating valve; after reaction, a crude ester is cooled by a condenser and then flows into a buffering tank; a low-boiling point substance in the crude ester is refluxed to a buffering tank by means of the condenser; a non-condensable gas is emptied; the crude ester in the buffering tank is injected into a rectification column by means of the metering pump; the crude ester is then subjected to rectification to obtain a product of methyl acetoacetate or ethyl acetoacetate. Compared with a traditional intermittent process, the reaction retention time is greatly shortened, thereby reducing the generation of side reactions, increasing the product yield and content, and reducing the difficulty of rectification separation, reducing production costs, and greatly reducing the safety risks of production.