PROCESS METHOD FOR PREPARING ACETIC ACID BY CARBONYLATING METHANOL BY MEANS OF REACTOR THERMALLY COUPLED WITH RECTIFYING TOWER

摘要

The present invention relates to a process method for preparing acetic acid by carbonylating methanol by means of a reactor thermally coupled with a rectifying tower. The process method comprises: introducing methanol and CO into the reactor for a carbonylation reaction, sending a reaction liquid at an outlet port of the reactor to a flash evaporator for flash evaporation in order to separate a liquid phase component and a gas phase component, and returning the liquid phase component to the reactor; allowing the gas phase component to enter a catalyst trap, returning the trapped catalyst to the bottom of the flash evaporator, and allowing the gas phase to enter a light component tower for separation in order to obtain a first overhead light component and a first tower kettle heavy component; and sending the first tower kettle heavy component into a heavy component tower for separation in order to obtain an acetic acid product, wherein the reaction liquid in the reactor and the tower kettle material in the heavy component tower undergo coupled heat transfer. Compared with the prior art, the present invention has the advantages of energy efficiency, reduced emissions, a high product purity, easy control of the system, stable operation, etc.