System for preparing propionate through ethylene carbonylation

Abstract

The invention relates to a system for preparing propionate through ethylene carbonylation. The system comprises a separating and refining unit and a bubbling reactor (R1) coupled with the separating and refining unit, a gas-phase reaction raw material (G1) and a liquid-phase reaction raw material (L1) for preparing the propionate product (L6) are subjected to a carbonylation reaction in a bubbling reactor (R1), and a generated propionate-containing material (L2) is separated and purified by a separating and refining unit to prepare the propionate product (L6). Compared with the prior art, through the bubbling reactor, gas-liquid two-phase contact is more sufficient, the gas-liquid two-phase reaction rate is increased, and the raw material conversion rate is increased; the content of the deactivated catalyst in the material returned to the reactor is reduced through the membrane-based solid-liquid separator, the enrichment and regeneration of the deactivated catalyst can be realized, and the utilization rate of the catalyst is also improved.

Description

technical field [0001] The invention relates to the technical field of ethylene carbonylation to produce propionate, in particular to a system for ethylene carbonylation to produce propionate. Background technique [0002] Methyl propionate (MP) is a colorless transparent liquid that is slightly soluble in water but miscible in ethanol and ether, and has the general properties of an ester. As an important raw material in the organic synthesis industry, methyl propionate can be used to synthesize ethyl propionate and benzyl propionate through transesterification for the production of wine and flavor industries, and it is also a high-grade solvent for food and cosmetics and antiseptic additives. [0003] According to the different raw materials and the way to produce products, the traditional preparation process of methyl propionate is divided into two types: the process of synthesizing propionic acid and co-production of propionate, and the process of directly catalyzing est...

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Problems solved by technology

The applicant of the present invention found that, first of all, the carbonylation reactor in this patent still adopts a high-pressure reactor with stirring function, and there is still the problem that the two phases of gas and liquid cannot be fully contacted to affect the reaction rate; secondly, the flash evaporator of this patent Most of the heavy phase in the heavy phase is directly recycled into the carbonylation reactor, and a part of the deactivated catalyst (solid) will enter the reactor together with the heavy components of the tower kettle, which will affect the catalytic reaction to a certain extent, and it is difficult to fully recover the deactivated catalyst. Active catalyst, in addition, in the process of deactivated catalyst entering the recovery device, it will lead to blockage of the pipeline; moreover, although the patent uses high-temperature water extraction to recover the catalyst, but because it will recover the lower water phase The mixture, which cannot be effectively distinguished from the deactivated catalyst, and is recycled to the carbonylation reactor in the form of water phase, contains water, which will affect the progress of the reaction

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