Ethylene glycol refining and separating method and system

Abstract

The invention discloses an ethylene glycol refining and separating method and system, solving the problems of complex process, difficult separation and high equipment investment and energy consumption existing in the prior art. Reaction mixed gas from an ethylene glycol synthetic system is cooled and then is separated by a first gas-liquid separator, the gas phase is fed into the ethylene glycol synthetic system as hydrogen-containing circulating gas, and the liquid phase is fed into a methanol recovering tower to product methanol from the top of the tower; the reaction mixed gas is fed into the second gas-liquid separator after cooling, the gas phase is cooled further and then is fed into the first gas-liquid separator, the liquid phase is mixed with a tower bottom liquid from the methanol recovering tower and then is fed into a degreasing tower, mixed ethanol ester is produced from the top of the degreasing tower, the tower bottom liquid is fed into a hydrogen removing tower, light alcohol is produced from the top of the hydrogen removing tower, the tower bottom liquid is fed into a refining tower, and qualified ethylene glycol is produced from the top of the refining tower, a side-draw is arranged at the same time to extract high-quality ethylene glycol. The process is simple, the operation is simple and convenient, the equipment investment and running cost are low, the impurity separation effect is favorable, and the yield is high.

Description

technical field [0001] The invention relates to a method and system for separating ethylene glycol, in particular to a method for refining and separating ethylene glycol and a system thereof. Background technique [0002] The ethylene oxide hydration method is the most widely used in the preparation of ethylene glycol. Due to the impact of the oil crisis in recent years, research on the preparation of ethylene glycol by non-petroleum routes is increasing at home and abroad. The CO gas-phase oxidative coupling method instead of the petroleum route to prepare ethylene glycol has the advantages of abundant raw material sources, low cost, no pollution, mild reaction conditions, high product purity, continuous production, etc. It is an advanced clean production and environment-friendly green chemistry process. Its successful development and development has an important role and significance in changing the existing traditional process routes of oxalate esters, ethylene glycol, a...

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Problems solved by technology

[0004] On the other hand, in the past, when the reaction synthesis gas from the ethylene glycol synthesis system was used for the first step of methanol recovery, gas-liquid separation was required, so that the liquid phase containing methanol entered the methanol recovery tower to separate methanol, and the liquid volume of this part was large. It often requires a bulky methanol recovery tower for processing, which has the problems of large equipment volume, high investment and operating costs, and high energy consumption

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