Method for preparing ethylene glycol by catalysis hydration

Abstract

The present invention discloses a method for preparing ethylene alcohol by a catalyzing and hydration method, which comprises the following steps: the ethylene alcohol solution EC/EG/H2O/CAT includingDioxo carbonate and even catalyzer absorbs EO gas; the most part of EC/EG/H2O/CAT/EO solution reacts with CO2 to obtain EC/EG/H2O/CAT solution for the repeated use; the EC/EG/H2O/CAT/EO solution absorbs the residual solution and takes hydrolyzing reaction with water as well as taking hydration reaction with water to obtain EG/H2O/CAT/DEG solution; and then ethylene alcohol is obtained by the distilling operation. The condition for the hydration of ethylene alcohol and the hydrolyzing of Dioxo carbonate is: the molar ratio between the total molar of water and the total molar of ethylene alcohol and Dioxo carbonate is 1-5; the reaction temperature is 60-200 Celsius system; the pressure is 0.10-3.0MPa; and the reaction time is 5-240 minutes.

Description

technical field [0001] The invention relates to a production method for preparing ethylene glycol by hydrating ethylene oxide, and more specifically relates to a method for producing ethylene glycol based on catalytic hydration to reduce energy consumption. Background technique [0002] Ethylene glycol (Ethylene Glycol, EG), sometimes in order to distinguish it from related homologues Diethylene Glycol (DEG), Triethylene Glycol (Triethylene Glycol, TEG) and polyethylene glycol, also known as monoethylene glycol ( Monoethylene Glycol, MEG), as a bulk organic chemical product, is widely used in the production of polyester products such as polyester fibers, films, containers and bottles, as well as automobile antifreeze agents, and can also be used as deicing agents, surface coatings, surfactants, Plasticizers, unsaturated polyester resins and raw materials for the synthesis of glycol ethers, glyoxal, oxalic acid and other chemical products. [0003] The hydration of ethylene ...

AI Technical Summary

Problems solved by technology

However, direct absorption of C with ethylene carbonate EC solution 2 h 4 The ethylene oxide reaction gas obtained by oxidation will absorb trace impurities such as acid aldehydes in the ethylene oxide EO reaction gas. The introduction of these impurities will greatly affect the quality of ethylene glycol products, and it is difficult to ensure high-quality polyethylene glycol. Ester-grade EG and EO products; and the quaternary salt catalyst used has certain toxicity; at the same time, the esterification reaction is a reaction in which ethylene oxide is completely converted into ethylene carbonate, and the generation of EC due to the EO esterification reaction is very exothermic However, the generation of EG by the hydrolysis reaction of EC has a small heat release, so the esterification reaction of the absorption solution needs to remove a large amount of additional heat, and the rehydrolysis of the product of the esterification reaction to obtain ethylene glycol requires additional energy, which gives a reasonable optimization of the reaction heat. Utilization brings a lot of difficulties; the cycle gas after absorption has a great influence on C 2 h 4 The influence of oxidation reaction to generate EO needs to be further examined

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