System for preparing ethylene glycol from ethane via epoxyethane

Abstract

The invention provides a system to prepare glycol, which comprises: an oxirane reaction system with a tube-row fixed bed reactor with the tube size within 40~50mm, an oxirane hydration reaction system, a glycol evaporation system with a multi-effect evaporator system in series and a heat exchanger with low-pressure steam as heat source, and a vacuum dewatering system with a pre-heater arranged in front of the tower to heat the feeding solution to or more than its bubble point temperature; Wherein, the reboiler in the evaporation system has tube plate as dual-face composite structure steel plate, basic material layer as carbon steel, tube side composite layer as Monel alloy, and shell side composite layer as stainless steel. This invention takes small land, needs low investment, solves effectively the corrosion protection and coking problems for device, and has well economic benefit.

Description

Technical field [0001] The invention relates to a system for producing ethylene glycol, in particular to a system for producing ethylene glycol from ethylene through ethylene oxide. Background technique [0002] Ethylene oxide / ethylene glycol (EG) is the third largest variety in the ethylene series. It has a wide range of uses. It is an important chemical raw material for the production of polyester, surfactants, antifreeze, etc. [0003] The method of preparing monoethylene glycol from ethylene via ethylene oxide is to use ethylene and oxygen in the presence of a silver catalyst to generate ethylene oxide through a catalytic oxidation reaction, and then ethylene oxide is hydrolyzed to generate ethylene glycol. The entire production system includes an ethylene oxide reaction system, an ethylene oxide hydration reaction system, and an ethylene glycol separation and purification system. The ethylene glycol separation and purification system includes an evaporation system and a vacu...

AI Technical Summary

Problems solved by technology

[0008] 2. The load of the evaporation system brought about by the expansion of the ethylene oxide / ethylene glycol production system:

[0020] In the existing production equipment, the problem of coking in the reboiler of the dehydration tower has greatly affected the load of the dehydration tower and the load of the entire equipment; Correspondingly, a large amount of water is brought in to meet the requirements of increased production capacity, which leads to a large increase in the dehydration load of the dehydration tower. If the load of the whole set of equipment is increased by more than 10%, the coking situation will be more serious, and the number of shutdowns to clean the coke will be more. up

Therefore, the problem of coking in the reboiler of the dehydration tower needs to be solved urgently

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