SU402203A1 - METHOD OF OBTAINING OXYPOLYETHYLENE GLYLEVOLATE ETHERS - Google Patents

Description

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This invention relates to a process for the preparation of oxy polyethylene glycol ethers, which can be used as non-ionic surfactants.

A known method for the preparation of oxy-ethylene glycol ethers of the general formula

R-X- (C2H4O) -H

where X is O, S, N;

R is alkyl,

by reacting ethylene oxide with compounds containing a mobile hydrogen atom in the presence of an alkaline catalyst at 125–200 ° C. At the same time, liquid ethylene oxide is fed to the reactor, which immediately evaporates at the temperature of the reakini, and already in the gas phase of this oxide, a mixture containing a mobile hydrogen atom and a catalyst is introduced into a finely dispersed state. Such an implementation of the process does not provide the necessary contact between the reacting components, as well as sufficient movement, as a result of which the reaction time is increased and 3-4% of by-products, polyglycols, are formed. In addition, the process goes with the release of heat, the removal of which by a known method, carried out by circulating an already partially ethoxylated product, which has

In some cases, the viscous consistency is not sufficiently effective.

In order to eliminate these drawbacks, it has been proposed to introduce ethylene oxide in the liquid state into the turbulent flow of a compound containing a mobile hydrogen atom and a catalyst.

The process is desirable to conduct at. The drawing shows the installation diagram

to implement the proposed method.

The starting material, for example nonylfeiol, dried in vacuum, freed from dissolved oxygen and containing the catalyst, is circulated by pump 1 in

closed) system of intermediate tank. Using the metering device 2, liquid ethylene oxide is added to the circulating liquid in the thin-dispersion state and intensively moves them in the diffuser.

mixing chamber 3. From this chamber, the mixture is deposited in the heat exchanger 4, where the main part of the reaction takes place. Prior to the start of the reaction, as well as before the start of the addition of ethylene oxide, the heat exchanger is preheated, for example, with steam in order to bring the temperature of the starting material to the reaction temperature. From the heat exchanger, the mixture is fed to the vessel 5, where only that part of the reaction mixture volume is collected, which corresponds to an increase due to the addition of Luke ethylene. By the beginning of loading of the initial substance, the vessel pocht-1I is empty. For this reason, it is necessary to introduce at least such an amount of the initial substance that all the rest of the circulating system with the circulating pump running is filled with liquid. During the progress of the reaction, the liquid level in the vessel rises to the corresponding amount of ethylene oxide added. The reaction conditions remain seeded throughout the process. The capacity of the circulating pump does not depend on the amount of ethylene oxide introduced. The dosing system consists of a Venturi mixing valve, in which ethylene oxide is added to the smallest non-sectional section through an external nozzle. However, other devices may be used to finely disperse ethylene oxide. As a heat exchanger, it is advisable to use a heat exchanger in the form of a bundle of tubes. In the proposed method, the reaction starts directly at the site of supply of ethylene oxide and continues in the reaction mixture 25 as it flows through the mixing chamber and the heat exchange element. In the mixing chamber, part of the ethylene oxide evaporates, which further enhances the turbulence and displacement efficiency. The mixing effect of vapors also occurs in the heat exchanger, as a result of which there is a significant improvement in ten-transfer. The reaction mixture is under conditions of continuous circulation, and the reaction released in 35 is caused by the tenlo discharged with a heat exchanger connected to the circulating system and constantly washed by the reaction mass. The ethylene oxide in the liquid state is fed into the turbulent flow of the reaction mixture and the resulting mixture is directed through the mixing chamber and then through the heat exchanger, which also represents the reactor at the same time, as it reacts about 50% of the fed ethyl oxide. 45 The process is carried out by recirculating the stock mass until the desired degree of oxyethylation is achieved. The proposed method makes it possible to reduce the formation of by-products to 1% and to obtain high-quality final products with a yield of up to 6000 kg / l-hour instead of 2900 kg / l-hour by a known method. Example 1. Preparation of the product of the addition of 55 neni on average 10 mol of ethylene oxide to 1 mol of nopylphenol. 5 4000 kg of nonylphenol containing as a catalyst 0.2 Bes.% Of caustic soda is loaded into the container, and it is stored under vacuum. Then over the course of 1.8 hours, 4500 kg / h of ethylene oxide are fed under a pressure of 4 atm. At the same time, the temperature of the reaction mixture rises to and further maintained at this level. After cooling the mixture under conditions that exclude air and neutralize 6–7 kg of acetic acid, 12,000 kg of the final product is obtained in the form of a water-like liquid, which contains 0.5 wt. % nobochnogo product (polyethylene glycol). Volume-time output of 6000 kg / l-hour. According to a known method, the process proceeds within 5 hours, the volume-yield of the final product is 2900 kg / l-hour, the content of polyglycol by-product in the target is 2 wt.%. Example 2. Preparation of an addition product on average 10 mol of ethylene oxide to 1 mol of fatty alcohols of fat. 4230 kg of fatty alcohols with 0.2% by weight of sodium hydroxide as a catalyst are loaded into a container and dried under vacuum at 110 ° C. Then, at 150 ° C for 2 hours and 15 minutes, 4000 kg / h of ethylene oxide are gradually supplied under a pressure of 4 atm. After cooling under conditions excluding the access of air, 13200 kg of the final product is obtained in the form of a water-like liquid containing no more than 1% of a by-product (polyglycol). The volume-time yield is 5200 kg / l-hour. According to a known method, the reaction time is 6.3 hours, the volume-time yield is 2100 kg / l-hour, the content of by-product (polyglycol) is 3-4 wt.%. The subject of the invention 1. A method for producing hydroxypolyethylene glycol ethers by reacting ethylene oxide with compounds containing a mobile hydrogen atom in the presence of an alkaline catalyst at elevated temperatures under conditions of continuous circulation of the reaction, mass and removal of the heat generated during the process, followed by separation of the target product by known methods, characterized in that, in order to reduce the formation of nocite products, ethylene oxide in the liquid state is fed into the turbulent flow of the compound containing a movable hydrogen atom and a catalyst. 2. A method according to claim 1, characterized in that the process is carried out at Re 2300.

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