[Background and Overview][1][2]
Ethylene glycol butyl ether is one of the important derivatives of ethylene oxide (EO). It is a green and environmentally friendly solvent. It is a colorless liquid with a molecular weight of 118.17 and a distillation range of 163~174°C. It is not easily volatile and has a relative density of 0.9019. , boiling point 171.1℃, flash point 60.5℃, toxic, miscible with water and linseed oil hydrocarbon solvents, has strong dissolving ability for synthetic rubber, suitable for use as a solvent for natural rubber and synthetic rubber, and also used Used as a solvent for rosin, shellac, kauri and indene resin, ethyl cellulose and nitrocellulose. Ethylene glycol butyl ether is one of the important industrial derivatives of epoxy compounds and an extremely important fine chemical. Because its chemical structure has two groups with strong dissolving function – ether bond and hydroxyl group, the former is lipophilic and can dissolve hydrophobic compounds, and the latter is hydrophilic and can dissolve hydrophilic compounds, so it has a strong Its dissolving ability makes it known as the “universal solvent”.
Since foreign countries began to use ethylene glycol butyl ether as a solvent in the mid-1970s, ethylene glycol butyl ether has been widely used in paint, leather, coatings, textiles, organic chemicals and other industries. The synthesis of ethylene glycol butyl ether is a typical etherification reaction. Currently, potassium hydroxide is mostly used as a catalyst in industry. Although potassium hydroxide has the advantages of high catalytic activity and short reaction time, there are also problems such as difficulty in separation and recovery of the catalyst, wide product distribution, equipment corrosion, environmental pollution and other problems. There is an urgent need to use non-corrosive, non-polluting, Replacing it with a new type of easily separated catalyst and using a solid alkali catalyst is an effective way to eliminate the shortcomings of the traditional etherification reaction process. Ethylene glycol butyl ether includes ethylene glycol monobutyl ether, diethylene glycol monobutyl ether and triethylene glycol monobutyl ether. Among them, ethylene glycol monobutyl ether has the largest production and consumption, accounting for about 10% of ethylene glycol butyl ether. About 70%. Since the molecular structure of ethylene glycol monobutyl ether contains hydroxyl and ether bonds, it is both hydrophilic and lipophilic, and can be dissolved in water, methanol, ethanol, ether, acetone, benzene, carbon tetrachloride, heptane and other organic solvents and More than 75% of mineral oil is used as a solvent for coatings, inks, cleaning agents, etc. Its non-solvent uses include brake fluid, antifreeze and other chemical intermediates. At present, the import volume of ethylene glycol butyl ether products in the domestic market is still increasing year by year. Therefore, developing this product and studying the corresponding catalytic reaction process have broad application prospects.
[Application][3]
Ethylene glycol butyl etherBecause its molecule contains both ether bonds and hydroxyl groups, this unique property allows it to dissolve organic molecules, synthetic or Natural polymer compounds are miscible with water or water-soluble compounds to varying degrees, so they are widely used as coatings, inks, cleaning agents, pharmaceutical extractants, etc. According to statistics, my country’s coating and ink industry consumed approximately 200,000 tons of glycol ether in 2010, accounting for approximately 80% of the total consumption of glycol ether. The cleaning agent industry consumes approximately 20,000 tons of glycol ethers, accounting for approximately 8% of the total consumption of glycol ethers. It can be seen that solvents for coatings are still the largest application field of glycol ethers. However, recent studies have shown that glycol ethers (especially methyl ether and ethyl ether) may cause blood diseases and fetal malformations, and developed countries have begun to partially restrict their production and use. However, ethylene glycol butyl ether does not show similar toxicity, and it is not transported and stored as dangerous goods abroad. Therefore, it is imperative to use ethylene glycol butyl ether in solvents instead of ethylene glycol methyl ether and diethyl ether.
Currently, ethylene glycol butyl ether is the largest consumer in my country, accounting for approximately 60% of the total consumption of ethylene glycol ether products. However, due to the immaturity of domestic production technology for ethylene glycol butyl ether, my country’s source of ethylene glycol butyl ether mainly relies on imports, with imports accounting for more than 90% of the total. In recent years, my country’s production of ethylene glycol butyl ether Demand is growing at an average annual growth rate of 10%, and the imbalance between supply and demand is becoming increasingly serious. Therefore, it is particularly important to develop a feasible production route for ethylene glycol butyl ether. In the past 20 years, my country’s glycol ether products have developed rapidly. In 1988, the country only consumed 260 tons of glycol ether. By 2007, the annual consumption of glycol ether exceeded 200,000 tons. In 2009, only ethylene glycol butyl ether was consumed. The consumption exceeded 110,000 tons. Due to the rapid development of my country’s coating industry, it has become inevitable to replace oil-based coatings with water-based coatings, which has greatly increased the demand for glycol ether products, especially ethylene glycol butyl ether. It is expected that in the next few years, my country’s demand for ethylene glycol butyl ether will maintain a rapid growth rate of more than 10% per year.
【Preparation】[4][5]
my country’s huge glycol ether market has spawned the participation of some private enterprises, but the scale is generally small, the domestic production technology level is not high, and the operating rate is low. After years of competition in the same industry and the impact of imported products, there are currently several companies with annual production capacities exceeding 10,000 tons, and their technical levels have also been greatly improved. For example, the 60,000 t/a ethylene glycol butyl ether unit of Dana (Nanjing) Chemical Co., Ltd., which was put into operation in July 2009, uses new catalyst technology to produce ethylene glycol butyl ether with a yield of more than 90%, and the by-product diethylene glycol butyl ether is Butyl alcohol ether is controlled below 10%, while the target product yield of the currently internationally used ethylene glycol butyl ether catalytic technology is only within 75%. Examples of its preparation methods are as follows:
A method for synthesizing ethylene glycol butyl ether, said methodIncluding the following processes:
a. The synthesis of ethylene glycol butyl ether consists of three steps. The first step is as shown in equation (1). Methyl and butanol synthesize butoxymethoxymethane; the second step is as shown in equation (2). ), butoxymethoxymethane is directional carbonylated to generate butoxymethyl acetate; in the third step, as shown in equation (3), butoxymethyl acetate is hydrogenated to generate ethylene glycol butyl ether and methanol ;
b. Preparation of butoxymethoxymethane, using dimethoxymethane and n-butanol as raw materials, using liquid acid and supported liquid acid as catalyst under temperature and pressure, to prepare butoxymethoxymethane Methane. The liquid acid catalyst is one or more inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, etc.; the mass fraction of the sulfuric acid catalyst is 0 to 98%, the hydrochloric acid catalyst is an aqueous solution containing 0 to 38% hydrogen chloride, and the nitric acid catalyst is an aqueous solution containing 0 to 38% hydrogen chloride. The mass fraction is between 0 and 95%, and the mass fraction of hydrofluoric acid catalyst is between 0 and 55%. According to the method for synthesizing ethylene glycol butyl ether, the reaction temperature is 0-160°C, and the reaction pressure is 0.1-10.0 MPa; the filling gas is an inert gas, argon, helium, carbon dioxide, or nitrogen. One or mixed gas; the reactor is a fixed bed or a kettle type reactor; a kettle type reactor is further preferred. In the method for synthesizing ethylene glycol butyl ether, the carrier of the supported solid acid catalyst is activated carbon, silica, aluminum oxide, titanium dioxide, zirconium dioxide, tungsten oxide, beryllium oxide, etc. or more.
[Main reference materials]
[1] Concise Dictionary of Fine Chemicals
[2] Guo Dengfeng; Liu Zhun; Liu Hong; Cao Huiqing; Cai Xiangyang. A method for synthesizing ethylene glycol butyl ether. CN201010252085.4, application date 2010-08-12
[3] Zhang Yueli. “Domestic market survey of ethylene glycol butyl ether.” Chemical Industry 12 (2010): 19-21.
[4] Guo Dengfeng, Liu Hong, Liu Zhun, Cao Huiqing, Zhao Wen, Shi Zhaojun. Synthesis of ethylene glycol butyl ether catalyzed by solid base catalyst KF/Al_2O_3 [J]. Journal of Nanjing University of Science and Technology (Natural Science Edition), 2011, 35(01):122-126.
[5] Shi Lei; Yao Jie; Zhao Jia; Li Zhenquan.3 A method of synthesizing ethylene glycol butyl ether CN201610198140.3, application date 2016-04-01
