Preparation method of triethanolamine
Ethylene oxide and ammonia water are sent into the reactor. Under the reaction temperature of 30-40 ℃ and the reaction pressure of 70.9-304kPa, the condensation reaction is carried out to produce a mixture of monoethanolamine, diethanolamine and triethanolamine. After dehydration and concentration at 90-120 ℃, the mixture is sent to three vacuum distillation towers for vacuum distillation. Fractions are cut according to different boiling points, and the finished products of monoethanolamine, diethanolamine and triethanolamine with purity of 99% can be obtained. In the reaction process, if the proportion of ethylene oxide is increased, the proportion of diethylamine and triethanolamine will increase, which can improve the yield of diethylamine and triethanolamine.
Refining method: the content of triethanolamine in industrial products is more than 80%, and the rest contains less than 1.0% water, less than 2.5% ethanolamine, 15% diethanolamine and a small amount of polyethylene glycol and other impurities. During refining, ethanolamine is removed by steam distillation, and sodium hydroxide is added to make triethanolamine precipitate into alkali metal salt. After separation, it is neutralized, and then purified by vacuum distillation.
It is refined and extracted by industrial triethanolamine vacuum distillation.
Synthesis of triethanolamine
1. Put ethylene oxide and ammonia into the reactor, conduct condensation reaction at reaction temperature of 30-40 ℃ and reaction pressure of 70.9-304kPa to produce mixed solution of monoethanolamine, diethanolamine and triethanolamine, and then dehydrate and concentrate at 90-120 ℃, and then send it to three vacuum distillation Chemicalbook columns for vacuum distillation. Cut off the fractions according to different boiling points to obtain finished products of monoethanolamine, diethanolamine and triethanolamine with purity of 99%. In the reaction process, if the proportion of ethylene oxide is increased, the proportion of diethylamine and triethanolamine will increase, which can improve the yield of diethylamine and triethanolamine.
2. It is formed by condensation reaction of ethylene oxide and ammonia at 30~40 ℃ and pressure of 71~304kPa, wherein the molar concentration ratio of ethylene oxide and ammonia is about 2.0. After reaction, it is obtained by vacuum distillation in the distillation tower, and the fraction near 360 ℃ is intercepted.
Triethanolamine has certain toxicity. Due to the low volatility of the product, the possibility of inhalation poisoning is small. However, dermatitis and eczema can be seen on the back of hands and forearms if the product is contaminated or contacted. Therefore, the skin of hands must be protected. Respiratory organs must be protected when aerosols are present. In synthetic fiber production and metal processing industry, exhaust devices should be installed in the production or storage and transportation sites of triethanolamine. Personal hygiene should be maintained. Wear protective equipment. Come to our website for more relevant content http://www.dbtg3h.com Ask!