Simulation And Optimization Of Process For Preparation Of Ethyleneamines From Ethylene Glycol

Ethylenediamine, diethylenetriamine, triethylenetetramine and the cyclic amine, such as piperazine, aminoethyl piperazine, hydroxyethyl piperazine etc, are collectively known as ethylenediamines. The main products of high additional value are ethylenediamine and piperazine. At the present stage of Chinese technologies about ethylenediamine and piperazine are still in a relatively backward state, the domestic enterprises have disadvantages of small scale, lack of funds, the energy consumption and outputs are not proportional as well as the purity of the product is low. Therefore, the main content of this thesis are the synthetic process of ethylenediamines and the separation of productions:1 Through the comparison of ethylenediamine synthetic processes, this thesis simulated the anaerobic and aerobic reaction process of ethylene glycol. The results showed that:the oxidation of alcohols on the thermodynamics was an unfavorable process, the heat release from the reaction of oxygen and hydrogen exceeded the heat release from glycol oxidation of aldehydes. The addition of oxygen could significantly shorten the reaction time and decrease the reaction temperature.2 Analyzed the theoretical basis of ethylenediamine-water azeotropic system of separation. Simulated and optimized the process of extractive distillation, azeotropic distillation, and double-effect distillation. The results showed that:The mass fraction of ethylenediamine of extractive distillation method was 98%, energy consumption of reboiler was 1258kw; the mass fraction of ethylenediamine of azeotropic distillation method was 99%, energy consumption of reboiler was 2280kw; the mass fraction of ethylenediamine of double-effect distillation method was more than 99.99%, energy consumption of reboiler was 72kw.3 The synthesis of piperazine by ethylene glycol and ethylene diamine required no precious metal; it can be manufactured in a continuous manner. This thesis simulated and optimized the synthesis of piperazine and the distillation of piperazine-water system. The results showed that:anhydrous piperazine was obtained by the method of azeotropic separation; the separating agent chosen cyclohexane, the mole flow rate of azeotropic agent was 17kmol/h. The mass fraction of piperazine was more than 98%, which achieved the requirement.In the synthesis of ethylenediamine and piperazine, ethylene glycol method was adopted instead of ethanolamine and dichloroethane method. This method has shortened production cycles and avoids the corrosion of the equipments. The pressure swing distillation separation of ethylenediamine provides a new idea for the purification of ethylenediamine, also it could greatly improve the efficiency of the column.