Research And Development Of Hydrazine Hydrate Production Process

Hydrazine hydrate(N2H4·H2O), a kind of fine chemical product, is widely used.At present, the production process of hydrazine hydrate by urea method or the ketazine method is mainly applied in China. But as the former is behind the latter, it will be weeded out in the future. In the meantime, there are still some problems too difficult to solve in the ketazine method, which makes the technique dissatisfactory.On the basis of the existing ketazine method, this article is aimed at improving the technique and developing more optimized technique through the optimization of operating conditions, wastewater treatment and equipment improvement.First of all, according to the data of a chemical factory, which needs 20,000 tons/year(convert to 100% hydrazine hydrate) hydrazine hydrate for the manufacturing technique, the mathematical models were established using the chemical process simulation software Aspen Plus. And the hydrolysis tower mainly uses the reactive distillation model and chooses the ELECNRTL based on the properties of the involved material. At the same time, the ketazine not in the database was physically estimated.And then the whole process was simulated, results were basically consistent with the actual, and the yield was about 95%.Secondly, the sensitivity analysis of distillation tower and hydrolysis tower were simulated respectively. The change of such factors as stage number, feed stage and reflux ratio on the influence of the process were studied. The optimum operating conditions were determined, results were as follows. The distillation tower had 30 stages, with feed in the 9 stage, reflux ratio of 4, and side product at the 10 stage. The hydrolysis tower had 25 stages, with feed in the 12 stage, reflux ratio of 4. Then the whole process was simulated again in the operating conditions. The results showed that the hydrazine hydrate production was increased. Eventually the production of earning hydrazine hydrate(80%) was about 3144 kg/h, the yield was about 98.5%.Then, due to large amounts of by-product organic wastewater is difficult to deal with, a kind of organic wastewater treatment process which used high temperature and high pressure oxidation was put forward. The process was simulated and analyzed by Aspen Plus. The results showed that most of the organic were removed, theoretical conversion of the reaction was 100%, which proved the feasibility of the method theoretically. Then the reactor model was established by Fluent software. The fluidflow inside the reactor was simulated and analyzed. The results showed that the designment of the reactor was reasonable. The vapor phase and liquid phase touch each other and got in a continuous mixing, and then react.In addition, consider of the material leakage of distillation tower, a new type of distillation tower was designed to avoid the material leaked effectively, even the phenomenon of explosion.