Piperazine

The paper has reviewed physical and chemical properties, production status and related uses of piperazine. Based on consulting the domestic and international reference documents, deamination of ethylenediamine on normal pressure is determined by a comparison of processes available. Modified Ca-ZSM-5 zeolite catalysts are prepared with the method of ion-exchange. The effects of the ratio of silicon to aluminum, ions used to exchange and preparation conditions on the reaction was discussed in quantity. Then monofactor method and multifactor orthogonalizing design method are applied to get the optimum processing conditions in preparation of piperazine. After that the macrokinetics model on the gas-liquid reaction is established based on related theories. Finally, the economic analysis on production of 300t/a piperazine was made on the basis of the results in the experiment.The following have been obtained through lots of experiments.1. Higher activity and selectivity of Ca-ZSM-5 catalyst prepared by the methodof ion-exchange was obtained. The optimum conditions for preparing catalysts: H-ZSM-5 zeolite catalysts with the ratio of silicon to aluminum 50; infused for 48 hours at 25℃ in 1.0mol/L CaCl2; dried for 3 hours at 110℃; activated for 6 hours at 500℃.2. The optimum processing conditions: the concentration of EDA 40%(mass fraction); reaction temperature 360±5℃; space velocity 0.016mol.g-1.hr-1. In these conditions, the conversition of EDA is 95.30%, the yield of PA is 65.44%, the yield of TEDA is 25.66% and the total is 91.10%. At the same time, the purity of PA is 99.3% and the purity of TEDA is 98.4%.3. The study of macrokinetics shows that the apparent reaction kinetics is approximately in 1.45-order. The established model in 330℃-360℃ is as follow:4. It is possible to synthesize piperazine using EDA as raw material. The economic analysis on production of 300t/a piperazine shows that the process has great social and economic benifits.