Pilot Study, Anhydrous Piperazine

Piperazine is an important pharmaceutical intermediate and raw material of fine chemicals. Conducting research and development on synthesis of piperazine could not only economize foreign exchange,but also promote the development of Medicine, Pesticides and other related Industries in China.This paper first introduces the synthetic methods of anhydrous piperazine used home and aboard,which have been industrialized or have the prospect of industrialization.Then gives a short brief to the small scale technology which the pilot project adopted.Secondly, based on the data of small scale production and the requirements of industrial design, the pilot scale design of anhydrous piperazine with an annual production of 23 tons is carried out, including the simulation and technological calculation of production process, the design and the mode selection of each equipment and the arrangement of workshop and facilities and so on. According to the design requierment and the computing results,we draw out the flow chart, the equipment chart and the plant arrangement chart.According to the results of the pilot scale design, equipment installation were completed and the pressure and leak etc. were tested during commissioning. Before set the machine in operation, pipes and tanks were all cleaned and purged. During operation, improvements and optimizations to the technological process and equipment were taken against all the problems emerging. On this basis, studied the scale-up effect and found out the optimum operating conditions in this pilot scale conditions.The main results are included as follow:①Fixed the matured and complete industrial process route of the synthesis of piperazine, including production process and utility system.②Because the scale-up effect is mainly displayed by space velocity, the space velocity of pilot scale has greater improvement than the small scale, but the reaction temperature and the concentration of EDA was close to the results of small scale, the pilot scale test showed.③The optimum processing conditions under pilotscale conditions:the concentration of EDA 50%(mass fraction), reaction temperature 360℃, space velocity 30L/h. In these conditions, the conversion of EDA is 91.19%, the yield of PA is 65.34%, the yield of TEDA is 25.74%.