The Dynamic Simulation Of O-Xylene Oxidation To Phthalic Anhydride

Phthalic anhydride, a chemical of considerable importance, is mainly used in chemical, medicine, electron, agriculture and dope industry. This paper presents a dynamic simulation system of PA devices which are in alkene factory of Qilu petrifaction. We simulate the process of starting and stopping, the operations under normal and abnormal conditions with a super real time speed for the first time.It is a very complex reaction system of o-xylene oxidation to phthalic anhydride, therefore we predigest the reaction network. According to technology of BASF, the reaction network and kinetics were determined in the present investigation.The oxidation reactor is simplified into six CSTR which is linked one by one. We can observe the dynamic responds in the reactor bed clearly. The results of simulation are consistent with practical data, which proves that the model can be used in diverse conditions.In flash calculation, a constant volume flash model which suits to dynamic simulation has been adopted. It uses "Inside-Out" approach to determine phase equilibrium parameters, which not only guarantees the accuracy and stability , but also improves the speed of calculation.Finally we successfully use Euler method to calculate diferential ations.