Advanced Process Control Technology And Application Research At Acrylo-Nitrile Plant

Acrylo-Nitrile(AN) is China’s second big derivatives, it is the important monomer synthesis, with the broad prospect, mainly uses the ammonia oxidation production, including reactor, distillation column and so on. In the process of operation, there exists reactor temperature is not stable, recycling acrylonitrile energy consumption; acetonitrile column can not be controlled.About the problem of the reactor part, this paper created the soft sensor model of AN yield by Aspen IQ technology, and developed the Advance Process Control reactor model based on DMCPlus software, Those steps increased the acrylonitrile yield of the reactor, reduced the disturbance of "U" tube switching; About the major energy consumer recovery column, this paper optimized the operation of recycle column, and reduced the dosage of low pressure steam; The project also decreased the work load of operation staffs at the ACN unit.This project used the DMCPlus software of the Aspen, the communication with DCS is based on the OPC technology. After the implementation of the project, the reactor feed load increased from103%to105%, the acrylonitrile yield of reactor units achieved good optimization control and the yield increased obviously by the previous80.523, to80.641; The reactor temperature fluctuations reduced significantly, and the standard deviation reduced from0.725223to0.227269; Recovery tower of low pressure steam consumption reduced1.912tons/hour. Acetonitrile column occupied50%working time of operation staff, and partly took over by advanced control system, the effect is obvious. This project investment recovery period is three months, the annual economic benefits about7.8779million yuan. Therefore, the design scheme is feasible, project is successes.