Use of gPROMS in the Dynamic Modeling of Polymerization Reactors

ASTEASUAIN, MARIANO; TONELLI, S.; BANDONI, ALBERTO; BRANDOLIN, ADRIANA

Florianópolis

Congreso; II Congreso de Ingeniería de Procesos del Mercosur (ENPROMER ?99); 1999

Here we present a dynamic model for the high pressure ethylene polymerization. High pressure polymerization of ethylene to produce low-density polyethylene is a highly complex process, carried out under rigorous operating conditions. Mathematical models allow to study safely and economically the influence of the different design and operative variables on production and product quality. Several authors have presented different models dealing with the stationary state of this process. However, there is hardly any bibliography about the dynamic behavior of this reactor. A dynamic model is indispensable to study the cyclic pressure pulse, startup and shutdown strategies and optimization. The simulation tool we used is the gPROMS package (generalized PRocess Modeling System), which is an equation oriented dynamic simulator. In gPROMS, each operation unit model contains all the information regarding physicochemical behavior of the equipment. On the other hand, external actions over the unit are declared independently. This allows to use the same model when the equipment is repeated several times within the same process. Taking advantage of this property, the reactor was simulated as a series of tubular reactors. Each link of the chain represents a division in the whole reactor due to a different jacket temperature or a lateral feed.