OP-II-3

PP-II-54Polymerization in reactors R200, R201 and R202 proceeds in the environment ofliquid phase with hydrogen addition. Co-polymerization reaction proceeds in the gasphasereactor on "living" polymer with ethylene and propylene. Contact time is120 minutes.The change of transformation degree onto the reactors cascade is constructed onthe basis of computer model. Also the temperature profile on the reactors cascade isconstructed (fig. 2). The isothermal mode is supported.Fig. 2 The transformation degree and the temperature profile on the reactors cascadeThe pre-polymerization proceeds under the lower temperature because a part ofthe active centers is deactivated irreversible under the raised temperature.Catalyst introducing into a reaction zone at polymerization temperature 70°Сleads to the formation of polypropylene with the lowered bulk density. The possiblereason of this phenomenon is partial or a final fracture of a catalyst particle during theintensive beginning of polymerization.The catalyst introducing into polymerization phase under the lowered temperatureand the carrying out pre-polymerization under the soft conditions provide thedemanded bulk density of polypropylene. The temperature into R201 and R202reactors is supported at level 70°С.On the basis of computer experiments the dependence of the gas phasecomposition is constructed at temperature change in liquid-phase reactors. Undertemperature 75°С the propylene passes from a liquid phase in the gaseous one.432