MODELING AND CONTROL OF AN AUTOREFRIGERATED CSTR POLYMERIZATION REACTOR: IMPACT OF THE NON-CONDENSABLE GASES

Resumo

The concept of process intensification is applied to a CSTR polymerization reactor, where bulk reactions take place via styrene free-radicals, connected to a semi-flooded horizontal condenser; the aim is to operate the system in a safe and efficient way. The results obtained show that the developed model was able to reproduce the major dynamic characteristics, even with the presence of non-condensable gases. The existence of such gases prevents the reactor from ever reaching a steady-state, as they accumulate in the system, increasing the condenser pressure and the reactor temperature and reducing the contact area and the mass of liquid in the condenser. To overcome this problem, the control strategy of this work proposes a regular purge of the condenser gases in order to avoid a collapse of the system. In this context, different control algorithms were also analyzed and it was concluded that a fast and reliable control of the reactor is only possible when advanced controllers are used.