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

Abstract

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.