Safe optimization of 2-octanol oxidation and vinyl acetate emulsion polymerization

In this work the possibility to develop reliable optimization procedures, particularly suitable for full plant exothermic semibatch processes operated in the isoperibolic temperature control mode, has been investigated. It has been found that a general optimization procedure could be developed by using a particular curve, called topological curve, resulting from the numerical solution of the ordinary differential equation system describing the process dynamics. Such a curve exhibits a series of inversion points that represent, physically, transitions between different system thermal behaviour regions. The optimization procedure based on the analysis of the topological curve uses the QFS inversion as a boundary beyond which the optimum operating conditions can be searched accounting for reacting mixture thermal stability and desired productivity constraints. Experimental temperature vs. time data spring from laboratory studies of two different potentially runaway systems (the nitric acid oxidation of 2-octanol to 2-octanone and the free radical emulsion homopolymerization of vinyl acetate) have been modelled to demonstrate that the topological criterion for the QFS detection is independent of all the thermodynamic and process variables control equations used to describe the system. Such a result suggests that this approach could be safely used to optimize even processes operated at the full plant scale.