Boundaries of Feasible Operating Regions

In addition to phase behaviour, it is also important to evaluate the density of the reaction mixture. This variable plays a major role in both reaction equilibrium and kinetics. The control of density is more complex in supercritical reactors, where it can change dramatically with small perturbations in temperature, pressure or composition. The more direct application of density, in the case of continuous reactors, is to calculate the residence time of the reaction mixture for a given operating pressure and temperature. It is important to keep in mind that the volumetric flow measured downstream of the reactor can be very different from the flow inside the reactor due to the high variability of the density at supercritical conditions. In the case of batch reactors there are two 

Neither the Group Contribution Association equation of state nor Soave-Redlich-Kwong equations of state with MHV2 mixing rules are recommended methods to prediet mixture densities. The Peng-Robinson equation of state with classical mixing rules is the more preeise model among the van der Waals family of equation of state to predict molar volumes of mixtures particularly when the volume eorrection has been used as proposed by Peneloux et 

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