ABSTRACT
Material and energy balances were needed for a liquid phase phthalic anhydride plant. The unit operations included a simultaneous reaction and phase equilibrium, recovery operations, three phase flashes, and purification towers. Inasmuch as the project was in the process development phase, considerable interaction between the design effort and the pilot plant work was anticipated, therefore a process simulation appeared to be justified. An in-house process simulator was to be used. The most difficult problem in this development was the estimation of activity coefficient parameters. The group contribution approach was used to estimate binary parameters for mixtures of minor importance. There are a great many systems in the chemical industry which are composed exclusively of nonelectrolytes and which operate at moderate pressures. However, those simplifications quite often are negated by the presence of highly non-ideal mixtures and the very many components.
