Abstract
In this paper, we present an application of particle size distribution (PSD) simulation technique to the crystallization process in a large-scale Purified Terephthalic Acid (PTA) plant. The crystallization process in the PTA plant employs a multistage continuous crystallizer. Each stage is a stirred tank crystallizer, which is modeled using several compartments. The flow rates between compartments and mean velocity in each compartment were estimated from computational fluid dynamics (CFD) simulation of fluid flow in the crystallizers. The primary and secondary nucleation and size independent crystal growth were modeled while agglomeration and breakage were neglected. The parameters in the nucleation and growth rate equations were determined from the plant data. The model developed takes into account different crystallizer configurations (crystallizer scale, feed and withdrawal position, etc) and different operating conditions (feed rate, mean residence time, pressure, etc).
