PREDICTIVE LOCAL COMPOSITION MODELS FOR SOLID LIQUID EQUILIBRIUM IN N-ALKANE SYSTEMS - WILSON EQUATION FOR MULTICOMPONENT SYSTEMS/

The predictive local composition model is applied to multicomponent hy drocarbon systems with long-chain n-alkanes as solutes. The results sh ow that it can successfully be extended to high-order systems and accu rately predict the solid appearance temperature, also known as cloud p oint, in solutions of known composition using only binary information. The model can describe the experimentally well-known capacity of heav y alkanes to act as cloud-point depressants and explains it in terms o f the nonideality of the solid solutions formed. There are good indica tions that no significant error is introduced by considering the multi ple orthorhombic phases as a single phase. It is shown that for low co ncentrations in heavy fraction the interaction parameter alpha(1s) can be neglected and thus the model becomes purely predictive.