Abstract
Local composition models (UNIQUAC, Wilson and NRTL) and regular solution models (Won and Pedersen) were applied to predict the cloud point temperature of systems with n-alkanes and acceptable results were obtained by these models. The prediction of wax formation and the composition below cloud point temperature were done by UNIQUAC model using two different structural parameter for solid phase activity coefficient (UNIQUAC10 and Coutinho 2000). The results that are more accurate for calculating the wax content and the composition at different temperatures below cloud point were obtained using UNIQUAC10.