In transportation and refining process of petroleum fluids solid wax phases may form at low temperature due to the presence of heavy paraffins. Wax precipitation in the oil transfer pipeline will lead to the blockage of the pipes and also a need to increase the required power for transferring oil fluids. Therefore, prediction of Wax Appearance Temperature (WAT) or Wax Disappearance Temperature (WDT) by using appropriate thermodynamic model has attracted considerable attention. Different thermodynamic models have been studied in order to predict these temperatures. In this paper, the predictive Wilson model has been used to predict WDT. In this model, a new equation has been used for estimation fusion temperature of hydrocarbons which resulted increased in the accuracy of calculating WDT in comparison with the previous works. This increase in the accuracy of calculations is more apparent in higher pressures. In this work, the WDT predictions in higher pressures showed 0.45 AAD%, while the error of the previous works for the predictive Wilson model is about o.8 AAD%.
