Comparison of Threshold Models of Hydrocarbon Fouling Formation in Preheaters of Distillation Columns

Hydrocarbon fouling of preheat exchangers causes several detrimental impacts on operation, environment, safety, as well as economy of oil refineries. To investigate threshold fouling models, a variety of hydrocarbon fouling data, such as temperature, oil flow, fluid properties, and geometries of such exchangers, has been gathered from the literature. The most accurate models for predicting the fouling rate are the Polley, Ebert, and Panchal models, with slopes of 0.352, 0.108, and 0.022, respectively, based on fitted curves on the computational fouling rates in terms of comparable experimental values. The sensitivity analysis indicates that the two factors that profoundly affect the fouling rate are the surface temperature and Reynolds number. Using the Polley's equation, the fouling rate in preheat exchangers may be predicted with the highest degree of accuracy, mean sensitivity analysis of 0.29, based on the consistency of calculated and experimental data.