Modeling multicomponent wax deposition and aging on cold surfaces with application to pipeline fouling

AbstractA multicomponent model is developed for wax deposition onto a cold finger from a stirred wax-containing oil. It utilizes Coutinho's thermodynamic equations for wax component concentrations and energy and mass transport equations within the deposit and from the oil and is the first cold-finger model to predict both deposit thickness growth and aging by selective precipitation of heavier wax components. While it captures well deposit thickness growth, it requires preventing re-dissolution of deposited wax to avoid shrinkage not observed in experiments. The model predicts deposit aging reasonably well but with quantitative deviations for the heavier wax of up to a factor of two. Possible explanations include the inadequacy of Hayduk-Minhas and Cussler's hindered-diffusion models to the soluble multicomponent wax diffusivities. Using pseudo two- and one-component representation can reasonably predict the deposit thickness and aging of multi-component deposits. This work shows an improved approach to modeling wax deposition and aging.

Source: AIChE Journal - February 16, 2024 Category: Science Authors: Samuel A. Ogunwale, Luqman Hakim Ahmad Mahir, Ronald G. Larson Tags: RESEARCH ARTICLE Source Type: research