(85c) The Effect of Cyclic Molecules on the Gelation Characteristics of Polydisperse n-Alkane Systems
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Upstream Engineering and Flow Assurance Forum
Fundamentals and Applications of Flow Assurance
Monday, October 29, 2018 - 8:34am to 8:51am
Wax deposition in the pipelines is a very complex and costly problem present in the petroleum industry. In many cases, the major components of the wax are n-alkanes. However, other components in the crude oil can also influence the gelation properties. Although a significant amount of
research has been done on the effects of asphaltenes, resins and n-alkanes on crude oil gelation, the role of aromatics in wax gelation has been less explored. To gain more fundamental insights on n-alkane gelation, the effects of cyclic molecules on n-alkane gelation were studied. Model waxes composed of one or two alkanes selected from three n-alkanes C28, C32 and C36, were mixed with either a single-ringed aromatic compound durene and polycyclic compound phenanthrene in a dodecane (C12) solvent. Rheometry experiments using oscillatory stress and specified cooling rate was used to assess the gel points of each model oil sample. Based on the gel point results, it was found that solubility, molecular size and amount each species in the model oil all influence the gelation, both individually and together. The least
soluble species that crystallized first usually determined the gelation in terms of gel points. However, the molecular size difference can have an influence on the dispersant effect that can hinder gelation for polydisperse n-alkane systems. It is hypothesized that the aromaticity plays an
important role in the gelation process by fostering the self-aggregation of shorter-chained n-alkanes, preventing them to interact with longer-chained alkanes.
research has been done on the effects of asphaltenes, resins and n-alkanes on crude oil gelation, the role of aromatics in wax gelation has been less explored. To gain more fundamental insights on n-alkane gelation, the effects of cyclic molecules on n-alkane gelation were studied. Model waxes composed of one or two alkanes selected from three n-alkanes C28, C32 and C36, were mixed with either a single-ringed aromatic compound durene and polycyclic compound phenanthrene in a dodecane (C12) solvent. Rheometry experiments using oscillatory stress and specified cooling rate was used to assess the gel points of each model oil sample. Based on the gel point results, it was found that solubility, molecular size and amount each species in the model oil all influence the gelation, both individually and together. The least
soluble species that crystallized first usually determined the gelation in terms of gel points. However, the molecular size difference can have an influence on the dispersant effect that can hinder gelation for polydisperse n-alkane systems. It is hypothesized that the aromaticity plays an
important role in the gelation process by fostering the self-aggregation of shorter-chained n-alkanes, preventing them to interact with longer-chained alkanes.