Thermal and morphological evaluation of wax crystals: effect of solvent and wax concentration

by Viviane Karcher, Tayanne Santos Ligeiro, Ivanei Ferreira Pinheiro, Letícia Bizarre, Charlie Van Der Geest, Vanessa Guersoni, Antonio Carlos Bannwart, presented at Rio Oil & Gas 2022, September 2022.


Petroleum is a complex mixture of hydrocarbons varying from saturate, resins, asphaltenes and aromatics. Wax, also known as paraffin, normally refers to the range of n-alkanes in the crude oil with carbon numbers higher than 18. The waxes present in crude oils are divided into two categories: macrocrystalline wax, tends to form large plate-like crystals and, microcrystalline, tends to form solids with a lower degree of crystallinity. It has not been possible to establish a pattern that links the tendency of type of solvent and type of paraffin, due to the complexity of the wax crystal morphology. The objective of this research is to study the thermal properties of macro and microcrystalline paraffin under solubilization of several solvents through experimental techniques of DSC (Differential Scanning Calorimetry) and CPM (Cross Polarized Microscopy). The interaction of each type of n-paraffin in different solvents causes distinct influences on the crystal morphology and, consequently, influences on their thermal behavior. This study is relevant since elucidating this behavior helps to optimize deposition models and thus, define more effective mitigation resources in the problem of wax deposition.


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