Determination of Wax Precipitation Temperature and Amount of Precipitated Solid Wax versus Temperature for Crude Oils Using FT-IR Spectroscopy

Abstract

Wax precipitation in crude oils can produce problems in production and transportation operations. A novel FT-IR spectroscopy method is described for the determination of the wax precipitation temperature (WPT), and the estimation of the amount of precipitated solid wax material (both crystalline and amorphous) present in petroleum crude oils. A reference model oil system is analyzed using the described method. Comparisons are provided between FT-IR generated data and data generated using conventional analyses for Alaska North Slope, Utah, and Gulf of Mexico crude oils. The FT-IR method is shown to provide comparative results with conventional analysis methods, and offers several advantages over existing test methods.

Experimental and Modeling Studies of Wax Deposition in Crude-Oil-Carrying Pipelines

“…The Wax Appearance Point (WAP) and the wt-% solids versus temperature were obtained by using a novel FTIR technique [1].…”

Experimental investigation and thermodynamic modeling of wax disappearance temperature for n-undecane+n-hexadecane+n-octadecane and n-tetradecane+n-hexadecane+n-octadecane ternary systems

“…On the basis of the applications, researchers have measured WAT and WDT using different measurement techniques like cross polar microscopy [12], acoustic measurements [13] and FT-IR spectroscopy [14] and/or proposed thermodynamic models to predict the thermodynamic behavior of multi-component systems. For example, Coto et al [15] checked a procedure to study wax precipitation from petroleum mixtures based on the use of DSC technique.…”

Wax Deposition and Fouling

“…There are several methods of determination the point of wax precipitation from crude oil such as gravimetric, fractional precipitation, gas chromatographic, infrared (IR) spectroscopy, viscometer, cross-polarized microscopy, differential scanning calorimetry, and by centrifugation, which are dependent on the separation of waxes from crude by means of mixing the crude with or without solvent then decreasing the temperature of the mixture to precipitate the wax then separate it by filtration (Lira-Galeana and Hammami, 2000;Roehner and Hanson, 2001).…”