Phase Transformation and Rheological Behaviour of Highly Paraffinic “Waxy” Mixtures

Authors

  • Dharmendra Tiwary,

    1. Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada T2N 1N4
    Current affiliation:
    1. Hyprotech Ltd., Suite 900, 125–9th Ave SW, Calgary, AB, Canada T2G 0P6
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  • Anil K. Mehrotra

    Corresponding author
    1. Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada T2N 1N4
    • Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada T2N 1N4
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Abstract

An experimental investigation was undertaken for the rheology and phase transformation of prepared solutions comprising a paraffin wax dissolved in n-dodecane or n-hexadecane. The liquid-solid phase transformation in wax-solvent mixtures was investigated through the measurement of wax appearance/disappearance temperature (using cross polar microscopy, differential scanning calorimetry, viscometry and a visual method), pour point temperature and crystallization temperature. The results were utilized to prepare a temperature-composition phase diagram for the wax+n-C16H34 pseudo-binary system. The effects of composition, temperature, cooling rate and shear rate were studied on the rheology of wax-solvent mixtures. A correlation was developed for the apparent viscosity of wax-solvent mixtures.

Abstract

On a entrepris une étude expérimentale de la rhéologie et du changement de phase de solutions préparées comprenant une cire de paraffine dissoute dans du n-dodécane ou du n-hexadécane. On a étudié le changement de phase liquide-solide dans ces mélanges cire-solvant en mesurant la température d'apparition/disparition de la cire (par microscopie polaire transversale, calorimétrie à balayage différentielle, viscométrie et par une méthode visuelle), la température du point d'écoulement et la température de cristallisation. Les résultats ont permis de préparer un diagramme température-composition pour un système pseudo-binaire cire + n-C16H34. On a étudié l'effet de la composition, de la température, de la vitesse de refroidissement et de la vitesse de cisaillement sur la rhéologie des mélanges cire-solvant.

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