Experimental Determination and Characterization of Wax Fractions Precipitated as a Function of Temperature

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• 作者：Carmen Martos ; Baudilio Coto ; Juan J. Espada ; Mar&#xed ; a D. Robustillo ; Susana Gó ; mez ; José ; L. Peñ ; a
• 刊名：Energy & Fuels
• 出版年：2008
• 出版时间：March 2008
• 年：2008
• 卷：22
• 期：2
• 页码：708 - 714
• 全文大小：222K
• 年卷期：v.22,no.2(March 2008)
• ISSN：1520-5029

文摘

Wax precipitation at low temperatures in petroleum mixtures is one of the most important problems in flow assurance. Experimental quantification of such processes and the further characterization of the precipitated mixtures are very difficult and extremely time-consuming, and therefore, the available experimental information is scarce and usually not very confident. In this work, wax samples were precipitated from two crude oils at different temperatures and they were characterized by optical microscopy, elemental analysis, ¹H NMR spectroscopy, differential scanning calorimetry (DSC), and mass spectroscopy. The obtained results show the presence of different compounds in such mixtures regarding the chemical nature of the crude oil. The well-known presence of soaked crude oils in the precipitated fractions was experimentally estimated from ¹H NMR and mass spectroscopy, and the obtained results suggest a decrease in the soaked crude oil amount as the precipitation temperature becomes lower, in agreement with the qualitative paraffinic content determined by elemental analysis. These values were used to correct the amount of solid wax precipitated experimentally and the final comparison between such corrected values and the precipitation curve calculated from DSC results shows a good agreement within the high experimental uncertainties.