چكيده به لاتين
Wax precipitation phenomenon is one of the most severe problems that cause the clogging of surface production and transportation facilities. Several experiments and thermodynamic models are developed to prevent such incidents from happening. Paraffinic hydrocarbons play a pivotal role in the Wax precipitation process. However, the majority of the models do not differentiate between precipitating compounds based on their paraffinic, naphthenic, and aromatic distribution, and this leads to the overestimation or underestimation of Wax precipitation parameters. First, the Wax precipitation data of three synthetic mixtures from Pauly et al. are estimated, and the modeling results are compared to the predicted results of Dalirsefat and Feyzi and Schou Pedersen et al. Also, two crude oil samples with Paraffin, Naphthene, and Aromatic (PNA) content from Pan et al. [4] are used for evaluation. Finally, the suggested model is used to calculate weight percent of precipitated Wax and Wax appearance temperature (WAT) of six crude oil samples from North Sea. The calculated predictions of the suggested model are compared to the works of Schou Pedersen et al., Lira‐Galeana et al., and Bagherinia et al.. The deviations for WATs and precipitation amounts from experimental data are lower compared to previous studies. The average absolute deviation for precipitated Wax weight of the North Sea samples is 0.19 in comparison to 0.61, 0.33, and 0.4 of Schou Pedersen et al., Lira‐Galeana et al., and Bagherinia et al., respectively. Furthermore, we employed a predictive Paraffin, Naphthene, and Aromatic (PNA) estimation technique to divide the petroleum cuts. This characterization method prevented the implementation of average properties for petroleum fractions. A sequential multi-solid framework is selected for the Wax precipitation analysis. The perturbed chain statistical association fluid theory (PC-SAFT) equation of state (EOS) is utilized for the determination of liquid properties. The binary interaction coefficients of non-paraffin hydrocarbons are modified by an adjustable variable to improve the accuracy of the model for the calculation of Wax weight and Wax appearance temperature (WAT). Five crude oils from the North Sea are elected to check the reliability of the proposed model. The contribution of each precipitating hydrocarbons is investigated, and the results depict a considerable improvement in comparison to previous studies. The calculated WAT presents a negligible deviation from the measured data. Moreover, the outcome of our work is compared to models of Lira Galeana, et al. and Bagherinia, et al. The average estimation error of Wax weight for all crude oils is about 0.18, while this value increases to 0.36 and 0.38 for the works of Lira Galeana, et al. and Bagherinia, et al .
