Archives

  • 2018-07
  • 2018-10
  • 2018-11
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2019-11
  • 2019-12
  • 2020-01
  • 2020-02
  • 2020-03
  • 2020-04
  • 2020-05
  • 2020-06
  • 2020-07
  • 2020-08
  • HOAt Compared with the two former cases

    2020-07-30

    Compared with the two former cases (pure hydrocarbons and oil fractions), predicting water solubility in heavy crudes and bitumens is more challenging due to the complexity of their properties and high asphaltene content of these mixtures. In the case of heavy oils/bitumens + water binary mixtures, water solubility experimental data in Coalinga, Cat Canyon, Huntington Beach and Peace River bitumens [5] were investigated. Mw and SG of these crudes were measured by Ref. [5]. For these heavy crudes, Tb cannot be identified with precision and Tb was estimated using Soreide model [65]. Predicted values using adjusted and predicted are exhibited in Fig. 5. As before, the correlated cross-association volume parameter seems enough to properly predict the fluid phase behavior. Fig. 5 confirms that CPA can make an acceptable prediction of water solubility in heavy HOAt and bitumens in a wide range of temperatures suitable for thermal recovery applications. In the last and the most challenging part, three mixtures were selected to evaluate the reliability of the presented correlation and the CPA model. For Athabasca bitumen, Amani et al. [25] measured the experimental data at very high temperatures compared to the thermal recovery range up to 644 K (near the water critical temperature). Nonetheless, we used the correlation to estimate the cross-association volume parameter for this mixture. With regard to the high experimental error at elevated temperatures [55], evaluated values shown in Fig. 6 and AARD of 6.1% confirms that CPA can precisely estimate water solubility in Athabasca bitumen. Other mixtures that were considered to investigate the model performance include two mixtures of Athabasca bitumen + toluene + water [26]. As different amount of toluene were added to the mixture of Athabasca bitumen + water, the ternary mixtures had different properties. The hydrocarbon mixtures\' properties are taken from the literature [25]. Water solubility data for these two mixtures were measured with ∼30% uncertainty from 512 up to 573 K. Water solubility reported in Fig. 7 shows an acceptable and accurate prediction using predicted with correlation. The AARD for the ternary mixtures with the Mw of 127.2 and 171.6 is 8.2% and 11.6%, respectively. The presented correlation is specifically developed using water solubility in hydrocarbon rich phase experimental data, and one may not expect to obtain precise predictions for the hydrocarbon solubility in aqueous phase with the same parameters. The mutual solubilities of 1-octene and water [12] are illustrated in Fig. 8 to justify the performance of the model against experimental data. As shown, the water solubility data are in good agreement with the experimental data, while the hydrocarbon solubility data are poorly predicted. According to the results obtained, Periodicity of DNA is possible to predict the cross-association volume parameter of the CPA model using simple hydrocarbon\'s properties. In the last part, in order to improve the proposed correlation (equation (11)), all solubility data presented in Table 2 including three Athabasca bitumen mixtures are considered. The correlation for cross-association volume parameter using the entire set of data is: