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Figure 2. CAPE-OPEN conceptual approach THERMODYNAMIC APPROACH Asphaltene precipitation has been proved to be a difficult problem to define and study. In such a case, models are needed based on theoretical considerations and experimental results, which can help in the prediction of asphaltene precipitation. sphaltene precipitation has been proved to be a difficult

Figure 2 CAPE-OPEN conceptual approach THERMODYNAMIC APPROACH Asphaltene precipitation has been proved to be a difficult problem to define and study. In such a case, models are needed based on theoretical considerations and experimental results, which can help in the prediction of asphaltene precipitation. sphaltene precipitation has been proved to be a difficult

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Figure 1. Interaction between components In this sense, the main objective of the CAPE-OPEN project is to allow process simulator components to be replaced for others from independent sources, which are part of another application, or software components developed by third parties, focused on its scope of standards for communication interfaces between software components of and process simulators.
Figure 1. Interaction between components In this sense, the main objective of the CAPE-OPEN project is to allow process simulator components to be replaced for others from independent sources, which are part of another application, or software components developed by third parties, focused on its scope of standards for communication interfaces between software components of and process simulators.
Figure 3 shows a scheme to visualize the mechanism of asphaltene precipitation according to groups’ of thermodynamic models. Figure 3. Mechanism of asphaltene precipitation Solubility models assume that asphaltenes are dissolved in the crude oil. This equilibrium can be solid-liquid (S-L) or liquid- liquid (L-L) type. In the S-L type, precipitated asphaltene is treated as a single component residing in the solid phase, while oil and gas phases are modeled with a cubic equation of state (EOS). Nghiem et al. (1996) proposed their model by considering the precipitated asphaltene as a pure dense phase, while the heaviest component in the oil can be split into two parts: non-precipitating and _ precipitating (asphaltene) components. However, asphaltenes are solids with no defined melting point. Asphaltenes are molecules with high solubility parameters and moderately high molar masses. Having a high aromatic content, they form true solutions in aromatic solvents. However, since their molar masses are moderately high, the entropy of mixing is not sufficient to keep them in solution if the interaction with the remainder of the solution becomes unfavorable, such as upon addition of an aliphatic fluid, according to Sirota (2005). The phase separation which results is thermodynamically a Liquid-Liquid phase separation which can be understood in the context of solution theory of molecules.
Figure 3 shows a scheme to visualize the mechanism of asphaltene precipitation according to groups’ of thermodynamic models. Figure 3. Mechanism of asphaltene precipitation Solubility models assume that asphaltenes are dissolved in the crude oil. This equilibrium can be solid-liquid (S-L) or liquid- liquid (L-L) type. In the S-L type, precipitated asphaltene is treated as a single component residing in the solid phase, while oil and gas phases are modeled with a cubic equation of state (EOS). Nghiem et al. (1996) proposed their model by considering the precipitated asphaltene as a pure dense phase, while the heaviest component in the oil can be split into two parts: non-precipitating and _ precipitating (asphaltene) components. However, asphaltenes are solids with no defined melting point. Asphaltenes are molecules with high solubility parameters and moderately high molar masses. Having a high aromatic content, they form true solutions in aromatic solvents. However, since their molar masses are moderately high, the entropy of mixing is not sufficient to keep them in solution if the interaction with the remainder of the solution becomes unfavorable, such as upon addition of an aliphatic fluid, according to Sirota (2005). The phase separation which results is thermodynamically a Liquid-Liquid phase separation which can be understood in the context of solution theory of molecules.
Table 1. Adjustable functional Parameters In respect to Equation 1, the weight fraction of asphaltene
Table 1. Adjustable functional Parameters In respect to Equation 1, the weight fraction of asphaltene
Where X is described as following equation: PROCEDURES
Where X is described as following equation: PROCEDURES
methods required in such unit operation. Figure 5 describes the
methods required in such unit operation. Figure 5 describes the
Table 3. Solubility parameters and molar masses for several solvents Sequence of calculation for the empirical model described
Table 3. Solubility parameters and molar masses for several solvents Sequence of calculation for the empirical model described
Bitumen/Heavy Oil MW? ,¢ (g/mol)
Bitumen/Heavy Oil MW? ,¢ (g/mol)
Table 4. Mole fraction of component in crude oil RESULTS AND DISCUSSION
Table 4. Mole fraction of component in crude oil RESULTS AND DISCUSSION
Figure 6. Activity diagram predict asphaltene precipitation regarding to its proper operation was verified. The experimental data of asphaltene precipitation for an oil sample reported in Nikookar et al. (2008) are used in this validation. The composition of 011 sample is shown in Table 4.
Figure 6. Activity diagram predict asphaltene precipitation regarding to its proper operation was verified. The experimental data of asphaltene precipitation for an oil sample reported in Nikookar et al. (2008) are used in this validation. The composition of 011 sample is shown in Table 4.
Figure 8 shows the validation of the communication performed between PRO/II, a commercial simulator, and developed module. Figure 8. “asphaltine” seen from PRO/II Figure 9 shows the calculation interface for selecting solvent and functional parameter model of "asphaltine" from COCO Simulator. Figure 7. “asphaltine” seen from COCO Simulator
Figure 8 shows the validation of the communication performed between PRO/II, a commercial simulator, and developed module. Figure 8. “asphaltine” seen from PRO/II Figure 9 shows the calculation interface for selecting solvent and functional parameter model of "asphaltine" from COCO Simulator. Figure 7. “asphaltine” seen from COCO Simulator
As shown in Figure 7, COCO Simulator, cost-free application to model chemical process at steady state, is used as a simulation environment to perform validation and testing of “asphaltine”. As shown in Figure 7, COCO Simulator, cost-free application
As shown in Figure 7, COCO Simulator, cost-free application to model chemical process at steady state, is used as a simulation environment to perform validation and testing of “asphaltine”. As shown in Figure 7, COCO Simulator, cost-free application
Figure 10 shows the calculation interface for selecting solvent and functional parameter model of "asphaltine" from PRO/II. Figure 10 shows the calculation interface for selecting solvent
Figure 10 shows the calculation interface for selecting solvent and functional parameter model of "asphaltine" from PRO/II. Figure 10 shows the calculation interface for selecting solvent
Figure 10. “asphaltine” calculation interface seen from PRO/II Figure 11 shows an example of a report generated by "asphaltine" as a HTML file extension for the calculation of the asnhaltene fraction usine the method described.
Figure 10. “asphaltine” calculation interface seen from PRO/II Figure 11 shows an example of a report generated by "asphaltine" as a HTML file extension for the calculation of the asnhaltene fraction usine the method described.
In the preceding table, it can be observed that incorporated model as a software component called “asphaltine” is reproducible in the simulator, showing its corresponding deviations respect to experimental data. In the preceding table, it can be observed that incorporated Table 5. Comparison between values of asphaltene
In the preceding table, it can be observed that incorporated model as a software component called “asphaltine” is reproducible in the simulator, showing its corresponding deviations respect to experimental data. In the preceding table, it can be observed that incorporated Table 5. Comparison between values of asphaltene
sphaltene precipitation obtained from experimental data and
sphaltene precipitation obtained from experimental data and
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