کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1743039 | 1521990 | 2014 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Modeling of the NH3–CO2–H2O vapor–liquid equilibria behavior with species-group Pitzer activity coefficient model Modeling of the NH3–CO2–H2O vapor–liquid equilibria behavior with species-group Pitzer activity coefficient model](/preview/png/1743039.png)
• Application of the species-group Pitzer activity coefficient model.
• A new set of regressed parameters and validation of the thermodynamic model.
• The method for enthalpy calculation.
The vapor–liquid equilibria (VLE) model of the NH3–CO2–H2O system is crucial to the ammonia-based CO2 capture processes simulation and the proposition of innovation processes. Though traditional VLE models could describe the behavior of this system, they are always suffering too many regressed parameters and, more serious, the number of these parameters increases with the number of real species in the solution raised to the power of higher than 2. To conquer this problem, an upgraded thermodynamic model of the NH3–CO2–H2O system with the species-group Pizter activity coefficient model has been developed on the basis of the original model proposed by Krop (1999). Comparing with the commonly used activity coefficient models such as E-NRTL, extended UNIQUAC and original Pitzer model, the species-group Pizter activity coefficient model relates the parameters to the groups of species instead of real species in the solution, leading to significantly reducing the number of regressed parameters and simplifying the calculation. However, in the original model, the precipitation was not considered, which makes the validity of the model questionable, and the calculation of enthalpy, great importance for CO2 emission abatement processes, was also not taken into account. Therefore, in this work, the solid–liquid equilibria (SLE) of the NH4HCO3–H2O system were employed in the upgraded model to represent the precipitation and a new set of parameters were refitted against VLE data with genetic algorithm. The results indicate that this simplified thermodynamic model could satisfactorily describe the thermodynamic behavior of the NH3–CO2–H2O system.
Journal: International Journal of Greenhouse Gas Control - Volume 31, December 2014, Pages 113–120