Abdelhakim BEGAR, Cherif SAİB, Mohamed-saïd CHEBBAH

Use of Pitzer’s model to calculate thermodynamic properties of aqueous electrolyte solutions of sulfuric acid

Over this study we calculated the coefficients of activity of different species and the concentration in the presence of H+ ion when H2SO4 is alone in solution. The coefficient of average activity was calculated using the model of Pitzer. The constants of dissociation of these reactions were calculated from the values of the free standard energies. The reaction reaches a balance while producing H+, HSO4- and SO42-. The research reported here concentrated on the effect of some important operational parameters on dissolution process. The parameters were investigated and their ranges are as follows: initial molality ranging from 0.001 to 5 mol.kg-1 and temperatures between 25 and 200°C. Fortran 90 (Mathematical formula translating system) was used to perform all mathematical calculations. The numerical code can be used to calculate the molarity of ion H+ of an aqueous solution of sulfuric acid. The objective of the present work is to optimize the parameters of leaching such as activity of sulfuric acid on the dissociation phenomena.

Keywords:

Leaching, Pitzer Activity, Dissociation, Molality,

PDF

___

1. Campbell DM, Millero FJ, Roy R, Roy L, Lawson M, Vogel KM, et al. The standard potential for the hydrogen-silver, silver chloride electrode in synthetic seawater. Mar Chem. 1993 Dec 1;44(2–4):221–33.
2. Waters JF, Millero FJ. The free proton concentration scale for seawater pH. Mar Chem. 2013 Feb 20;149:8–22.
3. Clegg SL, Whitfield M. A chemical model of seawater including dissolved ammonia and the stoichiometric dissociation constant of ammonia in estuarine water and seawater from −2 to 40°C. Geochim Cosmochim Acta. 1995 Jun 1;59(12):2403–21.
4. Chihara K, Suzuki ; Finlayson M, Knaehel BA, Hill ; Knoblauch FB, Mitchell K, Shendalman ; Shendalman LH, et al. An NRTL model for representation and prediction of deviation from ideality in electrolyte solutions compared to the models of Chen (1982) and Pitzer (1973). AIChE Journal [Internet]. 1985 Mar 1 [cited 2023 May 23];31(3):392–9.
5. Ball F ‐X, Planche H, Fürst W, Renon H. Representation of deviation from ideality in concentrated aqueous solutions of electrolytes using a mean spherical approximation molecular model. AIChE Journal [Internet]. 1985 Aug 1 [cited 2023 May 23];31(8):1233–40.
6. Pitzer KS, Roy RN, Silvester LF. Thermodynamics of Electrolytes. 7. Sulfuric Acid. J Am Chem Soc [Internet]. 1977 [cited 2023 May 23];99(15):4930–6.
7. Pitzer KS, Mayorga G. Thermodynamics of electrolytes. III. Activity and osmotic coefficients for 2-2 electrolytes. J Solution Chem [Internet]. 1974 Jul [cited 2023 May 23];3(7):539–46.
8. Bradley DJ, Pitzer KS. Thermodynamics of electrolytes. 12. Dielectric properties of water and Debye-Hückel parameters to 350 °C and 1 kbar. Journal of Physical Chemistry [Internet]. 1979 [cited 2023 May 23];83(12):1599–603.
9. Rogers PSZ, Pitzer KS. High-temperature thermodynamic properties of aqueous sodium sulfate solutions. Journal of Physical Chemistry [Internet]. 1981 [cited 2023 May 23];85(20):2886–95.
10. Pitzer KS, Raton B, Arbor A, London B. Activity Coefficients in Electrolyte Solutions 2nd Edition.
11. Greenberg JP, Møller N. The prediction of mineral solubilities in natural waters: A chemical equilibrium model for the Na-K-Ca-Cl-SO4-H2O system to high concentration from 0 to 250°C. Geochim Cosmochim Acta. 1989 Oct 1;53(10):2503–18.
12. Zemaitis Jr JF, Clark DM, Rafal M, Scrivner NC. Handbook of Aqueous Electrolyte Thermodynamics: Theory & Application.
13. Harvie CE, Weare JH. The prediction of mineral solubilities in natural waters: the NaKMgCaClSO4H2O system from zero to high concentration at 25° C. Geochim Cosmochim Acta. 1980 Jul 1;44(7):981–97.
14. Archer DG. Thermodynamic Properties of the NaCl+H 2 O System l. Thermodynamic Properties of NaCl(cr). Aqueous Sodium Chloride Solutions Journal of Physical and Chemical Reference Data [Internet]. 1992 [cited 2023 May 23];21:15.
15. Pitzer KS, Simonson JM. Thermodynamics of multicomponent, miscible, ionic systems: Theory and equations. Journal of Physical Chemistry [Internet]. 1986 [cited 2023 May 23];90(13):3005–9.
16. Sippola H. Critical evaluation of the 2nd dissociation constants for aqueous sulfuric acid. Thermochim Acta. 2012 Mar 20;532:65–77.
17. Thermodynamic Dissociation Constant of the Bisulfate Ion from Raman and Ion Interaction Modeling Studies of Aqueous Sulfuric Acid at Low Temperatures | The Journal of Physical Chemistry A [Internet]. [cited 2023 May 23].
18. Pitzer KS. Activity Coefficients in Electrolyte Solutions. Activity Coefficients in Electrolyte Solutions. 2018 May 4;
19. Que H, Song Y, Chen CC. Thermodynamic Modeling of the Sulfuric Acid−Water−Sulfur Trioxide System with the Symmetric Electrolyte NRTL Model. J Chem Eng Data [Internet]. 2011 Apr 14 [cited 2023 May 23];56(4):963–77.
20. Sippola H. Thermodynamic modelling of concentrated sulfuric acid solutions. Calphad. 2012 Sep 1;38:168–76.
21. Sippola H, Taskinen P. Thermodynamic properties of aqueous sulfuric acid. J Chem Eng Data [Internet]. 2014 Aug 14 [cited 2023 May 23];59(8):2389–407.
22. Bouchkira I, Latifi AM, Khamar L, Benjelloun S. Global sensitivity based estimability analysis for the parameter identification of Pitzer’s thermodynamic model. Reliab Eng Syst Saf. 2021 Mar 1;207:107263.