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Thermodynamic modeling of HNO 3 ‐H 2 SO 4 ‐H 2 O ternary system with symmetric electrolyte NRTL model
Author(s) -
Wang Meng,
Kaur Harnoor,
Chen ChauChyun
Publication year - 2017
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15679
Subject(s) - nitric acid , sulfuric acid , ternary operation , chemistry , non random two liquid model , ternary numeral system , inorganic chemistry , electrolyte , thermodynamics , aqueous solution , activity coefficient , organic chemistry , phase (matter) , physics , computer science , programming language , electrode
The nitric acid concentration/sulfuric acid concentration (NAC/SAC) process has been widely used for concentrating dilute aqueous nitric acid and recovering spent sulfuric acid. Dilute nitric acid (65 to 80 wt %) is concentrated using sulfuric acid to bind water and break the nitric acid‐water azeotrope at approximately 68 wt % nitric acid. To support heat and mass balance calculations and process simulation for NAC/SAC processes, we develop a comprehensive thermodynamic model for nitric acid‐sulfuric acid‐water ternary system based on previously published thermodynamic models of nitric acid‐water and sulfuric acid‐water binary systems with eNRTL equation. The ternary system model correlates well the isobaric vapor‐liquid equilibrium data at one atmosphere and the water and nitric acid activities data at 273.15 K for the ternary. Contour plots of boiling points, vapor phase composition, and specific heat capacity of the ternary system, as well as a Merkel enthalpy‐concentration chart are generated for engineering use. © 2017 American Institute of Chemical Engineers AIChE J , 63: 3110–3117, 2017