Physical Chemistry of Aqueous Systems: Meeting the Needs of Industry

ISBN Print: 978-1-56700-034-4

ISBN Online: 978-1-56700-445-8

AQUEOUS IONIC EQUILIBRIA TO 350°C: PREDICTIONS COMPARED WITH EXPERIMENT

DOI: 10.1615/ICPWS-1994.860
pages 669-676

Sinopsis

Practical thermodynamic calculations for aqueous systems at high temperatures frequently require estimation of equilibrium data that have not been measured. Isocoulombic extrapolations from measurements at low temperature, in combination with generic activity coefficients and appropriate speciation models, have been used for MULTEQ, a computer code developed by the Electric Power Research Institute. Examples are given of three diverse types of prediction where comparison with experiment can now be made at temperatures to 350°C: volatility of HCl in steam; NaCl activity coefficients at high concentrations; and liquid­liquid immiscibility in Na2B4O7 solutions. Agreement exceeds expectations.