Na2CO3 and K3PO4 solubility measurements at 30 MPa in near-critical and supercritical water using conductimetry and high pressure calorimetry

Knowledge of the phase equilibria and solubility of inorganic salts is crucial to improving the handling of salt precipitation in supercritical water oxidation (SCWO) processes. However, there is little such data in the literature, especially at 30 MPa, the pressure at which the continuous SCWO proc...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of supercritical fluids 2017, Vol.130
Main Authors: Lemoine, G., Turc, Ha, Leybros, A., Ruiz, Jc, Sommer de Gelicourt, Y., Muhr, H.
Format: Article
Language:English
Subjects:
Nuclear Experiment
Nuclear Theory
Physics
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Knowledge of the phase equilibria and solubility of inorganic salts is crucial to improving the handling of salt precipitation in supercritical water oxidation (SCWO) processes. However, there is little such data in the literature, especially at 30 MPa, the pressure at which the continuous SCWO processes of the CEA (the French atomic energy commission) operate. In this study, the solubility of Na2CO3 and K3PO4 was determined under near-critical and supercritical conditions (320 DC < T < 500 DC, P = 30 MPa) by high pressure differential scanning calorimetry or by measuring the conductivity of samples taken from a high-pressure vessel. This approach enabled different phase changes to be detected for the two salts: direct solid precipitation from the homogeneous fluid phase for Na2CO3, and the appearance of a gas-liquid equilibrium before precipitation for K3PO4. On the whole, the results obtained are in agreement with Valyashko’s classification of binary water/salt systems.
ISSN:0896-8446
DOI:10.1016/j.supflu.2017.07.035