Thermodynamic and Kinetic Properties of Natural Brines

Abstract

The physical chemistry of natural brines made up of mostly NaCl has been studied over the years. In this article, the work on the thermodynamics and kinetics of processes in NaCl brines will be examined. The importance of ionic interactions of the processes will be stressed. This will include the pressure–volume–temperature and physical–chemical properties of NaCl and other brine salts from 0 to 6 m, 0 to 200°C, and 0 to 1,000 bar applied pressures. Acid–base, gas–liquid, solid–liquid, and ion–complex formation processes in NaCl are examined. Equations that can be used to estimate the equilibria in NaCl are given. Pitzer models are discussed that can be used to estimate ionic equilibria in brines. The oxidation of Fe(II) and Cu(I) with O2 and H2O2 and the reduction of Cu(II) with H2O2 in NaCl are examined in terms of ionic complexes of metals with OH− and CO3 2−. The oxidation of H2S with O2 and H2O2 is also examined in NaCl media. Equations are given that can be used to estimate the effect of ionic interactions on kinetic processes in NaCl.