Robert Wood is funded by a grant from the Theoretical and Computational Chemistry Program to continue his experimental research in thermodynamic measurements of aqueous solutions at high temperatures. Wood will measure the electrical conductance of aqueous solutions of a variety of salts at temperatures from 300 to 425 C and pressures up to 28 MPa. Systems to be studied include Sodium Sulfate, Calcium Chloride, Magnesium Chloride, Hydrochloric Acid and Sodium Hydroxide. The measurements will yield accurate values of the association constants for the formation of ion pairs. Additional studies at higher temperatures and pressures will be performed in collaboration with scientists at Oak Ridge National Labs. The results of the measurements for Sodium Sulfate, Magnesium Chloride and Calcium Chloride together with heat capacities and volumes measured by V. Majer in France will be used to construct models for these salt solutions near the critical point of water. Model classical Hamiltonians for the forces between the atomic sites in the molecules will also be developed to make predictions, using molecular dynamics, in regions where experiments are not possible. High temperature aqueous solutions play an important role in a wide variety of industrial and natural processes. Examples of these processes are mineral transport, deposition and alteration, hydrocarbon formation, migration and accumulation, electric power boiler corrosion, and hydrothermal reservoir utilization. There is also interest in using supercritical water as a reaction medium for oxidative degradation of hazardous waste, conversion of coal to gasoline, and as a reaction medium for organic synthesis to replace conventional organic solvents. Wood's research will help to provide a basic understanding of ionic solutions at high temperatures and pressures which is fundamentally important to the efficient development of industrial uses of supercritical wate
