Supercritical Water: A Green Solvent – Properties and Uses

YIZHAK MARCUS, PhD, is Professor Emeritus of Inorganic and Analytical Chemistry at The Hebrew University of Jerusalem. His research focuses on solution chemistry, including aqueous, non-aqueous, and mixed solvents as well as solutions of electrolytes and non-electrolytes. Dr. Marcus has published six books and more than 300 papers in peer-reviewed journals.

Preface ix List of Acronyms and Symbols xiii 1 Introduction 1 1.1 Phase Diagrams of Single Fluids / 1 1.2 The Critical Point / 3 1.3 Supercritical Fluids as Solvents / 5 1.4 Gaseous and Liquid Water / 8 1.5 Near-Critical Water / 15 1.6 Summary / 17 2 Bulk Properties of SCW 22 2.1 Equations of State(EoS) / 22 2.1.1 PVT Data for SCW / 22 2.1.2 Classical Equations of State of SCW / 24 2.1.3 Scaling Equations of State for SCW / 26 2.1.4 EoS of Supercritical Heavy Water / 29 2.2 Thermophysical Properties of SCW / 30 2.2.1 Heat Capacity / 30 2.2.2 Enthalpy and Entropy / 32 2.2.3 Sound Velocity / 34 2.3 Electrical and Optical Properties / 34 2.3.1 Static Relative Permittivity / 34 2.3.2 Electrical Conductivity / 37 2.3.3 Light Refraction / 38 2.4 Transport Properties / 39 2.4.1 Viscosity / 39 2.4.2 Self-Diffusion / 41 2.4.3 Thermal Conductivity / 42 2.5 Ionic Dissociation of SCW / 44 2.6 Properties Related to the Solvent Power of SCW / 47 2.7 Summary / 49 3 Molecular Properties of SCW 57 3.1 Diffraction Studies of SCW Structure / 60 3.1.1 X-Ray Diffraction Studies of SCW Structure / 61 3.1.2 Neutron Diffraction Studies of SCW Structure / 62 3.2 Computer Simulations of SCW / 66 3.2.1 Monte Carlo Simulations / 67 3.2.2 Molecular Dynamics Simulations / 70 3.3 Spectroscopic Studies of SCW / 74 3.3.1 Infrared Absorption Spectroscopy / 74 3.3.2 Raman Scattering Spectroscopy / 77 3.3.3 Nuclear Magnetic Resonance / 79 3.3.4 Dielectric Relaxation Spectroscopy / 82 3.4 The Extent of Hydrogen Bonding in SCW / 83 3.5 The Dynamics of Water Molecules in SCW / 90 3.6 Summary / 92 4 SCW as a "Green" Solvent 100 4.1 Solutions of Gases in SCW / 101 4.1.1 Phase Equilibria / 101 4.1.2 Interactions in the Solutions / 104 4.2 Solutions of Organic Substances in SCW / 106 4.2.1 Phase Equilibria / 106 4.2.2 Interactions in the Solutions / 111 4.3 Solutions of Salts and Ions in SCW / 115 4.3.1 Solubilities of Salts and Electrolytes / 115 4.3.2 Thermodynamic Properties / 121 4.3.3 Transport Properties / 123 4.3.4 Ion Association in SCW / 129 4.3.5 Ion Hydration in SCW / 134 4.4 Binary Mixtures of Cosolvents with SCW / 138 4.5 Summary / 141 5 Applications of SCW 151 5.1 Conversion of Organic Substances to Fuel / 152 5.1.1 Conversion to Hydrogen and Natural Gas / 152 5.1.2 Conversion to Liquid Fuel / 156 5.2 Supercritical Water Oxidation / 157 5.2.1 General Aspects of SCWO Process / 158 5.2.2 Examples of SCWO Applications / 160 5.3 Uses of SCW in Organic Synthesis / 162 5.4 Uses in Powder Technology of Inorganic Substances / 164 5.5 Geothermal Aspects of SCW / 166 5.6 Application of SCW in Nuclear Reactors / 169 5.7 Corrosion Problems with SCW / 171 5.8 Summary / 174 Author Index 183 Subject Index 199