Calorimetric Study of Ionization and Oxidation Reactions in Supercritical Water.

Abstract

The investigation of chemical reactions in the supercritical region of water requires a knowledge of the thermodynamic quantities (equilibrium constants, enthalpy changes, entropy changes, and heat capacity changes) associated with water dissociation and solute-solute interaction in this region. In this study, these quantities have been determined to 350 or, in some cases, to 370 deg C for water ionization and alkali and alkaline earth chloride ion interaction. The determinations were made using a high precision flow calorimeter designed and constructed to withstand the corrosive and high temperature conditions encountered in the study. The results are consistent with a model involving water molecules as active participants in the reactions. As temperature increases, the percentage of water molecules participating in hydrogen bonding decreases with resulting large effects on enthalpy changes, entropy changes and heat capacity changes values for chemical reactions. The equilibrium constants and enthalpy changes values provide essential information for the design of processes intended to operate under supercritical water conditions.

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Document Details

Document Type
Technical Report
Publication Date
Mar 25, 1997
Accession Number
ADA324739

Entities

People

  • John L. Oscarson
  • Reed Izatt

Organizations

  • Brigham Young University

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Human Systems
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Abstracts
  • Aqueous Solutions
  • Calorimeters
  • Chemical Reaction Properties
  • Chemical Reactions
  • Chlorides
  • Corrosion Resistance
  • Dissociation
  • Enthalpy Changes
  • Heat Capacity
  • High Temperature
  • Hydration
  • Hydrogen
  • Ionization
  • Molecules
  • Oxidation
  • Platinum Alloys

Fields of Study

  • Chemistry

Readers

  • Materials Science and Engineering.
  • Organic Chemistry
  • Quantum Chemistry