Experimental studies of the volatility of ammonium chloride
A platinum-lined autoclave is being used to investigate the partitioning of ammonia and chloride between the vapor and liquid phases of aqueous ammonium chloride. The apparatus is designed to allow the sampling of both phases via inert tubing (platinum and PEEK tubing and valves) over a temperature range of approximately 150 to 350{degree}C. Initial experiments have been carried out at 150{degree}C using acidic ammonium chloride solutions with varying molalities and acidities and a range of vapor sampling rates to ensure equilibrium had been established. Relatively high molalities of NH{sub 4}Cl have been used to provide sufficient solute partitioning to the vapor phase to allow precise determination of the vapor-phase composition by ion chromatography. The ammonium concentration in the vapor phase in excess of that calculated for ammonia volatility provides a direct measure of the maximum volatility of ammonium chloride at that temperature. The calculation of the expected ammonia and hydrochloric acid volatilities is based on a knowledge of the activity coefficients of the ionic species in solution as well as the equilibrium constants for the liquid-vapor partitioning. Activity coefficients of all the ionic solutes and the volatility of HCL have been measured in this laboratory; the thermodynamics of the volatility of ammonia are described in previously published works. The results at 150{degree}C are used to demonstrate how maximum ammonium chloride concentrations in the vapor phase can be calculated, including the proportion of total vapor-phase chloride due to NH{sub 4}Cl and HCl partitioning, for solution compositions relevant to power generating cycles. It should be emphasized that this study is still in progress and that temperatures corresponding to those in power-generating plants will be investigated. 7 refs., 6 figs., 1 tab.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5843931
- Report Number(s):
- CONF-9106189-1; ON: DE91012526
- Resource Relation:
- Conference: International conference on cycle chemistry in fossil plants, Baltimore, MD (USA), 4-6 Jun 1991
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measurements of the volatilities of solutes from aqueous solutions and their application to water/steam cycles
Distribution of ammonium salts between liquid and steam at high temperatures
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
20 FOSSIL-FUELED POWER PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
AMMONIUM CHLORIDES
VOLATILITY
BOILERS
FEEDWATER
TEMPERATURE DEPENDENCE
MATHEMATICAL MODELS
COOLANTS
EXPERIMENTAL DATA
PARTITION
PH VALUE
POWER PLANTS
THERMODYNAMIC ACTIVITY
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
CHLORIDES
CHLORINE COMPOUNDS
DATA
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
OXYGEN COMPOUNDS
WATER
400201* - Chemical & Physicochemical Properties
200101 - Fossil-Fueled Power Plants- Cooling & Heat Transfer Equipment & Systems
220200 - Nuclear Reactor Technology- Components & Accessories