US EPA

2020424 

Journal Article 

Thermodynamic Modeling of the NH3-CO2-H2O System with Electrolyte NRTL Model 

Que, H; Chen, CC 

2011 

Yes 

Industrial and Engineering Chemistry Research
ISSN: 0888-5885
EISSN: 1520-5045 

50 

19 

11406-11421 

English 

10.1021/ie201276m 

WOS:000295237000055 

To facilitate simulation, design, and optimization of chilled ammonia processes for CO 2 capture, we develop a thermodynamicmodel for theNH 3-CO 2-H 2Osystem with the electrolyte NRTL activity coefficientmodel. The thermodynamic model explicitly accounts for the solution chemistry which includes dissociations of H 2O, NH 3, and CO 2, formation of ammonium carbamate, and precipitation of ammonium bicarbonate. The electrolyte NRTL activity coefficient model parameters are identified by fitting against selected experimental data for vapor-liquid equilibrium, heat of solution, and heat capacity of the NH 3-H 2O binary, solid-liquid equilibrium of the NH 4HCO 3-H 2O binary, and vapor-liquid equilibrium and speciation of the NH 3-CO 2-H 2O ternary. The model is further validated with additional VLE, speciation, heat capacity, and heat of solution data for the NH 3-CO 2-H 2Osystem. Overall the model satisfactorily represents the thermodynamic properties of the NH 3-CO 2-H 2O system with temperature up to 473 K, pressure up to 7 MPa, NH 3 concentration up to 30 wt %, and CO 2 loading up to unity. © 2011 American Chemical Society. 

Ammonium bicarbonates; Ammonium carbamates; Electrolyte-NRTL; Electrolyte-NRTL model; Experimental data; Heat of solution; Solid liquid equilibrium; Solution chemistry; Thermodynamic model; Thermodynamic modeling; Vapor-liquid equilibrium; Ammonium compounds; Electrolytes; Loading; Phase equilibria; Specific heat; Thermochemistry; Vapors; Carbon dioxide