Thermodynamic Equilibrium Calculations on the System Uranium-Carbon-Fluorine

1978 ◽  
Vol 17 (4) ◽  
pp. 256-259 ◽  
Author(s):  
M. J. P. C. Nieskens ◽  
H. N. Stein ◽  
J. Kistemaker
Keyword(s):  
Thermodynamic Equilibrium ◽  
Equilibrium Calculations ◽  
Thermodynamic Equilibrium Calculations

scholarly journals Thermodynamic characterization of Mexico City aerosol during MILAGRO 2006

2007 ◽  
Vol 7 (3) ◽  
pp. 9203-9233 ◽  
Author(s):  
C. Fountoukis ◽  
A. Nenes ◽  
A. Sullivan ◽  
R. Weber ◽  
T. VanReken ◽  
...  
Keyword(s):  
Gas Phase ◽  
Mexico City ◽  
Thermodynamic Equilibrium ◽  
Phase State ◽  
Molar Ratio ◽  
Inorganic Species ◽  
Equilibrium Calculations ◽  
Thermodynamic Equilibrium Model ◽  
Thermodynamic Equilibrium Calculations

Abstract. Fast measurements of aerosol and gas-phase constituents coupled with the ISORROPIA-II thermodynamic equilibrium model are used to study the partitioning of semivolatile inorganic species and phase state of Mexico City aerosol sampled at the T1 site during the MILAGRO 2006 campaign. Overall, predicted semivolatile partitioning agrees well with measurements. PM2.5 is insensitive to changes in ammonia but is to acidic semivolatile species. Semi-volatile partitioning equilibrates on a timescale between 6 and 20 min. When the aerosol sulfate-to-nitrate molar ratio is less than 1, predictions improve substantially if the aerosol is assumed to follow the deliquescent phase diagram. Treating crustal species as "equivalent sodium" (rather than explicitly) in the thermodynamic equilibrium calculations introduces important biases in predicted aerosol water uptake, nitrate and ammonium; neglecting crustals further increases errors dramatically. This suggests that explicitly considering crustals in the thermodynamic calculations are required to accurately predict the partitioning and phase state of aerosols.

scholarly journals Thermodynamic Equilibrium Calculations on the Oxidation Behavior of the Mo-Ru-Rh-Pd Alloys

2012 ◽  
Vol 11 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Yuji OHISHI ◽  
Ken KUROSAKI ◽  
Tohru SUGAHARA ◽  
Aikebaier YUSUFU ◽  
Yusuke MASAHIRA ◽  
...  
Keyword(s):  
Thermodynamic Equilibrium ◽  
Oxidation Behavior ◽  
Equilibrium Calculations ◽  
Thermodynamic Equilibrium Calculations

Thermodynamic equilibrium calculations of the volatilization and condensation of inorganics during wood gasification

Fuel ◽  
2013 ◽  
Vol 107 ◽  
pp. 269-281 ◽  
Author(s):  
K. Froment ◽  
F. Defoort ◽  
C. Bertrand ◽  
J.M. Seiler ◽  
J. Berjonneau ◽  
...  
Keyword(s):  
Thermodynamic Equilibrium ◽  
Equilibrium Calculations ◽  
Thermodynamic Equilibrium Calculations

Carbon Deposition Simulation in Porous SOFC Anodes: A Detailed Numerical Analysis of Major Carbon Precursors

2015 ◽  
Vol 12 (5) ◽  
Author(s):  
C. Schluckner ◽  
V. Subotić ◽  
V. Lawlor ◽  
C. Hochenauer
Keyword(s):  
Carbon Monoxide ◽  
Thermodynamic Equilibrium ◽  
Operating Conditions ◽  
Carbon Formation ◽  
Fuel Supply ◽  
Wide Range ◽  
Pure Methane ◽  
Equilibrium Calculations ◽  
Elementary Carbon ◽  
Thermodynamic Equilibrium Calculations

Solid oxide fuel cells (SOFCs) can be operated on a wide range of fuels, including hydrocarbons. Such a fuel supply includes the risk of carbon formation on the catalytically active nickel centers within the porous anodic substrate. Coking is very critical for the reliability and durability of the SOFCs. Thus, within this study, coking propensity of the most prominent carbon containing fuels was analyzed by thermodynamic equilibrium calculations for two fundamentally different types of carbon and detailed transient numerical simulations based on heterogeneous reforming kinetics. This approach is new to the literature and reveals the strengths and weaknesses of both fundamentally different approaches. It was shown that in thermodynamic equilibrium calculations, carbon formation is most likely due to pure methane. Carbon monoxide will form the least amounts of carbon in typical SOFC temperature ranges. Furthermore, based on a validated computational fluid dynamics (CFD) simulation model, detailed heterogeneous reaction kinetics were used to directly simulate elementary carbon adsorbed to the reactive substrate surface. The amounts, spatial and temporal distribution, of carbon atoms within the porous structure were identified between 600 °C and 1000 °C for a broad steam-to-carbon ratio range of 0.5–2. It was shown that most carbon is formed at the beginning of the substrate. A key finding was that steady-state results differ greatly from results within the first few seconds of fuel supply. An increment in temperature causes a significant increase in the amount of carbon formed, making the highest temperatures the most critical for the SOFC operation. Moreover, it was shown that mixtures of pure methane deliver the highest amounts of adsorbed elementary carbon. Equimolar mixtures of CH4/CO cause second highest surface coverages. Pure carbon monoxide blends led to least significant carbon formations. This work has shown the important contribution that thermodynamic equilibrium calculation results, as well as the outcomes of the detailed CFD simulations, allow to identify suitable operating conditions for the SOFC systems and to minimize the risk of coking on porous anodes.

Thermodynamic equilibrium calculations of sulfur poisoning in Ce–O–S and La–O–S systems

2005 ◽  
Vol 100 (3-4) ◽  
pp. 291-295 ◽  
Author(s):  
Heidi Karjalainen ◽  
Ulla Lassi ◽  
Katariina Rahkamaa-Tolonen ◽  
Virpi Kröger ◽  
Riitta L. Keiski
Keyword(s):  
Thermodynamic Equilibrium ◽  
Sulfur Poisoning ◽  
Equilibrium Calculations ◽  
Thermodynamic Equilibrium Calculations
Sign in / Sign up

Export Citation Format

Share Document