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 characterization of Mexico City aerosol during MILAGRO 2006

2009 ◽  
Vol 9 (6) ◽  
pp. 2141-2156 ◽  
Author(s):  
C. Fountoukis ◽  
A. Nenes ◽  
A. Sullivan ◽  
R. Weber ◽  
T. Van Reken ◽  
...  
Keyword(s):  
Gas Phase ◽  
Mexico City ◽  
Thermodynamic Equilibrium ◽  
Phase State ◽  
Early Morning ◽  
Molar Ratio ◽  
Aerosol Composition ◽  
Inorganic Species ◽  
Thermodynamic Equilibrium Model

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. For particle sizes up to 1μm diameter, semi-volatile partitioning requires 15–30 min to equilibrate; longer time is typically required during the night and early morning hours. Aerosol and gas-phase speciation always exhibits substantial temporal variability, so that aerosol composition measurements (bulk or size-resolved) obtained over large integration periods are not reflective of its true state. When the aerosol sulfate-to-nitrate molar ratio is less than unity, 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 is 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

Production, Injection and Flow of Petroleum with High Levels of CO2: Operational and Flow Assurance Aspects

2016 ◽  
Vol 830 ◽  
pp. 78-84
Author(s):  
Ivanilto Andreolli ◽  
Luciene de Arruda Bernardo
Keyword(s):  
Gas Phase ◽  
Molar Ratio ◽  
Flow Assurance ◽  
Daily Production ◽  
Treatment And Disposal ◽  
Export System ◽  
Theoretical Analyses ◽  
Concentration Levels ◽  
Operational Aspects

Petroleum production always comes accompanied by some contaminants, including CO2. Recent pre-salt exploration in Brazil indicates significant carbon dioxide (CO2) concentration levels. Whereas in post-salt areas a ratio of 1 to 2% in CO2 concentration was observed, in the pre-salt area this molar ratio increased to 15 to 20% in relation to the gas phase, and were even higher in some cases. Several challenges have emerged in the production, treatment and disposal of oil with such high levels of CO2. The aim of this study is to show the management of CO2 in a pre-salt producing platform whose CO2 content is about 18% molar in the gas phase. The focus is on the operational aspects of daily production, where theoretical analyses are compared with the data observed in the field. Scenarios of production, injection, treatment and export are presented with emphasis on the aspects of flow assurance, the characterization of fluids, the integration of the injection-production-export system, and the dilution of CO2.

scholarly journals Implementation of a Markov Chain Monte Carlo Method to inorganic aerosol modeling of observations from the MCMA-2003 Campaign. Part II: Model application to the CENICA, Pedregal and Santa Ana sites

2006 ◽  
Vol 6 (4) ◽  
pp. 5999-6040
Author(s):  
F. M. San Martini ◽  
E. J. Dunlea ◽  
R. Volkamer ◽  
T. B. Onasch ◽  
J. T. Jayne ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Nitric Acid ◽  
Gas Phase ◽  
Mexico City ◽  
Monte Carlo Model ◽  
Rural Site ◽  
Inorganic Species ◽  
Inorganic Aerosol

Abstract. A Markov Chain Monte Carlo model for integrating the observations of inorganic species with a thermodynamic equilibrium model was presented in Part I of this series. Using observations taken at three ground sites, i.e. a residential, industrial and rural site, during the MCMA-2003 campaign in Mexico City, the model is used to analyze the inorganic aerosol and ammonia data and predict gas phase concentrations of nitric and hydrochloric acid. In general the model is able to accurately predict the observed inorganic aerosol concentrations at all three sites. The agreement between the predicted and observed gas phase ammonia concentration is excellent. The NOz concentration calculated from the NOy, NO and NO2 observations is of limited use in constraining the gas phase nitric acid concentration given the large uncertainties in this measure of nitric acid and additional reactive nitrogen species. Focusing on the acidic period of 9–11 April identified by Salcedo et al. (2006), the model accurately predicts the aerosol phase observations during this period with the exception of the nitrate predictions after 10:00 a.m. (CDT) on 9 April, where the model underpredicts the observations by, on average, 20%. For periods when the aerosol chloride observations are consistently above the detection limit, the model is able to both accurately predict the aerosol chloride predictions and provide well-constrained HCl (g) concentrations. When the aerosols are aqueous, the most likely concentrations of HCl (g) are in the sub-ppbv range. The most likely predicted concentration of HCl (g) was found to reach concentrations of order 10 ppbv if the aerosols are dry. Finally, the atmospheric relevance of HCl (g) is discussed in terms of its indicator properties for the possible influence of chlorine-mediated photochemistry in Mexico City.

scholarly journals Implementation of a Markov Chain Monte Carlo method to inorganic aerosol modeling of observations from the MCMA-2003 campaign – Part II: Model application to the CENICA, Pedregal and Santa Ana sites

2006 ◽  
Vol 6 (12) ◽  
pp. 4889-4904 ◽  
Author(s):  
F. M. San Martini ◽  
E. J. Dunlea ◽  
R. Volkamer ◽  
T. B. Onasch ◽  
J. T. Jayne ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Nitric Acid ◽  
Gas Phase ◽  
Mexico City ◽  
Monte Carlo Model ◽  
Rural Site ◽  
Inorganic Particle ◽  
Inorganic Species

Abstract. A Markov Chain Monte Carlo model for integrating the observations of inorganic species with a thermodynamic equilibrium model was presented in Part I of this series. Using observations taken at three ground sites, i.e. a residential, industrial and rural site, during the MCMA-2003 campaign in Mexico City, the model is used to analyze the inorganic particle and ammonia data and to predict gas phase concentrations of nitric and hydrochloric acid. In general, the model is able to accurately predict the observed inorganic particle concentrations at all three sites. The agreement between the predicted and observed gas phase ammonia concentration is excellent. The NOz concentration calculated from the NOy, NO and NO2 observations is of limited use in constraining the gas phase nitric acid concentration given the large uncertainties in this measure of nitric acid and additional reactive nitrogen species. Focusing on the acidic period of 9–11 April identified by Salcedo et al. (2006), the model accurately predicts the particle phase observations during this period with the exception of the nitrate predictions after 10:00 a.m. (Central Daylight Time, CDT) on 9 April, where the model underpredicts the observations by, on average, 20%. This period had a low planetary boundary layer, very high particle concentrations, and higher than expected nitrogen dioxide concentrations. For periods when the particle chloride observations are consistently above the detection limit, the model is able to both accurately predict the particle chloride mass concentrations and provide well-constrained HCl (g) concentrations. The availability of gas-phase ammonia observations helps constrain the predicted HCl (g) concentrations. When the particles are aqueous, the most likely concentrations of HCl (g) are in the sub-ppbv range. The most likely predicted concentration of HCl (g) was found to reach concentrations of order 10 ppbv if the particles are dry. Finally, the atmospheric relevance of HCl (g) is discussed in terms of its indicator properties for the possible influence of chlorine-mediated photochemistry in Mexico City.

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