scholarly journals Contribution of gaseous and particulate species to droplet solute composition

2003 ◽  
Vol 3 (1) ◽  
pp. 479-519 ◽  
Author(s):  
K. Sellegri ◽  
P. Laj ◽  
A. Marinoni ◽  
R. Dupuy ◽  
M. Legrand ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Carboxylic Acids ◽  
Chemical Transformation ◽  
Removal Rate ◽  
Multiphase System ◽  
Complex Nature ◽  
Gaseous Species ◽  
Phase Partitioning ◽  
Hygroscopic Properties

Abstract. Chemical reactions of dissolved gases in the liquid phase play a key role in atmospheric processes both in the formation of secondary atmospheric compounds and their wet removal rate but also in the regulation of the oxidizing capacity of the troposphere (Lelieveld and Crutzen, 1991). The behaviour of gaseous species and their chemical transformation in clouds are difficult to observe experimentally given the complex nature of clouds. In this study, we have deployed an experimental set-up to provide an in-situ quantification of phase partitioning and chemical transformation of both organic (CH3COOH, HCOOH, H2C2O4) and inorganic (NH3, HNO3, SO2, HCl) species in clouds. We found that, carboxylic acids, nitrate, and chloride can be considered close to Henry's law equilibrium, within analytical uncertainty and instrumental errors. On another hand, for reduced nitrogen species, dissolution of material from the gas phase is kinetically limited and never reaches the equilibrium predicted by thermodynamics, resulting in significant sub-saturation of the liquid phase. On the contrary, sulfate is supersaturated in the liquid phase, indicating the presence of significant aerosol-derived material transferred through nucleation scavenging. Upon droplet evaporation, most species, including SO2, tend to efficiently return back into the gas phase. In that sense, these species contribute to acidification (for carboxylic acids) or neutralization (for NH3) of the liquid-phase but not totally of the processed aerosols. The only species that appears to be modified in the multiphase system is nitrate. A fraction of at least 10 to 40% of the liquid phase NO3 originates from dissolved HNO3 of which only a fraction evaporates back to the gas phase upon evaporation, resulting in an NO3 enrichment of the aerosol phase. In-cloud gas-to-particle transfer of HNO3 possibly plays a key role in aerosol acidification and in the modification of their hygroscopic properties. Our study emphasizes the need to account for the in-cloud interaction between particles and gases to provide an adequate modeling of multiphase chemistry systems and its impact on the atmospheric aerosol and gas phases.

scholarly journals Contribution of gaseous and particulate species to droplet solute composition at the Puy de Dôme, France

2003 ◽  
Vol 3 (5) ◽  
pp. 1509-1522 ◽  
Author(s):  
K. Sellegri ◽  
P. Laj ◽  
A. Marinoni ◽  
R. Dupuy ◽  
M. Legrand ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Removal Rate ◽  
Chemical Species ◽  
Solute Concentration ◽  
Complex Nature ◽  
Gaseous Species ◽  
Phase Partitioning ◽  
Gas Phases ◽  
Set Up

Abstract. Chemical reactions of dissolved gases in the liquid phase play a key role in atmospheric processes both in the formation of secondary atmospheric compounds and their wet removal rate but also in the regulation of the oxidizing capacity of the troposphere. The behavior of gaseous species and their chemical transformation in clouds are difficult to observe experimentally given the complex nature of clouds. During a winter field campaign at the summit of the Puy de Dôme (central France, 1465 m a.s.l), we have deployed an experimental set-up to provide a quantification of phase partitioning of both organic (CH3COOH, HCOOH, H2C2O4) and inorganic (NH3, HNO3, SO2, HCl) species in clouds. We found that nitric and hydrochloric acids can be considered close to Henry's law equilibrium, within analytical uncertainty and instrumental errors. On another hand, for NH3 and carboxylic acids, dissolution of material from the gas phase is kinetically limited and never reaches the equilibrium predicted by thermodynamics, resulting in significant sub-saturation of the liquid phase. On the contrary, SIV is supersaturated in the liquid phase, in addition to the presence of significant aerosol-derived SVI transferred through nucleation scavenging. Upon droplet evaporation, a significant part of most species, including SIV, tends to efficiently return back into the gas phase. Overall, gas contribution to the droplet solute concentration ranges from at least 48.5 to 98% depending on the chemical species. This is particularly important considering that aerosol scavenging efficiencies are often calculated assuming a negligible gas-phase contribution to the solute concentration. Our study emphasizes the need to account for the in-cloud interaction between particles and gases to provide an adequate modeling of multiphase chemistry systems and its impact on the atmospheric aerosol and gas phases.

New MESSy scavenging subroutine to treat aerosol particles gas-phase partitioning in convective clouds

2021 ◽  
Author(s):  
Giorgio Taverna ◽  
Marc Barra ◽  
Holger Tost
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Phase Partitioning ◽  
Convective Clouds ◽  
Terrestrial Atmosphere ◽  
Deep Convective Clouds ◽  
High Level

<p>The Modular Earth Submodel System (MESSy) has been proven to be successful in the understanding of several processes which characterize the terrestrial atmosphere and climate.</p><p>However, the complexity of aerosol particles/gas phase partitioning of species in deep convective clouds together with the inherent problems of modelling sub-grid scale processes, make MESSy results significant underestimated, especially in case of SO<sub>2</sub>, when compared with available flight observations. For this reason, the subroutine which reproduce the scavenging of these species has been updated to include a more realistic treatment of liquid/phase partitioning of aerosol induced species in high level clouds.</p><p>Results obtained are shown in this poster.</p>

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

Theoretical analysis of counter-current absorption of a poorly soluble gas based on the PDE-AD model

1986 ◽  
Vol 51 (6) ◽  
pp. 1222-1239 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Gas Phase ◽  
Transfer Functions ◽  
Packed Bed ◽  
Packed Bed Column ◽  
Interfacial Transport ◽  
Gaseous Component ◽  
Poorly Soluble ◽  
Counter Current

Expression have been derived in the paper for all four possible transfer functions between the inlet and the outlet gas and liquid steams under the counter-current absorption of a poorly soluble gas in a packed bed column. The transfer functions have been derived for the axially dispersed model with stagnant zone in the liquid phase and the axially dispersed model for the gas phase with interfacial transport of a gaseous component (PDE - AD). calculations with practical values of parameters suggest that only two of these transfer functions are applicable for experimental data evaluation.

Reesterification of ethyl acetate by propanol catalysed by glycidyl methacrylate copolymers containing sulphonic acid groups

1981 ◽  
Vol 46 (8) ◽  
pp. 1941-1946 ◽  
Author(s):  
Karel Setínek
Keyword(s):  
Liquid Phase ◽  
Ethyl Acetate ◽  
Kinetic Study ◽  
Gas Phase ◽  
Nonlinear Regression ◽  
Kinetic Data ◽  
Glycidyl Methacrylate ◽  
Kinetic Equations ◽  
Methacrylate Copolymers ◽  
Styrene Divinylbenzene

A series of differently crosslinked macroporous 2,3-epoxypropyl methacrylate-ethylenedimethacrylate copolymers with chemically bonded propylsulphonic acid groups were used as catalysts for the kinetic study of reesterification of ethyl acetate by n-propanol in the liquid phase at 52 °C and in the gas phase at 90 °C. Analysis of kinetic data by the method of nonlinear regression for a series of equations of the Langmuir-Hinshelwood type showed that kinetic equations which describe best the course of the reaction are the same as for the earlier studied sulphonated macroporous styrene-divinylbenzene copolymers. Compared types of catalysts differ, however, in the dependence of their activity on the degree of crosslinking of the copolymer used.

scholarly journals How volatile components catalyze vapor nucleation

2021 ◽  
Vol 7 (3) ◽  
pp. eabd9954 ◽  
Author(s):  
Chenxi Li ◽  
Jan Krohn ◽  
Martina Lippe ◽  
Ruth Signorell
Keyword(s):  
Gas Phase ◽  
Molecular Level ◽  
Volatile Components ◽  
Transient Species ◽  
Gaseous Species ◽  
Alternative Pathways ◽  
Nucleation Mechanisms ◽  
Designed Experiment ◽  
Phase Nucleation ◽  
Vapor Nucleation

Gas phase nucleation is a ubiquitous phenomenon in planetary atmospheres and technical processes, yet our understanding of it is far from complete. In particular, the enhancement of nucleation by the addition of a more volatile, weakly interacting gaseous species to a nucleating vapor has escaped molecular-level experimental investigation. Here, we use a specially designed experiment to directly measure the chemical composition and the concentration of nucleating clusters in various binary CO2-containing vapors. Our analysis suggests that CO2 essentially catalyzes nucleation of the low vapor pressure component through the formation of transient, hetero-molecular clusters and thus provides alternative pathways for nucleation to proceed more efficiently. This work opens up new avenues for the quantitative assessment of nucleation mechanisms involving transient species in multicomponent vapors.

scholarly journals Crystal Phase Effects on the Gas‐Phase Ketonization of Small Carboxylic Acids over TiO 2 Catalysts

ChemSusChem ◽  
2021 ◽  
Author(s):  
Egor V. Fufachev ◽  
Bert M. Weckhuysen ◽  
Pieter C. A. Bruijnincx
Keyword(s):  
Gas Phase ◽  
Carboxylic Acids ◽  
Crystal Phase

S-Acylation of aliphatic and aromatic thiols with carboxylic acids and their esters over solid acid catalysts in the gas phase at temperatures above 200°C

2013 ◽  
Vol 464-465 ◽  
pp. 332-338 ◽  
Author(s):  
Sayoko Nagashima ◽  
Hitomi Yamazaki ◽  
Kentaro Kudo ◽  
Satoshi Kamiguchi ◽  
Teiji Chihara
Keyword(s):  
Gas Phase ◽  
Carboxylic Acids ◽  
Solid Acid ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Aromatic Thiols

The Dielectric Discharge as an Efficient Generator of Active Nitrogen for Chemiluminescence and Analysis

1983 ◽  
Vol 37 (6) ◽  
pp. 545-552 ◽  
Author(s):  
John Kishman ◽  
Eric Barish ◽  
Ralph Allen
Keyword(s):  
Gas Phase ◽  
Ground State ◽  
Band System ◽  
Electrothermal Atomization ◽  
Characteristic Radiation ◽  
Gaseous Species ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
Excited Species ◽  
Intense Emission

A predominantly blue “active nitrogen” afterglow was generated in pure flowing nitrogen or in air by using a dielectric discharge at pressures from 1 to 20 Torr. The afterglow contains triplet state molecules and vibrationally excited ground state molecules. These species are produced directly by electron impact without the formation and recombination of nitrogen atoms. The most intense emission is the N2 second positive band system. The N2 first positive and N2+ first negative systems are also observed. The spectral and electrical properties of this discharge are discussed in order to establish guidelines for the analytical use of the afterglow for chemiluminescence reactions. The metastatic nitrogen efficiently transfers its energy to atomic and molecular species which are introduced into the gas phase and these excited species emit characteristic radiation. The effects of electrothermal atomization of Zn and the introduction of gaseous species (e.g., NO) on the afterglow are described.

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