scholarly journals Hydrogen Storage: Thermodynamic Analysis of Alkyl-Quinolines and Alkyl-Pyridines as Potential Liquid Organic Hydrogen Carriers (LOHC)

2021 ◽  
Vol 11 (24) ◽  
pp. 11758
Author(s):  
Sergey P. Verevkin ◽  
Sergey P. Safronov ◽  
Artemiy A. Samarov ◽  
Sergey V. Vostrikov
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Wood Preservation ◽  
Enthalpies Of Formation ◽  
Vapor Pressures ◽  
Liquid Phase Hydrogenation ◽  
Substituted Quinolines ◽  
Attractive Option ◽  
Substituted Pyridines ◽  
High Level

The liquid organic hydrogen carriers (LOHC) are aromatic molecules, which can be considered as an attractive option for the storage and transport of hydrogen. A considerable amount of hydrogen up to 7–8% wt. can be loaded and unloaded with a reversible chemical reaction. Substituted quinolines and pyridines are available from petroleum, coal processing, and wood preservation, or they can be synthesized from aniline. Quinolines and pyridines can be considered as potential LOHC systems, provided they have favorable thermodynamic properties, which were the focus of this current study. The absolute vapor pressures of methyl-quinolines were measured using the transpiration method. The standard molar enthalpies of vaporization of alkyl-substituted quinolines and pyridines were derived from the vapor pressure temperature dependencies. Thermodynamic data on vaporization and formation enthalpies available in the literature were collected, evaluated, and combined with our own experimental results. The theoretical standard molar gas-phase enthalpies of formation of quinolines and pyridines, calculated using the quantum-chemical G4 methods, agreed well with the evaluated experimental data. Reliable standard molar enthalpies of formation in the liquid phase were derived by combining high-level quantum chemistry values of gas-phase enthalpies of formation with experimentally determined enthalpies of vaporization. The liquid-phase hydrogenation/dehydrogenation reaction enthalpies of alkyl-substituted pyridines and quinolines were calculated and compared with the data for other potential liquid organic hydrogen carriers. The comparatively low enthalpies of reaction make these heteroaromatics a seminal LOHC system.

Phase equilibrium in n-octane/water separation units: vapor pressures, vapor and liquid molar fractions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jeonghoon Kong ◽  
Salvador Escobedo ◽  
Sandra Lopez-Zamora ◽  
Hugo de Lasa
Keyword(s):  
Phase Equilibrium ◽  
Liquid Phase ◽  
Thermodynamic Model ◽  
Vapor Pressures ◽  
Auxiliary Equipment ◽  
Water Separation ◽  
Aspen Hysys ◽  
Special Value ◽  
Accurate Procedure ◽  
High Level

Abstract The present study reports result from research into vapor–liquid–liquid phase equilibrium for n-octane highly diluted in water and water highly diluted in n-octane blends, using a dynamic method implemented in a constant volume CREC-VL-Cell. In the CREC-VL-Cell, a very high level of mixing is achieved, allowing for dispersions to be formed in the liquid phase and good mixing in the gas phase. This VL-Cell and its auxiliary equipment provide an increasing temperature ramp in the 30–110 °C range. It is found that the CREC-VL-Cell is of special value, for studying immiscible or partially miscible blends, such as is the case of n-octane in water. With the data obtained, which includes vapor pressures and temperatures, data analyses involving mass and molar balances, allow establishing overall liquid and vapor molar fractions. The recorded vapor pressures together with the calculated liquid and vapor molar fractions offer valuable data for VL thermodynamic model discrimination. For instance, it can be shown that vapor pressures, vapor and liquid molar fractions, as calculated with the Aspen-Hysys Peng Robinson Equation of State (Hysys-Aspen PR-EoS) provide only a first approximation of the experimental data, with significant discrepancies in the prediction of an n-octane disengagement temperatures. Thus, the determination of combined measured vapor pressures and calculated overall liquid molar fractions in the CREC-VL-Cell, offers a valuable and accurate procedure for thermodynamic model validation and discrimination.

scholarly journals Experimental and Theoretical Investigation on the Thermochemistry of 3-Methyl-2-benzoxazolinone and 6-Nitro-2-benzoxazolinone

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 24
Author(s):  
Ana L. R. Silva ◽  
Vânia M. S. Costa ◽  
Maria D. M. C. Ribeiro da Silva
Keyword(s):  
Gas Phase ◽  
Structural Characteristics ◽  
Enthalpies Of Formation ◽  
Calvet Microcalorimetry ◽  
Static Bomb ◽  
High Level ◽  
The Relationship ◽  
Related Compounds ◽  
Enthalpies Of Sublimation

The determination of the reliable thermodynamic properties of 2-benzoxazolinone derivatives is the main goal of this work. Some correlations are established between the energetic properties determined and the structural characteristics of the title compounds, and the reactivity of this class of compounds is also evaluated. Static-bomb combustion calorimetry and high-temperature Calvet microcalorimetry were used to determine, respectively, the standard molar enthalpies of formation in the solid state and the standard molar enthalpies of sublimation, both at T = 298.15 K. Using the results obtained for each compound, the respective gas-phase standard molar enthalpy of formation was derived. High-level quantum chemical calculations were performed to estimate the same property and the results evidence good accordance. Moreover, the gas-phase relative thermodynamic stability of 2-benzoxazolinone derivatives was also evaluated using the respective gas-phase standard molar Gibbs energy of formation. In addition, the relationship between the energetic and structural characteristics of the benzoxazolinones is presented, evidencing the enthalpic increments associated with the presence of a methyl and a nitro groups in the molecule, and this effect is compared with similar ones in other structurally related compounds.

scholarly journals Gas-phase and liquid-phase hydrogenation of acetylene in lean and enriched mixtures over supported modified palladium catalysts

2019 ◽  
Vol 62 (1-2) ◽  
pp. 89-109 ◽  
Author(s):  
DV . Glyzdova ◽  
N.S . Smirnova ◽  
D.A . Shlyapin ◽  
P.G. Tsyrul’nikov
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Selective Hydrogenation ◽  
Palladium Catalysts ◽  
Raw Materials ◽  
Liquid Phase Hydrogenation ◽  
Selective Hydrogenation Of Acetylene ◽  
Bimetallic Palladium

In the presented review the results of studies devoted to the selective hydrogenation of acetylene to ethylene over bimetallic palladium-containing catalysts are systematized. General regularities and peculiarities of the catalysts action in gas-phase hydrogenation of traces of acetylene in the acetylene-ethylene mixture obtained by pyrolysis of petroleum raw materials, as well as in the process of liquid-phase hydrogenation of mixtures enriched with acetylene and hydrogen are analyzed. The advantages of obtaining ethylene by hydrogenation of acetylene in the liquid phase are shown and ways of increasing the selectivity of this process are considered.

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>

scholarly journals Energetic and Structural Studies of Two Biomass-Derived Compounds: 6- and 7-hydroxy-1-indanones

2020 ◽  
Vol 10 (23) ◽  
pp. 8512
Author(s):  
Ana Luisa Ribeiro da Silva ◽  
Maria D. M. C. Ribeiro da Silva
Keyword(s):  
Gas Phase ◽  
Computational Study ◽  
Intramolecular Proton Transfer ◽  
Molecular Structures ◽  
Experimental Techniques ◽  
Hydroxyl Group ◽  
Enthalpies Of Formation ◽  
Calvet Microcalorimetry ◽  
Computational Calculations ◽  
High Level

The energetic study of 6-hydroxy-1-indanone and 7-hydroxy-1-indanone was performed using experimental techniques and computational calculations. The enthalpies of combustion and sublimation of the two compounds were determined and allowed to derive the corresponding gas-phase standard molar enthalpies of formation. For this purpose, static-bomb combustion calorimetry and drop-method Calvet microcalorimetry were the experimental techniques used. Further, the enthalpy of fusion of each compound was obtained from scanning differential calorimetry measurements. Additionally, the gas-phase standard molar enthalpies of formation of these compounds were calculated through high-level ab initio calculations. The computational study of the molecular structures of the indanones was carried out and two possible conformers were observed for 6-hydroxy-1-indanone. Furthermore, the energetic effects associated with the presence of one hydroxyl group as a substituent on the benzenic ring of 1-indanone were also evaluated. Both experimental and theoretical methods show that 7-hydroxy-1-indanone is thermodynamically more stable than the 6-isomer in the gaseous phase and these results provide evidence for the existence of a strong intramolecular H-bond in 7-hydroxy-1-indanone. Finally, the intramolecular proton transfer in 7-hydroxy-1-indanone has been evaluated and as expected, it is not energetically favorable.

A bi-overlayer type plasmonic photocatalyst consisting of mesoporous Au/TiO2 and CuO/SnO2 films separately coated on FTO

2015 ◽  
Vol 17 (27) ◽  
pp. 18004-18010 ◽  
Author(s):  
Shin-ichi Naya ◽  
Takahiro Kume ◽  
Nozomi Okumura ◽  
Hiroaki Tada
Keyword(s):  
Liquid Phase ◽  
Visible Light ◽  
Gas Phase ◽  
Plasmonic Photocatalyst ◽  
Light Activity ◽  
High Level

A bi-overlayer type “plasmonic photocatalyst” consisting of Au/mp-TiO2 and CuO/mp-SnO2 separately formed on the FTO substrate exhibits a high level of visible-light activity for the gas-phase and liquid-phase reactions.

Comparison of Selective Gas Phase- and Liquid Phase Hydrogenation of (Cyclo-)Alkadienes towards Cycloalkenes on Pd/Alumina Egg-Shell Catalysts

2006 ◽  
Vol 29 (12) ◽  
pp. 1487-1495 ◽  
Author(s):  
N. Wuchter ◽  
P. Schäfer ◽  
C. Schüler ◽  
J. Gaube ◽  
G. Miehe ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Liquid Phase Hydrogenation ◽  
Egg Shell

scholarly journals INFLUENCE OF GAS-PHASE REDUCTION DURATION ON THE COMPOSITION OF POLYMER-STABILIZED CATALYTIC SYSTEMS OF LIQUID-PHASE HYDROGENATION OF BENZENE

2020 ◽  
pp. 73-84
Author(s):  
Алексей Владимирович Быков ◽  
Галина Николаевна Демиденко ◽  
Линда Жанновна Никошвили
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflection ◽  
Catalytic Systems ◽  
X Ray ◽  
Hydrogen Flow ◽  
Liquid Phase Hydrogenation ◽  
Phase Reduction ◽  
Polymer Stabilized

В работе исследовано влияние продолжительности восстановления металлосодержащих полимерстабилизированных систем Ме/MN100 на их активность в процессе жидкофазного гидрирования бензола. Каталитические системы охарактеризованы методами инфракрасной спектроскопии диффузного отражения и рентгенофотоэлектронной спектроскопии. В ходе исследования показано, что продолжительность восстановления в токе водорода при 300С влияет на активность изученных систем и состав их поверхности. The effect of the reduction duration of metal-containing polymer-stabilized Me/MN100 systems on their activity in the process of liquid-phase hydrogenation of benzene is studied. Catalytic systems are characterized by diffuse reflection infrared spectroscopy and x-ray photoelectron spectroscopy. The study shows that the duration of reduction in the hydrogen flow at 300C affects the activity of the studied systems and the composition of their surface.

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