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 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.

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.

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.

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.

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