scholarly journals Enhancement of Desulfurization Capacity with Cu-Based Macro-Porous Sorbents for Hydrogen Production by Gasification of Petroleum Cokes

2021 ◽  
Vol 11 (17) ◽  
pp. 7775
Author(s):  
Dongjoon Kim ◽  
Dasol Bae ◽  
Yu Jin Kim ◽  
Seung Jong Lee ◽  
Jin Wook Lee ◽  
...  
Keyword(s):  
Density Functional ◽  
Porous Alumina ◽  
Carbonyl Sulfide ◽  
Density Functional Theory Calculations ◽  
Gas Diffusion ◽  
Diffusion Resistance ◽  
Functional Theory ◽  
Powder Type ◽  
Porous Sorbents ◽  
Kinetics Of

Macro-porous alumina was used as a support for a pellet-type Cu-based desulfurization sorbent in the gas purification process for producing blue hydrogen by the gasification of petroleum coke. The effects of the macro-porous alumina on the pellet-type sorbents in reducing the gas diffusion resistance into the pores were investigated. The results showed that the macro-porous alumina enhances the diffusion resistance, resulting in an improved sulfur capacity of CuO absorbents. Such effects were more significant on the pellet type CuO absorbents than the powder type. In addition, CO production was observed experimentally during the desulfurization reaction of carbonyl sulfide (COS) at low temperatures (~473 K). Density functional theory calculations were also performed to understand the kinetics of desulfurization and CO production. The simulation results predicted that the kinetics of desulfurization is strongly affected by the local surface environment. The CO generated from C–O bond breaking from COS had a lower adsorption energy than the CO2 formation. These results suggest that the Cu-based desulfurization sorbent has potential catalytic activity for producing CO from COS dissociation.

scholarly journals Thermal Stability and Decomposition Kinetics of 1-Alkyl-2,3-Dimethylimidazolium Nitrate Ionic Liquids: TGA and DFT Study

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2560
Author(s):  
Jianwen Meng ◽  
Yong Pan ◽  
Fan Yang ◽  
Yanjun Wang ◽  
Zhongyu Zheng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Density Functional Theory ◽  
Ionic Liquids ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Nitrogen Atmosphere ◽  
Decomposition Kinetics ◽  
Heating Rates ◽  
Functional Theory ◽  
Kinetics Of

The thermal stability and decomposition kinetics analysis of 1-alkyl-2,3-dimethylimidazole nitrate ionic liquids with different alkyl chains (ethyl, butyl, hexyl, octyl and decyl) were investigated by using isothermal and nonisothermal thermogravimetric analysis combined with thermoanalytical kinetics calculations (Kissinger, Friedman and Flynn-Wall-Ozawa) and density functional theory (DFT) calculations. Isothermal experiments were performed in a nitrogen atmosphere at 240, 250, 260 and 270 °C. In addition, the nonisothermal experiments were carried out in nitrogen and air atmospheres from 30 to 600 °C with heating rates of 5, 10, 15, 20 and 25 °C/min. The results of two heating modes, three activation energy calculations and density functional theory calculations consistently showed that the thermal stability of 1-alkyl-2,3-dimethylimidazolium nitrate ionic liquids decreases with the increasing length of the alkyl chain of the substituent on the cation, and then the thermal hazard increases. This study could provide some guidance for the safety design and use of imidazolium nitrate ionic liquids for engineering.

Modeling Reaction Kinetics of Twin Polymerization via Differential Scanning Calorimetry

2018 ◽  
Vol 43 (4) ◽  
pp. 347-357
Author(s):  
Janett Prehl ◽  
Robin Masser ◽  
Peter Salamon ◽  
Karl Heinz Hoffmann
Keyword(s):  
Reaction Mechanism ◽  
Density Functional ◽  
Reaction Rate ◽  
Density Functional Theory Calculations ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Reaction Rate Constants ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Derivatives Of

Abstract We present a kinetic model for the reaction mechanism of acid-catalyzed twin polymerization. Our model characterizes the reaction mechanism not by the reactants, intermediate structures, and products, but via reaction-relevant moieties. We apply our model for three different derivatives of 2,2’-Spirobi[4H-1,3,2-benzodioxasiline] and determine activation energies, reaction enthalpies, and reaction rate constants for the reaction steps in our mechanism. We compare our findings to previously reported values obtained from density functional theory calculations. Furthermore, with this approach we are also able to follow the time development of the concentrations of the reaction-relevant moieties.

Accelerating the oxygen evolution reaction kinetics of Co3O4 in neutral electrolyte by decorating RuO2

2021 ◽  
Author(s):  
Kaifa Lu ◽  
Guanru Chang ◽  
Hui Zhang ◽  
Xin-Yao Yu
Keyword(s):  
Density Functional Theory ◽  
Reaction Kinetics ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Neutral Electrolyte ◽  
Kinetics Of

By combining density functional theory calculations and experiments, we have demonstrated that the decoration of RuO2 can effectively accelerate the oxygen evolution reaction kinetics of Co3O4 in neutral electrolyte.

Experimental (FTIR, BDS) and theoretical analysis of mutarotation kinetics of d-fructose mixed with different alcohols in the supercooled region

RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 57634-57646 ◽  
Author(s):  
M. Dulski ◽  
A. Cecotka ◽  
S. N. Tripathy ◽  
A. Sakalouski ◽  
K. Wolnica ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Fourier Transform ◽  
Theoretical Analysis ◽  
Binary Mixture ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Broadband Dielectric Spectroscopy ◽  
Kinetics Of ◽  
Supercooled Region

The mutarotation kinetics of pure molten d-fructose and its binary mixture with alcohols (i.e., sorbitol and maltitol) have been reported using Fourier transform infrared, broadband dielectric spectroscopy and density functional theory calculations.

On the Linear Geometry of Lanthanide Hydroxide (Ln—OH, Ln=La-Lu)

2019 ◽  
Author(s):  
Hassan Harb ◽  
Lee Thompson ◽  
Hrant Hratchian
Keyword(s):  
Triple Bond ◽  
Density Functional ◽  
Valence Electron ◽  
Density Functional Theory Calculations ◽  
Electron Configuration ◽  
Functional Theory ◽  
Key Species ◽  
Pi Orbitals ◽  
Lanthanide Hydroxide ◽  
Linear Geometry

Lanthanide hydroxides are key species in a variety of catalytic processes and in the preparation of corresponding oxides. This work explores the fundamental structure and bonding of the simplest lanthanide hydroxide, LnOH (Ln=La-Lu), using density functional theory calculations. Interestingly, the calculations predict that all structures of this series will be linear. Furthermore, these results indicate a valence electron configuration featuring an occupied sigma orbital and two occupied pi orbitals for all LnOH compounds, suggesting that the lanthanide-hydroxide bond is best characterized as a covalent triple bond.

On the Linear Geometry of Lanthanide Hydroxide (Ln—OH, Ln=La-Lu)

2019 ◽  
Author(s):  
Hassan Harb ◽  
Lee Thompson ◽  
Hrant Hratchian
Keyword(s):  
Triple Bond ◽  
Density Functional ◽  
Valence Electron ◽  
Density Functional Theory Calculations ◽  
Electron Configuration ◽  
Functional Theory ◽  
Key Species ◽  
Pi Orbitals ◽  
Lanthanide Hydroxide ◽  
Linear Geometry

Lanthanide hydroxides are key species in a variety of catalytic processes and in the preparation of corresponding oxides. This work explores the fundamental structure and bonding of the simplest lanthanide hydroxide, LnOH (Ln=La-Lu), using density functional theory calculations. Interestingly, the calculations predict that all structures of this series will be linear. Furthermore, these results indicate a valence electron configuration featuring an occupied sigma orbital and two occupied pi orbitals for all LnOH compounds, suggesting that the lanthanide-hydroxide bond is best characterized as a covalent triple bond.

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