The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Robert F. Mudde - One of the best experts on this subject based on the ideXlab platform.
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Direct numerical simulation of an exothermic Gas-Phase Reaction in a packed bed with random particle distribution
Chemical Engineering Science, 2013Co-Authors: Fatemeh Mousazadeh, H.e.a. Van Den Akker, Robert F. MuddeAbstract:We performed Direct Numerical Simulation (DNS) of an exothermic Gas-Phase Reaction under laminar flow condition in a 2-D packed bed reactor with random distribution of cylindrical particles of 2.9. mm diameter. The Reaction used in this work is of Arrhenius type between Ethylene and Oxygen with Ethylene Oxide as a product. The Gas flows into the reactor as a mixture of Ethylene and Oxygen. The simulations show that there is a region in the reactor with high Reaction rate where basically all heat is produced. There is a large temperature gradient in this region in the radial direction and in the other parts of the reactor there is no temperature gradient in the radial direction. There is not a big convection term in the radial direction in the modeled packed bed. This rather small convection in the radial direction is the result of the arrangement of the particles. CFD simulations provide useful data on the flow field and radial convective term inside the packed beds which can be used for the improvement and further optimization on the design and operation of the packed bed reactors. ?? 2013 Elsevier Ltd.
Josep M Anglada - One of the best experts on this subject based on the ideXlab platform.
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Gas Phase Reaction of nitric acid with hydroxyl radical without and with water a theoretical investigation
Journal of Physical Chemistry A, 2010Co-Authors: Javier Gonzalez, Josep M AngladaAbstract:The Gas Phase Reaction between nitric acid and hydroxyl radical, without and with a single water molecule, has been investigated theoretically using the DFT-B3LYP, MP2, QCISD, and CCSD(T) theoretical approaches with the 6-311+G(2df,2p) and aug-cc-pVTZ basis sets. The Reaction without water begins with the formation of a prereactive hydrogen-bonded complex and has several elementary Reactions processes. They include proton coupled electron transfer, hydrogen atom transfer, and proton transfer mechanisms, and our kinetic study shows a quite good agreement of the behavior of the rate constant with respect to the temperature and to the pressure with the experimental results from the literature. The addition of a single water molecule results in a much more complex potential energy surface although the different elementary Reactions found have the same electronic features that the naked Reaction. Two transition states are stabilized by the effect of a hydrogen bond interaction originated by the water molecule,...
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different catalytic effects of a single water molecule the Gas Phase Reaction of formic acid with hydroxyl radical in water vapor
ChemPhysChem, 2009Co-Authors: Josep M Anglada, Javier GonzalezAbstract:The effect of a single water molecule on the Reaction mechanism of the Gas-Phase Reaction between formic acid and the hydroxyl radical was investigated with high-level quantum mechanical calculations using DFT-B3LYP, MP2 and CCSD(T) theoretical approaches in concert with the 6-311 +G(2df,2p) and aug-cc-pVTZ basis sets. The Reaction between HCOOH and HO has a very complex mechanism involving a proton-coupled electron transfer process (pcet), two hydrogen-atom transfer Reactions (hat) and a double proton transfer process (dpt). The hydroxyl radical predominantly abstracts the acidic hydrogen of formic acid through a pcet mechanism. A single water molecule affects each one of these Reaction mechanisms in different ways, depending on the way the water interacts. Very interesting is also the fact that our calculations predict that the participation of a single water molecule results in the abstraction of the formyl hydrogen of formic acid through a hydrogen atom transfer process (hat).
Javier Gonzalez - One of the best experts on this subject based on the ideXlab platform.
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Gas Phase Reaction of nitric acid with hydroxyl radical without and with water a theoretical investigation
Journal of Physical Chemistry A, 2010Co-Authors: Javier Gonzalez, Josep M AngladaAbstract:The Gas Phase Reaction between nitric acid and hydroxyl radical, without and with a single water molecule, has been investigated theoretically using the DFT-B3LYP, MP2, QCISD, and CCSD(T) theoretical approaches with the 6-311+G(2df,2p) and aug-cc-pVTZ basis sets. The Reaction without water begins with the formation of a prereactive hydrogen-bonded complex and has several elementary Reactions processes. They include proton coupled electron transfer, hydrogen atom transfer, and proton transfer mechanisms, and our kinetic study shows a quite good agreement of the behavior of the rate constant with respect to the temperature and to the pressure with the experimental results from the literature. The addition of a single water molecule results in a much more complex potential energy surface although the different elementary Reactions found have the same electronic features that the naked Reaction. Two transition states are stabilized by the effect of a hydrogen bond interaction originated by the water molecule,...
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different catalytic effects of a single water molecule the Gas Phase Reaction of formic acid with hydroxyl radical in water vapor
ChemPhysChem, 2009Co-Authors: Josep M Anglada, Javier GonzalezAbstract:The effect of a single water molecule on the Reaction mechanism of the Gas-Phase Reaction between formic acid and the hydroxyl radical was investigated with high-level quantum mechanical calculations using DFT-B3LYP, MP2 and CCSD(T) theoretical approaches in concert with the 6-311 +G(2df,2p) and aug-cc-pVTZ basis sets. The Reaction between HCOOH and HO has a very complex mechanism involving a proton-coupled electron transfer process (pcet), two hydrogen-atom transfer Reactions (hat) and a double proton transfer process (dpt). The hydroxyl radical predominantly abstracts the acidic hydrogen of formic acid through a pcet mechanism. A single water molecule affects each one of these Reaction mechanisms in different ways, depending on the way the water interacts. Very interesting is also the fact that our calculations predict that the participation of a single water molecule results in the abstraction of the formyl hydrogen of formic acid through a hydrogen atom transfer process (hat).
Fatemeh Mousazadeh - One of the best experts on this subject based on the ideXlab platform.
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Direct numerical simulation of an exothermic Gas-Phase Reaction in a packed bed with random particle distribution
Chemical Engineering Science, 2013Co-Authors: Fatemeh Mousazadeh, H.e.a. Van Den Akker, Robert F. MuddeAbstract:We performed Direct Numerical Simulation (DNS) of an exothermic Gas-Phase Reaction under laminar flow condition in a 2-D packed bed reactor with random distribution of cylindrical particles of 2.9. mm diameter. The Reaction used in this work is of Arrhenius type between Ethylene and Oxygen with Ethylene Oxide as a product. The Gas flows into the reactor as a mixture of Ethylene and Oxygen. The simulations show that there is a region in the reactor with high Reaction rate where basically all heat is produced. There is a large temperature gradient in this region in the radial direction and in the other parts of the reactor there is no temperature gradient in the radial direction. There is not a big convection term in the radial direction in the modeled packed bed. This rather small convection in the radial direction is the result of the arrangement of the particles. CFD simulations provide useful data on the flow field and radial convective term inside the packed beds which can be used for the improvement and further optimization on the design and operation of the packed bed reactors. ?? 2013 Elsevier Ltd.
Gregory L Huey - One of the best experts on this subject based on the ideXlab platform.
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kinetics and products of the Gas Phase Reaction of so3 with water
The Journal of Physical Chemistry, 1996Co-Authors: Edward R Lovejoy, And David R Hanson, Gregory L HueyAbstract:The kinetics of the Gas-Phase Reactions of SO3 with H2O and D2O were studied over the temperature range 250−360 K in N2 with a laminar flow reactor coupled to a chemical ionization mass spectrometer. The SO3 loss is second order in the water concentration, is independent of pressure (20−80 Torr N2, 300 K), and has a strong negative temperature dependence and a significant H/D isotope effect (kH2O ≈ 2kD2O). The yield of sulfuric acid is 1.0 ± 0.5 per SO3 consumed. These observations are consistent with the rapid association of SO3 and H2O to form the adduct H2OSO3 which reacts with water to produce sulfuric acid. The first-order rate coefficients for loss of SO3 by Reaction with H2O and D2O are given by kI(s-1) = (2.26 ± 0.85) × 10-43T exp((6544 ± 106)/T)[H2O]2 and (9.45 ± 2.68) × 10-44T exp((6573 ± 82)/T)[D2O]2, where T ≡ K and [H2O, D2O] ≡ molecule cm-3. The errors are the uncertainty at the 95% confidence level for precision only. Analysis of the temperature dependence of the SO3 loss yields an upper li...
