SO2 oxidation in a reverse-flow reactor: Influence of a vanadium catalyst dynamic properties

Bunimovich, Grigori A.; Vernikovskaya, N.V.; Strots, Vadim O.; Бальжинимаев, Б. С.; Matros, Yu. Sh.

doi:10.1016/0009-2509(94)00443-u

Cited by 40 publications

(13 citation statements)

References 8 publications

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“…This idea has typically been limited to “one-fuel” systems on account of the complexity of the process. − A second strategy is “temporal” coupling of the two reactions, where the exothermic and endothermic reactions are alternately carried out in the same reaction chamber. The reverse flow reactor is a possible avenue for achieving this and has been well-investigated, among others by Dudukovic and co-workers, for example. − This approach has been successful for weakly exothermic streams where the energy is “trapped” within the reactor. However, the valves necessary for periodic reversal are susceptible to failure.…”

Section: Introductionmentioning

confidence: 99%

CFD Simulations of Coupled, Countercurrent Combustor/Reformer Microdevices for Hydrogen Production

Deshmukh

Vlachos

2005

Ind. Eng. Chem. Res.

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Two-dimensional computational fluid dynamics (CFD) simulations are used to study spatially segregated, multifunctional, microchemical devices for hydrogen production. In particular, coupling between homogeneous propane combustion and catalytic ammonia decomposition on a Ru catalyst is studied in a microdevice consisting of alternating combustion and decomposition channels as a function of flow rate and materials conductivity in the countercurrent flow configuration. It is found that the high temperatures generated via homogeneous combustion lead to high conversions in short contact times and thus to compact devices. Different performance measures are evaluated to assess the operability of the device. Sufficiently high ammonia flow rates serve a dual purpose by lowering device temperatures and enabling the production of larger flow rates of hydrogen. Finally, it is shown that device operation is limited only to high-conductivity materials and fast ammonia flows.

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Section: Introductionmentioning

confidence: 99%

CFD Simulations of Coupled, Countercurrent Combustor/Reformer Microdevices for Hydrogen Production

Deshmukh

Vlachos

2005

Ind. Eng. Chem. Res.

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“…When the V IV concentration in the melt exceeds the solubility limit, precipitation of crystalline V IV compounds occurs. 52 We speculate that the presence of vanadium in linked V V chains hinders the formation of V IV compounds and therefore the depletion of the melt from active V V species. One additional role of Cs might therefore be that of stabilizing vanadium in the active V V state by forming linked structures at low temperature.…”

Section: Discussionmentioning

confidence: 86%

“…When the V IV concentration in the melt exceeds the solubility limit, precipitation of crystalline V IV compounds occurs . We speculate that the presence of vanadium in linked V V chains hinders the formation of V IV compounds and therefore the depletion of the melt from active V V species.…”

Section: Discussionmentioning

confidence: 89%

Vanadia-Based Catalysts for the Sulfur Dioxide Oxidation StudiedIn Situby Transmission Electron Microscopy and Raman Spectroscopy

et al. 2017

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The industrial production of sulfuric acid involves the oxidation of sulfur dioxide, which is catalyzed by a silica-supported phase consisting of V 2 O 5 species dissolved in a pyrosulfate melt with Na, K, and Cs added as promoters. As the molten phase is only present during the catalytic reaction and solidifies at room temperature, in situ studies are necessary to address the working state of the SO 2 oxidation catalyst. Here we combine transmission electron microscopy (TEM) and Raman spectroscopy to study in situ a vanadia-based SO 2 oxidation catalyst upon activation and reaction in an SO 2 / O 2 gas mixture. The observations reveal that the vanadia phase dynamically redistributes on the support upon heating in an SO 2 /O 2 mixture. Surprisingly, the vanadia phase can disperse into partially crystalline islands on convex surfaces of the silica support and into a molten state on concave areas of the support. The presence of Cs was found to lower the temperature for the pyrosulfate formation and stabilize vanadium in the active V V state by forming linked structures at low temperature. Combining these in situ studies with activity measurements leads to the proposal that the linked structures stabilize the catalyst in the active state.

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“…The technology was patented by the Boreskov Institute of Catalyst [5] and was deployed at industrial-scale for processing low-concentration gases (1-5% SO 2 ) in nonferrous metallurgy. The process was studied experimentally and by means of simulations to understand the dynamics of the process [65][66][67][68]. Different reactor configurations were proposed [5]: adiabatic operation, with intermediate heat exchangers to extract the excess heat (concentrations higher than 2-3% SO…”

Section: Oxidation Of Sulphur Dioxidementioning

confidence: 99%

Reverse flow reactors as sustainable devices for performing exothermic reactions: Applications and engineering aspects

Marín

Dı́ez

Ordóñez

2019

Chemical Engineering and Processing - Process Intensification

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Reverse flow reactors are fixed-bed reactors combining in a single intensified device chemical reaction and regenerative heat transfer (energy is stored in a bed as sensible heat). To accomplish this goal, reverse flow reactors are operated in a forced unsteady state created by periodically changing the flow direction. The most important applications of reverse flow reactor are reviewed: oxidation of hydrocarbons and sulphur dioxide, and selective catalytic reduction of nitrogen oxides. These applications involve exothermic reactions. However, recent developments have also made possible it possible the use of reverse flow reactors with endothermic reactions, such methane steam reforming.The modelling of reverse flow reactors is addressed based on the models available for fixed-bed reactors. Practical considerations regarding reverse flow reactors are considered: the selection of the type of bed, the issues of the use of lab-scale devices at dynamic conditions, the assessment of autothermal operation and heat extraction and the integrated adsorption concept. The latter is an innovative concept based on the periodical adsorption in the bed of some of the reactants, products or other feed compounds. This mass regeneration can be combined with the heat regeneration capabilities of reverse flow reactors to increase the degree of process intensification.

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SO2 oxidation in a reverse-flow reactor: Influence of a vanadium catalyst dynamic properties

Cited by 40 publications

References 8 publications

CFD Simulations of Coupled, Countercurrent Combustor/Reformer Microdevices for Hydrogen Production

CFD Simulations of Coupled, Countercurrent Combustor/Reformer Microdevices for Hydrogen Production

Vanadia-Based Catalysts for the Sulfur Dioxide Oxidation StudiedIn Situby Transmission Electron Microscopy and Raman Spectroscopy

Reverse flow reactors as sustainable devices for performing exothermic reactions: Applications and engineering aspects

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