Fluid mechanics of heterogeneously catalyzed steam reforming reactors with different catalyst support material porosity
Description
The volumetric flow rate data with different catalyst support material porosity are presented for heterogeneously catalyzed steam reforming reactors. In fluid mechanics, the volumetric flow rate is the volume of fluid which passes per unit time. The heterogeneously catalyzed steam reforming reactor provides for continuous and simultaneous reaction of two different process reaction streams in the channels defined between the walls, wherein a first process reaction stream undergoes a high temperature exothermic reaction in the first set of flow channels and a second process reaction stream undergoes an endothermic heat-consuming reaction in the second set of flow channels separated from the first set of flow channels by the heat transfer separating walls. More specifically, the reactor includes a set of reforming channels for steam reformation of methanol and a set of oxidation channels for heating the reactor to operating temperature. The channels are 0.7 millimeters in height and in width and 30.0 millimeters in length. To ensure the mechanical strength at elevated pressures, the thickness of the uncoated walls and the catalyst layers is 0.7 millimeters and 0.1 millimeters, respectively. The oxidation catalyst consists essentially of oxides of copper, zinc and aluminum. The reforming catalyst consists essentially of copper and oxides of zinc and aluminum. The exothermic and endothermic processes are conducted with a methanol-air equivalence ratio of 0.8 and a steam-to-methanol molar ratio of 1.17. The inlet temperature of the mixtures is 373 degrees kelvin. The gas velocity is 2.0 meters per second at the reforming channel inlets and 0.6 meters per second at the oxidation channel inlets. The Reynolds numbers are very small so that the gases flow through the channels in a laminar flow regime. The mathematical formalism developed to describe transport phenomena and chemical kinetics is implemented into ANSYS FLUENT. More specifically, ANSYS FLUENT is applied to define the terms in the equations relating to conservation, thermodynamics, chemical production rates, and equation of state, and then combine the results to define the problem involving surface chemistry. To describe the surface reaction mechanisms in symbolic form, the following information is required, including the thermochemical properties of surface species in the surface phases, names of the surface species, site densities, names of all surface phases, Arrhenius rate coefficients, reaction descriptions, and any optional coverage parameters. Contributor: Junjie Chen, E-mail address: koncjj@gmail.com, ORCID: 0000-0002-5022-6863, Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China
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Steps to reproduce
ANSYS FLUENT is applied to the problem involving surface chemistry. The problem is solved using structured meshes. The under-relaxation factors are reduced for all variables. The mesh is refined in the computational domains of the catalytically active layers. The solution converges when the residuals reach the specified tolerance and overall property conservation is satisfied.