Steam mole fraction data pertaining to the oxidation process in heterogeneously catalyzed reforming reactors with different catalyst support porosity
Description
The steam mole fraction data are presented for illustrating the oxidation process in heterogeneously catalyzed reforming reactors with different catalyst support porosity. The steam mole fraction data are directed to a parallel reaction system, especially a chemical processing micro-system, which can simultaneously carry out exothermic and endothermic reactions in separate micro-channels and simultaneously adjust feed composition and flow rates. Specifically, the present study relates to a catalytic process of steam-methanol reforming for the production of hydrogen in a heterogeneous reactor system. The steam reforming process has several drawbacks, the primary ones being that the porosity of the catalyst supports is not as high as would appear to be optimum. To obtain the solution of the problem, numerical simulations are performed using fluid mechanics. The thermal conductivity of the wall material is 18.0 watts per meter-kelvin at room temperature. To assure that adequate temperatures are provided for endothermic reforming, operating flow conditions are specified for the reactor by giving the gas velocity. 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, thereby assuring sufficient heat in the reactor to carry out endothermic reforming of methanol. The effective thermal conductivity of the catalyst layers is 16 watts per meter-kelvin at room temperature. The cross-sectional configuration of the channels is square. The channels are 0.7 millimeters in height and in width and 30.0 millimeters in length. Channel height refers to the inside height of a channel. To ensure the mechanical strength at elevated pressures, the thickness of the uncoated walls is 0.7 millimeters. 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 at a pressure of 0.8 megapascals, 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 temperature of the reactor can be regulated by the balance of the flow rates so that the catalyst is not overheated by the exothermic process and thus damaged. To facilitate computational modeling of transport phenomena and chemical kinetics in the reactor system, steady-state analyses are performed and fluid mechanics is used. ANSYS FLUENT is applied to the problem involving surface chemistry. 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
Numerical simulations are performed within ANSYS FLUENT using fluid mechanics. The governing equations are solved numerically for the conservation of mass and momentum and for energy and species. The residuals decrease by at least six orders of magnitude. The solution converges when the residuals reach the specified tolerance and overall property conservation is satisfied.