Hydrogen yield data pertaining to the performance evaluation of microchannel reforming reactors under different porosity conditions
Description
The hydrogen yield data are obtained for evaluating the performance of microchannel reforming reactors under different porosity conditions. The reforming process proceeds in one set of the channels through which the endothermic reactants flow, and the exothermic oxidation process proceeds in the second set of the channels. Exothermic and endothermic reactions take place simultaneously whereby the heat required for the latter is supplied by the former. Heat transfer occurs via conduction through the walls of the reactor. For the endothermic reaction, the structure is especially effective because both the internal surfaces of the walls are coated with structured catalysts, which is capable of providing more efficient heat exchange and minimizing the problem of loss of catalytic activity. The ratio of the height of the channels to the width of the channels may vary. 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 and the catalyst layers is 0.7 millimeters and 0.1 millimeters, respectively. The reforming catalyst consists essentially of copper and oxides of zinc and aluminum. The oxidation catalyst consists essentially of oxides of copper, zinc and aluminum. The oxidation catalyst allows for initial start-up and the heat-up of the reactor system. 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 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 boundary conditions relate macroscopic fluid flow at a catalytically active surface to the rates of surface reactions. Heterogeneous reactions at a catalytically active surface affect the heat and mass balance at the surface. Each porous medium is modeled by adding a momentum source term to the standard momentum conservation equations. 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
The endothermic process is modeled in such a way as to take into account methanol steam reforming and decomposition and the water-gas shift reaction. Boundary conditions are specified and physical properties are defined for the fluids, solids, and mixtures. Physical properties depend on temperature and composition.