Iron oxide, FeO(s) (mol mass 71.85 g/mol and specific mass 2.5g/cm3) is reduced to metallic iron, Fe(s), in high-temperature furnaces according to the reaction: FeO(s) + H2(g) →Fe(s)+H2O(g) Consider the condition in which pure H2(g) gas (mol mass 2 g/mol) diffuses through a layer of metallic iron of thickness δ and at the lower interface reacts with FeO(s) to form Fe(s) (see Figure 1). The process takes place at 400K and 1 atm and is limited by the diffusion of H2 in metallic iron. At the solid phase interface, the concentration of H2 is given by Sievert's law: CA=SPA1/2, where S is the solubility of H2 in metallic iron and PA is the partial pressure of H2. It is asked: (a) Indicate in the figure the location and geometry of the control volume and the axis reference adopted for the mass balance; (b) Obtain a theoretical (literal) equation for the concentration distribution of H2 inside the metallic iron layer, justifying all the considerations and procedures adopted in the resolution; (c) Obtain a theoretical equation to estimate the molar flow of consumption of H2;
Chemical engineering
Iron oxide, FeO(s) (mol mass 71.85 g/mol and specific mass 2.5g/cm3) is reduced to metallic iron, Fe(s), in high-temperature furnaces according to the reaction:
FeO(s) + H2(g) →Fe(s)+H2O(g)
Consider the condition in which pure H2(g) gas (mol mass 2 g/mol) diffuses through a layer of metallic iron of thickness δ and at the lower interface reacts with FeO(s) to form Fe(s) (see Figure 1).
The process takes place at 400K and 1 atm and is limited by the diffusion of H2 in metallic iron. At the solid phase interface, the concentration of H2 is given by Sievert's law: CA=SPA1/2, where S is the solubility of H2 in metallic iron and PA is the partial pressure of H2. It is asked:
(a) Indicate in the figure the location and geometry of the control volume and the axis
reference adopted for the mass balance;
(b) Obtain a theoretical (literal) equation for the concentration distribution of H2 inside the metallic iron layer, justifying all the considerations and procedures adopted in the resolution;
(c) Obtain a theoretical equation to estimate the molar flow of consumption of H2;
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