A theoretical study of asymptotic solutions (constant-pattern solutions) of fixed-bed hydriding processes is presented for systems with finite longitudinal dispersion in a bed and finite resistances to mass transfer. A closed form of the solutions is obtained under conditions where a metal hydride has a plateau pressure on its equilibrium isotherm. If the equilibrium isotherm does not intersect a straight line connecting two points of an influent condition and an initial one of the bed on an x-ymdiagram, a single asymptotic mass transfer zone propagates through the bed. On the other hand, if the isotherm does intersect the line, a twin asymptotic mass transfer zone propagates. Then a plateau zone is formed between the two zones. Application to a titanium hydride bed demonstrates the usefulness of the analytical results on the basis of the asymptotic solutions.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)