Modeling of Hollow Cylindrical Catalytic Pellets – Analytical Solutions for First Order Reaction

Mathematical modeling of catalytic reaction was performed for hollow cylindrical pellets with infinitely long or finite length. For isothermal irreversible first order reaction, intra-particle concentration could be predicted from analytical solutions obtained by solving reaction-diffusion equations. Both diffusional and surface film resistance were considered in the Factors affecting distribution reactant inside pellet surrounded large medium studied adjusting thickness core (x’), aspect ratio (γ0), Thiele modulus (Φ), Biot number (Bi). Transient length also derived unsteady-state partial differential equation using separation variables eigenfunction expansion method, respectively. Analytical effectiveness factor (η), which increased increasing x’ decreasing γ0 due to decrease active volume pellet. length, η as two different mathematical expressions, are advantageous evaluate eigenvalues various γ0. series (A→B→C), secondary (ηB→C) time apply pseudo steady-state approximation batch fixed bed reactors. The performance reactors consecutive Φ. Maximum intermittent product reactor pellets, compared conventional pellets. simple (A→B), transient exit stream containing Reaction conversion at steady state enhanced smaller γ0, while pressure drop reduced,