Hydrogen adsorption on Ni/γ-Al2O3 in a fixed-bed adsorber: Experimental validation and numerical modelling

This work studies a dynamics mathematical model coupled the adsorption isotherm (Toth model) that describes the adsorption of H-2 in a fixed-bed adsorber (FBA). The developed dynamics modelling reports the diffusion-adsorption process in terms of mass transfer phenomena (external and internal). The adsorption equilibrium experimental data of H-2 were measured using an electromagnetic suspension microbalance for Ni (1.37%wt)/gamma-Al2O3 and Ni(5.72%wt)/gamma-Al2O3. The experimental data were correlated with the Toth isotherm model using nonlinear regression technique for three different temperatures 300, 310 and 325K. The nonlinear Levenberg-Marquardt parameter estimation method was used to estimate the parameters of the Toth isotherm. The mathematical model was validated against a set of experimental data (breakthrough curves) where model results adequately matched the experimental curves. The effects of flow rate, bed length and inlet H-2 concentration (simulations) on the breakthrough curves have been reported. Modelling and simulation of the breakthrough curves have shown a good performance during the estimation (D-cp,D-H2,D-0 vertical bar r(cp)(2), E-a) and validation stages. A simulating study was developed to analyze the concentration of H-2 in the gaseous phase of different axial positions (dimensionless (z/L)) from FBA as well as the gas concentration of H-2 of different radial positions (dimensionless (r/Rp)) of the catalyst particle. Moreover, the concentration profiles of H-2 of different adsorption time were investigated. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.