Pure hydrogen generation in a fluidized bed membrane reactor: Application of the generalized comprehensive reactor model

• Published in: Chemical engineering science Vol. 64; no. 17; pp. 3826 - 3846
• Main Authors: Mahecha-Botero, Andrés, Grace, John R., Jim Lim, C., Elnashaie, S.S.E.H., Boyd, Tony, Gulamhusein, Ali
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2009; Elsevier
• Subjects: Applied sciences; Chemical engineering; Chemical reactors; Exact sciences and technology; Fluidization; Heat and mass transfer. Packings, plates; Hydrodynamics of contact apparatus; Membrane reactor; Membranes; Reactor modelling; Reactors; Simulation; Steam methane reforming; Membrane reactor; Membranes; Simulation; Fluidization; Chemical reactors; Reactor modelling; Steam methane reforming; High density; Interphase; Prediction; Catalytic reactor; Hydrodynamics; Crossflow; Reforming; Water vapor; Modeling; Mass transfer; Operating conditions; Chemical reactor; Flow regime; Hydrogen production; Fluidized bed
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2009.05.025

A generalized comprehensive model was developed to simulate a wide variety of fluidized-bed catalytic reactors. The model characterizes multiple phases and regions (low-density phase, high-density phase, staged membranes, freeboard region) and allows for a seamless introduction of features and/or simplifications depending on the system of interest. The model is implemented here for a fluidized-bed membrane reactor generating hydrogen. A concomitant experimental program was performed to collect detailed experimental data in a pilot scale prototype reactor operated under steam methane reforming (SMR) and auto-thermal reforming (ATR) conditions, without and with membranes of different areas under diverse operating conditions. The results of this program were published in Mahecha-Botero et al. [2008a. Pure hydrogen generation in a fluidized bed membrane reactor: experimental findings. Chem. Eng. Sci. 63(10), pp. 2752–2762]. The reactor model is tested in this second paper of the series by comparing its simulation predictions against axially distributed concentration in the pilot reactor. This leads to a better understanding of phenomena along the reactor including: mass transfer, distributed selective removal of species, interphase cross-flow, flow regime variations, changes in volumetric flow, feed distribution, and fluidization hydrodynamics. The model does not use any adjustable parameters giving reasonably good predictions for the system of study.