Sorption Enhanced Steam Methane Reforming Process Performance and Bubbling Fluidized Bed Reactor Design Analysis by Use of a Two-Fluid Model

This paper discusses simulations of reactive flows in a two-dimensional cylindrical bubbling fluidized bed reactor by using an Eulerian modeling approach. The study is intended to elucidate some aspects of high relevance for the development of novel concepts in the area of hydrogen production by means of steam methane reforming (SMR). The work is initiated with a practical model validation of reactive gas−solid flows with simulations of laboratory-scale experiments of the ozone decomposition reaction. The predicted outlet concentrations for various fluidization velocities are in very good agreement with reported experimental data. Further, investigations of sorption enhanced steam methane reforming (SE-SMR) in bubbling fluidized beds are conducted with lithium zirconate as the CO2 adsorbent. As long as extensive gas mixing is avoided, wide reactors are the most favorable choice for industrial applications since variations in bed diameter have a minor influence on the outlet hydrogen concentration. Running the process at elevated operating pressures and/or higher fluidization velocities requires increased bed heights. The most interesting finding of this work is the demonstration of how internal circulation and spatial temperature variations affect the reactor performance.