Abstract:
One-dimensional heterogeneous model for sorption enhanced steam methane reforming (SESMR) process is developed for an adiabatic packed bed reactor and implemented this
mathematical model in gPROMS Modelbuilder®. The reactor model is based on both gas and solid, mass and energy transfer principles along with the empirical correlations. The kinetic equations for CaO, lithium zirconate (LZC) and hydrotalcite (HTC) published in literature were used in the model. The performance of SE-SMR process is modelled to find the optimum operational conditions of temperature, pressure, steam to carbon ratio (S/C) and gas mass flow velocity (Gs). Concept of pre-breakthrough curve of these sorbents were studied using the transient temperature profiles. In the present work, low pressure (3 – 11 bar) is used for the SESMR process. The sensitive analysis was carried out by changing the operational parameters like temperature, pressure, S/C and Gs to study the CH4 conversion, H2 purity and yield, and CO2 capture efficiency during the SE-SMR process. The simulation results were also compare with the equilibrium results generated through chemical equilibrium and application (CEA) software. It was concluded from the analysis that 82% CH4 conversion and 85% H2 purity can be
achieved at 900 K, 3 bar, 3.5 kgm-2s-1 and S/C of 3.0 by using CaO sorbent. LZC and HTC gave high CH4 conversion, 91.3 and 92.6% respectively, and H2 purity 94.08 and 95.7% respectively. HTC gave more CH4 conversion enhancement (CF) than CaO and LZC, but with slow capture kinetics. In case of HTC, 5 bar, 900 K, and S/C of 3.0 gave 118% CF