Simulation of Hydrogen Production with In Situ CO2 Removal Using Aspen Plus

Abstract

In this work, the sorption-enhanced steam methane reforming (SE-SMR) in which the integration of steam reforming reaction and carbon dioxide removal can be carried out in a single step was investigated in the thermodynamics aspects by using AspenPlusTM. Thermodynamics analysis was performed on both conventional steam methane reforming (SMR) and sorption-enhanced steam methane reformingprocesses based on minimization of Gibbs free energy method to determine the favorable operating conditions of each process. The effects of operating conditions (i.e., pressure, temperature and steam to carbon ratio) on hydrogen production were examined. The simulation results show that the optimal steam to carbon ratio is 6 and 5 for SMR and SE-SMR process, respectively. For SMR process, the maximum hydrogen purity of 78 % (dry basis) can be obtained at 950 K. While, the SE-SMR process offers two advantages over SMR process: (1) higher purity of hydrogen product can be achieved to 99 % (dry basis) and (2) required operating temperature is lower in the range of 700-850 K which is 100-150 K lower than SMR process, indicating that the SE-SMR process is less requirement of energy consumption.