Enhancement of Hydrogen Production and Carbon Dioxide Capturing in a Novel Methane Steam Reformer Coupled with Chemical Looping Combustion and Assisted by Hydrogen Perm-Selective Membranes

In this novel paper, application of chemical looping combustion (CLC) instead of furnace in a steam reformer assisted by Pd-Ag hydrogen perm-selective membranes (CLC-SRM) for CO2 capture and hydrogen production has been analyzed. NiO18-alpha Al2O3 particles have been employed as oxygen carriers in CLC-SRM. These particles have shown very high reactivity and allow for working at high temperatures in a CLC process with full methane conversion due to Ni-based oxygen carriers. In the CLC-SRM configuration, the air reactor (AR) and fuel reactor (FR) operate in fast and bubbling fluidization, respectively. In this configuration, reforming tubes are located vertically inside the AR so that methane steam reforming occurs in these fixed bed catalytic tubes that have been covered by the membranes. A steady state one-dimensional heterogeneous catalytic reaction model is applied to analyze the performance of CLC-SRM. Performance of conventional steam reformer (CSR) has been compared with CLC-SRM by investigation of important parameters such as temperature, mole fractions, heat of reaction, rate of reactions, methane conversion, and hydrogen production. The simulation results of CLC-SRM show that by employing CLC-SRM, methane conversion and hydrogen production increase 7.54% and 25.48%, respectively, in comparison with CSR. In addition, results indicated that by increasing feed flow rate of FR from 90 to 180 mol s(-1) methane conversion and hydrogen production can increase 16.73% and 40%, respectively. In CLC-SRM, the total amount of methane consumed in the FR and combustion efficiency increases to 1 in the FR, and a huge amount of almost pure carbon dioxide (410 ton day(-1)) can be captured by removal of water from the FR outlet stream with condensation.