Evaluation of a novel coupling process for the simultaneous production of syngas and ultra-pure hydrogen from natural gas with in situ utilization of carbon dioxide

Abstract

Recently, with the aim of developing clean and efficient energy systems, various designs based on chemical looping combustion and reforming have been suggested. This study proposed and investigated the production of ultra-pure hydrogen in dual-purpose integrated zero-emission reforming (UPH2-DPIZER) process based on the sorption-enhanced chemical looping steam methane reforming (SECLSMR). This process is proposed on the basis of reduction in the emissions of carbon dioxide as well as the simultaneous generation of pure hydrogen and syngas for use in a wide range of applications. One of the most novel aspects of this research is that the proposed UPH2-DPIZER process can reduce or eliminate carbon dioxide emissions because all the produced and chemisorbed CO2 can be applied directly in the reforming process without any additional purification. Furthermore, the synthesized 30 wt%NiO-5wt.%CeO2/Al2O3 oxygen carrier was examined using the X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) techniques along with evaluation in SECLSMR process. The attained results of experimental tests are applied to adapt and validate the simulations of novel proposed process. The other objectives of this study are the reduction in required energy for the whole process along with reduction in the direct consumption of fossil fuels. The experiments showed high H2/CO molar ratio of 36 at 550 °C with appropriate methane conversion of about 74 %, while at 750 °C, nearly a complete conversion of CH4 occurs. The obtained results from the simulation of proposed UPH2-DPIZER showed the production of ultra-pure hydrogen along with syngas with H2/CO molar ratio of about 1 with negligible CO2 release.