Hydrogen Production from the Carbon Dioxide Sorption-Enhanced Steam Reforming of Biogas Over a Ni-Based Hybrid Material with a Calcium Oxide Sorbent

Carbon dioxide (CO2) sorption-enhanced steam reforming of biogas (SESRB) is a promising approach for the production of hydrogen (H2). This method applies hybrid dual-functional materials comprising a reforming catalyst and a CO2 chemisorbent. Biogas, produced from the anaerobic digestion of biowaste, is an alternative feedstock for H2 production. In this work, H2 was produced from a simulated biogas mixture (CH4 = 60 vol %, CO2 = 40 vol %) in a fixed-bed reactor using a hybrid material (HM) comprising a nickel (Ni) catalyst and a calcium oxide sorbent. Using several techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, electron microscopy, and nitrogen adsorption-desorption, HM was comprehensively studied. Material performance was tested in the 650-850 degrees C range using feeds with varying S/M ratios (steam-to-methane, 1.5-7.5 mol/mol). High S/M ratio and low gas hourly space velocity facilitated H2 production from SESRB. Both H2 purity (88 mol %) and CH4 conversion (93 mol %) were high at 850 degrees C. HM endured 15 reaction-regeneration cycles and loaded 7 mol of CO2/kg sorbent. Thus, SESRB is attractive for the sustainable production of H2 from biogas.