Hydrogen production via sorption enhanced reforming of methane: Development of a novel hybrid material—reforming catalyst and CO2 sorbent

This study presents the development and the evaluation of a new hybrid material, NiO–CaO–Ca12Al14O33, which functions simultaneously as reforming catalyst and CO2 sorbent for application in sorption enhanced reforming. CaO–Ca12Al14O33 acts as an effective CO2 sorbent and also as a support for the active metallic Ni particles. This idea aims to overcome the complex problems related with handling of the two different solids (catalyst and CO2 sorbent) required for sorption enhanced reforming and also to increase the industrial potential of the process by decreasing the cost of the total solid material used. The CO2 fixation ability of the new material (56% carbonation conversion) remains unchanged for 45 cycles of sorption-desorption. It is assumed that the presence of NiO acts synergetically with Ca12Al14O33 to the excellent stability of the novel material compared with other CaO-based sorbents. The effect of NiO loading on the catalytic functionality of the material, under methane sorption enhanced reforming conditions was studied and the results showed that conversion goes through a maximum (80%) in the presence of the hybrid material with 16 wt% Ni loading. The hybrid material with the optimum metallic loading was tested at 650 °C and methane to steam ratio equal to 3.4. The presence of free CaO resulted in the capture of CO2 formed, producing a stream rich in H2 (90%) and poor in CO2 (2.8%) and CO (2%).