Sorption-enhanced steam reforming of glycerol on Ni-based multifunctional catalysts

• Multifunctional catalysts for SERP with simultaneous CO2 removal were synthesized.
• Catalyst with 41.21% NiO, 28.02% Al2O3 and 30.77% CaO presented high activity.
• Desorption and sorption temperatures for CO2 removal in SERP were determined.
• Multi-cycles SERP and regeneration for high-purity H2 depended on catalyst activity.

The Ni-based multifunctional catalysts for the sorption-enhanced steam reforming process (SERP) with simultaneous in-situ CO2 removal were synthesized by the co-precipitation method with rising pH technique, and the crystalline spinel phases of NiAl2O4 and MgAl2O4 in the catalysts were formed under the calcination temperature of 900 °C. The catalysts were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermo-gravimetric analysis (TGA), and N2 adsorption-desorption. Nonisothermal and isothermal CO2 sorption experiments were carried out to evaluate the activity of catalysts for CO2 removal. Desorption and optimum sorption temperatures for CO2 removal were determined. Hydrogen production from SERP of glycerol over the multifunctional catalysts has been experimentally evaluated under 550 °C and steam to carbon (S/C) ratio of 3. The multifunctional catalyst with the composition of 41.21 wt% NiO, 28.02 wt% Al2O3 and 30.77 wt% CaO presented satisfactory hydrogen purity in the multi-cycles of reforming and regeneration processes. Enhanced hydrogen production was mainly depended on in-situ CO2 removal, and the operation durations for producing high purity hydrogen in the initial 30 min were relatively stable. The multifunctional catalyst possesses uniform distribution of Ni, Ca and Al, contributing significantly to the excellent CO2 sorbent capacity and reforming activity. This multifunctional catalyst synthesized offers a new scheme other than the conventional mixture of sorbent and catalyst for SERP.