Chemical looping steam reforming of glycerol for hydrogen production over NiO–Fe(2)O(3)/Al(2)O(3) oxygen carriers

Fe-based oxygen carriers (OCs) are widely used in chemical looping steam reforming (CLSR) due to excellent resistance to carbon buildup, low toxicity, and high activity. In this study, a type of nano NiO–Fe(2)O(3)/Al(2)O(3) Fe-based OC that can easily be reduced by fuels and re-oxidized by air was developed for use in glycerol CLSR. It was synthesized by co-precipitation and impregnation. Based on the quadratic regression orthogonal model, a quadratic polynomial function was established to investigate the effects of temperature (T), water/carbon ratio (S/C), and loading (M) on hydrogen content (HL) and hydrogen selectivity (S). The OCs were characterized by XRD, XPS, SEM/EDX-mapping, TEM, and H(2)-TPR to determine their physicochemical properties. XPS shows the Fe phase highly interacted with the Al(2)O(3) supporting matrix by forming Fe aluminates in NiO–Fe(2)O(3)/Al(2)O(3). The S (85.33%) and HL (78.41%) were obtained under the optimal conditions T = 600 °C, S/C = 1.0 mol mol(−1) and M = 0. A hydrogen content fluctuation within 4% was obtained under T = 700 °C, S/C = 1.0 mol mol(−1), and M = 2.5%, which means the cycle stability is perfect because of the addition of Ni. This study provides a basis for the development of efficient oxygen carriers in the CLSR system.