Hydrogen Production From Sorption Enhanced Chemical Looping Steam Ethanol Reforming Using Calcium Oxide/ Copper Oxide/ Nickel Oxide Multifunctional Catalyst

Abstract

Multifunctional catalyst was developed for hydrogen production via sorption enhanced chemical looping ethanol steam reforming. Calcium acetate (Ca2Ac) and calcium chloride (CaCl) were used as calcium precursor. Sodium carbonate (Na2CO3) and urea (CO(NH2)2) were used as carbonate precursor. The NiO/CaOAc-Urea-Ca12Al14O33 showed the longest pre-breakthrough period of 60 min and 88% of hydrogen purity at steam to ethanol molar ratio (S/E) of 4:1, temperature 600 ﹾC. Stability of NiO/CaOAc-Urea-Ca12Al14O33 was tested over 10 cycles and the results showed hydrogen purity can be maintained at 90% during pre-breakthrough period. The effect of synthesis method: sol-mixing and sol-gel, on hydrogen production was compared and the result found that sol-gel method produced hydrogen purity (91%) higher than sol-mixing method (88%). The copper addition into multifunctional catalyst by sol-gel method was studied with different strategies. The preparation method in one-pot synthesis Ni-Cu-CA offered the highest hydrogen purity ca. 93% for 60 min, while, the impregnation synthesis of Cu into Ni-CA (Cu/(Ni-CA)) produced hydrogen purity ca. 89%, and Ni/(Cu-CA) showed hydrogen purity ca. 83%. The stability of Cu/(Ni-CA) can be maintained at ca. 88%, whereas Ni-Cu-CA slightly decreased from 93% to 87% after 5 cycles.