Bi-metallic CuO-NiO based multifunctional material for hydrogen production from sorption-enhanced chemical looping autothermal reforming of ethanol

摘要

Bi-metallic CuO-NiO based multifunctional materials were developed and employed for H-2 production via sorptionenhanced chemical looping autothermal reforming (SE-CLAR) of ethanol. The effects of adding copper oxide (CuO) as a co-oxygen carrier and material preparation method on H-2 production performances, including activity, reusability, and energy penalty, were studied. The results revealed that adding CuO into one-body multifunctional material provided positive impacts on H-2 production performances. The use of multifunctional material could reduce reforming temperature to milder temperature at 500 degrees C. The key finding is that position of CuO in the multifunctional material showed a significant effect. Placing of CuO on the surface could enhance catalytic property whereas placing NiO closed to CaO could reduce heat for CaO regeneration. For the SE-CLAR operating temperature at 500 degrees C and steam to ethanol ratio (S/E) = 3, impregnation of NiO on the surface of homogeneous CuO-CaO-Ca12Al14O33, NiO/CuO-CaOCa12Al14O33, produced 83% H-2 purity for 30 min while impregnation of CuO on the surface of homogeneous NiO-CaOCa12Al14O33, CuO/NiO-CaO-Ca12Al14O33, produced 89% H-2 for 45 min. Sol-gel one-pot synthesis method of NiO-CuOCaO-Ca12Al14O33 produced 91% H-2 purity for 60 min. Complete regeneration temperature of CaO was achieved at 800 degrees C, which accounts for 14% thermal energy reduction for the CuO/NiO-CaO-Ca12Al14O33. The NiO/CuO-CaOCa12Al14O33 could maintain its performance on producing high H-2 purity for at least five consecutive operating cycles.