화학공학소재연구정보센터
Energy & Fuels, Vol.29, No.6, 3870-3878, 2015
Improved Hydrogen Production by Sorption-Enhanced Steam Methane Reforming over Hydrotalcite- and Calcium-Based Hybrid Materials
The sorption-enhanced reforming process (or SERP), which combines steam reforming and in situ carbon dioxide (CO2) capture by adsorption, is a candidate technique for improved hydrogen (H-2) production. In the present work, the performance of hybrid materials comprising a Ni-based reforming catalyst and hydrotalcite- (Ni-HTc or HM1) or calcium-based sorbents (Ni-CaO/Al2O3 or HM2) for sorption-enhanced steam methane reforming was compared. It was found that such lab-made hybrid materials exhibit superior adsorption characteristics and longer breakthrough times than powdered mixtures of commercial Ni/Al2O3 catalyst and the respective sorbent (HTc or CaO). H-2-rich gas (98.5 and 97.9%) was obtained using the investigated hybrid materials HM1 and HM2 for SERP. The influence of reaction variables such as temperature, steam/carbon ratio, and gas hourly space velocity on methane conversion and product gas composition was investigated. Stability tests for both the hybrid materials were performed for 20 cycles. Hydrotalcite-based hybrid material HM1 adsorbed up to 1.1 mol CO2/kg sorbent at 673 K and was stable for 16 cycles. Conversely, the calcium-based hybrid material HM2 showed an adsorption capacity of 12.3 mol of CO2/kg sorbent at 823 K and remained stable up to 11 cycles.