Catalytic steam methane reforming enhanced by CO2 capture on CaO based bi-functional compounds

• 来源期刊: 能源化学
• 年，卷（期）: 2017,（5）
• 页码范围: 1014-1025
• 页数: 12页
• 语种: 英文

摘要

Sorption enhanced steam methane reforming (SE-SMR) was performed to maximize hydrogen production and contemporary remove CO2 from the product stream using bi-functional sorbent-catalyst compounds.Samples were tested at two different scales:micro and laboratory.The CaO amount varied in the CaO-Ca12Al14O33 sorbent system synthesized by wet mixing (CaO content of 100 wt％,56 wt％,30 wt％,or 0 wt％ and balance of Ca12Al14O33) which were upgraded to bi-functional compounds by impregnation of 3 wt％ of Ni.Nitrogen adsorption (BET/BJH),X-Ray Diffraction (XRD),Temperature-Programmed Reduction (TPR) and Scanning and Transmission Electronic Microscopy (SEM and TEM,respectively) analyses were performed to characterize structural and textural properties and reducibility of the bi-functional materials and evaluate their catalytic behavior.A fixed sorbent composition CaO-Ca12Al14O33 (56 wt％ of CaO and Ca12Al14O33 balance),was chosen to study the effect of different weight hourly space times (WHST) and CH4 stream compositions in SE-SMR activity.Impregnated mayenite at both micro and laboratory scales showed stable H2 content of almost 74％,with CH4 conversion of 72％ similarly to the values reported by the sample containing 30 wt％ of CaO in the post-breakthrough.Sample with 30 wt％ of CaO showed promisingly behavior,enhancing H2 content up to almost 94.5％.When the sorption enhanced reaction is performed roughly 89％ of CH4 conversion is achieved,and after the pre-breakthmugh,the catalyst worked at the thermodynamic level.During cycling sorption/regeneration experiments,even if CO2 removal efficiency slightly decreases,CH4 conversion and H2 yield remain stable.