Prussian blue derived Ca-Fe bifunctional materials for chemical looping CO2 capture and in-situ conversion

• Published in: Separation and purification technology 2023-09, Vol.320, p.123975, Article 123975
• Main Authors: Jin, Bo, Ouyang, Tong, Zhang, Zhineng, Zhao, Yunlei, Zhang, Haiyan, Yao, Wenxing, Huang, Guiqiu, Liang, Zhiwu
• Format: Article
• Language: English
• Subjects: Ca-Fe bifunctional material; Chemical looping; CO production; Integrated CO2 capture and conversion; Prussian blue
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2023.123975

[Display omitted] •A new chemical looping CO2 capture and in-situ conversion scheme is demonstrated.•Prussian blue derived Ca-Fe bifunctional materials are developed for CL-ICCC.•CO production is achieved during both CO2 capture and conversion half-cycles.•FCZ136 exhibits the best STYCO and CO yield with no deactivation during cycles.•ZrO2 and CaZrO3 keeps stability but high iron loading causes sintering for sample. Chemical looping CO2 capture and in-situ reverse water gas shift (CL-ICCC-RWGS) is a promising way to realize integrated CO2 capture and conversion for responding CO2 emission issue. Most bifunctional materials are performed in a reaction configuration of sorbent-catalyst, however, altering the reaction configuration into a sorbent-oxygen-carrying form by introducing a redox couple would result in a new CL-ICCC-RWGS scheme. In this work, a new integrated CO2 capture and conversion scheme is proposed and experimentally demonstrated by synthesizing a series of Prussian blue derived Ca-Fe bifunctional materials with varying iron loadings and exploring their cyclic capture-conversion reactivity. The bifunctional materials with both Ca and Fe species show CO production during isothermal cycles, since CO2 re-oxidation of metallic iron and reverse water gas shift occur in capture and conversion half-cycles, respectively. FCZ136 exhibits the best averaged CO space time yield (238.25 mmolCO∙s−1∙kgFe2O3−1 and 3.00 mmolCO∙s−1∙kgCaO−1) and CO yield (142.95 molCO∙kgFe2O3−1 and 1.80 molCO∙kgCaO−1) with no deactivation after ten isothermal cycles at 650 °C. This is mainly ascribed to two aspects: (i) high iron dispersion improves CO generation rate, (ii) the presence of two inert promoters (t-ZrO2 and CaZrO3) maintains a superior stability. The result provides a new strategy to design efficient bifunctional material and achieve integrated CO2 capture and conversion.