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Sorption-enhanced chemical looping reforming of ethanol for hydrogen production was investigated using Fe2O3 as oxygen carrier and modified CaO-based Al2O3 as CO2 sorbent. Combined Fe2O3/CaO-Al2O3 multifunctional catalysts were demonstrated and prepared by different methods including sol-gel, mechanical mixing, and impregnation at different Fe contents (5, 10, and 15 wt%). The results showed that the multifunctional catalyst prepared by impregnation method with 5 wt% Fe loading provided the highest H2 purity of 70% in the pre-breakthrough period which lasted for 60 min at 600 °C. This was attributed to the preserving of Ca12Al14O33 inert support in the structure during the preparation as shown by XRD results, leading to higher surface area as determined by N2 physisorption and to prevention of particle agglomeration as evidenced by SEM-EDX. Although the H2 production was inhibited by the presence of Ca2Fe2O5 phase, a stable performance was found for at least 5 repeated cycles both for sorption capacity and oxygen carrier. The ease of decarbonation was also observed with this material as confirmed by DSC-TGA analysis. This highlighted the mutual advantages of Fe in CaO sorption stability and Ca in Fe oxygen carrier stability which could offset their intrinsic weak robustness. [ABSTRACT FROM AUTHOR]

Iron open metal site in metal-organic frameworks, MIL-88A and MIL-127(Fe), was tested to investigate its performance on CO2 separation from a binary mixture CO2/N2 under simulated post-combustion system. The sorption experiment tests were conducted via a fixed-bed reactor with different temperatures ranging between 30°C and 60°C at atmospheric pressure. Maximum CO2 sorption capacity was observed at low temperature of 30°C, where 5.24 mmol could be adsorbed by one gram of MIL-127(Fe) and 4.95 mmol CO2 could be adsorbed by one gram of MIL-88A. The presence of moisture in the gas mixture affected CO2 sorption capacity by reducing CO2 capacity as high as 0.5 mmol CO2 per one gram sorbent. In this work, a dynamic breakthrough model was applied to investigate adsorption behavior of the metal-organic frameworks (MOFs) and of the system. The predicted model showed good agreement with experimental results; the Langmuir isotherm model fitted well with our sorption system, suggesting one molecule of CO2 is held at localized sites of the MOFs, which plausibly be at unsaturated Fe2+ metal ion site. Rate of sorption was found to increase with increasing sorption temperature for either intra-particle diffusivity or external mass transfer. Our study suggests that the MOFs containing Fe open metal sites offer an outstanding prospective for CO2 sorption and both MIL-88A and MIL-127(Fe) are good representatives applied for post-combustion CO2 capture. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]