The use of STRONTIUM FERRITE (cas 12023-91-5) in chemical looping systems

Add time:07/29/2019    Source:sciencedirect.com

This work reports a detailed chemical looping investigation of STRONTIUM FERRITE (cas 12023-91-5) (SrFeO3−δ), a material with the perovskite structure type able to donate oxygen and stay in a nonstoichiometric form over a broad range of oxygen partial pressures, starting at temperatures as low as 250°C (reduction in CO, measured in TGA). SrFeO3−δ is an economically attractive, simple, but remarkably stable material that can withstand repeated phase transitions during redox cycling. Mechanical mixing and calcination of iron oxide and strontium carbonate was evaluated as an effective way to obtain pure SrFeO3−δ. In–situ XRD was performed to analyse structure transformations during reduction and reoxidation. Our work reports that much deeper reduction, from SrFeO3−δ to SrO and Fe, is reversible and results in oxygen release at a chemical potential suitable for hydrogen production. Thermogravimetric experiments with different gas compositions were applied to characterize the material and evaluate its available oxygen capacity. In both TGA and in-situ XRD experiments the material was reduced below δ = 0.5 followed by reoxidation either with CO2 or air, to study phase segregation and reversibility of crystal structure transitions. As revealed by in-situ XRD, even deeply reduced material regenerates at 900°C to SrFeO3–δ with a cubic structure. To investigate the catalytic behaviour of SrFeO3−δ in methane combustion, experiments were performed in a fluidized bed rig. These showed SrFeO3−δ donates O2 into the gas phase but also assists with CH4 combustion by supplying lattice oxygen. To test the material for combustion and hydrogen production, long cycling experiments in a fluidized bed rig were also performed. SrFeO3−δ showed stability over 30 redox cycles, both in experiments with a 2-step oxidation performed in CO2 followed by air, as well as a single step oxidation in CO2 alone. Finally, the influence of CO/CO2 mixtures on material performance was tested; a fast and deep reduction in elevated pCO2 makes the material susceptible to carbonation, but the process can be reversed by increasing the temperature or lowering pCO2.

We also recommend Trading Suppliers and Manufacturers of STRONTIUM FERRITE (cas 12023-91-5). Pls Click Website Link as below: cas 12023-91-5 suppliers

Prev:Investigations on the structural, magnetic and mossbauer properties of cerium doped STRONTIUM FERRITE (cas 12023-91-5)
Next:Aluminum-doped STRONTIUM FERRITE (cas 12023-91-5)s for a two-step solar thermochemical air separation cycle: Thermodynamic characterization and cycle analysis)