Fabrication process parameters significantly affect the perovskite oxygen carriers materials (OCM) performance in chemical looping with oxygen uncoupling (CLOU)

Abstract

The CLOU performance of the CaTi x Mn 0.9-x Mg 0.1 O 3 (CMTM) perovskite-type system was investigated, comparing materials produced at laboratory scale with those made at industrial ton scale. The CLOU and conversion performances were studied by a micropacked bed reactor, and crystalline phase structure and homogeneity and bulk density identified as the most important parameters affecting the performance of the OCM. Bulk density is correlated with the sintering temperature, atmosphere and time at sintering temperature, while phase homogeneity is a function of the raw materials chosen, agglomeration method and sintering procedure. Specific challenges are identified in the control of slurry homogeneity and sintering conditions in upscaled production. The degree of sintering affects the chemo-mechanical properties of the material (crushing strength and attrition index), physical properties (specific surface area), and more importantly the crystalline phases formed and their homogeneity: the quantity of ''active'' crystalline phases present directly determines the thermochemical conversion properties (i.e., CLOU capacity and methane conversion), oxygen transfer capacity and kinetics.

Oxygen‐Carrier Development of Calcium Manganite–Based Materials with Perovskite Structure for Chemical‐Looping Combustion of Methane

“…Flemish Institute for Technological Research NV (VITO) together with Euro Support produced the oxygen‐carrier materials through spray‐drying and upscaled the process . Spray‐drying production parameters were investigated and specific tests, such as sulfur tolerance, were conducted . Furthermore, different materials were screened in batch testing, and operational tests were conducted in CLC units with 300 W and 10 kW nominal fuel input, respectively, the results of which are presented here.…”

Sulfur Interaction and Regeneration of CaMn0.775Ti0.125Mg0.1O2.9−δ Perovskite as Oxygen Carrier during Combustion of Sour Gas in a 500 Wth Chemical Looping Combustion Unit

“…The process that uses this kind of material is known as chemical looping with oxygen uncoupling (CLOU), which promotes the conversion of a fuel by direct combustion with released O 2 . In the specific case of the combustion technology for gaseous fuels through the CLOU process, CaMnO 3 -based perovskite materials have aroused great interest within the scientific community thanks to their high reactivity with natural gas and suitable mechanical stability. − Cabello et al recently summarized all the experimental experience of CaMnO 3 -based perovskites in continuous CLC plants with gaseous fuels.…”

Novel La 1− x Ca x MnO 3 perovskite materials for chemical looping combustion applications

“…Their main drawbacks relate with stability issues concerning both high sensitivity to sulfur‐based impurities and activity loss after prolonged redox cycles. Other metal incorporation (Sr, Fe) targets stabilization of the perovskite structure, while other synthesis parameters (ie, calcination temperature) are reported as crucial for the derived material's performance 28 . Various metal cations (Fe, Ni, Co, V, Al) incorporated into CaMnO 3 perovskite are reported to result in promising phase stability under oxygen uncoupling redox conditions, while Fe‐doped CaMnO 3 materials exhibits notable performance even at temperatures as low as 600°C 29 .…”

“…Other metal incorporation (Sr, Fe) targets stabilization of the perovskite structure, while other synthesis parameters (ie, calcination temperature) are reported as crucial for the derived material's performance. 28 Various metal cations (Fe, Ni, Co, V, Al) incorporated into CaMnO 3 perovskite are reported to result in promising phase stability under oxygen uncoupling redox conditions, while Fe-doped CaMnO 3 materials exhibits notable performance even at temperatures as low as 600 C. 29 Doping the A site with La and Sr and B site by Fe and Zr in CaMn-based perovskites was also investigated in an effort to improve the stability and oxygen capacity of the derived materials, applying the upscalable extrusion technique as the synthesis method. 30 Utilization of CaMn-based perovskites is wellreviewed in a very recent study, 31 where activation of a CaMn 0.775 Ti 0.125 Mg 0.1 O 2.9 À δ perovskite by full reduction by H 2 significantly enhanced its CLC performance.…”