Examining SrCuO2 as an oxygen carrier for chemical looping combustion

Abstract

This paper contains the results of research work on chemical looping combustion (CLC). CLC is one of the most promising combustion technologies and has the main advantage of producing a concentrated CO 2 stream, which is obtained after water condensation without any energy penalty for CO 2 separation. The objective of this work was to study the chemical looping reaction performance for a novel spinel-type oxygen carrier. The SrCuO 2 was tested for the purpose of CLC for power generation, and hydrogen was utilized as a syngas component. SrCuO 2 was prepared as a powder. Reactivity tests were performed under isothermal conditions for multiple redox cycles using a thermogravimetric (TG) analyzer (Netzsch STA 409 PG Luxx). For the reduction, 3 % H 2 was used, and for the oxidation cycle, air was used. The effect of both reaction temperature (600-800°C) and reducing/oxidizing cycles (five cycles at each temperature) on the reaction performance of the oxygen carrier samples developed in this study was evaluated. The stability, oxygen transport capacity and reaction rates were analyzed based on experimental TG data. The material was systematically investigated by scanning electron microscopy, X-ray diffraction measurements, N 2 porosimetry, particle size distribution and studying the melting behavior. Investigation of the oxidation/reduction behavior of SrCuO 2 showed stable chemical looping performance, with great recyclability after continuous multiple redox reactions maintaining the chemical properties. Moreover, excellent oxygen capacity was maintained within cycling combustion tests.Furthermore, the oxygen carrier sample attained a high melting temperature, which provides attractive thermal resistivity. For comparison purposes, another Cu-based oxygen carrier was prepared and analyzed in the same manner. The CuO/TiO 2 carrier transported similar amounts of oxygen to the fuel, but its stability to reaction was questionable. The promising results obtained from CLC allowed us to conclude that SrCuO 2 is possibly a capable and suitable candidate for CLC for power generation.

Exploration of the material property space for chemical looping air separation applied to carbon capture and storage

“…Sr 2 Cu 2 O 5 was synthesized at 1123 K and 100 kbar using SrCuO 2 as a precursor [44], conditions beyond those expected in chemical looping systems. However, SrCuO 2 was used as an oxygen carrier in chemical looping combustion, releasing oxygen equal to around 8% of its mass at 873 K to form SrCuO 1.075 [45]. This oxygen carrier system exhibited further stability over 20 redox cycles at 1223 K.…”

Extremely Stable and Durable Mixed Fe–Mn Oxides Supported on ZrO2 for Practical Utilization in CLOU and CLC Processes

“…Many materials were recently under consideration as suitable candidates for OCs, including natural ores (e.g., ilmenite, iron ores etc.) [6] or synthetic materials purposely designated for that role as OCs based on mixed oxides, or perovskite-based OCs [7,8]. As a result of advanced study, various transitional metals oxides were examined as potential candidates for OCs such as copper, nickel, iron, manganese, or cobalt oxides.…”

Theoretical Study of the Reactive Mechanisms of Li-Doped Ni-Based Oxygen Carrier during Chemical Looping Combustion

“…The presence of OCs plays a crucial role in facilitating the successful implementation of CLC. To date, over 500 diverse OCs materials suitable for CLC have been investigated, encompassing perovskite-type oxides, natural ores, synthesized materials, and transition metal oxides. − Transition metal oxides, such as Ni, Co, Fe, Mn, or Cu oxides in various forms, have been extensively investigated as promising candidates for OCs. − Among these metal complexes, Ni-based OCs are notable for its exceptional performance at high temperatures (900 to 1100 °C), favorable kinetic properties, and remarkable catalytic proficiency in breaking C–C and C–H bonds. − However, the utilization of pure NiO in the CLC process is subject to certain limitations, including carbon deposition and lower reaction activity . The efficiency of methane combustion in CLC was observed to decrease with successive cycles due to carbon deposition, as reported by Cheng et al…”