Chemical looping oxygen uncoupling of biochar using CuO: Influence of oxygen carrier on combustion efficiency

Güleç, Fatih; Moyles, Ciaran; Tagg, Harrison; Marshall, Alexander; Craft, Jack; Batchelor, Andrew; Duran-Jimenez, Gabriela

Abstract

Despite the consensus on the urgent need to mitigate climate change by reducing CO2 emissions, technological advancements lag the escalating levels of CO2. This study investigates the impact of process conditions and oxygen carrier quality on the chemical looping oxygen uncoupling (CLOU) of biochar with CuO as a promising bioenergy production with CO2 capture and storage (BECCS) approach. This work offers new insights into the role of CuO synthesis method and material source on biochar combustion efficiency in a CLOU framework, comparing both commercial and in-house formulations. Combustion efficiency increases from 67.9 vol% at 750 °C to 98.2 vol% at 900 °C. The stoichiometric ratio also influenced performance, improving from 71.2 vol% at a ratio of 1.0 to 95.7 vol% at 1.5. Higher-quality CuO samples, such as CuO (Honeywell), demonstrated superior performance, achieving 98.3 vol% efficiency compared to 71.2 vol% for CuO (Inoxia) at 850 °C. CuO (Honeywell) also exhibited greater stability across multiple redox cycles, maintaining 99.0 vol% capacity after six cycles, while CuO (Inoxia) suffered a significant decline to 84 vol% due to sintering and agglomeration. Lab-prepared Cu80Al20-WI displayed stable performance, retaining 97.1 vol% after six cycles, outperforming Cu80Al20-CP, which degraded to 83.9 vol%. This performance was mainly attributed to gas diffusional effect and larger availability of active sites in Cu80Al20-WI for oxygen in reduction/oxidation CLC processes. These results highlight the importance of optimising both process conditions and oxygen carrier quality for efficient CLOU applciaiton.

Citation

Güleç, F., Moyles, C., Tagg, H., Marshall, A., Craft, J., Batchelor, A., & Duran-Jimenez, G. (2025). Chemical looping oxygen uncoupling of biochar using CuO: Influence of oxygen carrier on combustion efficiency. Fuel, 399, Article 135685. https://doi.org/10.1016/j.fuel.2025.135685

• Journal Article Type: Article
• Acceptance Date: May 13, 2025
• Online Publication Date: May 16, 2025
• Publication Date: Nov 1, 2025
• Deposit Date: May 28, 2025
• Publicly Available Date: May 29, 2025
• Journal: Fuel
• Print ISSN: 0016-2361
• Electronic ISSN: 1873-7153
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 399
• Article Number: 135685
• DOI: https://doi.org/10.1016/j.fuel.2025.135685
• Public URL: https://nottingham-repository.worktribe.com/output/49557285
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0016236125014103?via%3Dihub
• Additional Information: This article is maintained by: Elsevier; Article Title: Chemical looping oxygen uncoupling of biochar using CuO: Influence of oxygen carrier on combustion efficiency; Journal Title: Fuel; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.fuel.2025.135685; Content Type: article; Copyright: © 2025 The Authors. Published by Elsevier Ltd.