Abstract Chemical looping combustion (CLC) offers a low emission route for fossil fuel-based power generation. In this study, a compact fully looped chemical looping reactor was developed in-house, and operated continuously with a Victorian brown coal as fuel and an Australian ilmenite as oxygen carrier at 940–980 °C and atmospheric pressure for 36 h. The study found that the CLC performance increased with increasing operation time. The CO2/CO molar ratio, used to evaluate the CLC reaction degree, increased from 2.3 to 8.9 over the 36 h of operation. Specifically, this paper provides a comprehensive study and evaluation of the ilmenite characteristics on morphology changes and ash interaction, due to the continuous operation. No noticeable effect by ash interaction on the CLC performance or operation was observed during the continuous operation. The characterisation results revealed a clear segregation of iron species from the iron‑titanium matrix, its migration to and enrichment over the particle surfaces. Hematite (Fe2O3) formation became more pronounced while pores developed internal and external of the ilmenite particles. These changes are believed to improve the carrier reactivity, and so the CLC performance, but also to weaken the mechanical strength of the carrier, promoting particle attrition and leading to its loss by elutriation.

中文翻译：

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维多利亚褐煤化学循环燃烧过程中澳大利亚钛铁矿氧载体的表征

摘要 化学循环燃烧 (CLC) 为基于化石燃料的发电提供了一种低排放途径。在这项研究中，内部开发了一个紧凑的全回路化学回路反应器，并以维多利亚褐煤为燃料，以澳大利亚钛铁矿为氧载体，在 940-980°C 和大气压下连续运行 36 小时。研究发现，CLC 性能随着操作时间的增加而提高。在 36 小时的操作中，用于评估 CLC 反应程度的 CO2/CO 摩尔比从 2.3 增加到 8.9。具体而言，本文对钛铁矿由于连续操作而对形态变化和灰分相互作用的特征进行了全面的研究和评估。在连续运行期间没有观察到灰分相互作用对 CLC 性能或运行的显着影响。表征结果显示铁物质从铁钛基体中明显分离，迁移到颗粒表面并在颗粒表面富集。赤铁矿 (Fe2O3) 的形成变得更加明显，而钛铁矿颗粒的内部和外部都形成了孔隙。据信，这些变化会提高载体反应性，从而提高 CLC 性能，但也会削弱载体的机械强度，促进颗粒磨损并导致其因淘析而损失。