The direct reduction of iron (DRI) process plays a pivotal role in the ironmaking and steelmaking industry and has emerged as a promising solution for reducing CO2 emissions. This intricate process spans metallurgy and chemical engineering, encompassing multiple scales (macroscale, mesoscale, microscale, nanoscale) and various reaction systems, including catalytic gas–solid (reformer) and non-catalytic gas–solid (shaft furnace) processes. The shaft furnace operated as a multiscale moving bed reactor including iron oxide pellets where a complex interplay of 17 non-catalytic gas–solid reactions and several gas reactions is observed. This review covers all relevant fields of gaseous-based DRI and introduces essential mathematical models for shaft furnaces and reformers. Key non-catalytic gas–solid and shaft furnace models developed over the last century are compared and analyzed. The effects of crucial parameters such as solid structure, gas phase conditions, clustering, carbon formation, and lattice defects are discussed. In addition, the reformer in the DRI unit functions as a bottom-fired furnace, comprising a combustion chamber and tubes that carry three types of heterogeneous catalysts, operating as a fixed bed reactor. Diverse radiative and kinetic models have been discussed to characterize the combustion chamber and reactions in detail. Finally, the review discusses potential artificial intelligence (AI) applications in this context and identifies research gaps for future investigations.

中文翻译：

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竖炉和重整炉在直接还原氧化铁中的多尺度综合综述


直接还原铁 （DRI） 工艺在炼铁和炼钢行业中起着举足轻重的作用，并已成为减少 CO2 排放的一种有前途的解决方案。这个复杂的过程跨越冶金和化学工程，包括多个尺度（宏观、中尺度、微观、纳米尺度）和各种反应系统，包括催化气-固（重整器）和非催化气-固（竖炉）工艺。竖炉作为多尺度移动床反应器运行，包括氧化铁颗粒，其中观察到 17 个非催化气固反应和几个气体反应的复杂相互作用。这篇综述涵盖了气基 DRI 的所有相关领域，并介绍了竖炉和重整器的基本数学模型。对上个世纪开发的关键非催化气固和竖炉模型进行了比较和分析。讨论了关键参数（如固体结构、气相条件、聚集、碳形成和晶格缺陷）的影响。此外，DRI 装置中的重整器用作底燃炉，包括一个燃烧室和携带三种类型非均相催化剂的管道，作为固定床反应器运行。已经讨论了不同的辐射和动力学模型来详细表征燃烧室和反应。最后，本综述讨论了人工智能 （AI） 在此背景下的潜在应用，并确定了未来调查的研究差距。