Abstract. Global crude steel production is expected to continue to increase in the coming decades to meet the demands of the growing world population. Currently, the dominant steelmaking technology worldwide is the conventional highly CO2-intensive blast furnace–basic oxygen furnace production route (also known as the Linz–Donawitz process), which uses iron ore as raw material and coke as a reducing agent. As a result, large quantities of special gases that are rich in carbon monoxide (CO) are by-products of the various stages of the steelmaking process. Given the challenges associated with satellite-based estimates of carbon dioxide (CO2) emissions at the scale of emitting installations due to significant background levels, co-emitted CO may serve as a valuable indicator of the carbon footprint of steel plants. We show that regional CO release from steel production sites can be monitored from space using 5 years of measurements (2018–2022) from the TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel-5 Precursor satellite, benefiting from its relatively high spatial resolution and daily global coverage. We analyse all German steel plants with blast furnaces and basic oxygen furnaces and obtain associated CO emissions in the range of 50–400 kt yr−1 per site. A comparison with the respective CO2 emissions on the level of emitting installations available from emissions trading data of the European Union Emissions Trading System yields a linear relationship with a sector-specific CO/CO2 emission ratio for the analysed steelworks of 3.24 % [2.73–3.89; 1σ], suggesting the feasibility of using CO as a proxy for CO2 emissions from comparable steel production sites. An evaluation at other steel production sites indicates that the derived CO/CO2 emission ratio is also representative of other highly optimised state-of-the-art Linz–Donawitz steelworks outside Germany and that the emission ratio is potentially valuable for estimating sector-specific CO2 emissions from remotely sensed CO emissions, provided that the underlying CO emission estimate is not affected by other sources.

中文翻译：

---

实现特定部门的 CO/CO2 排放比：基于卫星的德国钢铁生产 CO 排放观测


摘要。预计未来几十年全球粗钢产量将继续增加，以满足不断增长的世界人口的需求。目前，全球主导的炼钢技术是传统的高二氧化碳密集型高炉-碱性氧气转炉生产路线（也称为林茨-多纳维茨工艺），该工艺以铁矿石为原料，焦炭为还原剂。因此，大量富含一氧化碳 (CO) 的特殊气体是炼钢过程各个阶段的副产品。考虑到由于背景水平较高而基于卫星对排放装置规模的二氧化碳 (CO2) 排放量进行估算所面临的挑战，共同排放的二氧化碳可以作为钢厂碳足迹的一个有价值的指标。我们表明，利用 Sentinel-5 Precursor 卫星上的 TROPOspheric 监测仪器 (TROPOMI) 进行的 5 年（2018-2022 年）测量，可以从太空监测钢铁生产场所的区域二氧化碳排放，这得益于其相对较高的空间分辨率和每日全球报道。我们分析了所有拥有高炉和氧气转炉的德国钢铁厂，并获得每个工厂 50–400 kt yr−1 范围内的相关二氧化碳排放量。与欧盟排放交易系统排放交易数据中各排放装置水平的二氧化碳排放量进行比较，得出与所分析的钢铁厂特定行业二氧化碳/二氧化碳排放比为 3.24 % [2.73–3.89] 的线性关系。 ; 1σ]，表明使用 CO 作为可比钢铁生产场所 CO2 排放量的替代指标的可行性。 对其他钢铁生产基地的评估表明，得出的 CO/CO2 排放比也代表了德国以外其他高度优化的最先进林茨-多纳维茨钢铁厂，并且该排放比对于估算特定行业的 CO2 具有潜在价值遥感 CO 排放量，前提是基础 CO 排放量估算不受其他来源的影响。