Institute of Urban Safety and Environmental Science, Beijing Academy of Science and Technology, Beijing 100054, China.
State Key Laboratory of Marine Resources Utilization in South China Sea, School of Marine Science and Engineering, Hainan University, Haikou 570228, China.
Environ Sci Technol. 2023 Aug 8;57(31):11510-11519. doi: 10.1021/acs.est.3c02624. Epub 2023 Jul 25.
Accurately tracking carbon flows is the first step toward reducing the climate impacts of the iron and steel industry (ISI), which is still lacking in China. In this study, we track carbon flows from coal/mineral mines to end steel users by coupling the cross-process material and energy flow model, point-based emission inventory, and interprovincial trade matrices. In 2020, ISI emitted 2288 Tg of CO equivalent (COeq, including CH and CO), 96% of which came from energy use and 4% from raw material decomposition. Often overlooked off-gas use and CH leakage in coal mines account for 25% of life-cycle emissions. Due to limited scrap resources and a high proportion of pig iron feed, the life-cycle emission intensity of the electric arc furnace (EAF) (1.15 t COeq/t steel) is slightly lower than the basic oxygen furnace (BOF) (1.58 t COeq/t steel) in China. In addition, over 49% of producer-based emissions are driven by interprovincial coal/coke/steel trade. In particular, nearly all user-based emissions in Zhejiang and Beijing are transferred to steelmaking bases. Therefore, we highlight the need for life-cycle and spatial shifts in user-side carbon management.
准确追踪碳流是减少钢铁行业（钢铁行业）气候影响的第一步，而中国在这方面仍有所欠缺。在本研究中，我们通过耦合跨工艺物质和能量流模型、基于点的排放清单和省际贸易矩阵，追踪了从煤矿/矿山到最终钢铁用户的碳流。2020 年，钢铁行业排放了 2288 太吨二氧化碳当量（包括 CH 和 CO），其中 96%来自能源使用，4%来自原材料分解。通常被忽视的煤矿废气利用和 CH 泄漏占生命周期排放的 25%。由于有限的废钢资源和高比例的生铁进料，电弧炉（EAF）的生命周期排放强度（1.15 吨 COeq/吨钢）略低于中国的转炉（BOF）（1.58 吨 COeq/吨钢）。此外，超过 49%的基于生产者的排放是由省际煤炭/焦炭/钢铁贸易驱动的。特别是，浙江和北京的几乎所有基于用户的排放都转移到了炼钢基地。因此，我们强调需要在用户侧的碳管理方面进行生命周期和空间转移。
