Finding alternative technologies to reduce carbon emissions of the steel industry has become a pressing concern. Supercritical water gasification (SCWG) combined with Hydrogen Production-Shaft furnace-Electric arc furnace (HSE) process offers a promising low-carbon alternative. The proposed route converts biomass to biosyngas through SCWG technology to produce direct reduced iron, followed by an electric arc furnace process to produce crude steel. In this study, the environmental impact of the SCWG-HSE process was evaluated using life cycle assessment (LCA). LCA was conducted using the Gabi V9.2 software, and the Ecoinvent 3.6 database within the program. It was found that the SCWG-HSE process has a 61 % lower global warming potential compared to the conventional BF-BOF process, and a 28 %–30 % reduction compared to the Coal gasification- HSE and Natural gas based- HSE processes. It is comparable to the renewable hydrogen-based HSE route. The cradle-to-gate global warming potential of the proposed system is estimated to be 803 kg CO2 eq./t crude steel. In the process, the hydrogen production and electric arc furnace segments are the main sources of global warming potential. Further analysis shows that an additional global warming potential reduction of about 38 % can be achieved by integrating Carbon Capture and Storage technologies, while optimization of the electricity supply structure is expected to achieve a global warming potential reduction of up to 63 %. This study is not limited to assessing global warming potential, but also covers other environmental impact indicators. The results show that the SCWG-HSE process has significant potential in terms of environmental performance.

中文翻译：

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将超临界水气化与直接还原铁生产相结合的工艺的生命周期评估


寻找替代技术来减少钢铁行业的碳排放已成为一个紧迫的问题。超临界水气化 （SCWG） 与制氢-竖炉-电弧炉 （HSE） 工艺相结合，提供了一种很有前途的低碳替代方案。拟议的路线通过 SCWG 技术将生物质转化为生物合成气以生产直接还原铁，然后采用电弧炉工艺生产粗钢。在本研究中，使用生命周期评估 （LCA） 评估了 SCWG-HSE 过程的环境影响。LCA 是使用 Gabi V9.2 软件和程序中的 Ecoinvent 3.6 数据库进行的。研究发现，与传统的 BF-BOF 工艺相比，SCWG-HSE 工艺的全球变暖潜能值降低了 61%，与煤气化 HSE 和天然气基 HSE 工艺相比，全球变暖潜能值降低了 28 %–30%。它与基于可再生氢的 HSE 路线相当。拟议系统的“摇篮到大门”全球变暖潜能值估计为 803 kg CO2 当量/t 粗钢。在此过程中，氢气生产和电弧炉部分是全球变暖潜能值的主要来源。进一步分析表明，通过整合碳捕获和封存技术，可以额外减少约 38% 的全球变暖潜势，而优化电力供应结构有望实现高达 63% 的全球变暖潜势降低。这项研究不仅限于评估全球变暖潜力，还涵盖了其他环境影响指标。结果表明，SCWG-HSE 过程在环境绩效方面具有巨大潜力。