The iron and steel industry accounts for 6 % of the global CO₂ emissions and it is one of the main hard-to-abate sectors that must be un-locked to reach climate neutrality in the coming decades. The objective of this work is to assess the economics of the FReSMe (From Residual Steel gases to Methanol) process for reducing the carbon footprint of conventional steel plants based on the Blast Furnace route. This reduction is achieved by capturing and converting part of the steel plants residual gases into methanol. The process includes the Sorption Enhanced Water Gas Shift (SEWGS) technology to treat the residual gases separating the CO₂ and producing a H₂-rich stream. The latter can be recirculated back to the steel plant to cover part of its primary energy demand or reacted together with part of the separated CO₂ to synthetize methanol. The CO₂ excess can be used for underground storage. Four different process configurations with different methanol production capacities are investigated. Costs and performances of each configuration are assessed and compared to two reference cases. Results show that the FReSMe process allows to avoid around the 60 % of the overall steel plant CO₂ emissions, while the reference plant with post-combustion capture in the power section only 18 %. The cost of CO₂ avoided is in the range 40.6 €/t_CO2 – 46.2 €/t_CO2. When no carbon tax is considered, the optimal methanol production capacity results 600 t/day with a Levelized Cost of Hot Rolled Coil of around 520 €/t_HRC, 9.4 % higher than in the base case (476 €/t_HRC). With a carbon tax rate above 40.6 €/t_CO2, the optimal configuration has a methanol production capacity of 300 t/day and it ensures higher emissions reduction and lower costs than conventional post-combustion carbon capture systems.

钢铁行业占全球 CO ₂排放量的6%，是未来几十年必须解锁以实现气候中和的主要难以减排的行业之一。这项工作的目的是评估 FReSMe（从钢渣气体到甲醇）工艺的经济性，以减少基于高炉路线的传统钢厂的碳足迹。这种减少是通过捕获部分钢铁厂残余气体并将其转化为甲醇来实现的。该工艺包括吸附增强型水煤气变换 (SEWGS) 技术，用于处理残余气体，分离 CO ₂并产生 H ₂- 丰富的流。后者可以再循环回钢铁厂以满足其部分一次能源需求，或者与部分分离的 CO ₂一起反应以合成甲醇。多余的 CO ₂可用于地下储存。研究了具有不同甲醇生产能力的四种不同工艺配置。评估每种配置的成本和性能，并将其与两个参考案例进行比较。结果表明，FReSMe 工艺可以避免约 60% 的整个钢铁厂 CO ₂排放，而在动力部分具有燃烧后捕获的参考工厂仅占 18%。避免的 CO ₂成本范围为 40.6 €/t _CO2 – 46.2 €/t _CO2. 在不考虑碳税的情况下，最佳甲醇生产能力为 600 吨/天，热轧卷的平准化成本约为 520 欧元/吨_HRC，比基本情况（476 欧元/吨_HRC）高 9.4% 。碳税率高于 40.6 欧元/吨_二氧化碳，最佳配置的甲醇生产能力为 300 吨/天，与传统的燃烧后碳捕获系统相比，可确保更高的减排量和更低的成本。