To achieve climate goals, the iron and steel industry needs to find energy efficient and cost saving pathways for implementing CO₂ capture. This paper evaluates two integration alternatives of excess-heat powered CO₂ capture at an integrated iron and steel plant using the concept of partial capture. The two sources of CO₂ investigated were the blast furnace gas (BFG) and flue gas from the combined heat and power (CHP) plant, representing a high and low level integration alternative, respectively. An amine capture system was simulated in Aspen Plus, and optimized for low energy requirement. To analyze the effects on the iron and steel system and the level of available excess heat, an in-house model was used containing interlinked energy and mass balances of each process step available. The results show that high level integration of CO₂ capture gives a lower specific heat demand and improves the overall energy efficiency of the steel plant, resulting in more available heat. For this reason, it is possible to capture 3% more from BFG without any extensive alterations to the plant to recover excess heat. The total available excess heat at the plant will sustain capture of up to 46% of the steel plants total CO₂ emissions, and beyond that point steam has to be imported.

为了实现气候目标，钢铁行业需要找到节能和节约成本的途径来实施CO ₂捕集。本文使用部分捕集的概念，评估了钢铁联合工厂中利用余热驱动的CO ₂捕集的两种替代方案。CO ₂的两种来源研究对象是热电联产厂的高炉煤气（BFG）和烟气，分别代表了高水平和低水平的集成方案。胺捕获系统在Aspen Plus中进行了模拟，并针对低能耗进行了优化。为了分析对钢铁系统和可用余热水平的影响，使用了一个内部模型，其中包含每个可用工艺步骤的相互联系的能量和质量平衡。结果表明，CO _2的高度集成捕集能降低比热需求并提高钢铁厂的整体能源效率，从而产生更多的热量。因此，无需对工厂进行任何大的改动即可回收高热量，从而可以从高炉煤气中再捕集3％的热量。工厂中所有可用的多余热量将持续吸收高达46％的钢铁厂总CO ₂排放量，超过此点必须进口蒸汽。