Bailera Manuel, Nakagaki Takao, Kataoka Ryoma
Graduate School of Creative Science and Engineering, Waseda University, Tokyo, 1698555, Japan.
Escuela de Ingeniería y Arquitectura, University of Zaragoza, Zaragoza, 50018, Spain.
Open Res Eur. 2021 Nov 29;1:141. doi: 10.12688/openreseurope.14275.1. eCollection 2021.
The Rist diagram is useful for predicting changes in blast furnaces when the operating conditions are modified. In this paper, we revisit this methodology to provide a general model with additions and corrections. The reason for this is to study a new concept proposal that combines oxygen blast furnaces with Power to Gas technology. The latter produces synthetic methane by using renewable electricity and CO to partly replace the fossil input in the blast furnace. Carbon is thus continuously recycled in a closed loop and geological storage is avoided. The new model is validated with three data sets corresponding to (1) an air-blown blast furnace without auxiliary injections, (2) an air-blown blast furnace with pulverized coal injection and (3) an oxygen blast furnace with top gas recycling and pulverized coal injection. The error is below 8% in all cases. Assuming a 280 t /h oxygen blast furnace that produces 1154 kg /t , we can reduce the CO emissions between 6.1% and 7.4% by coupling a 150 MW Power to Gas plant. This produces 21.8 kg/t of synthetic methane that replaces 22.8 kg/t of coke or 30.2 kg/t of coal. The gross energy penalization of the CO avoidance is 27.1 MJ/kg when coke is replaced and 22.4 MJ/kg when coal is replaced. Considering the energy content of the saved fossil fuel, and the electricity no longer consumed in the air separation unit thanks to the O coming from the electrolyzer, the net energy penalizations are 23.1 MJ/kg and 17.9 MJ/kg , respectively. The proposed integration has energy penalizations greater than conventional amine carbon capture (typically 3.7 - 4.8 MJ/kg ), but in return it could reduce the economic costs thanks to diminishing the coke/coal consumption, reducing the electricity consumption in the air separation unit, and eliminating the requirement of geological storage.
里斯图对于预测高炉在操作条件改变时的变化很有用。在本文中，我们重新审视这种方法，以提供一个有补充和修正的通用模型。这样做的原因是研究一个将氧气高炉与“电转气”技术相结合的新概念提议。后者利用可再生电力和一氧化碳生产合成甲烷，以部分替代高炉中的化石燃料输入。碳因此在一个闭环中持续循环，避免了地质封存。新模型用三个数据集进行了验证，分别对应于：（1）无辅助喷吹的鼓风高炉；（2）喷吹煤粉的鼓风高炉；（3）采用炉顶煤气循环和喷吹煤粉的氧气高炉。在所有情况下误差均低于8%。假设一座每小时产氧量为280吨、每吨铁产量为1154千克的氧气高炉，通过耦合一座150兆瓦的“电转气”工厂，我们可以将一氧化碳排放量降低6.1%至7.4%。这会产生每吨铁21.8千克的合成甲烷，可替代每吨铁22.8千克的焦炭或30.2千克的煤。当替代焦炭时，避免一氧化碳排放的总能量惩罚为每千克27.1兆焦；当替代煤时，为每千克22.4兆焦。考虑到节省的化石燃料的能量含量，以及由于来自电解槽的氧气而不再在空气分离单元中消耗的电力，净能量惩罚分别为每千克23.1兆焦和17.9兆焦。所提议的整合的能量惩罚大于传统的胺基碳捕获（通常为每千克3.7 - 4.8兆焦），但作为回报，由于减少了焦炭/煤的消耗、降低了空气分离单元的电力消耗以及消除了地质封存的需求，它可以降低经济成本。
