China′s iron and steel industry is dominated by the long blast furnace - converter process, with primary energy consumption mainly pulverized coal and coke. The large amount of fossil energy consumption leads to high carbon emissions, 70% of whichare generated by the blast furnace ironmaking process. To realize the " Dual Carbon" targets earlier, it′s urgent to develop low-carbonironmaking technologies to reduce the energy consumption and CO emissions from the blast furnace process. In this study, a biomass reformed gas injection-Oxygen Blast Furnace (BRGI-OBF) process was proposed. In this process, the gasifier process parameters were optimized, and biomass reforming was adopted instead of pulverized coal reforming. Thus, the reformed gas meets the blast furnace′s hydrogen-rich smelting demand and reduces fossil fuel consumption. Combined with carbon capture in the oxygen-enriched combustion of blastfurnace gas, CO in the end-stream flue gas can be greatly enriched, thus realizing low energy consumption and low carbon (negative carbon) emission of the blast furnace. In order to analyze the low-carbon potential of the BRGI-OBF process, a model of the BRGI-OBFprocess was first constructed by the chemical process analysis software Aspen Plus. Then, the effects of the heat input to the gasifier andthe type of biomass on the process performance were analyzed. Furthermore, based on the calculated process parameters, the traditionalblast furnace process and the top gas recycle-oxygen blast furnace (TGR-OBF) process were horizontally compared in terms of energy consumption and carbon flow by applying the energy consumption calculation method of the blast furnace ironmaking process. The results show that supplying appropriate heat to the gasifier effectively reduces pulverized coal consumption by up to 124.2 kg/ t(per metricton of hot metal) and increases the amount of recycled gas. Notably, different biomass types have a significant effect on the amount of biomass and the composition of reformed gas. When poplar semi-coke is used for reforming, 204 kg/ t of poplar semi-coke would be consumed with up to 29.91% of H in the reformed gas, fulfilling the needs of hydrogen-rich smelting. In addition, the BRGI-OBF processsignificantly improves the energy structure with a fossil energy share of about 55%, reducing the consumption of pulverized coal and cokeby 17.6% and 29.3%, respectively, compared to conventional blast furnaces. With the process coupled to oxygen-enriched combustion carbon capture technology, 372.6 kg/ t of carbon exists in the end stream in the form of highly concentrated CO(>90%) that can beeasily compressed and captured. Deducting the carbon emission from poplar semi-coke, the total carbon emission would be -109.9 kg/ t,which is equivalent to 403 kg of additional CO capture per ton of iron produced. This process can realize the carbon negative technology ofbiomass + CCS, which significantly support the iron and steel industry to achieve deep decarbonization.

毛文超(1998—),男,江西南昌人,博士研究生。E-mail:d202380575@hust.edu.cn

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MAO Wenchao,HUANG Zhihui,ZHANG Zewu,et al.Analysis of low carbon potential of biomass reforming gas injection-oxygen blast furnaces[J].Clean Coal Technology,2024,30(8):138-149.