Analysis of low carbon potential of biomass reforming gas injection-oxygen blast furnaces
China's iron and steel industry is dominated by the long blast furnace-converter process,with primary energy consump-tion mainly pulverized coal and coke.The large amount of fossil energy consumption leads to high carbon emissions,70％of which are generated by the blast furnace ironmaking process.To realize the"Dual Carbon"targets earlier,it's urgent to develop low-carbon ironmaking technologies to reduce the energy consumption and CO2 emissions from the blast furnace process.In this study,a biomass re-formed gas injection-Oxygen Blast Furnace(BRGI-OBF)process was proposed.In this process,the gasifier process parameters were op-timized,and biomass reforming was adopted instead of pulverized coal reforming.Thus,the reformed gas meets the blast furnace's hydro-gen-rich smelting demand and reduces fossil fuel consumption.Combined with carbon capture in the oxygen-enriched combustion of blast furnace gas,CO2 in the end-stream flue gas can be greatly enriched,thus realizing low energy consumption and low carbon(negative car-bon)emission of the blast furnace.In order to analyze the low-carbon potential of the BRGI-OBF process,a model of the BRGI-OBF process was first constructed by the chemical process analysis software Aspen Plus.Then,the effects of the heat input to the gasifier and the type of biomass on the process performance were analyzed.Furthermore,based on the calculated process parameters,the traditional blast furnace process and the top gas recycle-oxygen blast furnace(TGR-OBF)process were horizontally compared in terms of ener-gy consumption and carbon flow by applying the energy consumption calculation method of the blast furnace ironmaking process.The re-sults show that supplying appropriate heat to the gasifier effectively reduces pulverized coal consumption by up to 124.2 kg/t(per metric ton of hot metal)and increases the amount of recycled gas.Notably,different biomass types have a significant effect on the amount of bio-mass and the composition of reformed gas.When poplar semi-coke is used for reforming,204 kg/t of poplar semi-coke would be con-sumed with up to 29.91％of H2 in the reformed gas,fulfilling the needs of hydrogen-rich smelting.In addition,the BRGI-OBF process significantly improves the energy structure with a fossil energy share of about 55％,reducing the consumption of pulverized coal and coke by 17.6％and 29.3％,respectively,compared to conventional blast furnaces.With the process coupled to oxygen-enriched combus-tion carbon capture technology,372.6 kg/t of carbon exists in the end stream in the form of highly concentrated CO2(＞90％)that can be easily 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 CO2 capture per ton of iron produced.This process can realize the carbon negative technology of biomass+CCS,which significantly support the iron and steel industry to achieve deep decarbonization.
iron and steel industrycarbon neutrallow carbon technologybiomassreforming gas injection-oxygen blast furnace
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