Numerical Study on Pulverized Biochar Injection in Blast Furnace

抄録

The possibility of injecting pulverized biochar instead of conventional pulverized coal in blast furnace ironmaking was investigated numerically. More detailed reactions including the water-related reactions were considered here. The combustion process from the tuyere to the raceway of a blast furnace was simulated. Oak char (volatile matter wt.% dry basis, VM = 27.11 wt.%-db) provided a lower temperature than Taiheiyo coal (VM = 44.60 wt.%-db). Increasing the O₂ concentration from 23 to 27 wt.% resulted in a higher combustibility of both solid fuels. However, the effect of increasing oxygen concentration was still insufficient for the Oak char at high injection rates because of its inadequate volatile content. Biochar properties become increasingly important as the injection rate increases. Compared with Oak char that provided a combustibility of 68% at an injection rate of 200 [(kg solid fuel)/(1000 Nm³ feed gas)] and hot blast of 27 wt.% O₂ concentration, Oak char 1 (VM = 32.09 wt.%-db) had a higher combustibility of 71%.