Biomass has a novel advantage, i.e., no CO
2 emissions, because of carbon neutral. We proposed semi-charcoal composite iron oxide pellets in order to decrease reducing agent at blast furnace and CO
2 emissions. Japanese cedar were carbonized partly at maximum carbonization temperatures (T
C, max = 823, 1073 and 1273 K) in order to obtain semi-charcoal with residual volatile matter (V.M.). It was found that the semi-charcoal retained much V.M., mainly H
2, at T
C, max = 823 K and that the semi-charcoal with some residual V.M. could be prepared by controlling T
C, max in the carbonization. Composite pellets using such semi-charcoal have been prepared and reduced at reduction temperature (T
R) in N
2 gas atmosphere. Fractional reductions
F(%) of the semi-charcoal composite pellets at T
C, max = 823, 1073 and 1273 K were 17 ∼ 24 % for 60 min at T
R = 1073 K. Moreover, fractional reduction
F(%) of the semi-charcoal composite pellet at T
C, max = 823 K was 62 % for 60 min at T
R = 1173 K and was higher than the pellet at T
C, max = 1273 K by about 30 %. When T
C, max was lower, namely the pellet had more residual V.M., the reduction of iron oxide was more accelerated at T
R = 1073 and 1173 K. Fractional reductions
F(%) of all the semi-charcoal composite pellets were about 100 % for 50 ∼ 60 min at T
R = 1273 K. These reducibility of semi-charcoal composite pellets were higher than those of semi-coal-char composite pellets at T
R = 1273 K.
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