Biochar derived from agricultural waste and its application as energy source in blast furnace

Abstract

Is biochar obtained from agricultural residues an alternative to the coal used in blast furnaces - BF? This work provided a comparison between biomass and PCI coal, and evaluated the influence of pyrolysis temperature on the combustion indexes and physicochemical properties of biochars. Coconut-shell, corncob, and eucalyptus bark biomasses were pyrolyzed at different temperatures (300 °C–500 °C) to produce biochar. Samples of biomasses and biochars were characterized using proximate analysis, HHV, FTIR, XRD and SEM coupled with EDXA. Pyrolysis led to increased fixed carbon content and HHV in the biochar. However, the higher the temperature, the lower the mass yield. The combustion indexes results revealed that the raw biomasses do not meet the reference values. Coconut-shell and corncob biochars produced at 300 °C and 350 °C demonstrated combustion indexes similar to those of reference PCI coal. The results suggested that both the choice of biomass and the pyrolysis temperature had influence on the properties of biochar produced. Coconut-shell and corncob biochars, produced at relatively low temperatures, exhibited suitable combustion properties and could serve as partial substitutes of PCI coal in a BF. Eucalyptus bark biochar, due to its higher ash content, may be less suitable for these applications.