Carbonization characteristics of biomass/coking coal blends for the application of bio-coke

Carbonization is a low-temperature thermochemical process that converts organic matter in the absence of oxygen mainly into char, gas, and liquids. Bio-coke is a char prepared from a mixture of biomass/charcoal and a coal blend. It can reduce greenhouse gas emissions by replacing coke and reducing coal consumption in the ironmaking process. In this study, the carbonization characteristics such as char conversion, gas and tar composition of bio-coke were determined using a batch-type carbonization reactor. Yellow poplar wood used as a biomass was added to a coking coal in different ratios (0, 10, 15, 20, and 30 wt%) and the resulting raw bio-coke was carbonized at different final temperatures (500–800 °C). The calorific value of bio-coke was higher than 7000 kcal/kg, exceeding the standard value. Moreover, the initiation combustion temperature of the resultant bio-coke determined using TGA was in the range of 400–600 °C. It is concluded that bio-coke is a suitable substitute for conventional fossil fuels reducing CO₂ emissions.