Producing bio-coke by redwood charcoal blending for blast furnace application

Coal consumption in the Indonesian metallurgical industry in 2015 has reached up to 3.5 million tons. One ton of pig iron required 0.5-0.6 tons of coke, 1.4 tons of iron ore, and 0.25 tons of limestone. Coke added by the charcoal is called bio- coke. Charcoal, as the raw material of coke from the carbonization process of Indonesian redwood residues, can reduce the consumption of coking coal. Biomass has been applied as an alternative renewable fuel to the industrial sector to reduce CO2 emissions. The use of biomass reduces the dependence on traditional fossil fuels whose resources are reduced every day. The purpose of this study was to obtain the best charcoal sizes from redwood and improve the quality of bio-coke through the dry cooling process. The final method of bio-coke can be done coke dry quenching to prevent the occurrence of cracks in the coke, increase coke strength, and less chemical activity during cooling. Redwood charcoal with particle size (10, 25, 50, and 80) mesh is blending with coking coal. The mixing, composition of coal with redwood charcoal is 90:10. Blended briquettes with the addition of molasses and wood tar are processed by re-carbonization at 1100 °C for 4 hours. Bio-coke charcoal 50 mesh has bulk density of 1071.44 kg/m3. The strength of bio-coke increases as bulk density increases. The maximum size of the redwood charcoal particles of the study on 50 mesh generated a compressive strength of 4.87 MPa.