PREPARATION AND CHARACTERIZATION OF BIO-COAL BRIQUETTES FROM PYROLYZED BIOMASS-COAL BLENDS

In this paper, the characteristics of bio-coal briquettes produced from a blend of pyrolyzed biomass and coal were investigated. Prior to being molded into the briquettes, biomass (in the form of oil palm shell and canarium nutshell) and coal were firstly pyrolyzed at 400 and 500 degrees C. The briquette was prepared by blending the pyrolyzed biomass and coal at various compositions (in the range of 12.5-87.5% of biomass) and then mixed thoroughly with a starch solution. A blend of 40 g of material was formed in a cylindrical shape (diameter of 5 cm, length of 3 cm) and was pressed at 10 tons using a hydraulic press. The bio-coal briquettes were measured its calorific value, equilibrium moisture content (EMC), burning characteristics (ignition time, burn out time, overall burning rate), and CO-CO2 emission from their burning. The measurement results showed that the briquette had a calorific value of 20.81-27.16 MJ/kg and EMC of 5.90-8.00%. The presence of biomass slightly lowered the calorific value and raised the EMC. On the contrary, the ignition time and burn out time were getting shorter and the overall burning rate became faster. The biomass in the briquettes also contributed significantly to decreasing CO and CO2 emission.