Large-scale pyrolysis of oil palm frond using two-box chamber pyrolyzer for cleaner biochar production

Oil palm plantations always produce frond which becomes residue and unutilized. The frond processing through natural composting emits a significant amount of methane which is environmentally threatening. Also, traditional pyrolysis can convert it to stable biochar but still release CO 2 as a greenhouse gas. For the purpose of cleaner biochar production, a two-box chamber pyrolyzer was utilized for its eminence in volatile gas recirculation to the fuel chamber. Pyrolysis of 1500 g of oil palm frond at 500 °C and holding time of 30 min succeeds to produce biochar that meets International Biochar Initiative (IBI) standards. It has a yield of 39.99% with highly porous biochar, calorific value of 22.55 MJ/kg, pyrolysis energy efficiency of 10.65%, and global warming potential of 1.351 kg-eq CO 2 /kg oil palm frond (53.2% lower than natural composting or 21.1% lower than traditional pyrolysis). From the economical potential aspect, biochar still can compete with other derivate products if it is processed into solid fuel in the form of briquette. Based on the properties, however, this biochar is strongly recommended for tailored soil amendment or planting medium because of its competitive selling value and no need for further processing cost. Graphical abstract