Pyrolysis of oil palm trunk biomass using a fixed bed reactor to produce raw material for bio-carbon black

Abstract

The abundance of palm oil plantation waste in Indonesia can be utilized as a raw material for making carbon black, which currently relies on fossil fuel-based raw materials. Out of the five types of palm oil biomass waste, including empty fruit bunches (EFB), palm kernel shells (PKS), palm mesocarp fibers (PMF), oil palm fronds (OPF), and oil palm trunks (OPT), one will be chosen as the raw material for carbon black production. Palm oil biomass waste typically has a relatively high ash content. To reduce the ash content, the biomass must first undergo pyrolysis to transform it into pyrolysis oil. The higher the carbon content and the lower the oxygen content, the more the pyrolysis oil meets the criteria for replacing crude oil. Among the criteria mentioned, the lowest ash content is found in palm kernel shells (1.4%). The highest carbon content is in palm trunks (55.8%), while the lowest oxygen content is also in palm kernel shells (34.5%). Palm kernel shells are the best palm oil biomass that can be used as a raw material for carbon black. However, because palm kernel shells are commonly used as boiler fuel, the second choice is palm trunks due to their high carbon content. Pyrolysis experiments were conducted using palm trunk biomass to produce bio-oil, which would be further processed into carbon black. The palm trunks were divided into three parts: outer trunk, middle trunk, and core trunk. The biomass size was also varied, with sizes of 20 mesh and 40 mesh. The pyrolysis process used a fixed bed reactor with a heating rate of 3°C/minute, reaching a pyrolysis temperature of 600°C, and maintaining that temperature for 1.5 hours. The highest yield of bio-oil obtained was from the outer trunk with a biomass size of 40 mesh (36.8%). Similarly, for a size of 20 mesh, the highest yield was also from the outer trunk (35.7%).