Production and characterization of Biochar from Various Biomass materials By slow Pyrolysis

Biochar is the carbonaceous solid product of biomass pyrolysis which can be used as chemical feedstock for various purposes such as energy production, and adsorption of pollutants. In particular, application of biochar to the soil is gaining greater interests, which can reduce fertilizer consumption, increase crop yields, and sequestrate carbon. This study compares the characteristics of biochar produced by slow pyrolysis at 500 oC for five biomass residues from Indonesia: sugarcane bagasse, cocopeat, paddy straw, palm kernel shell (PKS) and umbrella tree. In the biochar yield, the influence of the inert and lignin contents in the raw biomass was significant. From the organic fractions, the wood stem, bagasse and paddy straw had biochar yields of 24-28 wt.% while cocopeat had 46 wt.%. The carbon content of the biochar samples ranged from 84-89 wt.%, which corresponded to 43-63 % of carbon in the original biomass depending on the yield. Dominant inorganic elements widely varied between samples. The wood stem and bagasse biochar had well developed pores in the biochar over a wide size range with large surface areas over 200 m2/g. Although the surface area was significant, PKS biochar had dense matrix with few large pores. The pH of biochar was in the range of 9.3-10.5, except for PKS. These results can be used to establish ideal utilization routes of biomass for energy and/or biochar production.