Characteristics of biochar produced from slow pyrolysis of Geodae-Uksae 1

► Geodae-Uksae 1 (Giant Miscanthus) is a variety of Miscanthus sacchariflorus for energy crop. ► Ideal temperature to produce biochar by slow pyrolysis was 500°C. ► The biochar had a mass yield of 27wt.% at 500°C with a carbon content of 79wt.%. ► The surface area and large pores of biochar was well-developed at 500°C for application to soil. This study investigated producing biochar from Geodae-Uksae 1 for soil applications to sequestrate carbon from the atmosphere and improve the productivity of crops. Using a lab-scale packed bed reactor, pyrolysis products of Geodae-Uksae 1 were produced over a temperature range of 300–700°C with a heating rate of 10°C/min. Pyrolysis at 500°C was found appropriate for biochar production considering the properties of char and the amount of heat required. It yielded biochar of 27.2wt.% that contained approximately 48% carbon in the raw biomass. The surface area of the biochar rapidly increased to 181m2/g. Large cylindrical pores with diameters of 5–40μm developed within the biochar due to the vascular cell structure of the parent biomass. The byproducts (bio-oil and gases) were also analyzed for use as fuel.