Characteristics of Pyrolyzed and Activated Carbonaceous Materials From Japanese Cedar Bark

摘要

Abstract Japanese cedar (Cryptomeriajaponica D, Don) bark was pyrolyzed in a stream of N, at473-673 K for 3-12 h under atmospheric pressure. The resultant carbonaceous residues wereactivated in a stream of CO2 at 1173 K for 1 h. Adsorption of N2 at 77 K was measured toinvestigate the pore structure and the surface properties of the pyrolyzed and activated materialsfrom the cedar bark. Both specific surface areas and total pore volumes of the materials pyrolyzedat temperatures below 573 K were small, indicating that pore structures were not developed undermild conditions. However, those of the samples heated at 673 K increased with increasing time ofthe treatment, during which micro porosity was mainly developed. Activation of the pyrolyzedcedar bark led to drastic increase in specific surface area and pore volume. The increase was due tothe selective formation of the micro pores which distributed mainly less than 0.35 nm in radius.Analytical results of adsorption data using t-plot and a ,-plot and IR spectra methods suggestthat the surface properties of both pyrolyzed and activated cedar bark are different from those oftypical carbon black. It is indicated that organic moiety and oxygenated functional groupsoriginated from cedar bark may affect the surface characteristics of pyrolyzed and activated cedarbark.